This circuit is used to detect PLL signals from the 4046 IC. The circuit is from an Electronics Now from October 1994. The indication is made through LEDs.
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...