This crystal oscillator generates a 20 MHz signal. Equivalent transistors such as BF494 and 2N2222 can be used. The stabilizing diodes can be 1N4148.
The original purpose of the figure circuit, suggested by National Semiconductor, is to keep the...
The amplifier shown in the figure was obtained from the Anlog Devices linear integrated circuits...
When the sensor X1 is opened, the relay is energized. When waiting, the current drained is very...