We found this circuit in a Radio Electronics issue from July 1969. The lamp remains on until C1 opens. The time is given by capacitor C1.
This circuit was published in a January 1971 issue of Radio Electronics to check television...
Found in Popular Electronics from the 90's, this tuned to infrared modulated receiver uses a PLL....
This 1967 General Electric circuit makes use of an array of 3 (integrated) transistors for an...