This variable filter circuit was found in July 1975 Radio Electronics magazine. The circuit uses 3 general purpose op-amps like the 741 and must use a symmetrical source.
The circuit shown is from the GE semiconductor manual of 1977. In the table we have the values of the...
This 1967 Ferranti circuit uses company components. These transistors can be replaced by modern...
This 15 V regulator uses the integrated 100 mA L series. The circuit was suggested by Motorola's Linear...