Auto Switch-Off Power Supply (Variable Output 3.7V to 8.7V)

Auto Switch-Off Power Supply (Variable Output 3.7V to 8.7V)
Here is the auto switch-off power supply which will turn off itself when there is no load on the output. The output voltage can be vary from 3.7V upto 8.7V. Although this circuit uses fixed-voltage regulator LM7805, but its output voltage is adjustable, thanks to a potentiometer installed between common terminal of regulator IC and ground. For every 100-ohm increment in the in-circuit value of the resistance of potentiometer VR1, the output voltage increases by 1 volt. Thus, the

1-15V DC Digital Power Supply with 15 Steps

1-15V DC Digital Power Supply with 15 Steps
This is a simple digital power supply circuit diagram to obtain variable DC voltage from 1.25V to 15.19V in reasonably small steps. The steps of up and down voltage can be down by press the up and down switch, and it use LED indicator to show the level of the output voltage. You can use DC input voltage between 20V and 35V. You must prepare a DC power supply before built this circuit. (more…)

Power supply 4.5 A with 3 LM317 in parallel

Power supply 4.5 A with 3 LM317 in parallel
This lm317 variable power supply can supply a voltages from 1.2V to 30V with a current 3 amperes, just as the title of this series based on LM317T voltage regulator, the LM317T regulator provide around 1.5 amperes on the heatsink, so by installing a parallel two or three of them will get a voltage source capable of providing 3 amperes. Obviously this also depends on the transformer used. (more…)

Adjustable Regulated Power Supply 0-15V / 1A

Adjustable Regulated Power Supply 0-15V / 1A
This is the schematic diagram of adjustable power supply which the voltage output can be vary from 0V up to 15V with fixed current output maximum of 1A. The circuit is very simple and easy to build, finding the components is easy and inexpensive. The output voltage is stabilized and regulated in the range of 0V to +15 V, supplied with a maximum current of 1 A. (more…)

Variable Power Supply with Adjustable Current Limit

Variable Power Supply with Adjustable Current Limit
This circuit variable power supply with adjustable current limit using three terminal adjustable regulator LM117 which is used to regulate current and the voltage limits. Variable power supply input range is between 32 V to 40 VDC and can provide outputs up to 25 VDC and provide currents up to 1.2 A (more…)

Variable Power Supply 0 to 12 V

Variable Power Supply 0 to 12 V
This Power supply circuit is powered by 12 volt AC power supply rectifier diodes form VD1 ... VD4, included in a bridge circuit and the rectified voltage stabilizer - capacitors CI, C2, zener VD5 and transistors VT1 and VT2. Voltage power supply output from 0 to 12 regulate the variable resistor R2. The highest current given up power supply to the load (300 mA) is limited to permissible direct current rectifier diodes. (more…)

Simple Variable Power Supply using L4960

Simple Variable Power Supply using L4960
Modern circuit design and chip manufacturers make life easier for the designer's great-for example, when creating a power source. We demonstrate this on a chip factory L4960. The documentation on it is possible to produce regulated power supply with an output voltage of 5.1 V. .. 40 V, with load current 2.5 A, built-in protection for current and overheat, efficiency up to 90%. Power dissipation from the radiator - 15 watts, frequency conversion 50 .. 150 kHz. (more…)

1.5V-25V Power Supply with Preregulator

1.5V-25V Power Supply with Preregulator
This circuit using KR142EN12 (analog - LM317 ) ic regulator that can handle load currents up to 2 amperes. For higher currents can be used IC LT1083/84/85 that each can handle currents 7/5/3A. 2000uF capacitor C3 is selected from the calculation of the current 1 Ampere. Resistor R9 is used as a current sensor to an ammeter. (more…)