This 1968 Mallory circuit uses an uncommon integrated circuit today. The circuit has a 30 to 20,000 Hz response with lower power and is powered by 12 V.
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...