Variable Dummy Load for Power Supply Testing. How to test a voltage source to know if it is good or not?. What is the percentage regulation?.

Transistor – Zener diode Voltage regulator circuit. This circuit delivers an output voltage established by the voltage of the zener diode less 0.7 volts

Dual polarity variable voltage source (+/- 15 volts).

Voltage source with a maximum amplitude of +/- 15 volts an a current up to 1.5 amps.

12 to 5 volt converter circuit (for cars)

This 12 to 5 volt converter circuit for cars is very useful. It can be used to connect 5-volt electronic devices in a car with a 12v battery. (Automotive lead-acid batteries may have a voltage of up to 13.5 volts).

12 volt Power Supply using 7805

This 12 volt power supply circuit is simple and very useful. Sometimes a 12 Volt power source is needed, and we only have 5 or 9 volt regulators (7805, 7809)

Variable voltage regulator using 7805 and 741.

Very simple variable voltage regulator with very few components. Output Voltage from 5 to 30 volts

Mini variable power supply.

Totally transistorized with 0 to 30V output voltage range, and it can be used for projects where the current consumption is 1A max.

Current Limiter circuit for a Power Supply using a transistor and a resistor.

If the load current exceeds its maximum, an over current protection is needed

Surge Protection Circuit (Voltage Delay Circuit)

This Surge protection circuit is placed between the DC voltage source and the circuit that you want to power. This circuit delays the voltage given by the power source and allows the voltage to be applied to the circuit or device a few moments later.

12V Power Supply using Zener and 741 Op. Amp.

This 12V Power Supply has, as its main characteristic, a low output impedance. This is a very desirable feature in voltage sources and is achieved with a large open loop gain that the operational amplifier has.

Inverter for fluorescent lamps (12V to 120 / 220 VAC)

Simple circuit using the 555 timer, a transformer and a transistor Useful to use with a car battery.

5A Variable Power Supply with LM338 Voltage Regulator

The 5A Variable Power Supply uses the LM338 voltage regulator. The LM338 regulator works the same as the LM317 adjustable voltage regulator, known to all