Found in a 1970 EEE, this circuit uses general-purpose transistors of the time. Transistors support equivalents and the ramp time ranges from 0.1 seconds to a few seconds, depending on C1.
We found this circuit in a Hands-On Electroncs from the 90s. The circuit uses an LED indicator. Diodes...
This circuit was obtained in a 1973 national publication, translated from an English publication of the...
We found this circuit in a 1983 English magazine, but it can be easily assembled with the BC548...