This circuit was obtained in a 1967 Raytheon manual. The company's component is an optical coupler with a photo-resistor and a lamp. Transistors support equivalents.
The integrated circuits used in this 1999 project are not very common today. However, they can be...
This 3-digit thermometer, suggested by Texas Instruments, uses 3 integrated plus the display, with...
This circuit is from the National Semiconductor FET Databook. The coil data is provided with the...