Infrared modulated transmitter (CB7247E)

This simple Philips circuit from the 1960s can use any general-purpose transistor. The signal is modulated at 2.7 kHz.

Signal Tracer with MW Radio (CB20509)
In the figure we have a simple signal tracer circuit to be coupled to the volume control of an AM...
Flip Flop Toggle (CB24436E)
This circuit was found in documentation from the 90s, using components from that time. The...
Battery Desulfator Charger (CB19386E)
This circuit, obtained from old documentation, allows the recovery of sulfated batteries. The...