E)
This circuit uses a reversible double contact relay to obtain the trigger lock with the unijunction pulse. The relay must be of the sensitive type with at least 150 ohms of coil.
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...