Free Simple Circuit Diagram
A 40 watt fluorescent (tube lamp, TL) or two 20-watt tubes in series will be driven by this circuit. The transformer is wound on a ferrite rod 10mm dia and 8cm long. The diameters of the wire are not critical but our prototype used 0.61mm wire for the primary and 0.28mm wire for the secondary and feedback winding. When circuit […]
Read moreBelow is a Courtesy Light Extender for cars. When a door is closed in a car, it extends the ON time, so the passenger can see where he/she is sitting. Here is the schematic diagram of the circuit: The light normally goes off immediately when door switch is opened, but the circuit takes over and allows current to flow because […]
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When the microphone detects a loud sound, this circuit will turn the LED on. The “charge-pump” section consists of the 100n, 10k, signal diode and 10 uF electrolytic. Here is the schematic diagram of the circuit: The charge pump section has two functions: rectifying and multiplying the signal voltage. To illuminate the LED, a signal on the collector of the […]
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This is flashing LED circuit emulate the turning of incandescent lamp. The characteristic of incandescent lamp is that they can’t abruptly change the luminosity. This circuit is used to fade in and fade out the on and off state change. Here is the schematic diagram of the circuit: The time constant of this fading is equal to the value of […]
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