Free electronic circuit design and schematic diagram
Basic interruptible Power Supply Circuit consist of regular power supply adapter and battery connection. This basic system is a “hot” battery connection, meaning that there is no switching mechanism in connecting and disconnecting the battery, the battery is always connected! This hot connection is very simple to implement and very robust because there would be no switching delay, the output […]
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Many analog ohm meters have non linear scale, so the resolution become worse at higher resistance value. This because they use cheap current source, only a series resistance to approximate an ideal current source. An ideal current source will force a consistent current amount regardless of the tested resistor value. Using regulated current source, the current flowing through the tested […]
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Testing whether a transistor is shorted or open usually done by ohm meter. You test if the base to emitter or collector permit a current flow in one direction. Here is the circuit’s schematic diagram: The 555 timer ( IC1 ) operate as a 12hz oscillator. The output of this oscillator (pin 3) drives the 4027 flip-flop (IC2). Clocked by […]
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This 555 circuit will activate a buzzer and turn on a LED lamp when you touch the probe. Here is the circuit’s schematic diagram: lf you touch the plates, the lamp and the buzzer will be activated for a predetermined time period. The time period is determined by 100k resistor and the 10uF capacitor. You can easily change the value […]
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This circuit is not a voice operated switch (VOX) because this circuit is too dumb to differentiate between musical sound or human voice. This is rather a sound activated than voice activated. One interesting application is to control your disco lighting automatically by the musical sound from high power amplifier, when the music signal is dominating the sound space. The […]
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Electrolysis process has been the primary cause of your water level detector probes, and you can avoid this by sensing the current by this probe using alternating current. In alternating current, the electrolysis process will be reversed for every alternating cycles, making the probe will last longer to survive from corrosion. The electronic circuit for this alternating current sensing for […]
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Octave shifting or frequency doubling effect for electric guitar is done by rectifying the original signal, just like AC to DC conversion inside your AC-DC power supply adapter. The circuit for this audio effect is not new, I’ve seen it on many publications. Here I present the circuit’s schematic diagram, but I’ve redesigned the circuit to use single supply instead […]
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