This circuit uses a pickup coil to take the signal from a telephone line without contacts. The circuit is from a 90s Popular Electronics.
This circuit is from a manual based on information from Japanese components from 1981. The power...
Other operational amplifiers in the series, such as the MC34072, MC34074, MC35071, MC35072,...
The operating frequency of this circuit is 465 Hz and the input voltage is 12 VAC. The circuit is...