This circuit makes use of an operational amplifier from the 80's. The circuit can be implemented with modern transconductance operational and TTL logic working as a shield.
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...