This amplifier, from Philips Databook is suitable for automotive applications. The input resistance is 60k ohms and the frequency range is 20 to 20 kHz.
Found in an Electronic Design from 1965, this circuit makes use of transistors of the time. The...
Found in an EDN from the 90s, this circuit uses an electret microphone. The output can be used to...
This circuit compares the input voltages by providing an output according to the curve next to the...