Free Simple Circuit Diagram
This is a circuit of phone message flasher, an alternative way to get alarmed when there is an incoming call. When the phone rings, high line voltage will be detected by A differential amplifier with hysteresis (Q2, Q3, and Q1). This action will turn on multivibrator Q5/Q6, Q4. The LED will flashed via Q7. When the phone line voltage drops […]
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More important than environmental issue of energy saving, avoiding car battery failure when you leave the headlamp turned on overnight in the garage is possibly more important for your concern. This is a circuit of automobile lights-on reminder if you turn off the engine but forget to turn off the main lamp, this circuit will give warning when the headlights […]
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This is a three-modes lamp dimmer circuit with touch control. This circuit can be used to control a lamp in 3 operation modes: dim, off, and bright. A NE555 timer is used to generate a one-second pulse when we touch the touch plate. The human body produces ambient ac fields which will be used to trigger the NE555. An input […]
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The idea of a color organ is that any sound, including musical sound, can be transformed into light. As stated by wave theory, both music and light have similar properties: frequency. Any note, or combination of notes (chord) can be then mapped to a color. A low frequency sound can be associated to red or near infrared, and high frequency […]
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