We found this circuit in the June 1984 issue of Radio Electronics magazine. The circuit uses an integrated circuit that is not very common today.
We find the original version of this circuit in an English publication (1986). It is a...
In the original publication of the 90s a 556 consisting of a double 555 is suggested. The circuit...
Found in an old Raytheon transistor manual, this 4-scale voltmeter has an accuracy that depends on the...