Fahrenheit Sensor LM34 (CB14400E)

This circuit measures temperatures from +5 to + 300º F using a sensor from National Semiconductor not very easy to obtain.

Sensitive Touch Switch (CB488)
A touch in this circuit turns-on the lamp or the relay. Power supply is according the lamp or...
Four Transistor Reflex Receiver (CB961E)
This an old commercial receiver found in a year 1958 magazine. The circuit uses some transformer...
Audio and video cable tester (CB9327E)
We found this very simple cable fitting circuit in an Electronics Now from the 90s. ...