Simple Line Activated Solid State Switch Project Circuit Diagram
Let me ask this simply, then explain my use case below. This is a Easy Line Activated Solid State Switch Project . Each and every time a phone on the same line or calling numberis taken off-hook, the circuit will be activated to control an external electronic circuit. If several extension telephones are used on one phone line, the circuit can be useful as a busy indicator. LEDl contains a special flashing red LED that makes an excellent indicator for a busy circuit condition. Line Activated Solid State Switch Project Circuit Diagram The solid-state switch can be used for several other phone-activated applications, such as automatically turning on a cassette recorder, starting a phone-use timer or counter, etc. A small relay can be connected at points A and B, in place of LEDl, to control external circuits. A 117-Vac-to-6-Vdc plug-in power supply can be substituted for the battery to keep the operating cost at a minimum. The 48-Vdc, on-hook, phone-line voltage keeps Ql...
