Maker Pro
Maker Pro

Arduino relay driver circuit

Vikrama Chandar

Mar 12, 2017
4
Joined
Mar 12, 2017
Messages
4
Hey everyone...i just signed up on this forum and i'm not aware of how to use it. But my question is a little simple one. As u see in this given relay driver circuit, there is a diode which is connected paralell in reverse bias. What is the use of it???

Thanks in advance
 

Attachments

  • arduino-control-relay-schematic.png
    arduino-control-relay-schematic.png
    14.2 KB · Views: 86

Arouse1973

Adam
Dec 18, 2013
5,178
Joined
Dec 18, 2013
Messages
5,178
The diode protects the transistor from the potentially high fly-back voltage produced by the relay coil when the relay switches off.
Thanks
Adam
 

SalRu

Mar 16, 2017
12
Joined
Mar 16, 2017
Messages
12
Yes it's for protection.

When you switch of the relay, the diode avoid current to flow through the NPN and damage it

By!
 
Top