Photometer (CB7360E)

This 1964 Electronic Design circuit uses a photo-FET as a sensor. The component is rare today.

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Digital thermometer with the TL505 and TL502 (CB16050E)
This 3-digit thermometer, suggested by Texas Instruments, uses 3 integrated plus the display, with...
Sound Generator (CB4535E)
I found this circuit in an English magazine from July 1982. The circuit is still viable because all...
Portable ultraviolet source (CB7188E)
This 1965 circuit consists of a small inverter for an ultraviolet lamp. The circuit is from a...