Freeze Alarm (CB14454E)

The circuit of a 1968 publication can be implemented with more modern transistors such as BC548 for NPN and BC558 for PNP.

VU-Meter (CB10589E)
This circuit was published in an English magazine from 1977, but it can be easily assembled since...
Adjustable Regulator from 7 to 20 V 7805 (CB15335E)
The maximum current of this circuit is 1 A. The circuit is from Motorola Linear Interface ICs from...
Hendset Inductive Pickup Link 2 (CB4527E)
This circuit is a handset receiver that picks up the signal emitted by a coil under the rug or...