Simple Time Delay Circuit for DC Power uses SCR. It is very useful in many uses and is easy to understand. Need wait before device ON? Then this circuit gives delay after power ON. Circuit is good to turn devices one-by-one and avoid current spike. Max input DC for this circuit is 24V. Circuit Working: […]
Power Supply Circuits
Simple Mains Powered LED Light Circuit
Simple Mains Powered LED Light Circuit runs on 230V AC mains. It uses capacitor dropper to limit the current. LEDs in series-parallel are cheap and easy for mains lighting. They are with bright white light and no big transformer. It is good for low power light needs. Circuit Working: Parts List: Component Type Value/Specification Quantity […]
Simple AC Mains Powered LED Night Light Circuit
This is Simple AC Mains Powered LED Night Light Circuit which runs on AC mains power 230V. With no big transformer needed. It can light 24 bright white LEDs with each takes 50mA current. It is small, cheap and good for night room light. Circuit uses capacitor power supply, bridge rectifier and filter capacitor to […]
Simple Boost Converter LED Torch Circuit using IC MAX660
Simple Boost Converter LED Torch Circuit using IC MAX660 is small but useful light tool. This project use MAX660 chip to make LED torch work well. MAX660 boost 3V battery to higher voltage and can light many LEDs. It is good for battery devices needing more voltage and with no inductor needed. Circuit design also […]
Simple Light to Frequency Converter Circuit using Timer IC 555
Simple Light to Frequency Converter Circuit using Timer IC 555 changes light brightness into frequency signal. It is useful for light measure, optic sensing and automation. Circuit uses IC 555 timer in astable mode and photodiode to catch light. More light means more frequency which is easy to see link between light and output. Circuit […]
LM331 Based Frequency to Voltage Converter Circuit
Simple F/V converter is cool circuit. It changes signal with different frequency to DC voltage same as that frequency. It is used in many things like tachometer, speedometer and factory machines. LM331 is popular IC for this and it can do both V/F and F/V. It is very accurate and very flexible. Here LM331 works […]





