power supply voltage

[dave 216]

Hi, I run an Icom 737 and have just had to replace my power supply and the new supply i got puts out 14.6volts and i have confirmed this using two very good dmm,s

Looking in the manual for my Icom it says it needs a supply voltage of 13.8 volts + or - 15%, 15% on top of 13.8 is over 15.8 volts so to my way of thinking i should be fine if i run 14.6 volts

Is there a downside to runing the extra voltage?, A posative perhaps?

If icom say it can run off 15.8 volts it should be fine shoudent it?


Thanks in advance for any replies by techs that know there stuff




Dave

 

[W5LZ]

Dave,
Your radio should work just fine. It will have a voltage 'regulator' circuit to control the max amount that's applied to it, and that will 'allow' for some variations in supply voltage.
Most power supplies will show slightly more voltage than will be present when they are under load. The amount of voltage drop from a power supply shouldn't be very large at all depending on how well it's regulated, but there will be some. All things considered, I don't think you have a thing to worry about. Naturally, if there happens to be some 'odd', unexplainable changes, like the volume can't be turned down for comfortable listening, the watt meter's needle wraps it's self around the meter-stop from all the additional output power... can I have that power supply??
- 'Doc


(and just to be honest, I ain't no 'tech')

 

[ButtFuzz]

From experience, I would not set the output of your power supply more than what would be the maximum expected {regulated} charging output on an automobile of modern vintage: 14.6 vDC.

There is no sense in over-volting things TOO much to get that extra watt or three. It just isn't going to show up on the receiveing end, anyways.

Take care,
Rob

 

[W5LZ]

Before you start trying to set the voltage output level on that power supply, you'd be smart to check the voltage under load. Won't be the same as the un-loaded voltage. Why try to adjust something that doesn't need adjusting?
- 'Doc

 

[dave 216]

I agree that in a car it would see 14.6V or more quite reguarly so it should be fine, It is a very good supply with safety cuts etc and wont put out any more than 15V, Also i will check the voltage under load when i am back home tomorrow and see how much it climbs

If the radio has a voltage regulator circuit then i dont think there would be any gain by having the extra voltage?.. It would possibly be chewing up power for no reason as it regulates it down and if thats the case i wonder what it does step it down to



Dave

 

[TonyV225]

I was going to say I bet under a load with that radio that it drops to around 13.8

 

[HiDef]

Yup. Check it under load near the final amp after the power lead and connector voltage drop.. A few more volts can increase the dynamic headroom of the final and driver amp if you don't try to squeeze extra power out.