Print Page | Close Window

8 volt horns on car’s 12 volt system

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=105550
Printed Date: April 29, 2024 at 3:03 PM


Topic: 8 volt horns on car’s 12 volt system

Posted By: askal
Subject: 8 volt horns on car’s 12 volt system
Date Posted: June 18, 2008 at 10:00 AM

Hi, I hope someone could help me out.. I have a pair of Mitsuba Turbine type horns which came from Japan.  Im not really sure if I can hook the pair to my car since the specs "per" horn is 8volts 9amps 72watts.. can i safely use the horns in my car even though my ride's electrical system runs on 12v-14.4v?  Is there anything I could do to use it? Do I need a voltage regulator or something? Need help fast.. thank you for looking into my concern..

askal

Manila, Philippines




Replies:

Posted By: Big Dog
Date Posted: June 18, 2008 at 10:25 AM

I'm not familiar with your horn but if it's an electric motor driven turbine, you could try connecting the two in series.



-------------
Prepare your future. It wasn't the lack of stones that killed the stone age.




Posted By: techman93
Date Posted: June 18, 2008 at 4:49 PM
You can calculate a resistor to add in line to reduce voltage. I would think 10 ohms or so based on 13vdc and the horn needs 8vdc.

-------------
The wire I'm test'n isn't doin' what it's supposed to be doin'... I am so glad I printed that tech sheet, with the wrong info.
Do it right the first time... or I might have to fix it for ya




Posted By: i am an idiot
Date Posted: June 18, 2008 at 10:58 PM
I really think you need to wire them in series and see if they perform well enough for you. Are there 2 wires on each unit, or is there one wire and they depend on chassis for ground? A resistor will not reliably drop the voltage. The motor pulls more current at startup than they do when up to speed. When they need the voltage to startup, there will be more drop across the resistor




Posted By: askal
Date Posted: June 18, 2008 at 11:05 PM

So meaning to say, I must add a  10 ohms resistor in line per horn?  I tried installing it yesterday by putting a 30amp inline fuse and double throw relay per horn.. and it works but I need to make sure and be safer.  Would you consider the one I did PLUS the resistors or just add in a resistor per line?

BTW, what kind of resistor should I purchase? Brand, etc..

Thanks man, youre the coolest! :) 





Posted By: askal
Date Posted: June 18, 2008 at 11:08 PM

i am an idiot wrote:

I really think you need to wire them in series and see if they perform well enough for you. Are there 2 wires on each unit, or is there one wire and they depend on chassis for ground? A resistor will not reliably drop the voltage. The motor pulls more current at startup than they do when up to speed. When they need the voltage to startup, there will be more drop across the resistor

There is only one wire per unit and it depend on the chassis for ground.  Now my question is how do I reduce the voltage from 12v to 8vdc for the horn. 





Posted By: KarTuneMan
Date Posted: June 24, 2008 at 12:33 AM
Oh just hook em up..... they'll be REALLY loud!

-------------




Posted By: Mad Scientists
Date Posted: June 24, 2008 at 12:19 PM

It looks like it would be a 0.5 ohm 50w resistor.. that's kinda big.

Jim 






Print Page | Close Window