Suggested by a Philips documentation from 1970, this circuit uses period components, operating at 50 Hz. The current consumed is 10 A and the input voltage is 12 V.
Found in a 1968 EEE, this circuit accepts frequencies from 1 to 1000 Hz and control voltages from 0.1 to...
This circuit has appeared several times on this site in different applications. This is from 1997...
This setting appears other times in this section from other sources. This is from an 80's American...