The purpose of this circuit is only to increase the input resistance of a multimeter, since there is no voltage gain. The batteries are 9 V and operational equivalents can be used.
The circuit shown in the figure has elements for maximum gain at maximum speed. By setting the...
This instrument, based on a 555, measures frequencies up to 1 kHz, but its scale can be modified by...
Using a CA3130 operational amplifier, this circuit was found in an English publication from 1977....