Help With Relay

[sherif42]

Hi All ,

I am designing a circuit to control home devices working with 220V using the computer

I get 5V from the computer (as a control)
I will use a relay to control the devices

I just wanna know what is the type of relay i have to buy , is it depends on the 220V or the 5v ??
And also is it depends on the current passing to the device (220V) ??

or it just depends on the control voltage and current

thanks alot

 

[Russlk]

The relay has two ratings: (1) the contacts, which have to handle 220 VAC and the current that is being switched. (2) The coil voltage and current needed to operate the relay. The computer may not be able to drive the relay directly because the current required at 5 volts will be high. You will need a transistor amplifier.

 

[k7elp60]

relay question

You may want to consider a solid state relay. Most of them will operate with 5 volt input and about 10Ma of current. Load side for 220V and high currents available.