Linear Ohmmeter LM11 and TL431 (CB14548E)

We found this circuit in Motorola's Linear Databook in 1990. Integrated circuits are somewhat difficult to obtain today.

Alarm Power Supply (CB18673E)
This power supply was originally designed to power our next circuit (CB18672E) which consists of a...
Audio Switch (CB15742E)
This circuit allows the control of a low intensity audio signal from an external logic signal. The...
Zero crossing switch (CB21543E)
Found in a 1964 publication, this circuit makes use of transistors from the time. It operates on...