This circuit was obtained from a 90s Radio Electronics. The value of R1 determines the scale according to the table next to the diagram. The power suppley must be symmetrical.
This is a simple 1-digit voltmeter circuit using voltage comparators. It was found in a 2004...
This circuit is from old documentation, but the regulator may be 78xx series equivalent and the...
This circuit appeared in the November 1995 issue of Electronics Now magazine. The circuit uses...