Tuesday, November 18, 2014
Power Supply Variable 1 3V 12 2V 1A Circuit

Description:
R2 to set the output voltage. The maximum current is determined by R3, over-current protection circuit inside the LM723 to detect the voltage on R3, if it reaches 0.65 V, the voltage output will be off her. So the current through R3 can not exceed 0.65 / R3 although output short-circuit in his.
C3 and C4 are ceramic capacitors, as much as possible directly soldered to the PCB, this is because the LM723 is prone to oscillation that is not cool.
LM723 works with 9.5V input voltage to 40 V DC and the LM723 can generate its own current of 150mA when the output voltage is not more than 6-7V under input voltage.
Specifications:
Output (value estimated):
Vmin = (R4 + R5) / (R5 * 1.3)
Vmax = (7.15 / R5) * (R4 + R5)
Imax = 0.65/R3
Max. Power on R3: 0.42/R3
Min. DC Input Voltage (pin 12 to pin 7): Vmax + 5
Component List:
B1 40V/2.5A
C1 2200uF (3300uF even better)
C2 4.7uF
C3 100nF
C4 1NF
C5 330nF
C6 100uF
Green LED D1
D2 1N4003
F1 0.2A F
F2 2A M
IC1 LM723 (in a DIL14 plastic package)
R1 1k
R2 Pot. 5k
R3 0.56R/2W
R4 3.3k
R5 4.7k
S1 250V/1A
T1 2N3055 on a heatsink 5K / W
TR1 220V/17V/1.5
Power supply with Z2C
Z2C on the rectifier tube in power supply with tube above require a supply voltage for the filaments taken from the other side of the transformer secondary. Power supply with Z2C tube is a power supply that dapt used as a substitute power supply for power amplifier tubes with a diode in previous articles.
Monday, November 17, 2014
6 to 12 Volt Power Supply Inverter

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 See Notes
MISC Heatsink For Q3, Binding Posts (For Input/Output), Wire, Board
Power supply with driver TEA1507
Thursday, November 13, 2014
single supply NE5532 preamplifier circuit
Single-supply NE5532 chip preamp made on the breadboard
Single-supply preamp schematic
Amplifying resistors are selected to be the same (and thus preamp actually becomes a real one with amplifying ratio equal to 2) and to be equal to the input chain resistance (single supply shift made as resistor-based voltage divider and input resistor) to minimize bias current. Thats why there are so many resistors on the actual scheme to match resistance.
Now the results.
Square wave signal
Square wave signal peak details
What is a real problem, is the input signal range as a whole. Since I used 15V as a supply voltage, its inner ground will be roughly at 7.5 V (there is an appropriate voltage divider attached to the non-inverting input signal), so having total output amplitude of 4 V may be not appropriate for the chip operational amplifier.
Big sine signal cut
Now question, why do we need chip preamp for the chip amplifier? I believe that the main reason for preamp is to allow to connect power amplifier which may have not very high input resistance, so small preamp with good characteristics (like huge input resistance and very small output one) will not distort small enough input signal. But I think that most of the modern chip sound amplifiers like LM3886 already have big enough input resistance (as all others they have differential amplifier as the first cascade), maybe not that high if would be built with field-effect transistors, but I wonder if that is ever noticeble.
http://www.ioremap.net/node/141
Friday, November 7, 2014
LM317 variable power supply
LM317 variable power supply Circuit Diagram
Since LM317 is protected against short-circuit, no fuse is necessary. Thanks to automatic thermal shutdown, it will turn off if heating excessively. All in all, a very powerful (and affordable!) package, indeed.
Although LM317 is capable of delivering up to 37V, the circuit pictured here is limited to 25V for the sake of safety and simplicity. Any higher output voltage would require additional components and a larger heat sink.
Make sure that the input voltage is at least a couple of Volts higher than the desired output. Its ok to use a trimmer if youre building a fixed-voltage supply.Problems:Follow all the safety precautions when working with mains voltage. Insulate all connections on the transformer.
Possible uses:Variable workbench power supply, fixed-voltage supply... Just about any possible application when no more than 1.5A is necessary.
Sunday, November 2, 2014
100 watt Hiwatt amplifier model DR 103 power supply schematic circuit diagram
100 watt Hiwatt amplifier model DR 103 power supply schematic circuit diagram
100 watt Hiwatt amplifier model DR 103 power supply schematic circuit diagram
Tuesday, October 28, 2014
Minimal low supply rail detection
This turns on Q3 here proportion to this bias current which subsequently drives LED1. The brightness of the LED gives an indication of the severity of the low voltage condition. The brighter the LED, the minor the supply voltage. Trimpot VR1 is adjusted so to facilitate LED1 really comes on by the desired low-voltage promontory. The current consumption is typically take away than 2mA at what time LED1 is rotten. in conclusion, the price exposed in support of RLED is right for 6-12V surgery. For other voltages, RLED can ensue calculated using the formula RLED = (Vcc - 1.8)/0.01 (this equates to a current of with reference to 10mA).
Thursday, October 23, 2014
12V 3A Power Supply Circuit Diagram
Simple 5V Regulated Power Supply Circuit Diagram
The following circuit is the answer to the problem. This circuit can give +5V output at about 150 mA current, but it can be increased to 1 A when good cooling is added to 7805 regulator chip. The circuit has overload and thermal protection. The capacitors must have enough high voltage rating to safely handle the input voltage feed to circuit. The circuit is very easy to build for example into a piece of veroboard.
C1 = 100uF-25V electrolytic capacitor, at least 25V voltage rating
C2 = 10uF-25V electrolytic capacitor, at least 6-16V voltage rating
C3 = 100nF-63V ceramic or polyester capacitor
IC = 7805 regulator IC
ICs Pinout :
- Unregulated voltage in
- Ground (See Diagram)
- Regulated voltage out
Circuit features:
- Gives out well regulated +5V output, output current capability of 100 mA
- Built-in overheating protection shuts down output when regulator IC gets too hot
- Very simple and easy to build
- Very stable +5V output voltage, reliable operation
- Easy to get components, uses only very common basic components
- Based on datasheet example circuit, I have used this circuit succesfully as part of many electronics projects
- Part of electronics devices, small laboratory power supply
- Wide range of input unreglated DC 8-24V power supply
- Few dollars for the electronics components + the input transformer cost
More output current:
If you need more than 150 mA of output current, you can update the output current up to 1A doing the following modifications.
- Change the transformer from where you take the power to the circuit to a model which can give as much current as you need from output
- Put a heatsink to the 7805 regulator (so big that it does not overheat because of the extra losses in the regulator)
More output voltages:
Monday, October 20, 2014
Simple Dual Voltage Power Supply 12 Volt

Saturday, October 18, 2014
LM7905 LM7805 Dual Variable Regulator power supply 5 25V
When you want Dual power supply Variable Regulator be simple. I begs for to advise this circuit, because use the integrated circuit LM7805 and LM7905. Make have Voltage +5V to +25V and -5V to -25V unless. Still pay current get about 1A enough with general usability. The important factor is you should use Transformer at enough size doesn’t lower 2A and IC all stick let off the heat with. The detail is other see in circuit picture better sir.Wednesday, October 15, 2014
LM317 VARIABLE POWER SUPPLY Circuit Diagram
Since LM317 is protected against short-circuit, no fuse is necessary. Thanks to automatic thermal shutdown, it will turn off if heating excessively. All in all, a very powerful (and affordable!) package, indeed.
Although LM317 is capable of delivering up to 37V, the circuit pictured here is limited to 25V for the sake of safety and simplicity. Any higher output voltage would require additional components and a larger heat sink.
Make sure that the input voltage is at least a couple of Volts higher than the desired output. Its ok to use a trimmer if youre building a fixed-voltage supply.
Variable workbench power supply, fixed-voltage supply... Just about any possible application when no more than 1.5A is necessary.
Saturday, October 11, 2014
Power Supply for USB Devices Circuit Diagram
Sunday, October 5, 2014
Transformerless Power Supply Circuit
Transformerless Power Supply CircuitIf you are not accomplished in ambidextrous with it, again leave this activity alone.Although Mains accessories can itself absorb a lot of current, the circuits we body to ascendancy it, usually alone crave a few milliamps. Yet the low voltage ability accumulation is frequently the better allotment of the architecture and a abundant allocation of the cost.
This ambit will accumulation up to about 20ma at 12 volts. It uses capacitive reactance instead of resistance; and it doesnt accomplish actual abundant heat.The ambit draws about 30ma AC. Always use a agglutinate and/or a aqueous resistor to be on the safe side. The ethics accustomed are alone a guide. There should be added than abundant ability accessible for timers, ablaze operated switches, temperature controllers etc, provided that you use an optical isolator as your circuits achievement device. (E.g. MOC 3010/3020) If a broadcast is unavoidable, use one with a mains voltage braid and about-face the braid application the optical isolator.C1 should be of the suppressor type; fabricated to be affiliated anon beyond the admission Mains Supply. They are about covered with the logos of several altered Safety Standards Authorities. If you charge added current, use a beyond amount capacitor; or put two in parallel; but be accurate of what you are accomplishing to the Watts. The low voltage AC is supplied by ZD1 and ZD2.
The arch rectifier can be any of the baby Round, In-line, or DIL types; or you could use four abstracted diodes. If you appetite to, you can adapt R2 and ZD3 with a 78 Series regulator. The abounding sized ones will work; but if amplitude is tight, there are some baby 100ma versions accessible in TO 92 blazon cases. They attending like a BC 547. It is additionally account acquainted that abounding baby circuits will assignment with an able supply. You can, of course, adapt any or all of the Zenner diodes in adjustment to aftermath a altered achievement voltage. As for the mains voltage, the advancement apropos the 110v adaptation is aloof that, a suggestion. I havent congenital it, so be able to agreement a little.
Wednesday, September 24, 2014
Made Dual Regulated Power Supply
In this circuit, the 7815 regulatates the positive supply, and the 7915 regulates the negative supply. The transformer should have a primary rating of 240/220 volts for europe, or 120 volts for North America. The centre tapped secondary coil should be rated about 18 volts at 1 amp or higher, allowing for losses in the regulator. An application for this type of circuit would be for a small regulated bench power supply.
Tuesday, September 23, 2014
Dual Power Supply 78xx 79xx series
Dual Power Supply Schematic
This dual power supply project provides a dual power supply. With the appropriate choice of transformer and 3-terminal voltage regulator pairs you can easily build a small power supply delivering up to one amp at +/- 5V, +/- 9V, +/- 12V, +/- 15V or +/-18V. You have to provide the centre tapped transformer and the 3-terminal pair of regulators you want: 7805 & 7905, 7809 & 7909, 7812 & 7912, 7815 & 7915or 7818 & 7918.
Note that the + and - regulators do not have to be matched: you can for example, use a +5v and -9V pair. However, the positive regulator must be a 78xx regulator, and the negative a 79xx one. We have built in plenty of safety into this project so it should give many years of continuous service.
These protect mainly against any back emf which may come back into the power supply when it supplies power to inductive loads. They also provide additional short circuit protection in the case that the positive output is connected by accident to the negative output. If this happened the usual current limiting shutdown in each regulator may not work as intended. The diodes will short circuit in this case and protect the 2 regulators.
Dual Power Supply Parts
Monday, September 22, 2014
0 50V 2A Bench power supply circuit and description
Circuit diagram
I use the lm10 IC because it has a reference voltage and that’s useful for dc power supply. With two ICs can take different output voltage and amperage. This circuit is protected from short circuit.P2 is for controlling the current at the range of 0-2A. Stabilize the output voltage with R4 on negative pin on op-amp and with R2 & P1 on positive pin.
Op-amp output controls T1 that not let ripple of voltage.T1 increase or decrease ampere of R6 and control the voltage of T5 & T4. Pin 1 is the reference voltage and reference voltage is losing some voltage on R1 that has 100uA . This current passes through P1 too.
Vlose p1=100uA*Rp1
This lose voltage regulate output voltage rate of output current is compare between reference voltage of P3 and lose voltage on R11.T3 is protecting short circuit with R11. For reduce out put voltage to 0v should parallel one resistor 470 ohm in out put. Minimum voltage is 0.4v. The maximum output voltage is fixed with R1b and should not become over of 50v. Therefore your transformer should give 36V, 3A with 4700uF capacitor. T6, T5, T7 need heatsilk.
R1a = 2,2 K
R1b = read the text
R2 = 10 K
R3, R7 = 3.3 k
R4 = 390 Ohm
R5 = 47 K
R6 = 3.3 K 1Watt
R8 = 180 Ohm
R9, R10 = 0.47 Ohm 3Watt
R11 = 0.075 Ohm 2Watt
R12 = 470 Ohm
P1 = 500K liner potentiometer
P2 = 4.7 K potentiometer
P3 = 10 K potentiometer
C1 = 1nF
C2 = 10nF
C3 = 22nF
C4 = 47mF 63v electrolytic
C5 = 4700mF 80v electrolytic
T1, T2 = BC161
T3, T4 = BD141
T5 = BD241
T6, T7 = 2V3055
D1, D2 = 1N4148
D3, D4 = 1N4001
IC1, IC2 = LM10C
author:
e-mail: hamed_iranmehr@yahoo.com
web site: http://www.electronics-lab.com
0 50V 2A Bench power supply circuit and explanation
I use the lm10 IC because it has a reference voltage and that’s useful for dc power supply. With two ICs can take different output voltage and amperage. This circuit is protected from short circuit.P2 is for controlling the current at the range of 0-2A. Stabilize the output voltage with R4 on negative pin on op-amp and with R2 & P1 on positive pin.
Op-amp output controls T1 that not let ripple of voltage.T1 increase or decrease ampere of R6 and control the voltage of T5 & T4. Pin 1 is the reference voltage and reference voltage is losing some voltage on R1 that has 100uA . This current passes through P1 too.
Vlose p1=100uA*Rp1
This lose voltage regulate output voltage rate of output current is compare between reference voltage of P3 and lose voltage on R11.T3 is protecting short circuit with R11. For reduce out put voltage to 0v should parallel one resistor 470 ohm in out put. Minimum voltage is 0.4v. The maximum output voltage is fixed with R1b and should not become over of 50v. Therefore your transformer should give 36V, 3A with 4700uF capacitor. T6, T5, T7 need heatsilk.

R1a = 2,2 K
R1b = read the text
R2 = 10 K
R3, R7 = 3.3 k
R4 = 390 Ohm
R5 = 47 K
R6 = 3.3 K 1Watt
R8 = 180 Ohm
R9, R10 = 0.47 Ohm 3Watt
R11 = 0.075 Ohm 2Watt
R12 = 470 Ohm
P1 = 500K liner potentiometer
P2 = 4.7 K potentiometer
P3 = 10 K potentiometer
C1 = 1nF
C2 = 10nF
C3 = 22nF
C4 = 47mF 63v electrolytic
C5 = 4700mF 80v electrolytic
T1, T2 = BC161
T3, T4 = BD141
T5 = BD241
T6, T7 = 2V3055
D1, D2 = 1N4148
D3, D4 = 1N4001
IC1, IC2 = LM10C
author:
e-mail: hamed_iranmehr@yahoo.com
web site: http://www.electronics-lab.com
Saturday, September 20, 2014
TL594 12V DC Switch Mode Power Supply Wiring diagram Schematic
3) Able to operate over a variety of input power supply.
4) Able to have over output.

