This circuit was obtained in an Electronics World of 1968. The operational amplifiers ones are types of the time, no longer used today. The circuit responds from less than 20 Hz.
Found in American documentation from the 90s, this circuit uses components that are still common...
We found this circuit in the June 1991 issue of Radio Electronics magazine. The integrated circuit is...
When more current from a digital output is needed than a single output could source or drain, a...