This amplifier for hearing aid was found in a 1968 documentation using an integrated of the time. The power is from a battery, the consumption of 1.65 mA and the power of about to 1 mW.
Found in a 1960 General Electric documentation, this crowbar circuit blows the fuse in case of...
This circuit was originally designed for testing crystals used in color televisions, but it works...
This bridge-biased transistor test circuit measures gain in the range 0 to 300. Circuit is from...