This 1965 Philips circuit uses old company transistors like the BFY51 and BFY50. The circuit is powered by 12 V and the power gain is 8.9 dB.
This filter, from an audio publication from 1977, passes the frequency range corresponding to the...
In the figure we have three voltage doubler configurations that can be used in high and low...
This circuit was found in Motorola documentation from 1966. The lamps are according to power and...