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Did I choose the right relay? Answered

I am building a circuit in which a photoresistor triggers a relay which then powers a motor. The motor runs on a max of .75 amps and uses 4.5 VDC, while the photoresistor side must use a max of a few milliamps and can use anywhere from 1.5-6 VDC. This is the relay I am thinking of: http://search.digikey.com/us/en/products/TXS2-L-12V/255-1898-ND/650137 . I am pretty sure it's the right one, but I wanted to make sure. Is this the right relay for my purposes, and if not, what's wrong with it?

Tags:relay

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icengBest Answer (author)2012-01-29

12V COIL closes at 2.9ma and switches 1A contact rating DPDT

This is the sensitive relay you need  and if you parallel the contacts
( dashed lines ) it can handle 2A..

The wiring is light turns motor on.  .   .   .  A

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user
seraine (author)iceng2012-01-30

So the only "problem" with this relay is that it needs 12 VDC?

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iceng (author)seraine2012-01-30

I don't see 12 VDC as a problem.
Unless you want to run both the relay and motor on one battery ?

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iceng (author)2012-04-01

Try this circuit to test your transistor.
The danger is if your motor draws more then 150ma
that can overheat the 2N2222 Transistor.

A

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iceng (author)2012-01-30

Just to confuse the issue here is an easier way.
R1is selected when the photocell curve is known.
Any 1Amp 50 VDC NPN Transistor  from JAMECO or DIGI KEY

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