We found this circuit in a 1987 documentation. It is a multi-tester with neon lamp and LEDs operating with both low continuous voltage and high alternating voltage.
Indicated for scanning circuit applications, we found this generator in a Radio Electronics from the 80s....
The circuit shown in figure 3 uses a programmable unijunction transistor (PUT) of the BRY39 type...
This is the version of the previous circuit with a locking system. The supply voltage is according to...