Solid State Relay

This is the circuit diagram of solid state relay. In reality, it is not a relay after all. There’s no ‘relay’ found, just the electronics circuit which does the switching. It operates a similar way as a relay; it is possible to use a low voltage to switch a higher voltage or better than ordinary… Read More »

LEDs Temperature Indicator

A well-known IC LM35 is chosen to be the temperature sensor in this circuit. Output voltage of LM35 will increase by 10mV per degree rise in temperature. Output of LM35 is joined to the non inverting input of the operational amplifier (op-amp) of CA3130. The inverting input of the same op-amp could be provided using the required reference voltage using variable resistor R2.

12V Lead-Acid Battery Monitor

This easy circuit makes it possible to monitor the charging process to a higher level. Final adjustsments are simple and easy and the only device required is a digital voltmeter for the important accuracy and reliability. 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.

Automatic 9V Battery Charger

This is the scheme diagram of automatic 9V battery charger circuit, the parts list provided below the schematic image. The circuit was designed by Jan Hamer, translated by Tony Van Roon dan republished in this circuit diagram site. The circuit details are based on european standards: 120E, 150E, etc. The ‘E’ just stands for Ohms… Read More »

Dallas Arbiter Fuzz Face

This is the circuit diagram of Fuzz Face mods, guitar effect pedal. This is a modified diagram and simpler than the original Fuzz Face diagram. You will find apparently two identical designs of the fuzz face. In one Q1 and Q2 had been PNP germanium AC128 or NKT275 types, in the other they had been… Read More »

LED Pilot Light using FET

This is the LED pilot light (or LED indicator) circuit. LEDs (Light Emitting Diode) part are interesting things. They only operate at DC supply within specific tolerances, and generally connected with a current limiting resistor towards the power source. Rather than a resistor, it is possible to use a FET (Field Effect Transistor) like the… Read More »