This circuit is from a 1965 General Electric manual. It uses components from the time that admit equivalents. The SCR can be the TIC106 and the LDR of any type.
The voltage regulator circuit described is highly accurate and uses discrete components...
WWV is the standard frequency station of the United States government. This station broadcasts a...
Based on a 555, this 80's American documentation circuit detects the voltage of a battery and can then...