Free Circuit Diagram

Based on a request by FreeCircuitDiagram reader Helynn Schufletowski, here we present an AC powered-LED flasher circuit for all of you! DEADLY ELECTRICAL SHOCK WARNING: This circuit is not isolated from mains supply, don’t touch it when it’s plugged to the power line. The circuit is based on our previous transistor LED flasher [...]

Controlling the speed of three phase ac motor is done by controlling the frequency of the power line supply,  since the motor is synchronized with the line frequency. Three phase ac motor speed controller is actually nothing more than three phase sine wave power inverter with variable frequency. The three phase power inverter is a [...]

The DC to AC inverter circuit shown in the schematic here is very simple circuit since it produce square wave, but it’s enough to power many devices. Here is the schematic diagram of the inverter circuit: The MOSFET is configured as bridge, so the current will flow alternatively in through the primary windings [...]

The high durability nature of a light emitting diode (LED) make it suitable for ON/OFF indicator application. Because the limitation on low operating voltage, LEDs are normally applied on low voltage application.  Fortunately, there is a simple method to apply LED indicator for high powerline voltage: reactance of a capacitor can be used to limit [...]

This SMPS AC-DC converter gives good efficiency. Test data shows efficiency of 83.2% at 115 Vac input and 6A output current, and 85.4% at 230 Vac input and 6A output current. Moreover, the input voltage range is universal, accommodating 92 to 276 Vac variation with only 24 mV change in the output voltage. Here is [...]

This pin diagram will be  useful when viewing these connectors. Sometimes you hold a soldering iron to the back of the connector, and you don’t remember the numbering of the pin. Here is the pin diagram for your reference: The number of each pins are actually  stamped on both sides of any D-type [...]