Based on an integrated circuit of the time, this circuit appeared in the October 1979 issue of Radio Electronics magazine. The circuit monitors voltages in the range of 10.5 to 16.0 V.
The circuit shown in the figure is suggested by Allegro Micro (www.allegromicro.com) and consists of...
This circuit is a variation of the common grid dip meter, having been found in a 1975 publication on FETs....
The time obtained in this circuit, from a 1978 publication, depends on R3 and C. R3 can have...