Telephone Bell Simulator Circuit


Posted on Oct 4, 2012

This circuit is intended for use in a small private telephone installation. The ringing tone sequence is 400 ms on, 200 ms off, 400 ms on, 2 ms off. In the accompanying diagram, N1 and N2 form an oscillator that operates at a frequency of 5 Hz, which gives a period of 200 ms. The oscillator signal is fed to two decade scalers, which are connected in such a manner (by N3 and N4) that the input signal is divided by 15. The second input of N4 can be used to switch the divider on and off by logic levels.


Telephone Bell Simulator Circuit
Click here to download the full size of the above Circuit.

If this facility is not-used, the two inputs of N4 should be interconnected.




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