Print Page | Close Window

24 -12 volt

Printed From: the12volt.com
Forum Name: General Discussion
Forum Discription: General Mobile Electronics Questions and Answers
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=9526
Printed Date: May 14, 2024 at 7:36 AM


Topic: 24 -12 volt

Posted By: bopatom1
Subject: 24 -12 volt
Date Posted: February 14, 2003 at 8:58 PM

 I was wondering if I could use a relay and resistor to go from 24V to 12V a grader and loader have 24 volt system's and im trying to find a cheper way to wire up the 2-way radio's then to buy the expensive converter's

                                       Thanks !




Replies:

Posted By: auex
Date Posted: February 14, 2003 at 11:15 PM

I believe that there should be two 12 volt batteries in the battery tray that are just wired in series.  You could just take a power and ground from one of these and run wires to the radio.



-------------
Certified Security Specialist
Always check info with a digital multimeter.
I promise to be good.
Tell Darwin I sent you.

I've been sick lately, sorry I won't be on much.




Posted By: bopatom1
Date Posted: February 15, 2003 at 7:30 AM
 Thank's but I was thinking that I could just catch a wire in the cab and run from there.




Posted By: PLAYER69
Date Posted: February 15, 2003 at 7:49 AM

No you will have to do as auex suggested or get the converters.  Unless you know of something that is 12 volt in the system which is not likely.





Posted By: copcarguy
Date Posted: February 15, 2003 at 10:42 AM

As a two way radio dealer and manufacturer of specialty vehicles I recommend going the extra mile and purchasing the convertor. Sorry to be a spoil sport but it is the advice I would give my customers. If you are going to purchase one I use "Astron" convertors with a lot of success, particularly on heavy machinery subject to dirt and vibration. Good luck.

Also if the equipment allready has a convertor in it for an AM/FM or CB do not use it as it probably does not have the capacity to handle a two-way when transmitting.





Posted By: jrilla
Date Posted: February 17, 2003 at 8:50 AM
This may have no relevance to this type of system, but I was doing some sub-contracting work for my brothers company where they had me design and setup a PLC panel that would measure the volume of silicone being injected and shut off the valve after the proper volume had passed through the flow meter. Anyway tje sytem used a 120VAC to 24VDC converter, but there was a buzzer that I put on the injection gun to tell the operator that the valve had closed since they would not be able to see it stop. Anyway, the buzzer was only 12v so I had to drop the 24V down to 12V for thie buzzer to work. I just used 2 resistors, but then I got the bright idea one day to try to charge my wireless phone using this 12v output, and sure enough it worked fine for about 10 minutes and then it dropped to about 9 volts which stopped charging my phone. I just thought I would throw that story in here to confirm the suggestions of copcarguy and player69 and auex.

-------------
J Rilla

Owner/Installer




Posted By: Ronald Mark
Date Posted: February 19, 2003 at 3:59 PM
Never Center tap a battery on a 24 volt system. By doing this you will create an uneven load on the batterys and in time ruin the battery. Seems simple, but you cannot do it. I work for Cat, and if the machine doesn't already have a converter we suggest installing one. The resistor idea is OK if you have a consistant load, but in a two-way radio you have transmit and recieve. Each requires different current draws which will resault in differant voltage drops.

Its all ohms law applied.





Print Page | Close Window