This low power circuit was obtained from an American 80's documentation. The circuit indicates the voltage of a battery being trimmed by the trigger point. The transistors can be the BC549.
Found in an EDN from the 80's, this circuit makes use of an operational one of the time. The...
Other operational amplifiers from the same family such as MC34002, MC35001, MC34004 and MC35004 can...
We find this circuit in an old American documentation from the 80's. The integrated is from the...