This National Semiconductor circuit appears elsewhere on this site. The circuit must be powered by symmetrical source and equivalent modern operational can be used.
The output voltage is adjusted by the trimpot. The power transistor mist be mounted on a heatsink. The 3.9...
Originally, this circuit is from an English magazine, but I found it in Argentina's Radio Chassis...
The previously mentioned versions of monostable multivibrators in this section are not...