Skema Rangkaian Adaptor|Regulator

12 Volt Battery Monitor by IC LM3914

2011-06-21T11:31:00.002+07:00

This circuit makes it posible to monitor the charging process to a higher level. Final adjustsments are simple and the only thing needed is a digital voltmeter for the necessary accuracy. Connect an input voltage of 12.65 volt between the positive and negative poles and adjust the 10K trimmer potentiometer until Led 10 lights up. Lower the voltage and in sequence all other Led's will light up. Check that Led 1 lights up at approximately 11.89 volts.

Skema Rangkaian 12 Volt Battery Monitor lm3914

At 12.65 volt and higher the battery is fully charged, and at 11.89 is considered 'empty'. This circuit, with the components shown, uses less than 10mA. Ofcourse you can adapt this circuit to your own needs by making small modifications. The circuits above is set for 'DOT' mode, meaning only one Led at a time will be lit. If you wish to use the 'BAR' mode, then connect pin 9 to the positive supply rail, but obviously with increased current consumption. The LED brightness can be adjusted up- or down by choosing a different value for the 4K7 resistor connected at pin 6/7.

Rangkaian Sekering Elektronik 12VDC

2011-06-21T10:10:00.002+07:00

In electronics and electrical engineering a fuse is a type of over current protection devices. Its essential component is a metal wire or strip Pls That melts too much current flows, the which breaks the circuit in the which it is connected, thus protecting the circuit's other components from damage due to excessive current.

Skema Rangkaian Sekering Elektronik 12VDC

schematics circuit at the show above is an electronic fuse That Protects against short circuit the load voltage 12 VDC. You can adjust the current with using a 10K potentiometer. Will If you use the fuse with very high currents, the lower the resistor value 0.1/5W, Watt value of the resistor Should Be Increased also.

Note:

IC1 can use any of the op-amp IC (eg OA 741).
IC2 can use any SR latch flip-flop (eg 54HC279).
Use a 12V relay and currents that are customized to your needs.

Variable Voltage Regulator Circuit Using IC L146

2011-06-21T06:52:00.000+07:00

This reguator circuit is designed for general purpose use. Advantages of the circuit are first the voltage can be adjusted from 0V to greater and second it does not require a double sided secondary winding transformer. For high voltage outputs you can use L146 or alternatively if you need lower voltage outputs you can use IC 723.

L146 Variable Voltage Regulator Circuit

Regulation voltage for both integrated circuit is at least 2V. R3, R4, R5 and R6 resistors prevent this limitation and keep the output voltage at 0 level with the help of P2 potentiometer. If the input voltage is less than required, this resistors provides sufficient potential between 4 and 5 numbered pins.

LM723 - Variable Voltage Regulator circuit

2011-06-21T04:49:00.001+07:00

This is circuit variable voltage Regulator 3-30V at 3A max, by used IC LM723 for control volt stable regulated. The 2N3055 power transistor for boost up current to 3 amp. The VR1 used control output 3V to 30V. It suitable for general electronics work shop. Because it is a simple circuit and easy circuit.

LM723 - Variable Voltage Regulator circuit

Note:

T1 can be a 220V primary, 32VCT secondary, 3A step down transformer.
MJ3001 power transistor must be fitted on a proper heat sink.
Output voltage can be adjusted by using the POT RV1.

5 Volt Switching Regulator Circuit LM2678-5.0

2011-04-06T15:29:00.005+07:00

This is the circuit diagram of a 5V switching regulator based on the IC LM2678. The LM2678 series of regulators are monolithic integrated circuits which provide all necessary functions required for a buck switching regulator and can drive up to 5A loads. The IC has more than 90% efficiency and has excellent load and line regulation. The LM2678 is available in three fixed output voltages (3.3V, 5V, 12V) and an adjustable output version. The IC is also packed with a handful l of features like thermal shutdown, current limiting and ON/OFF control.

Skema Rangkaian 5 Volt Switching Regulator LM2678-5.0

LM2678-5.0 Pinout

Note:

The circuit given here is based on the version LM2678-5.0 which gives an output of 5V.
The power supply for the circuit can be anything between 8 to 40V DC.
The feedback wiring must be placed as away as possible from the inductor L1.
Do not use loads that consume more than 5A.
A heat sink is seriously recommended for the IC.

L200 Variable Power Supply

2011-04-04T05:54:00.007+07:00

Power supply with variable voltage and fixed current regulation made using the ubiquitous L200C regulator. The versatile 5 pin L200C regulator offers both voltage and current regulation in a single package. The IC also features thermal shutdown and input over voltage protection up to 60 Vdc. The package is also available as L200CV which has straight pins for mounting onto a PCB.

Skema Rangkaian L200 Variable Power supply

The above circuit has current limiting of 1 amp, hence Rsc = 0.45 ohm. The output voltage is variable from 2.85V to 36V. For voltages up to 36V then the input voltage, Vcc must be 40V. The supply voltage must always a few volts higher than the maximum output voltage. If you wanted to make a 9 Volt current limited PSU then the input voltage should be a minimum of 12 Volts.

L200 Pinout

L200 Chip Specifications:

DC Input Voltage: 40V max.
Peak Input Voltage: 60V max. for 10ms
Output Voltage Range: 2.85 to 36V
Output Current Range: 0.1 to 2A
Quiescent Current: 4.2mA
Output Noise: 80uV

This variable power supply circuit from www.zen22142.zen.co.uk

Rangkaian 12V Car Battery Chargers

2010-12-06T15:23:00.004+07:00

Unlike many battery charger circuits, this circuit continuously charges at maximum current, tapering off only near full battery voltage. In this unit, the full load current of the supply transformer/rectifier section was 4.4A. It tapers off to 4A at 13.5V, 3A at 14.0V, 2A at 14.5V and 0A at 15.0V.

Charger's vircuit input voltages are 20 volt AC. Q1 and IC requires a good heatsink. If they are mounted on the same heatsink and will throttle the circuit back if Q1 gets too hot.

Rangkaian 12V Car Battery Chargers

Transistor Q1, diodes D1-D3 and resistor R1 form a simple constant current source. R1 effectively sets the current through Q1 - the voltage across this resistor plus Q1's emitter-base voltage is equal to the voltage across D1-D3. Assuming 0.7V across each diode and across Q1's base-emitter junction, the current through R1 is approximately 1.4/0.34 = 4.1A. IC ensures that Q1 (and thus the constant current source) is turned on.

When the battery has fully charged, the current through IC drops to a very low value and so Q1 turns off (since there is no longer any base-emitter current). R2 limits the current through IC. It allows enough current to flow through the regulator so that Q1 is fully on for battery voltages up to about 13.5V. Decreasing the value of R2 effectively increases the final battery voltage by raising the current cutoff point. Conversely, a diode in series with one of the battery leads will reduce the fully-charged voltage by about 0.7V.

Rangkaian Car Battery Chargers Componet

R1         = 0.32R/5 Watt Resistor
R2         = 8.2R/1/2 Watt Resistor
C1         = 10,000uF/63V elektronik capasitor
D1, D2, D3 = 1N4004 1
BR1        = Diode bridge 6 A
Q1         = MJ1504 PNP Transistor Power
IC         = 7815 REG
B1         = 12 Volt Battery

Source http://www.extremecircuits.net.

Automatic 12V Battery Chargers

2010-12-06T14:58:00.005+07:00

Most battery chargers cannot be left connected to the battery for long periods of time as over-charging and consequent battery damage will occur. This add-on circuit is placed in series with the battery being charged and is powered by the battery itself. In effect, the circuit uses a high-current Mosfet to control the charging current and it turns off when the battery voltage reaches a preset threshold. Power for the circuit is fed from the battery to 3-terminal regulator REG1 which provides 8V.

Rangkaian Automatic 12V Battery Charger

LED1 indicates that the battery is connected and that power is available. The 555 timer IC is configured as an astable oscillator running at approximately 100kHz. It feeds a diode pump (D1 & D2) to generate adequate gate voltage for Mosfet Q3, enabling it to turn on with very little on resistance (typically 14 milliohms). With the Mosfet turned on, current flows from the charger's positive terminal so that charging can proceed. The battery voltage is monitored by 10kO pot VR1.

When the wiper voltage exceeds the conduction voltage of zener diode ZD1, transistor Q1 turns on and pulls pin 4 (reset) low to switch off the 555 and remove gate drive to the Mosfet. This process is progressive so that the cycle rapidly repeats itself as the battery charges. Eventually, a point is reached when the battery approaches its charged condition and the cycle slows right down. Transistor Q2 and LED2 function as a cycle indicator. When the battery is under charge, LED2 appears to be constantly on. When the battery is fully charged, LED2 briefly flicks off (charging) and returns to the on state (not charging) for a longer period.

Source http://www.extremecircuits.net.

Rangkaian 0- 18 V Adjustable Power Supply

2010-12-06T13:10:00.004+07:00

This is circuit of Adjustable supply Power Supply , are very simple in the manufacture, the finding of his materials , is very easy and cost, small. The output voltage is stabilised and is regulated in the region from 0V until 18V dc, with biggest provided current 1 A. The regulation of voltage, of expense becomes with potentiometer R2. The Q1 (2N3055) of is classic power transistor and it needs it is placed in heatsink, one and heating when it works continuously in the region of biggest current. The type of transformer is standard in the market.

Rangkaian 0- 18 V Adjustable Power Supply

Component list

 R1  : 56ohm/2Watt Resistor
 R2  : 330ohm Lin. pot
 C1  : 2200uF/35V elektronik capasitor
 C2  : 100uF/35V elektronik capasitor
 C3  : 10uF/25V elektronik capasitor
 C4  : 220uF/25V  elektronik capasitor
 C5  : 100nF Ceramic capacitor
 GR1 : 4 X 1N4007 1 A Diode 
 Q1  : 2N3055 BPN Transistor 
 T1  : 18V/1.5A Transformator step-down 
 D1  : 18V 1.5W zener diode

Rangkaian Inverter 12V to 220V

2010-12-06T12:22:00.007+07:00

This inverter circuit should solve that problem. It takes12 VDC and steps it up to220 VAC. The-Wattage depends on which transistors you use for T1 and T2, as well as how "big" a transformer you use for T1. The inverter can be constructed to supply anywhere from1 to1000 (1 KW)-Watts.

Rangkaian Inverter 12V to 220V

As the duty factor of the 555 output is a long way from being 1:1 (50%), it is used to drive a D-type flip-flop produced using a CMOS type 4013 IC. This produces perfect complementary square-wave signals (antiphase) on its Q and Q outputs suitable for driving the output power transistors. As the output current available from the CMOS 4013 is very small, Darlington power transistors (MJ3001s or any equivalent power Darlington
transistor) are used to arrive at the necessary output current.

These drive a 230 V to 2 × 9 V center-tapped transformer used ‘backwards’ to produce the 230 V output. The presence of the 230 VAC voltage is indicated by a neon light, while a VDR (voltage dependent resistor) type S10K250 or S07K250 clips off the spikes and surges that may appear at the transistor switching points. The output signal this circuit produces is approximately a square wave; only approximately, since it is somewhat distorted by passing through the transformer. Fortunately, it is suitable for the majority of electrical devices it is capable of supplying, whether they be light bulbs, small motors, or power supplies for electronic devices.

The Darlington transistors should be fitted onto a finned anodized aluminum heat-sink using the standard insulating accessories of mica washers and shouldered washers, as their collectors are connected to the metal cans and would otherwise be short-circuited. An output power of 30 VA implies a current consumption of the order of 3 A from the 12 V battery at the ‘primary side’. So the wires connecting the collectors of the MJ3001s [1] T1 and T2 to the transformer primary, the emitters of T1 and T2 to the battery negative terminal, and the battery positive terminal to the transformer primary will need to have a minimum cross-sectional area of 2 mm2 so as to minimize voltage drop.

The transformer can be any 230 V to 2 × 9 V type, with an E/I iron core or toroidal, rated at around 40 VA. Properly constructed on the board shown here, the circuit should work at once, the only adjustment being to set the output to a frequency of 50 Hz with P1. You should keep in minds that the frequency stability of the 555 is fairly poor by today’s standards, so you shouldn’t rely on it to drive your radio-alarm correctly – but is such a device very useful or indeed desirable to have on holiday anyway? Watch out too for the fact that the output voltage of this inverter is just as dangerous as the mains from your domestic power sockets.

Rangkaian inverter component

R1 = 18K
R2 = 3k3
R3 = 1k
R4,R5 = 1k?5
R6 = VDR S10K250 (or S07K250)
P1 = 100 k potentiometer
C1 = 330nF
C2 = 1000 µF 25V
T1,T2 = MJ3001
IC1 = 555
IC2 = 4013
LA1 = neon light 230 V
F1 = fuse, 5A
TR1 = mains transformer, 2x9V 40VA (see text)
4 solder pins

Source http://www.extremecircuits.net.

TPS62000 Step Down Converter Circuit

2010-11-14T01:46:00.013+07:00

Sometimes you have a situation where you have a 5-V supply voltage but part of the circuit needs a lower supply voltage. A voltage regulator from the Texas Instruments TPS62000 family is a good choice for this if the current consumption is less than 600 mA. You can thus use this device to build a very compact, highly efficient voltage converter.

Rangkaian TPS62000 Step Down Converter

The TSOP62000 provides an internal reference potential of 0.45 V, which can be used to set the output voltage in the range of 0.5 V to 5 V by means of resistors R2 and R3.

The formula for this is:

Vout = 0.45 V (0.45 V) × (R2 R3)

For relatively low voltages, the value of inductor L1 should be 10 µH, but a value of 22 µH is better if the output voltage is 3.3 V or more. The input voltage can be anywhere in the range of 2 V to 5.5 V, and of course it has to be higher than the desired output voltage. The output voltage is 3.3 V with the indicated component values and an input voltage of 5 V. If you want to reduce the component count even further, you can use a member of the family with a fixed output voltage. The available voltages are 0.9, 1.0, 1.2, 1.5, 1.8, 1.9, 2.5, and 3.3 V. With this approach you can omit R2, R3 and C3, so the output can be connected directly to pin 5.

DC to DC converters

2010-11-14T01:20:00.006+07:00

DC to DC converters are electronic devices used whenever we want to change DC electrical power efficiently from one voltage level to another. They’re needed because unlike AC, DC can’t simply be stepped up or down using a transformer. a DC-DC converter is the DC

equivalent of a transformer.

The circuit below is a DC to DC converter using a standard 12 VAC center tapped power transformer wired as a blocking oscillator. The circuit is not very efficient but will produce a high voltage usable for low power applications.

Rangkaian DC to DC converter

The input battery voltage is raised by a factor of 10 across the transformer and further raised by a voltage tripler consisting of three capacitors and diodes connected to the high voltage side of the transformer. The circuit draws about 40 milliamps and should operate for about 200 hours on a couple of 'D' alkaline batteries. Higher voltages can be obtained by reducing the 4.7K bias resistor.

Rangkaian Regulator 3 volt menggunakan IC LM317

2010-05-20T04:34:00.004+07:00

This is based circuit of the LM317 adjustable voltage regulator with a maximum output of 3V/1.5A. The output voltage depends on the Pin 1 (pin ADJ) of IC LM317 or R1 and R2 values, so the circuit Can be modified to use with a maximum output of greater than 3V. while for the maximum output current is related to the package options.In this circuit, LM317T, Which is capable of transferring up to 1.5A, is used.

Skema rangkaian regulator 3 volt

When we adjust the R2 to 1.2K then the output becomes nearly 1.56V which is a typical battery voltage level that can be used in development projects.

R6 sets the current of the current source so it operates as a zero adjustmend resistor. When the resistor R2 is set to zero, adjust R6 to see zero voltage at the output. R5 protects the transistor BCW33. Red LED is used as a light indicator.

IC LM117 pinning

The LM117 is a series of adjustable 3-terminal positive voltage regulators is capable of supplying in excess of 1.5A over a 1.2V to 37V output range. They are exceptionally easy to use and require only two external resistors to set the output voltage. Further, both line and load regulation are better than standard fixed regulators.

5 Volt Regulator menggunakan Dioda Zener

2009-12-26T04:22:00.007+07:00

Regulator Dioda Zener

The regulator circuit is basically used zener regulator is configured with an NPN transistor to produce a large amount of cash. the regulator working on the zener breakdown voltage so that it produces the same output with the zener voltage. VBE is the base-voltage emitor of the size of the transistor Q1 between 0.2 - 0.7 volt depending on the type of transistor used.

Rangkaian regulator menggunakan dioda zener

Components List:
* R1 = 560 ohms
* C1 = 1000uF/40V
* C2 = 10uF/25V
* C3 = 330nF
* Z1 = 5.7 V
* Q1 = ECG184, NTE184

This regulator series of functions to change the voltage 12 to be 5 volts. The core of this series is the zener diode. due to a fall in voltage Zener diode 12 will be 5.7 volts. voltage in 5.7 volt electrical currents strengthened by taransiator Q1

To get a different output voltage you can change the zener diode as needed. For example, if you need a converter from 12 to 9 volt change eat Zener Diode 5.7 to 10 volts

Adaptor Variabel Digital

2009-12-26T03:26:00.005+07:00

Rangkaian Adaptor Variabel Digital

This is the circut of the digital adapter variables, which have an output of 1.25V - 15.19V The first part consists of a digital circuit up and down counter is built around IC1, a quad 2-input NAND Schmitt trigger (CD4093), followed by IC2, a binary up -down counter (CD4029). Two gates of CD4093 are used to generate the up-down logic using the push buttons S1 and S2, respectively, while the other two gates form an oscillator to provide clock pulses to IC2 (CD4029). The frequency of oscillations can be varied by changing the value of capacitor C1 or preset VR1. IC2 receives clock pulses from the oscillator and produces a binary sequential output. As long as its pin 5 is low, the counter continues to count at the rising edge of each clock pulse, but stops counting as soon as its pin 5 is brought to logic 1. Logic 1 at pin 10 makes the counter to count upwards, while logic 0 makes it count downwards. Therefore the counter counts up by closing switch S1 and count down by closing switch S2. The output of counter IC2 is used to realize a Digitally variable resistor.

Skema rangkaian adaptor variabel digital

This section consists of four N / O reed Relays that need just about 5mA current for their operation. (The original circuit containing quad bilateral switch IC 4066 has been replaced by reed Relays switches operated by transistorised because of unreliable operation of the former.) The switching action is performed using BC548 transistors. External resistors are connected in parallel with the reed relay contacts. Particular if the relay contacts are opened by the control input at the base of a transistor, the correspond-ing resistor across the relay contacts gets connected to the circuit. The table shows the theoretical output for various combinations of digital inputs. The measured output is nearly equal to the theoretically calculated IC3 outputs across the regulator (LM317). output of this regulator minimum (1.25V). As count-up switch S1 is pressed, the binary count of IC2 increases and the output starts increasing too. At the highest count output of 1111, the output voltage is 15.19V (assuming the in-circuit resistance of the preset VR2 as zero). Preset VR2 can be used for trimming the output voltage as desired. To decrease the output voltage within the range of 1.25V to 15.2V, count-down switch S2 is to be depressed.

Regulator Variabel 0 - 30 Volt

2009-12-22T07:06:00.006+07:00

Regulator Variabel 0 - 30 Volt

The following project is a set of regulatory variables that use the base equipment, build is not difficult follow the fine-volt circuit can get 0-30V, give current get about 1-2A depend on the transformer at you choose to use. The prominent point of the circuit use the transistor join a pin BE replace Zener Diode. Then get around problems about seek buy Zener voltage that can not want. By 2N3638 transistors at use numbers or the number replaces. For transistor output, use 2N3055 with the ability to reach suplay current 2A.

Skema rangkaian regulator variabel 0 - 30 Volt

Note:

for better results use tranformator 32-Ct / 3 amperes
2n3055 power transistor must be given a large cooling

Absolute Maximum Ratings Transistor 2n3055

Collector-Base Voltage (IE = 0) 100 V
Collector-Emitter Voltage (RBE £ 100W) 70 V
Collector-Emitter Voltage (IB = 0) 60 V
Emitter-Base Voltage (IC = 0) 7 V
Collector Current 15 A
Base Current 7 A
Total Dissipation at Tc £ 25 oC 115 W
Storage Temperature -65 to 200 oC
Max. Operating Junction Temperature 200 oC

9 Volt Regulator Menggunakan TIP31

2009-12-22T06:24:00.006+07:00

This is a DC Power Supply 9 Volt Regulator using transistors TIP31, which can provide a flow of about 1 Amp arrived in 2Amp. transistors of this type is very easy to find in stores electronic component sales very cheaply, about RP 1500. VR1 can be decorated with both for a 9V DC voltage transistor can be improved according to TIP31, a friend can use another number right as TIP41, MJE3055, 2SC1061, etc. But the heat sink should be kept in accordance with. The other details, see the circuit yes.

Skema rangkaian 9 volt regulator menggunakan TIP31

Note:

use tranformator 12Vot 2 ampare
TIP31 must Transitor give good cooling
Use the capacitor (elco) with voltage 16volt

Absolute Maximum Ratings Transistor TIP31

VCBO Collector-Base Voltage :
TIP31 40V
TIP31A 60V
TIP31B 80V
TIP31C 100V

Collector-Emitter Voltage :
TIP31 40V
TIP31A 60V
TIP31B 80V
TIP31C 100V

Emitter-Base Voltage 5 V
Collector Current (DC) 3 A
Collector Current (Pulse) 5 A
Base Current 1 A
Collector Dissipation (TC=25 C) 40 W
Collector Dissipation (Ta=25 C) 2 W
Junction Temperature 150 C
Storage Temperature - 65 ~ 150 C

6 - 9Volt Regulator Berbasis Op-Amp 741

2009-12-22T06:05:00.009+07:00

Regulator Berbasis Op-Amp 741

The following is a series regulator power supply 6V to 9V. Preventing that have something through the circuit in. The parts that perform to heal strong a picture uses the integrated circuit op-amp 741 multi-purpose numbers in the character Comparator mode. The circuit protects the output transistors compose TR1-TR3. By the transistor TR1 perform straddle the acknowledge voltage resistors R3. Which have current work when about 250mA or more than flow through R3 when TR1 work truck loads C3 as a result will do way R5 10K package Resister values and thereafter 2 second railings. The voltage its will encourage enough. TR2 Cooperate TR1 which assemble Tiristor be rapidities are many onely. This circuit consumes current in the condition calmly do not arrive at Current 5mA and will fully protect a part 12mA railing to have sizes only.

Skema rangkaian regulator berbasis Op-Amp 741

Absolute maximum rating Op-Amp 741

Supply voltage (VCC) ±22 V.
Differential Input Voltage (Vid ) ±30 V.
Input Voltage (Vi ) ±15 V.
Power Dissipation (Ptot) 500 mW.
Storage Temperature Range (Tstg) -65 to +150 °C.

Rangkaian Converter 12 VDC To 24 VDC

2009-12-11T00:41:00.006+07:00

Converter 12 VDC To 24 VDC

This is DC to DC converter can provide up to 24V from a 12V volt DC. It can be used to run radios, small lights, relays, horns and other 24V accessories from a 12V vehicle with a maximum draw of about 800mA. It can be used to charge one 12V battery from another, or step up the voltage just enough to provide necessary overhead for a 12V linear regulator.

Skema Rangkaian Converter 12 VDC To 24 VDC

Note:

R6 sets the output voltage. This can be calculated by Vout = 12 x (R8/(R8+R7)) x (R6B/R6A).
L1 is made by winding 60 turns of 0.63MM magnet wire on a toroidial core measuring 15MM (OD) by 8MM (ID) by 6MM (H).
D2 can be any fast recovery diode rated at greater then 100V at 5A. It is very important that the diode be fast recovery and not a standard rectifier.
Transistor Q1 will need a heatsink.

Op-amp as a squarewave oscillator to ring an inductor and another op-amp in a feedback loop, it won't drift around under varying loads, providing a stable 24V source for many applications. With a wide adjustment in output this circuit has many uses.

List component

R1, R2, R3, R4, R8, R7 6 100K_____1/4W Resistor
R5_______________________470 Ohm 1/2W Resistor
R6_______________________10K Linear Pot
C1_______________________0.01uF Mylar Capacitor
C2_______________________0.1uF Ceramic Disc Capacitor
C3_______________________470uF 63V Electrolytic Capacitor
D1_______________________1N4004 Rectifier Diode
D2_______________________BY229-400 Fast Recovery Diode
Q1_______________________BC337 NPN Power Transistor
U1_______________________LM358 Dual Op Amp IC
L1_______________________ See Notes

Rangkain 6 VDC To 12 VDC Converter

2009-12-10T22:03:00.010+07:00

6 VDC To 12 VDC Converter

This is converter circuit can provide up to 800mA of 12V power from a 6V supply. For example, you could run 12V car accessories in a 6V battery. The circuit is simple, about 75% efficient and quite useful. By changing just a few components, you can also modify it for different voltages.

Skema Rangkain 6 VDC To 12 VDC Converter

Notes

L1 is a custom inductor wound with about 80 turns of 0.5mm magnet wire around a toroidal core with a 40mm outside diameter.
Different values of D3 can be used to get different output voltages from about 0.6V to around 30V. Note that at higher voltages the circuit might not perform as well and may not produce as much current. You may also need to use a larger C3 for higher voltages and/or higher currents.
You can use a larger value for C3 to provide better filtering.
The circuit will require about 2A from the 6V supply to provide the full 800mA at 12V.
The transistor Q3 and transistors must be mounted on heat sinks.

Componet List Of
R1, R4____________2.2K 1/4W Resistor
R2, R3____________4.7K 1/4W Resistor
R5_______________1K 1/4W Resistor
R6_______________1.5K 1/4W Resistor
R7_______________33K 1/4W Resistor
R8_______________10K 1/4W Resistor
C1,C2_____________0.1uF Ceramic Disc Capacitor
C3_______________470uF 25V Electrolytic Capcitor
D1_______________1N914 Diode
D2_______________1N4004 Diode
D3_______________12V 400mW Zener Diode
Q1, Q2, Q4_________BC547 NPN Transistor
Q3______________BD679 NPN Transistor
L1 ______________(coil) See Notes

LM317 Adaptor variabel 3.7 volt - 37 Volt

2009-11-12T03:41:00.006+07:00

although this adapter is very simple but this circuit is stable and can be used for voltages up to 37volt (by changing the value of R).

Fout is minimal 1.25volt if you require a higher power, can ic 5A replaced by LM338, LM350 3A, or also by adding external transistors cross I use it on some equipment.

Skema Rangkaian Adaptor variabel 3.7 volt - 37 Volt

stability of this LM317 slightly better than the 78xx class because it was used as the feedback output is not only a reference voltage (78xx kls can also be used as adjustable by lifting the voltage reference terminal wrote in the ground).
resistance value of the above is not ideal but I used to value used, to the ideal of R can be larger because the feedback terminal below only requires 1mA current.

Abaot IC LM317

The LM117 series of adjustable 3-terminal positive voltage regulators is capable of supplying in excess of 1.5A over a 1.2V to 37V output range. They are exceptionally easy to use and require only two external resistors to set the output voltage. Further, both line and load regulation are better than standard fixed regulators. Also, the LM117 is packaged in standard transistor packages which are easily mounted and handled.

Features IC LM317

• Guaranteed 1% output voltage tolerance (LM317A)
• Guaranteed max. 0.01%/V line regulation (LM317A)
• Guaranteed max. 0.3% load regulation (LM117)
• Guaranteed 1.5A output current
• Adjustable output down to 1.2V
• Current limit constant with temperature
• P + Product Enhancement tested
• 80 dB ripple rejection
• Output is short-circuit protected.
.

5 volt Regulator Menggunakan IC 7805

2009-11-09T01:16:00.013+07:00

The IC 7805 provides circuit designers with an easy way to regulate DC voltages to 5v. Encapsulated in a single chip/package (IC), the 7805 is a positive voltage DC regulator that has only 3 terminals. They are: Input voltage, Ground, Output Voltage.

Skema Rangkaian Regulator IC 7805

Although the 7805 were primarily designed for a fixed-voltage output (5V), it is indeed possible to use external components in order to obtain DC output voltages of: 5V, 6V, 8V, 9V, 10V, 12V, 15V, 18V, 20V, 24V. Note that the input voltage must, of course, be greater that the required output voltage, so that it can be regulated downwards

Features IC 7805
• Output Current up to 1A
• Output Voltages of 5 Volt
• Thermal Overload Protection
• Short Circuit Protection
• Output Transistor Safe Operating Area Protection

Input Voltage........................................ 35
Thermal Resistance Junction-Cases (TO-220)40......... 5 °C/W
Thermal Resistance Junction-Air (TO-220)............. 65 °C/W
Operating Temperature Range (KA78XX/A/R)............. 0 ~ +125 °C
Storage Temperature Range............................ -65 ~ +150 °C

10 volt Regulator menggunakan IC LM723

2009-11-09T00:34:00.012+07:00

This is a circuit of an IC LM723 voltage regulator. This IC has a voltage reference source, an error amplifier, a series pass transistor, and a current limiting tran sistor all contained in one small package. The device can be connected to operate as a positive or negative voltage regulator with an output voltage ranging from 2 V to 37 V, and output current levels upto 150 m A. The maximum supply voltage is 40 V, and the line and load regulations are each specified as 0.01%.

Skema rangkaian regulator menggunakan iC LM723

IC regulator LM 723 connected to operate as a positive voltage regulator. The output voltage can be set to any value between approximately 7 V (reference voltage) and 37 V by appropriate selection of resistors R1 and R2. A potentiometer may be included between R1 and R2, of course, to make the voltage adjustable. An external transistor may be Darlington connected to Q1 (as shown in earlier post) to handle large load current. The broken lines in the figure shows connections for simple (non-foldback) current limiting. (Foldback current limiting can also be used with IC LM723). A regulator output voltage less than the 7 V reference level can be obtained by using a voltage divider across the reference source [terminals 6 and 7 in earlier figure]. The potentially divided reference voltage is then connected to terminal 5.

It is important to note that the supply voltage, at the lowest point on the ripple waveform, should be at least 3 V greater than the output of the regulator and greater than VREF; otherwise a high-amplitude output ripple may occur.

Paramaters IC Regulator lm723

Output Current 150 mA
Output Voltage Undefined Volt
Input Min Voltage 9.5 Volt
Input Max Voltage 40 Volt
Adjustable Output Yes
On/Off Pin No
Error Flag No
Temperature Min -55 deg C
Temperature Max 150 deg C.

5 volt and 12 volt switching regulator

2009-11-08T23:54:00.005+07:00

Switching regulators are available is different circuit configurations in cluding the flyback, feed-forward, push-pull, and non-iso lated single-ended or single-polarity types. Also, the switching regulators can operate in any of three modes – step-down, step-up, or polarity inverting.

Skema rangkaian LM2575 step-down switching regulator

Skema rangkaian LM 2577 Step-up switching regulator

LM 2575 series of regulators developed by National Semiconductor are monolithic IC’s that provide the active functions for step-down (back) switching regulator, capable of driving a1A load with excellent line and load regulation. These devices are available in fixed output voltages of 3.3V, 5V, 12V, 15V and an adjustable output version.

Requiring a minimum number of external components, these regulators are simple to use and include internal frequency compensation and a fixed-frequency oscillator. LM 2575 series offers a high-efficiency replacement for popular 3-terminal linear regulators. It substantially reduces the size of the heat sink, and in many cases no heat sink is required. Fixed output voltage version is illustrated in figure.

The National Semiconductor LM 1577/LM 2577 are monolithic ICs that provide all of the power and control functions for step-up (boost), fly back, and forward converter switching regulators. The device is available in three different output voltage versions: 12 V, 15 V and adjustable.

Lay out rangkaian switching regulator

IC LM2575 step-down switching regulator

IC LM 2577 Step-up switching regulator

2- 37 Regulator Power Supplay Variable

2009-10-05T22:18:00.009+07:00

This is an variable regulator power supply with 2V to 37V output voltage and supply up to 3A direct current. This circuit featured with short circuit protection and overload protection.

Skema rangkaian 2- 37 Regulator variable

The IC LM723C is a voltage regulator designed primarily for series regulator applications. By itself, it will supply output currents up to 150 mA; but external transistors can be added to provide any desired load current. The circuit features extremely low standby current drain, and provision is made for either linear or foldback current limiting.

The IC LM723C is also useful in a wide range of other applications such as a shunt regulator, a current regulator or a temperature controller.

The LM723C is identical to the LM723 except that the LM723C has its performance guaranteed over a 0°C to +70°C temperature range, instead of -55°C to +125°C.

Features
150 mA output current without external pass transistor
Output currents in excess of 10A possible by adding external transistors
Input voltage 40V max
Output voltage adjustable from 2V to 37V
Can be used as either a linear or a switching regulator.

Dual Regulator power supplay +12 dan - 12

2009-09-23T00:29:00.007+07:00

This is of a dual regulated that provides +12V and -12V from the AC mains. A regulator like this is a very essential tool on the work bench of an electronic hobbyist.

Transformer T1 steps down the AC mains voltage and diodes D1, D2, D3 and D4 does the job of rectification. Capacitors C1 and C2 does of filtering.C3, C4, C7and C8 are decoupling capacitors. IC 7812 and 7912 are used for the purpose of voltage regulation in which the former is a positive 12V regulator and later is a negative 12V regulator. The output of 7812 will be +12V and that of 7912 will be -12V.

Skema Rangkaian Dual Regulator power supplay

Use Transformer 15-0-15 V, 1A secondary step-down transformer.
Capacitor C1,C2,C5 and C6 must be rated 50V or more.

IC regulator 78xx (7812) Description

Features IC LM7812

Output current in excess of 1A
Output Voltages of 5, 6, 8, 9, 10, 12, 15, 18 , 24V
Internal thermal overload protection
No external components required
Output transistor safe area protection
Internal short circuit current limit

Absolute Maximum Ratings IC LM7812

Input Voltage (VO = 5V, 12V and 15V) : 35V
Operating Temperature Range (TA) : 0°C to +70°C
Maximum Junction Temperature : 150°C
Storage Temperature Range −65°C to +150°C
Lead Temperature (Soldering, 10 sec.)

IC regulator 79xx (7912) Description

The LM79XX series of three-terminal negative regulators are available with several fixed output voltages, making them useful in a wide range of applications. Each type employs internal current limiting, thermal shutdown and safe operating area protection, making it essentially indestructible.

Features IC LM7912

• Output Current in Excess of 1A
• Output Voltages of -5, -6, -8, -9, -10, -12, -15, -18 , -24V
• Internal Thermal Overload Protection
No external components required
• Short Circuit Protection
• Output Transistor Safe Operating Area Compensation

Absolute Maximum Ratings IC LM7912

Input Voltage (VO = -5V, to 15V) : 35V
Operating Temperature Range (TA) : 0°C to +70°C
Maximum Junction Temperature : 150°C
Storage Temperature Range −65°C to +150°C
Lead Temperature (Soldering, 10 sec.).
.

Adaptor 5V Dengan overvoltage protection.

2009-09-14T01:54:00.004+07:00

For circuits using TTL ICs the supply voltage is a great concern and a slight increase in supply from the rated 5V may damage the IC. Using fuses alone does not solve the problem because a fuse may take several milliseconds to blow off and that’s enough time for the IC to get damaged.

In this circuit a crowbar scheme is used in which a triac short circuits the power supply and burns the fuse. The burning time of the fuse is not a concern because the power supply is already shorted by the triac and the output voltage will be zero. When the output voltage exceeds 5.6 volts the zener diode D2 conducts and switches ON the triac T1.Now T1 acts as a closed switch, shorting the circuit. The output voltage drops to zero and fuse gets burned off. Since the switching of triac takes place within few micro seconds there will be no damage to the TTL ICs or any other such voltage sensitive components in the load circuit.

Rangkaian Adaptor 5V Dengan overvoltage protection.

Note:

If 1A Bridge is not available, make one using four 1N4007 diodes.
The trip voltage can be varied by varying the values of D2 and R2.
All capacitors must be rated at least 25V.
The transformer T1 can be a 230 V AC primary, 12v secondary, 2A step-down transformer.

Data Sheet Ic Switching L4970A

2009-09-10T01:49:00.007+07:00

IC L4970A DESCRIPTION

The L4970A is a stepdown monolithic power switching regulator delivering 10A at a voltage
variable from 5.1 to 40V. Realized with BCD mixed technology, the device uses a DMOS output transistor to obtain very high efficiency and very fast switching times. Features of the L4970A include reset and power fail for microprocessors, feed forward line regulation, soft start, limiting current and thermal protection. The device is mounted in a 15-lead multiwatt plastic power package and requires few external components. Efficient operation at switching frequencies up to 500KHz allows reduction in the size and cost of external filter components. This is advanced information on a new product now in development or undergoing evaluation. Details are subject to change without notice.
June 2000

FEATURE IC L4970A

10A OUTPUT CURRENT
5.1V TO 40V OUTPUT VOLTAGERANGE
0 TO 90% DUTY CYCLE RANGE
INTERNAL FEED-FORWARD LINE REGULATION
INTERNAL CURRENT LIMITING
PRECISE 5.1V ± 2% ON CHIP REFERENCE
RESET AND POWER FAIL FUNCTIONS
SOFT START
INPUT/OUTPUT SYNC PIN
UNDER VOLTAGE LOCK OUT WITH HYSTERETIC
TURN-ON
PWM LATCH FOR SINGLE PULSE PER PERIOD
VERYHIGH EFFICIENCY
SWITCHING FREQUENCY UP TO 500KHz
THERMAL SHUTDOWN
CONTINUOUS MODE OPERATION

ABSOLUTE MAXIMUM RATINGS IC L4970A

IC L4970A PIN FUNCTIONS

5.1V / 10A Low Cost Application IC L4970A

10A Switching Regulator, Adjustable from 0V to 25V IC L4970A

Adaptor Variable 0-25V 10A - IC SwitChing L4970 SWITCHING

2009-09-10T01:20:00.009+07:00

This is a series circuit adapter regulator to generate a voltage range from 0V to 25V with maximum current 10A. If designed with care on a PCB, the circuit was quite small because the components used is IC

Skema Rangkaian Adaptor Variable 0-25V 10A

L4970 IC is a Switching Regulator, so can you imagine yourself is, how good the quality of the DC voltage generated from this circuit. Transformer you use, should not be less than 10Ampere, in addition to the transformer secondary winding produces an AC voltage 28V and 8V. For other components please see the draw.

L4970 Chip

fEATURE IC SWICTHING L4970

10A OUTPUT CURRENT
5.1V TO 40V OUTPUT VOLTAGERANGE
0 TO 90% DUTY CYCLE RANGE
INTERNAL FEED-FORWARD LINE REGULATION
INTERNAL CURRENT LIMITING
PRECISE 5.1V ± 2% ON CHIP REFERENCE
RESET AND POWER FAIL FUNCTIONS
SOFT START
INPUT/OUTPUT SYNC PIN
UNDER VOLTAGE LOCK OUT WITH HYSTERETIC
TURN-ON
PWM LATCH FOR SINGLE PULSE PER PERIOD
VERYHIGH EFFICIENCY
SWITCHING FREQUENCY UP TO 500KHz
THERMAL SHUTDOWN
CONTINUOUS MODE OPERATION

LM2575-5.0. 5V Switching regulator

2009-09-09T00:41:00.006+07:00

This is +5V Switching regulator used LM2575-5.0. You can make the stable voltage by using the 3 terminal regulator like LM317. However, because the output electric current and the inputted electric current are the same approximately, the difference between the input electric power (The input voltage x The input electric current) and the output power (The output voltage x The output current) is consumed as the heat with the regulator. Because it is, the efficiency isn’t good. In case of the switching regulator, it inputs only the electric power which is necessary to output from the input by the switching operation. Because it is, there is little electric power to consume with the regulator and it is efficient.

The switching regulator which introduces in this page is the step down type and is the one to get the output voltage which is lower than the input voltage. As for the regulator which uses this time, the output is 5-V fixation. The switching regulator of the step up type can be made the voltage which is higher than the input voltage.

Skema rangkaian 5 voltt Switching regulator

Features Ic LM2575-5.0.
• 3.3V, 5V, 12V, and adjustable output versions
• Voltage over specified line and load conditions:
Fixed version: ±3% max. output voltage
Adjustable version: ±2% max. feedback voltage
• Guaranteed 1A output current
• Wide input voltage range:
4V to 40V
• Wide output voltage range
1.23V to 37V
• Requires only 4 external components
• 52kHz fixed frequency internal oscillator
• Low power standby mode IQ typically <> 80%)
• Uses readily available standard inductors
• Thermal shutdown and current limit protection
• 100% electrical thermal limit burn-in

Adaptor 6 volt menggunakan 7806

2009-09-08T23:43:00.006+07:00

This is the circuit diagram of 6V 1A adapter using 7806 IC. Ic 7806 three-terminal positive voltage regulator is available in the TO-220/D-PAK package making them useful in a wide range of applications. 7806 employs internal current limiting, thermal shut down and safe operating area protection, making it essentially indestructible. If proper heat sinking is provided, it can deliver over 1 ampere output current.

Skema Rangkaian Adaptor 6 volt

Note:

Fit a proper heat sink with 7806 if your circuit draws more than 400mA current.

List Component Of Adaptor 6 volt
Di: Diode bridge 1 A or more
C1: 470uf/50volt Capasitor electrolic
C2,c3: 0.01uf Capasitor ceramic
IC1: 7806 IC three-terminal regulator
T1: transformer step down 0 - 9 volt

Data Sheet Ic Regulator IC LM138

2009-09-08T19:45:00.005+07:00

IC LM138 series of adjustable 3-terminal positive voltage regulators is capable of supplying in excess of 5A over a 1.2V to 32V output range. They are exceptionally easy to use and require only 2 resistors to set the output voltage. Careful circuit design has resulted in outstanding load and line regulation-comparable to many commercial power supplies. The LM138 family is supplied in a standard 3-lead transistor package.

A unique feature of the LM138 family is time-dependent current limiting. The current limit circuitry allows peak currents of up to 12A to be drawn from the regulator for short periods of time. This allows the LM138 to be used with heavy transient loads and speeds start-up under full-load conditions. Under sustained loading conditions, the current limit decreases to a safe value protecting the regulator. Also included on the chip are thermal overload protection and safe area protection for the power transistor. Overload protection remains functional even if the adjustment pin is accidentally disconnected.

Normally, no capacitors are needed unless the device is situated more than 6 inches from the input filter capacitors in which case an input bypass is needed. An output capacitor can be added to improve transient response, while bypassing the adjustment pin will increase the regulator's ripple rejection.

Besides replacing fixed regulators or discrete designs, the LM138 is useful in a wide variety of other applications. Since the regulator is "floating" and sees only the input-to-output differential voltage, supplies of several hundred volts can be regulated as long as the maximum input to output differential is not exceeded, i.e., do not short-circuit output to ground. The part numbers in the LM138 series which have a K suffix are packaged in a standard Steel TO-3 package, while those with a T suffix are packaged in a TO-220 plastic package. The LM138 is rated for -55°C - +150°C, and the LM338 is rated for 0°C - 125°C.

Rangkaian Aplikasi IC LM138

Features IC LM138
• Guaranteed 7A peak output current
• Guaranteed 5A output current
• Adjustable output down to 1.2V
• Guaranteed thermal regulation
• Current limit constant with temperature
• P+ Product Enhancement tested
• Output is short-circuit protected

Applications IC LM138
• Adjustable power supplies
• Constant current regulators
• Battery chargers

LM338 Adapator Variable 1.5V - 30 V

2009-09-08T19:22:00.007+07:00

This 1.2V-30V/5A adapter is based on the famous LM338 IC from the ST Microelectronics. The IC has time dependent current limiting, thermal regulation and is available in 3 lead transistor package. The IC can easily supply well over 5A at an output voltage range between 1.2V and 30V.

In adapter circuit the output voltage is determined by the two resistors R1 and R2. The output voltage can be varied by adjusting the R2.Diodes D2 and D3 are protection diodes. Capacitors C1 and C5 are filter capacitors while C2 and C3 are decoupling capacitors.

Gambar Skema Rangkaian Adaptor Variable

IC Regulator Adapter LM338
The LM138 series of adjustable 3-terminal positive voltage regulators is capable of supplying in excess of 5A over a 1.2V to 32V output range. They are exceptionally easy to use and require only 2 resistors to set the output voltage. Careful circuit design has resulted in outstanding load and line regulation-comparable to many commercial power supplies. The LM138 family is supplied in a standard 3-lead transistor package.
A unique feature of the LM138 family is time-dependent current limiting. The current limit circuitry allows peak currents of up to 12A to be drawn from the regulator for short periods of time. This allows the LM138 to be used with heavy transient loads and speeds start-up under full-load conditions. Under sustained loading conditions, the current limit decreases to a safe value protecting the regulator. Also included on the chip are thermal overload protection and safe area protection for the power transistor. Overload protection remains functional even if the adjustment pin is accidentally disconnected.
Normally, no capacitors are needed unless the device is situated more than 6 inches from the input filter capacitors in which case an input bypass is needed. An output capacitor can be added to improve transient response, while bypassing the adjustment pin will increase the regulator's ripple rejection.
Besides replacing fixed regulators or discrete designs, the LM138 is useful in a wide variety of other applications. Since the regulator is "floating" and sees only the input-to-output differential voltage, supplies of several hundred volts can be regulated as long as the maximum input to output differential is not exceeded, i.e., do not short-circuit output to ground. The part numbers in the LM138 series which have a K suffix are packaged in a standard Steel TO-3 package, while those with a T suffix are packaged in a TO-220 plastic package. The LM138 is rated for -55°C - +150°C, and the LM338 is rated for 0°C - 125°C.

Gambar IC regulator LM338

Features IC regulator LM338

Guaranteed 7A peak output current
Guaranteed 5A output current
Adjustable output down to 1.2V
Guaranteed thermal regulation
Current limit constant with temperature
P+ Product Enhancement tested
Output is short-circuit protected

ADAPTOR 5 VOLT 7805/ USB

2009-09-08T12:04:00.003+07:00

To get a 5 Volt DC without buying a new adapter which is very expensive of course - because it is unusual 5VDC used by household electronic equipment. Usually the adapter on the market that can produce 3,6,7.5,9, and 12Volt only. So what if we need a 5V DC only. Based on my experience, 5VDC can be obtained with 3 ways

1. Using zener diode, the current is so small I will not discuss it
2. Using converter circuit. If we have a source (power supply DC) 9 volt to 24 volts, then we can use to produce 5 volts DC with a few components, where components are cheap and can be easily obtained at the nearest electronics store.

Skema rangkaian adaptor 5 volt

List components of Adaptor 5 volt:

IC 7805 (1pce)
Electronic Condensator 100uF/16V (2pcs)

The raft was all above components according to the scheme of the circuit. Then connect the adapter 9 volts to 24 volts, or it could be associated with Accumulator / Aki motor vehicles.

2. Utilizing the USB cable. Peel the end of the USB cable, then we will get multicolored wires 4, the cable cut green and white colors, please let me as long distinguished in isolation does not occur brief relationship. Red wire is the source of 5V DC and ground the black wire. See the image below:

REGULATOR 12 VOLT 15 AMPRE TIP 2955

2009-09-08T00:31:00.003+07:00

This is circuit of adapter/ regulator 12V that can deliver up to 15 A of current. The common voltage regulator IC 7812(IC1) is used to keep the voltage at steady 12V and three TIP 2599 power transistors in parallel are wired in series pass mode to boost the output current. The 7812 can provide only up to 1A and rest of the current is supplied by the series pass transistors. The 15A bridge B1 does the job of rectifying the stepped down AC input. The capacitor C1, C2 and C3 act as filters. The 1A fuse F1 protects the IC1 from over current in case if the pass transistors fail. The 15A fuse F2 protects the entire circuit (especially the pass transistors) from over current.

With high current transformer, power transistors and high current bridge the circuit is a bit costly and you may try this only if there is a serious need.

Skema Rangkaia Regulator 12 volt 15 A

Note:

The T1 can be a 230V AC primary, 18V secondary, 15A type transformer.
The B1 can be a 15A bridge.
If 15A Bridge is not available, make one using four RURG1520CC diodes.
The IC1 and transistors must be mounted on heat sinks.

Features IC 78xx
Output current in excess of 1A
Internal thermal overload protection
No external components required
Output transistor safe area protection
Internal short circuit current limit
Available in the aluminum TO-3 package

Gambar IC regulator 7812

Voltage Range IC 78xx

LM7805C 5V
LM7812C 12V
LM7815C 15V

The LM78XX series of three terminal regulators is available with several fixed output voltages making them useful in a wide range of applications. One of these is local on card regulation, eliminating the distribution problems associated with single point regulation. The voltages available allow these regulators to be used in logic systems, instrumentation, HiFi, and other solid state electronic equipment. Although designed primarily as fixed voltage regulators these devices can be used with external components to obtain adjustable voltages and currents.

Considerable effort was expanded to make the LM78XX series of regulators easy to use and minimize the number of external components. It is not necessary to bypass the output, although this does improve transient response. Input bypassing is needed only if the regulator is located far from the filter capacitor of the power supply.

ADAPTOR 12 VOLT 2N3055

2009-08-20T09:20:00.004+07:00

This adapter circuit can deliver up to 3A at 12V output voltage. The circuit can be employed on occasions when a current of more that 3A is demanded for regulator. IC regulators of such high current rating are pretty hard to find.

The transformer T1 steps down mains voltage, to 12rms & the rectifier bridge D1 rectifies it to produce a DC voltage. The C1 filters the rectifier output and produces a DC level. The series pass transistor Q1 (2N 3055) is biased by resistor R1 (680Ω). Since zener diode D1 is under breakdown region the voltage across it will be 12V. So the total output voltage will be steady 12.7 V(theoretically). That is the zener voltage plus base emitter voltage of Q1.Here transistor Q1 will conduct the excess current required .

Skema rangkaian adaptor 12 volt 2N3055

Notes.

If 12V zener is not available ,use the nearest value.
The transformer T1 can be as 23oV primary;15V/5A secondary step down transformer.
The capacitors must be rated at least 25V.
By changing the value of the Zener diode, different output voltages can be obtained from the circuit.