This circuit was found in Philips documentation from 1967. The components are of the time, being transistors like BCY38 for TR1, BC108 for TR3, and others depending on currents.
This 3-digit thermometer, suggested by Texas Instruments, uses 3 integrated plus the display, with...
I found this circuit in an English magazine from July 1982. The circuit is still viable because all...
This 1965 circuit consists of a small inverter for an ultraviolet lamp. The circuit is from a...