This astable multivibrator has an active cycle of 30,000: 1. We found it in a 1970 EEE. The components used are from that time.
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...