Circuit Project Electronic

Phone In Use Indicator
Sunday, February 21st, 2010

With this circuit mounted in or near every phone in the house, it will allow users to know if the phone is being used and not to pick up the phone. When a phone is taken off hook, the voltage across the tip and ring terminals drops to 10 volts or less. This will cause [...]

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FM surveillance BuG Transmitter using 2N2222
Thursday, March 12th, 2009

The Circuit shown can transmit voice to exceptionally good range. Tune trimmer to hear the signal to your near radio. Frequency range is 88-108 MHz. Max current consumption is 30mA. You can power the bug with a 9Volt Battery, or you can plug a power supply to feed in 9-12 Volts. Link

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Burglar Alarm Circuit by 2N2222
Sunday, January 18th, 2009

At this period the economy not good, Make have steal plentiful. We come to try build the circuit steal model to is simple better. The Alarm Sound (Super Bell) loud forever until will cut power supply to go out. When the Switch of the magnet Senate was opened or strip metal torn. The R1 stand [...]

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