Based on an LM36000 OTA this circuit was found in the July 1988 issue of Radio Electronics magazine. It covers frequencies in the range of 45 Hz to 45 kHz.
This sensor works as an electronic push button, activating a power relay. The circuit must be...
This circuit is based on an old operational amplifier, having been found in documentation from the...
Found in a Maxim documentation, this 1980s circuit drives 4 LEDs on a bar scale. The circuit does...