This circuit uses a diode as a radiation sensor. The operational ones are old because the publication is from the 80's, but modern low voltage equivalents can be tested.
Found in General Electric's 1966 documentation, this circuit uses company reference diodes, which are...
This circuit uses a wire potentiometer, but the current is much more intense in the control thanks...
In the figure we have another application for the LT3518 integrated circuit from Linear Technology...