This circuit was found in the October 1987 Radio Electronics magazine. The circuit is a PWM control with a 555. It appears that the 555 is missing a connection that would be pin 4.
This circuit is from 1994 documentation by National Semiconductor. What it does is convert the...
This circuit with the known PLL 567 can be found in other versions in this section and in this...
This sophisticated circuit of the coin-toss game was found in an American 1980s documentation. The circuit...