This circuit is from a 60's documentation. The capacitance C1 can be between 20 pF and 0.01 uF depending on the generated frequency. Equivalent transistors may be employed.
This circuit that uses a mechanical tuning fork was found in Radio Electronics magazine from June...
In the presence of the supply voltage of a 3 to 12 V circuit, this circuit causes the LED to...
This circuit supplies a voltage of 110 V from car battery with 110 V x 100 W output. Transformer...