This circuit using the CK722 among others came out in a September 1950 Radio Electronics. It was one of the first circuits of this type published with transistors that started to reach the market.
This circuit was found in a 1986 publication. However, it can still be easily assembled, as the...
In the figure we have an anti-ring circuit with 4093. The duration of the pulse is given by R1 and...
This circuit was originally indicated to generate audio signal for analog TV sound. The circuit is from...