Linear photometer (CB7366E)

This circuit was found in a 1967 Philips publication. Transistors support equivalents and modern equivalents can be used.

Who is the Fastest? (CB203E)
Only one LED is turned on when S1 and S2 are pressed. The LED that will be on is just the...
Solar radio CK721 (CB20510E)
This circuit is based on one of the first germanium transistors. The power comes from a solar cell...
Electric fence (CB6231E)
This circuit was found in an American 80's circuit board. The components used are current except the...