This circuit uses components of the time. We found it in a 1968 US documentation. The delay is 100 ns and the input impedance is 1 k.
The gain for this circuit is given by the ratio between R2 and R1. The circuit is suggested by...
This receiver is from European documentation from the 90s. The integrated circuit is uncommon, and the coil...
Found in a 1970 EEE, this circuit can be applied to TTL ports. The supply is 5 V and the...