Relay phase selector (CB9278E)

We found this circuit in a 1965 Electronic Design. The transistors are from the era, and modern equivalents can be tried out.

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Amplifier with the TAA370 (CB6277E)
This amplifier for hearing aid was found in a 1968 documentation using an integrated of the time....
9-Band Current Meter with the CA3140 (CB12315E)
We obtained this circuit from a 1993 documentation. The circuit has 9 current ranges that are...
Simplex Optical Data Transmitter (CB15958E)
In the figure we have the transmitter of a data transmission system with optical fiber suggested by...