Laptop Power Supply (CB8171E)

This circuit was obtained in a 90s 73 magazine for radio amateurs. The power transistor must have a heat sink. The input voltage is 13.6 V.

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Hand Dryer (CB18786E)
With this circuit it is possible to use a common hair dryer as a hand dryer. The circuit is timed...
8 Channel Encoder with 4017 (CB4530E)
This circuit was obtained from an English magazine from 1979, but can be easily assembled today...
Continuity Tester (CB10617E)
This circuit was obtained in a 1975 magazine, but it can be easily assembled using BC548...