This circuit is suggested by National Semiconductor in its Linear Applications Handbook. The LM3909 integrated circuit consists of a very low consumption oscillator with a power supply of 1.2 V.
In the figure we have a simple signal tracer circuit to be coupled to the volume control of an AM...
This circuit was found in documentation from the 90s, using components from that time. The...
This circuit, obtained from old documentation, allows the recovery of sulfated batteries. The...