1mA Source with LM3900 (CB25177E)

This source draws a fixed constant current of 1 mA using a Norton operational amplifier. Other currents can be obtained by changing the components.

Crossing Signal for Railroad Modeling (CB3854E)
This circuit uses two sensors that are placed at the intersection of a miniature railway, causing...
Stereo Preamplifier (CB6035E)
This circuit with RIAA equalization is from 1985 US documentation. The circuit has a flat response...
Rocket Altimeter (CB25357E)
Today we have more compact solutions. This is from a Radio Electronics magazine from October 1990....