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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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iceng

Best Answer 6 years ago

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

CDS DPDT Rly.GIF
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seraineiceng

Answer 6 years ago

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

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icengseraine

Answer 6 years ago

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

CDS DPDT 2Rly.GIF
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iceng

6 years ago

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

A

TEST npn.GIF
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iceng

6 years ago

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

CDS npn.GIF