We found this circuit at Popular Electronics. The components are still current. Changes can be made to obtain higher voltages, as indicated in the second diagram.
The integrated circuit can be any operational and T1 can be a BC548 and T2 a TIP41 in this circuit of a...
This circuit was found in a 1964 Electronic Design. The circuit delays the firing of a load for a...
In the figure we have an old circuit of a crystal oscillator modulated by an audio signal. The...