28 volt pitot heat

[B2431]

Will running a 28 volt pitot tube heat on 12 volts heat it enough to use? I
keep seeing 28 volt pitot tubes on e-bay and was wondering if they would do the
job.

Dan, U.S. Air Force, retired

[rip]

No. A 28 volt pitot on a 14 volt system will only develop 1/4 of the
design wattage. I feel your pain; the price of pitot tubes these days is
absolutely, downright obscene.

Rip

B2431 wrote:
> Will running a 28 volt pitot tube heat on 12 volts heat it enough to use? I
> keep seeing 28 volt pitot tubes on e-bay and was wondering if they would do the
> job.
>
> Dan, U.S. Air Force, retired

[Richard Riley]

On Fri, 26 Mar 2004 23:57:43 GMT, rip >
wrote:

:No. A 28 volt pitot on a 14 volt system will only develop 1/4 of the
:design wattage. I feel your pain; the price of pitot tubes these days is
:absolutely, downright obscene.
:
:Rip
:
:B2431 wrote:
:> Will running a 28 volt pitot tube heat on 12 volts heat it enough to use? I
:> keep seeing 28 volt pitot tubes on e-bay and was wondering if they would do the
:> job.

Keep watching Ebay, I picked up a 12 and a 24 as a package for $18,
new old stock.

[UltraJohn]

Hummmmm
If you take a ceap 12v to 110 ac power inverter from Radio Shack and tack a
24-30 volt bell transformer with a rectifier and filter on the output you
could make your own 12v to 24 volt dc converter for about $20-$30 dollars.
Ask Jim Weir if he can come up with a project ;-)
John



Richard Riley wrote:

> On Fri, 26 Mar 2004 23:57:43 GMT, rip >
> wrote:
>
> :No. A 28 volt pitot on a 14 volt system will only develop 1/4 of the
> :design wattage. I feel your pain; the price of pitot tubes these days is
> :absolutely, downright obscene.
> :
> :Rip
> :
> :B2431 wrote:
> :> Will running a 28 volt pitot tube heat on 12 volts heat it enough to
> :> use? I keep seeing 28 volt pitot tubes on e-bay and was wondering if
> :> they would do the job.
>
> Keep watching Ebay, I picked up a 12 and a 24 as a package for $18,
> new old stock.
>

[UltraJohn]

Actually I just looked up the current requirements and that would not work!
I have found a site (www.solarseller.com) that carries the Solar
Converters, inc line of converters.
(model cv 12/24 - 50r24 looks to be what your need but check with them) it
appears to cost around $175.00 I don't know how cost effective that is!
Just a possibility
John



UltraJohn wrote:

> Hummmmm
> If you take a ceap 12v to 110 ac power inverter from Radio Shack and tack
> a 24-30 volt bell transformer with a rectifier and filter on the output
> you could make your own 12v to 24 volt dc converter for about $20-$30
> dollars. Ask Jim Weir if he can come up with a project ;-)
> John
>
>
>
> Richard Riley wrote:
>
>> On Fri, 26 Mar 2004 23:57:43 GMT, rip >
>> wrote:
>>
>> :No. A 28 volt pitot on a 14 volt system will only develop 1/4 of the
>> :design wattage. I feel your pain; the price of pitot tubes these days is
>> :absolutely, downright obscene.
>> :
>> :Rip
>> :
>> :B2431 wrote:
>> :> Will running a 28 volt pitot tube heat on 12 volts heat it enough to
>> :> use? I keep seeing 28 volt pitot tubes on e-bay and was wondering if
>> :> they would do the job.
>>
>> Keep watching Ebay, I picked up a 12 and a 24 as a package for $18,
>> new old stock.
>>
>
>

[B2431]

>From: UltraJohn
>
>Hummmmm
>If you take a ceap 12v to 110 ac power inverter from Radio Shack and tack a
>24-30 volt bell transformer with a rectifier and filter on the output you
>could make your own 12v to 24 volt dc converter for about $20-$30 dollars.
>Ask Jim Weir if he can come up with a project ;-)
>John
>
>
>
>Richard Riley wrote:
>
I wouldn't think you'd need to filter it. or rectify it. I bet the heater would
be happy with AC.

As a matter of fact I have seen pitot tubes with 115 VAC heaters.

Dan, U.S. Air Force, retired

[Big John]

rip

It might be possible?

Use an inverter and diode rectifirer of the resulting A/C or just run
on A/C.

One of our retired electrical engineers could probably come op with a
set of plans to build or how to modify a commercial Inverter
(12DC/110VAC) you can buy anyplace.

A basic question. How many homebuilts are IFR certified and are flown
in icing conditions and need a heated pitot tube?

Big John (I been lurking troops :o)


On Fri, 26 Mar 2004 23:57:43 GMT, rip >
wrote:

>No. A 28 volt pitot on a 14 volt system will only develop 1/4 of the
>design wattage. I feel your pain; the price of pitot tubes these days is
>absolutely, downright obscene.
>
>Rip
>
>B2431 wrote:
>> Will running a 28 volt pitot tube heat on 12 volts heat it enough to use? I
>> keep seeing 28 volt pitot tubes on e-bay and was wondering if they would do the
>> job.
>>
>> Dan, U.S. Air Force, retired

[Richard Riley]

On Sat, 27 Mar 2004 04:19:00 -0600, Big John >
wrote:
:
:A basic question. How many homebuilts are IFR certified and are flown
:in icing conditions and need a heated pitot tube?


A significant number are IFR certified. None (or nearly none) are
flown in *known* icing - it's when happens despite your best efforts
that you don't want it to kill you.

I don't think I'm going to put pitot heat on mine, despite a fully
redundant Uuber IFR panel from the 6th circle of Hell (2 of everything
except engine instruments). A while back I tried putting a post-it
note over my airspeed indicator, and found I could land just fine.
GPS gave me a general idea of airspeed, I knew what my approach looked
like and how much power I was carrying. If the nose started to bob, I
added a touch of power. I wouldn't do it in a conventional
configuration but in a canard it worked surprisingly well.

[Jay]

How much power does a typical pitot tube heater need?

(B2431) wrote in message >...
> Will running a 28 volt pitot tube heat on 12 volts heat it enough to use? I
> keep seeing 28 volt pitot tubes on e-bay and was wondering if they would do the
> job.
>
> Dan, U.S. Air Force, retired

[Ray Toews]

Don't waste your money and add the weight, learn to fly without a
pitot. mine has been frozen all winter (no place to warm it up) and I
have been doing fine. Kind of works as a back up altimeter tho :)
Spend the money you save on gas.

Ray
On 26 Mar 2004 22:56:24 GMT, (B2431) wrote:

>Will running a 28 volt pitot tube heat on 12 volts heat it enough to use? I
>keep seeing 28 volt pitot tubes on e-bay and was wondering if they would do the
>job.
>
>Dan, U.S. Air Force, retired

[B2431]

>From: (Jay)

>
>How much power does a typical pitot tube heater need?
>

Aircraft Spruce shows 10 amps for 12 V and 15 amps for 24 V.

Dan, U.S. Air Force, retired

[Jay]

I should have thought of looking there, thanks.

Very strange specs. It says that you need more current on the higher
voltage system, which is wrong. You actually need less than half the
current on the double voltage system to produce the same amount of
heat. So for those pitot tubes it says you need 120W of heat for a
12V airplane and 360W of heat on a 24V airplane. I figure both
airplanes will ice the same regardless of the battery inside.

On the same page there is a pitot heater that needs 3-4 amps at 24V
(90W), so something is fishy here. The 3-4 amp is pretty doable with
a boost converter, the higher current (15 amps) stuff gets a little
fancier.

One idea I'd suggest considering is just running the 24V heater on
your 12V system. Realize that you're only putting 1/4 the heat into
the tube and fly accordingly into icing conditions. Don't fly as
high, as fast, or for as long in ice clouds. Its better than a non
heated tube and you've got a ready to go solution. Later, if you have
time and money, you can add the power supply to give full heat. There
seems to be some variabity anyway on how much heat a pitot tube really
needs to have, compare the 90W vs 360W above which is 1/4.

Regards

(B2431) wrote in message >...
> >From: (Jay)
>
> >
> >How much power does a typical pitot tube heater need?
> >
>
> Aircraft Spruce shows 10 amps for 12 V and 15 amps for 24 V.
>
> Dan, U.S. Air Force, retired

[Bushy]

You might be able to convert a 12 volt soldeing iron for a lot cheaper than
the "aircraft" item.

A pitot tube is simply a metal tube and if the element will fit around it,
you may be able to roll it yourself.

Hope this helps,
Peter

[Paul Lee]

I made my own heated pitot with aluminum tubing and a 12V Cessna pitot
heater element. You can see the details at http://www.abri.com/sq2000/18.html
(about 5 frames from the bottom). The total cost was about $40 - and it's
"new".
-------------------------------------------
Paul Lee, SQ2000 canard www.abri.com/sq2000

(B2431) wrote in message >...
> Will running a 28 volt pitot tube heat on 12 volts heat it enough to use? I
> keep seeing 28 volt pitot tubes on e-bay and was wondering if they would do the
> job.
>
> Dan, U.S. Air Force, retired

[B2431]

>From: (Paul Lee)
>Date: 4/7/2004 11:06 PM Central Daylight Time
>Message-id: >
>
>I made my own heated pitot with aluminum tubing and a 12V Cessna pitot
>heater element. You can see the details at http://www.abri.com/sq2000/18.html
>(about 5 frames from the bottom). The total cost was about $40 - and it's
>"new".
>-------------------------------------------
>Paul Lee, SQ2000 canard www.abri.com/sq2000
>
(B2431) wrote in message
>...
>> Will running a 28 volt pitot tube heat on 12 volts heat it enough to use?
>I
>> keep seeing 28 volt pitot tubes on e-bay and was wondering if they would do
>the
>> job.
>>
>> Dan, U.S. Air Force, retired


I like it. Mind if I swipe the idea?

Dan, U.S. Air Force, retired

[dave]

Hi all,

Can the standard heated pitot tube element be changed?
I have looked at mine and can't figure how to get it apart.
I believe its the standard 5812-12v type.

Thanks

Dave

B2431 wrote:
>>From: (Paul Lee)
>>Date: 4/7/2004 11:06 PM Central Daylight Time
>>Message-id: >
>>
>>I made my own heated pitot with aluminum tubing and a 12V Cessna pitot
>>heater element. You can see the details at http://www.abri.com/sq2000/18.html
>>(about 5 frames from the bottom). The total cost was about $40 - and it's
>>"new".
>>-------------------------------------------
>>Paul Lee, SQ2000 canard www.abri.com/sq2000
>>
(B2431) wrote in message
>...
>>
>>>Will running a 28 volt pitot tube heat on 12 volts heat it enough to use?
>>
>>I
>>
>>>keep seeing 28 volt pitot tubes on e-bay and was wondering if they would do
>>
>>the
>>
>>>job.
>>>
>>>Dan, U.S. Air Force, retired
>
>
>
> I like it. Mind if I swipe the idea?
>
> Dan, U.S. Air Force, retired