Telephone Visual Ring Indicator


Posted on Jun 7, 2012

In this circuit, the ringing voltage on a telephone line causes NE-1 to break over, triggering SCR1, which


Telephone Visual Ring Indicator
Click here to download the full size of the above Circuit.

in turn triggers SCR2. If a call has been received, depressing S2 will cause LED1 to light. Depressing SI resets the circuit. This circuit has the advantage of lower battery drain because LED1 is not left on continuously after a ring signal, but only when S2 is depressed.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

10 LEDS Audio level vumeter
LED runner with 74LS163
There is an UART on the Nexus 4
Temperature To Pulse Width Converter Circuit Using LM3524
USB Bootloader
Variable gain amplifier circuit
811A produced by 10W tube final amplifier



Top