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Telephone Activated Power Supply Circuit

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Telephone Activated Power Supply Circuit
This telephone activated power supply circuit is a very unique design. The clips clip on to the telephone pair, red and green wires, anywhere along the pair. When the phone is on the hook, there are 0 outputs at the positive and negative terminals labeled (Output Voltage).

When the telephone is turned on - or activated, the device is turned on thus producing an output voltage that originates from the 9V battery. The actual output voltage depends on the loading of the device or circuit that is connected to the terminals. A 50 Ohm load will produce 5 Volts @ 100mA and a 300 Ohm load will produce 6.7 Volts @ 22mA. The higher loads will produce more voltage.

Basically it is an electronic switch that will power up whatever the output voltage terminals is connected to. The X points marks the spot where you can cut-in a double pole double throw switch as a failsafe switch, if desired to switch the unit on and off. Basically it is a trigger that will turn a connected circuit on or off depending on the status of the telephone on hook and off hook.