Easy DEW Heater

[TechnoViking (James)]

Hi IISers!
After a lot of umming and ahhing I bit the bullet and built a very cheap, and suprisingly good Dew heater.
I've taken a different approach then other people have, this one requires minimal soldering, controls 4 heating straps with independent control of each strap.

4 x 12/24volt 8amp dimmers from ebay $3.50 each free postage
4 x 12volt LEDS $7
4 x RCA Male jacks $8
1 x 4 way RCA female plate ( I had this lying around in my parts bin)
8mtrs of speaker wire $8
1 x Screw Box FREE!! spray painted black
12volt 2A power supply (scavenged from old dead flood light)
1 x toggle switch $2

its just a case of using the screw clamps inside the Dimmers to attach all your wires, run the 4 dimmers in parallel, mount it all in a box, drill some holes for the LED's and the Dimmers and hey presto, dew heater!

I went this direction as my electronics skills are very basic and I am doubtful i could build the JCar kits without sending myself insane! So this is the cheapest and easiest way i could find to build it.

Here are the photos

[Bassnut (Fred)]

Excellent. I designed a few dew heater controllers and never got close to $3.50 already built, it's just not possible. Smart easy build project and congrats on a new effort/ price point record, well done

[midnight (Darrin)]

Fantastic James. The PWM stuff coming out of HK is now so cheap and prebuilt and this one does up to 8A. Your ebay find will probably be a chopper style which is still fine for heaters.

I also found on ebay some buck switching regulators that have a variable output voltage down to just a few volts. Similar price and great for running things like my DSLR at the correct DC voltage (8V), guider (6V) etc. My aim is run everything off 12V.

Thanks for your effort and pointing us in this direction. I will now be revisiting my power box!!

Cheers,
Darrin...

[Poita (Peter)]

So the speaker wire works okay?
How heavy is it?

[Poita (Peter)]

Originally Posted by midnight

Fantastic James. The PWM stuff coming out of HK is now so cheap and prebuilt and this one does up to 8A. Your ebay find will probably be a chopper style which is still fine for heaters.

I also found on ebay some buck switching regulators that have a variable output voltage down to just a few volts. Similar price and great for running things like my DSLR at the correct DC voltage (8V), guider (6V) etc. My aim is run everything off 12V.

Thanks for your effort and pointing us in this direction. I will now be revisiting my power box!!

Cheers,
Darrin...

Got a link for those regulators?

[Astroman (Andrew Wall)]

Are these the ones, looks the same on the pics???

http://www.ebay.com.au/itm/LED-Strip...ht_4071wt_1037

[midnight (Darrin)]

Originally Posted by Poita

Got a link for those regulators?

Hello Peter. Please see the link below. Unfortunately, the seller is not posting to Australia now due to changes in the consumer protection laws which is unfortunate. I have contacted the sales rep directly last night as I want to buy 4 more.

I currently have 3 installed all from 12V DC source.
i) 6V for my NexGuide
ii) 5V for my USB hub
iii) 8.1V for my DSLR (7D or 6D).

I have placed a load of 2A continuous on each one for 4hrs and the module only gets just above "lukewarm". This is fine for my application. The 7D and 6D and modded 40D all work flawlessly with this module and even on liveview indefinitely. I would highly recommend something like this for those wishing to power their DSLR directly from a 12V (or other) DC source. I have lately added a Tantalum capacitor to the output to try and reject some higher frequency ripple evident when I placed a CRO on the output.

I'm sure there might be others around but I bought these from this e-shop only 3 months ago with no problems.

http://www.ebay.com.au/itm/LM2596-DC...item4ab3c71b28

The seller is "leadme-eshop" and has some really good stuff - if only he can change his policy on delivery

Darrin...

[Steffen]

Wow, that price sure beats the JayCar kits I've been using!

Cheers
Steffen.

[Poita (Peter)]

I bought some dc to dc modules from this guy:
http://www.ebay.com.au/sch/Power-Supplies-/50967/i.html?item=290605812144&_ssn=may13 9188
and they were excellent. He ships to Oz, it took about 10 days to arrive.

-P

[lacad01 (Adam)]

Dumb question but are you using the speaker wire as the dew straps . Not clear from original post what you're using as the actual heating elements. Apart from that what a great cheap project

[TechnoViking (James)]

Originally Posted by Poita

So the speaker wire works okay?
How heavy is it?

Hi Poita, the speaker wire is 2.5mm core oxygen free, and from my test loops ive made it seems to be fine without any issues. Im building my straps from 32guage ni-chrome wire which cost $14 for 100feet, just incase i make 90 feet of mistakes

im hoping in the next week to start building the heating straps, and i will post pictures when they are done.

[TechnoViking (James)]

Finally finished the dew control, tested it out last night (full cloud cover). The smaller straps i made have a nice ammount of heat no dew, the larger one (Orange and Black strap Pictured near dew sheild) seems to barely give any heat at all so after 2 hours the corrector had a decent covering of dew Im guessing i need more amps to that strap?

Here is a picture my dew solution fitted
*Orange and Black straps for the Corrector and EP
*Black strap for the finder

Including the straps this project has cost $55 in total + some basic sewing lessons from my wife, i didnt do too badly for someone who had a 5 minute crash course in sewing LOL now I need some cable management.