This configuration with the LM111 was found in your factory manual. The circuit can be implemented with modern operational equivalents. The power supply must be symmetrical.
This circuit was found in a Texas Instruments optoelectronics documentation. The gain depends on...
This oscillator circuit is from a Radio Electronics magazine from September 1960. The frequency depends...
Using a reed relay, this protection circuit depends only on the adjustment of the closing point by a wire...