Suggested by Siliconix in documentation from the 90s, this amplifier has its gain digitally selected. The components are from that time, not easy to find today.
This 7400 TTL circuit has a memory, keeping the LED on when a pulse is detected. The circuit must be...
August 2017 - STMicroelectronics' new DSL05 transient suppressors for 12 and 24 V voltages and...
The frequency depends on C, which must have the indicated value ratio, and also on R, which can be...