This circuit, from an old publication from the 70s, can be assembled with a 2N2646 unijunction transistor. The circuit produces pulses in frequency proportional to the input voltage. The circuit includes an 18 V supply which, in the original version, is stabilized by a zener diode. The other diodes can be of the 1N4002 type. The output transformer has a 1 to 1 ratio, and a transistorized radio driver may be used depending on the intensity desired for the pulses.
