WANTED--HEATER ***UPDATE-UPDATE***

[NiceBill]

The above photo is of a Davis heater assembly for the VP-2.  The elongated component on the top is the heater.  24 Watt 24 Volt.  I believe 1/2" in diameter and about 4-1/2" long.

I am in hopes of building my own heater assembly and am looking for the heater, any help would be appreciated.  I have all of the other components to complete the assembly.

Thanks for your time.

Best Regards,

Bill.>>>>>>>>>>>>>>>>>>

[SLOweather]

Well, as usual, I'll start typing and figure it out as I go.

Time for a little Ohm's law. In this case,

Watts = amps x volts
24w = X amps x 24 volts

solve for amps

24 w/24 v = 1 amp

Now, more Ohm's Law.

Volts = Amps x Resistance

24v = 1a x Xr

Solve for X

24v / 1a = 24 ohms

So, you need about a 24 ohm/24 watt power resistor.

A quick check of the Rat Shack site shows a few different power resistors. Time for more Ohm's Law. Resistors in series add, resistors in parallel divide.

http://www.radioshack.com/product/index.jsp?productId=2062293 is a 2-pack of 100 ohm/10 watt power resistors for $1.99. If we get 2 packs, we have 4 100 ohm resistors. If you wire all of them in parallel, you effectively get a 25 ohm, 40 watt resistor.

Try that. For 4 bucks, you can't go too far wrong. The resistance is the important parameter. The wattage rating is OK as long as it's bigger than the calculation.

In any case, try it on the bench first. Theory is OK, real life testing is better. I'm not sure what the heat gain will be.

Chris

[NiceBill]

Thanks Chris,

I think I just had a LOMA, just trying to figure out what it was.  Know the Ohm's law, haven't applied it in some years, I know it hasn't changed.

That's a great start.  Time to get fooling around.

Thanks again,

Bill.>>>>>>>>>>>>>>

[blackjack52]

Don't do the tongue test on this one Bill.

[NiceBill]

The way I would test a can when I was in High School, was to plug it in to an outlet and when classes would change, toss it to some guy and holler CATCH.  Great can tester.

Bill.>>>>>>>>>>>>>>>>>

[Mark / Ohio]

The way I would test a can when I was in High School, was to plug it in to an outlet and when classes would change, toss it to some guy and holler CATCH.  Great can tester.

Bill.>>>>>>>>>>>>>>>>>

Guy in our class took great joy in poking pieces of solder into electric outlets.  Fortunately for us he never enrolled in vocational electronics.  I can only imagine the fun he could have had with the vacuum tube TV's they had for us to learn on there.   

[Garth Bock]

Why do you want to make your own heater Bill ? I have a vision of a cold snowy winter day and your rain bucket steaming like the cooling tower of the Clinton nuke plant down the road from ya.....

[chief-david]

some one on the site built their own

http://www.wxforum.net/index.php?topic=1468.0

[NiceBill]

Hi Chief,

Thanks for the up date bump.  I like the pattern maker idea.

Mine is still with the idea of the old way.  It's coming along.

Thanks again for the post.

Bill.>>>>>>>>>

[NiceBill]

OK, an UPDATE on the heater thing.

I have completed my weather station heater.  The cost came to about $35.00.  $12.00 for the transformer plug, ( wall wart).  $10.00 for the power resistor.  $2.50 for the thermostat and the rest to miscellaneous,
fiber board and the terminal block (rat-shack).  I had the stay-cons and the 4-40 mch. screws.  One should be able to build the same for $40-45.00 if you buy everything + any S/H.  Pretty fair price as to $175.00.

The power resistor is Philco 25 OHM and I believe about 45 watts.  It's just over 4" long and 1/2" in diameter.  It has attachment tabs although not shown in the photos because I have it bent over to distance it from the cone.
The core temperature reaches 450* F.

The thermostat I got on eBay. Low end is about 85*F and it opens at 115*F.  The power transformer plugs are also available on eBay.

I did make a pattern as shown in a post in this thread, however I used thin bubble wrap and put aluminum foil on each side, just thought that would be better. (I did use silver duct tape.)

I setup the transformer plug with the end of a cutoff extension cord.  In the weather station, is the other end attached to the heater.   I will just plug the (wall wart) in an outlet in the garage and run a longer extension to the pug on the weather station heater in the colder months when needed.  No fancy on and off switch.

Some photos below:  The rain gauge housing with the insulation installed.  The (wall Wart) and some photos of the heater installed.

I have two extra Power resistors if any one is interested - $20.00 each plus $2.50 shipping.  Send me an email.  They are very hard to come by but you can look on eBay.

Hope this helps some.

Bill.>>>>>>>>>>>>>>>>>>

[W3DRM]

Very nicely done Bill! I may just have to try doing that myself. Where did you get the power resistor?

I am also working on a design for a sprayer that will spray a de-icer on my anemometer when it freezes up with ice during winter storms. If I ever get it working, I'll post the plans and pictures.

[NiceBill]

Hi Don,

Thank you for the kind words, it was a fun project of sorts.  A challenge to figure it out.

I had some help from folks hear and a gent I ran into on the net.

His old web site: www.LaEstrellitaObservatory.org  Kinda in to weather some, has lots of stuff.


I found the power resistor - three of them on eBay after looking for about two weeks and through 6000 +.
I noted at the end of my post I have two for sale.  If you wish one let me know. If you can't find the transformer plug, I have the address and phone No. where you can get one.

Regards,

Bill.>>>>>>>>>>>>>>>>>

[Mark / Ohio]

Dang Bill!  That looks good enough to go into production as a generic rain gauge heater!   

(Not that I would have expected anything less after seeing some of your other handy work.     )

[mackbig]

I was going to do the same thing.  My anemometer used to be on my garage (backyard separated from house).   I figured a small pump, resevoir, some drip system tubing, nozzle from drip system, and one of those windshield washer fluid heaters to warm up the liquid before it was sprayed.   The unit could be in the protection of the garage, and either be on a switch or setup a timer if expecting an ice storm.....

Would be interested in what you come up with.  Of course my anemometer is now on the second floor of my new house, so I think my idea would not work as easily now.

Andrew

I am also working on a design for a sprayer that will spray a de-icer on my anemometer when it freezes up with ice during winter storms. If I ever get it working, I'll post the plans and pictures.

[Anthony]

I could use something like this my self. My anemometer loves to freeze up under just the right weather conditions.

[mackbig]

Supersoaker filled with warm wiper fluid worked in my old location, as long as the wind was not too strong...  that stuff does not taste very good (and is mildy poisonous...)
Andrew

[NiceBill]

Hi folks,

I have had several inquiries as to where I obtained the items I used for the rain gauge heater I fabricated.

The (wall wart) transformer plug can be obtained from, at $12.95.

Laco Electronics, Inc
545 n. Martin Luther King Jr. Blvd.
Decatur, IL 62523
(217) 423 0494

The thermostat can be found hear:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=270135837081

I have two power resistors, the same as I have in use, see post #9

All  of the other components can be obtained at the Rat Shack.

Hope this helps some.

Bill.>>>>>>>>>>>>>>>>>>

[NiceBill]

An up date on my rain gauge, ice and snow melter heater design.

Today I went out and checked some external temperatures, using my non-contact infrared thermometer.

The fan aspirated housing and the sensor housing registered at 15*f.    The outer portion of the cone and around the area that captures the rain and snow registered at 71*f.
The tipping buckets and all internal components were totally free of any ice or moisture build up.

I am overwhelmed with its operation, pleased with the design of the heater and all for a bit less than $40.00.

Go back through this thread to see the construction of the heater.

Bill.>>>>>>>>>>>>>>

[Mark / Ohio]

Good deal Bill! 

That reminds me I was going to measure the surface temp of the funnel on mine.  Running a little lower wattage I seriously doubt it is that warm. 


Dang!  Now curiosity is going to get the best of me unless I put on a coat and go out in the current 14F and measure it.     Oh well, I need to finish getting my trash put out for tomorrow anyway.

[Mark / Ohio]

I'm back in by the fire again.   

Interesting readings and I'm not really sure what to make of some of them.  Totally dark out now so no radiation from the sun involved.  While standing on the ground and reaching up pointing the thermometer in the funnel the warmest temp I measured was right above the heater at 60F.  The lowest being the opposite side of the funnel at around 40F.

But this is the weird part measuring the radiation shield gave me a -4F reading and the outside of the cone was only slightly warmer this with air temp reading of 16F.  I do have the interior of the cone wrapped with sticky foam insulating tape pipe wrap with a foil surface opposite the sticky side.

I would have blamed the -4F on some unknown reflectivity error with my thermometer had I not measured the warm surface temp inside the cone.

My thermometer is not high end but has always seemed to measure pretty accurate when I compared it to air and contact type thermometers:

 http://www.sears.com/shc/s/p_10153_12605_03450466000P