This Mullard circuit was found in a 1969 documentation. It uses complementary transistors on the output and does not need a transformer. The bandwidth goes from 100 to 20 000 Hz.
The figure shows how to control the blinking of a 5 V blinking LED with an LDR. The LED only...
Suggested by Maxim in documentation from the 90s, this circuit has its response curve given next to...
This circuit is from a 1965 General Electric publication. It uses a thermistor to fire a reed...