Free Simple Circuit Diagram
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 […]
Read moreUsing circuit below, we can animate the bike turning signal using LED. The bike turning signal will blink from the right side (D1) to the left side (D5) in a bar style. To build a complete left and right turning signal, you must build two units of this circuit, and arrange the LEDs so the other circuit will blink to […]
Read moreBelow is the simplest circuit you can get. We can use any NPN. Connect the 220 ohm resistor, LED and transistor as shown in the figure below. Touch the top point with two fingers of one hand and the lower point with fingers of the other hand nad squeeze. When you squeeze harder, the LED will turn on brighter. We […]
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