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Using AC to operate a automotive 12 VDC relay Answered

My question is:  can a typical 12 vdc automotive relay be operated
(voltage across terminals 85-86)?

I am building a car from a riding lawn mower for our grandson.  I want to operate lights from the 12 VDC circuit but I need a signal voltage to actuate the relay across relay terminals 85-86.  I would like to use the existing AC powered light(s) voltage for this purpose?  Possible?

Discussions

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Downunder35m
Downunder35m

3 years ago

Option 1: Take a 24V relay.
Option 2: Use a SSR (Solid State Relay) as the operate on a wide range of input voltages, if it only supports DC you simly add a tiny rectifier.

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mndb1971
mndb1971

3 years ago

I was wondering if I could use AC power across 85-86 with a voltage range of 24-34 VAC.

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Toga_Dan
Toga_Dan

Reply 3 years ago

if you dont know if that is hot enough to fry the coil, there are 2 easy options. Risk frying it, and replace it if that happens, or throw some resistance in to reduce current (and effective V) at the coil.

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Toga_Dan
Toga_Dan

3 years ago

what relay is it? What voltage is the ac

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mndb1971
mndb1971

Reply 3 years ago

I will attach a photo of the relay....the AC voltage is said to range from 24-34 VAC...powers the lights on the mower.

IMG_20161113_061837990_HDR.jpgIMG_20161113_061849470_HDR.jpg
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Toga_Dan
Toga_Dan

Reply 3 years ago

is there a part number somewhere on this relay? usually step 1 is to google component specs.

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mndb1971
mndb1971

3 years ago

Thanks for your assistance.

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mndb1971
mndb1971

3 years ago

Well I left out the fact that I was wondering if I could use AC voltage across terminals 85-86. If the voltage is less than 12 vac, what happens?

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Downunder35m
Downunder35m

3 years ago

Should be no problem as long as it is 12V or higher.
On AC the relay will most likely be less powerfull but still work as planned.