This circuit is from an old Japanese publication of 1962. The circuit uses two batteries, one for the filaments of the tubes and the other one of high voltage for the plate circuits.
The Texas Instruments TIOS101 is a driver that can be connected to both high and low side sensors...
We found this circuit in the National Semiconductor Audio Handbook of 1977. The circuit produces...
When the sensor X1 is opened, the relay is energized. When waiting, the current drained is very...