This circuit generates various types of sounds and can be used as a toy. The circuit is from Radio Electronics from January 1983. The amplifier can be replaced with a more modern type.
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...