This configuration found in GE documentation from the 90s, can also be seen elsewhere in this section. It can operate with voltages from 1 to 6 V and consumes only 6 mW at 1.5 V.
In the figure we show how to trigger a triac for a continuous voltage of the order of 2 V,...
This 2005 Linear Technology circuit has separate outputs for monitoring the charge and discharge...
This circuit was obtained in a June 1987 magazine Hands-On. It is a circuit that indicates on two...