The circuit is from 1994 National Semiconductor documentation. The component is not easy to obtain, but there are equivalents that can be searched.
This circuit was found in 80's Popular Electronics. The components used are common and the number of...
The 556 integrated circuit is a double 555. The heats of the components depend on the frequency and the...
This 18 V x 300 mA power supply was found in a 1969 documentation. The integrated circuit is...