We found this circuit in the November 1992 Radio Electronics magazine. The circuit uses an LDR as a sensor and the transistor can be any general-purpose transistor.
This solid-state relay (SSR) or shield was found in a 1995 Electronics Now. The transistor can be...
The components used in this National Semiconductor circuit are not common today, but the...
The circuit presented in the figure is an amplifier for stereo sources with the Maxim MAX9723...