This circuit applies to an old dial phone by detecting light pulses in the dial. The circuit is from an old 80's Electronic Design.
This blocking oscillator was found in a publication from the 50's. The coils determine the...
This circuit was found in old documentation, appearing in several ways in this section. PUTs are...
TR1 must be mounted on a heatsink in this circuit. Voltage output is 8.6 V but this value can be...