Based on NXP 74HC logic, this circuit can be adapted for various uses. The circuit can also be used with 12V power, and the circuit replaced with a common 4046 PLL.
This circuit is from a 1979 publication. The sensor consists of plates or screens that, when...
Found in an 80's documentation this circuit uses an integrated from the uncommon era today. Other...
This circuit was found in a Popular Electronics from the 90s. It uses a LASCR which is a photo-SCR...