Why is the relay called relay?Do not know the name of this relay and his working principle how to contact
Relay in general, many people regard it as a switch, but in fact he played the role of the signal is amplified, the input of small current, the output of high current; I think the name is not important, understand the principle of it is true ;
Above are correct. The relay coil belongs to the control part, its several groups [contact] belong to the controlled part, through the control coil power and power, can make several groups [contact] at the same time connected and separated, played several groups of switches, It belongs to a wide range.
The first use of direct current transmission of information, that is, telegraph, but then a high voltage through a certain distance will also result in attenuation of the signal can not be received, so at intervals to arrange a person to receive a telegram and send to the next station.
???? The general telegraph needs to be recorded first, and then shoot out, and later appeared a good telegraph, he did not record, you can side of the side of the hair, improve efficiency, one day the telegraph found the telegraph receiver (an electromagnetic coil Control of the irons) beating the frequency and his hand to send the same frequency, so he put the irons and the sender together, it becomes the first relay.
Relay is the successor of the link he is actually equivalent to the original loop off as a switch to use, but he is not a switch is a link only function. I can only explain that
