Found in a 90s documentation, this circuit makes use of D1, a switching diode that is uncommon today. D3 is an LED. The circuit monitors 12 V batteries.
With the configuration shown in the figure, a common 12 V lamp lights up when light no longer...
This circuit was obtained in documentation on medical applications from 1966. The circuit is used in...
We found this circuit in an Australian publication from 1991. The circuit has good sensitivity, presenting...