Test circuit with bridge (CB22530E)

This bridge-biased transistor test circuit measures gain in the range 0 to 300. Circuit is from Radio Electronics June 1952.

Phonograph Preamplifier LM381 (CIR25278E)
This preamplifier for magnetic cartridges was found in the February 1990 issue of Radio...
Simple switch with SCR (CB25059E)
This circuit is used to switch direct current loads such as a lamp, for example. Remember that...
Unijunction Triac Control (CB25861E)
This power control circuit was found in an article in the June 1995 Electronis Now magazine. The...