This oscillator provides a sinusoidal signal and can be applied to other operational amplifiers. The stabilization is done by diodes and for the indicated component values the frequency is 1 kHz.
This circuit is from a 1979 publication. The sensor consists of plates or screens that, when...
The circuit is from a Radio Electronics from August 1989. The cells used at that time did not have...
The automatic modulated siren circuit shown in the figure really produces an interesting sound...