This circuit was obtained from American documentation from 1966. It triggers when the two input voltages are within a pre-established range. The circuit can be mounted with modern transistors.
We found this circuit in a 90's EDN. The circuit is based on a control integrated that is still...
This circuit uses two power transistors without the cover to expose the junctions to light and...
This circuit was found in a 1969s American documentation. With modern components, it can be used...