This circuit is from an old Electroics Now. Its purpose is to protect the fax and modem lines of two computers of the time. Suppressors are types of the time.
This is the circuit of the commercial Japanese megaphone of the 60s model DM-218. The circuit uses...
This circuit is better than the previous one in that the control is isolated by a transformer. The...
Found in American documentation, this basic circuit uses general purpose transistors. The circuit...