This circuit was found in Philips documentation from 1965. No information was given about the transformer. Transistors are from the era.
This circuit was found in an English magazine from 1979. The magazine no longer exists, but the...
This traditional TTL anti-clock setting was found in a 1993 American documentation. The circuit...
The astable multivibrator shown by the figure can produce signals in the 10 to 10 000 Hz band...