This circuit was found in the November 1966 issue of Electronics Now magazine. It uses an LDR as a sensor and has a Bargraph scale with the well-known LM3914.
Based on a 555, this 80's American documentation circuit detects the voltage of a battery and can then...
In the figure we have the use of one of the four existing amplifiers in the LM2900 and LM3900 as a...
12 V battery chargers provide higher unregulated voltage. With the regulator shown, obtained from...