Relay w/ transistor

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Forum Name: Relays
Forum Discription: Relay Diagrams, SPDT Relays, SPST Relays, DPDT Relays, Latching Relays, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=29804
Printed Date: July 25, 2025 at 8:51 AM

Topic: Relay w/ transistor

Posted By: Dlou87
Subject: Relay w/ transistor
Date Posted: April 06, 2004 at 10:10 AM

Hey guys,

I am using a Wireless relay board to trigger the relay input on another relay which is switching on something. My problem is, the wireless relay board puts out a signal of 12v DC, and the second relay which it needs to trigger needs 14v DC to trigger on...so I heard that I can use a transistor to increase the voltage of the 12v to 14v, but I have no idea how I would do that?? So what kind of transistor would I use to bump up the voltage?

Thanx

Replies:

Posted By: xetmes
Date Posted: April 06, 2004 at 11:07 AM

did you try the 14V relay with 12V? it may work just fine, 12V relays will trigger around 8V...

Posted By: Dlou87
Date Posted: April 06, 2004 at 1:41 PM

Yes I did, and it would not trigger with the 12v source...so any help with how I can do this???

Posted By: xetmes
Date Posted: April 06, 2004 at 8:28 PM

well the problem is that a transistor can only switch power it can not make something out of nothing. If the maximum voltage is 12V in the system then you cannot make 14 V without some exotic circuits.

Posted By: Toru
Date Posted: April 07, 2004 at 12:50 AM

Also known as a capacitive charge pump.

Posted By: xetmes
Date Posted: April 07, 2004 at 6:43 AM

yea a charge pump is one way, notice the first stage is an oscillator, you need switching. You can even get single chip solutions: like these

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