We found this time base of 0.1 to 90 seconds in a circuit manual from the 90s. The single-use transistors used are common and the frequencies given by the adjustment by the potentiometer.
National Semiconductor suggests the circuit in the figure for stabilizing the peak value of an...
This adjustable frequency circuit was found in December 1986, Radio Electronics magazine. The base...
This circuit, which can be built with several CMOS gates, was found in the March 1996 issue of...