We found this circuit in a Japanese 1968’s documentation. The circuit makes use of transistors from that country common at the time of publication. Observe the symmetrical power supply for the circuit.
This capacitor for small capacitances is based on the tuning of a receiver circuit. The variable is...
This 1995 documentation circuit detects when an extension on a phone line is active. Adjustment of the...
This analog tachometer can be used in cars with platinum or in robotic and automation applications to...