12v to 24v converter

This 12VDC to 24VDC step up converter is very useful to power devices that run on 24 VDC when we have a 12VDC voltage source as it could be a car battery or alike.

20 Amp Variable Power Supply using LM317

20 Amp Variable Power Supply with an output voltage from 1.5 to 15 volts using the LM317 regulator and 4 2N3055 power transistors to amplify the current capacity

12V to 9V DC Converter Circuit Diagram (PCB)

This 12V to 9V DC converter is very useful for powering 9V DC devices in a car that uses 12V battery. The maximum current consumption allowed by this circuit is 0.8 amps.

This darkness detector circuit beeps when the light drops below a certain level.

The main elements of this circuit are the 555 integrated circuit, working as an astable multivibrator and an LDR which is used as darkness sensor.

1.5 v Joule Thief Circuit with no Toroid Coil

This 1.5 V Joule Thief circuit can turn ON one LED. The circuit do not use a toroid coil but it is possible to turn on a common red, green or yellow LED

6 Watts Audio Amplifier Circuit with TDA2613 (Hi-Fi)

High fidelity 6 watts audio amplifier circuit with the TDA2613 Integrated Circuit, very easy to implement due to its very few external components

Battery Charge Monitor Circuit with LM3914 IC

This battery charge monitor shows, with colored LEDs, the charging process of a typical 12-volt car battery using the LM3914 Dot / Bar Display Driver.

Continuity Tester with Buzzer – Works on live circuits.

This continuity tester with buzzer works on live circuits. Very important, as common continuity testers are used with the power source disconnected.

6-LED VU meter using one transistor

This simple 6-LED VU meter allows us to visualize the level of an audio signal. Due to its few components, it is a cheap circuit and easy to build. Components are very common and very easy to obtain.

DC motor speed control with 4049 (PWM)

This DC motor speed control with 4049, is a circuit that allows varying the speed of small DC motors of 3 or 6 Volts that are often found in toys or small electronic devices.

This blown fuse indicator circuit warns us, lighting a LED, when there is a problem in an electrical installation protected by the fuse.

It is very important to correct the faults in the electrical system of an automobile or motorcycle or other, as soon as possible. This circuit will warn us when this happens.

Variable voltage regulator using 7805 and 741.

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