This circuit was published in an article in Radio Electronics magazine in October 1988. It uses components that are still common today, except for the sensor, which is a special type from that time.
This circuit for timing small loads was found in a 1964 General Electric documentation....
This circuit, for bands above 15 MHz, was found in an Argentine publication from the 1970s. The L1...
The 2 uF capacitor used in this circuit must be of excellent quality with a minimum of leakage to...