About this document
Polar Relay Usage in Teletype Systems by Random73 is a document available to read on EtoBox.
This document summarizes tests performed on an old Polar relay unit to determine its suitability for use in a teletype terminal to receive audio frequency-shifted signals. The tests measured coil resistances around 1400 ohms each and found the relay could handle currents of 10mA and 20mA without overheating. Pinouts for the coil connections and switch contacts were mapped by energizing each coil individually. Example circuits are provided to supply the appropriate currents to the coils from a 100-200V DC so
- Author
- Random73
- Language
- EN