Rick is correct. Modern alternators are of necessity set to higher charging
voltages, usually around 14.5 volts or more, because the newer batteries in
cars require these voltages for proper charging. Although I call these
"newer", this has actually been the case for more than 10 years. (I just
don't get many new cars ) :)
Also, the charging voltage is typically controlled to vary with outside
temperature. My Jeep charges at 15 volts on cold days, and a full volt less
on hot ones.
So mobile radios have been running at these higher voltages routinely for a
decade or more. I have not heard any reports of ill effects. Has anyone ?
73 de Gary, AA2IZ
----- Original Message -----
From: "Rick Denney" <rick@rickdenney.com>
To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Sent: Tuesday, February 05, 2008 3:38 AM
Subject: Re: [TenTec] Omni V Maximum voltage
> Stuart Rohre writes...
>
> > I would caution the poster to then, definitely NOT use the 15 volt
> > power supply if it is unregulated without some precautions or
> > additions.
>
> If the power supply is reasonably stable under 20 amps of load, what
> about using a forward-biased rectifier to drop the voltage? For
> example, I see a Fairchild FFH50US60S diode which is rated for 50 amps
> continuous forward current, 200 watts of power dissipation, and will
> drop the voltage about a volt at 20 amps. That should get the output
> power within the safe range on an Omni V, or any other radio intended
> for mobile use. My alternators routinely put out 14.5 to 15 volts on
> startup, and my radios don't seem to mind, though I've never run my V
> from an alternator. An alternator may put out anything from 13 to 15
> volts in normal service, by my observation.
>
> Rick, KR9D
>
> ---
> Richard W. Denney, Jr. PE|Iteris, Inc.
> Associate Vice President |107 Carpenter Dr. Ste 230 | 703.925.3819
> rwd@iteris.com |Sterling, VA 20164 |Fax 703.471.1757
>
> _______________________________________________
> TenTec mailing list
> TenTec@contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
>
>
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|