This circuit allows the activation of a remote telephone bell made with a common piezoelectric capsule. The circuit does not need power, as it is powered by the line call signal itself.
This VCO or Voltage Controlled Oscillator uses an 8038 integrated circuit that is not very easy to...
This circuit was obtained in a 1978 publication, but it can be assembled with equivalent...
This circuit serves to reinforce the AM band signals for receivers that use an external antenna. The...