Orion Dew Heaters?

[Matty P]

Has anyone had any experience with the Orion Dew Heater Controller and Orion Dew Heaters?

I"m currently looking for some dew heaters for my C8 and refractor. I've looked at the Thousand Oaks and Kendrick series but they seem fairly expensive compared to the Orion dew heaters.

I'll appreciate any comments and feedback on Dew heaters.

Thanks. :thumbsup:

[AlexN]

I cant speak on the Orion unit, but as to the price... The thousand oaks heater system was quite a bit cheaper than the Orion unit...

I got my Thousand Oaks heater unit here (http://www.sdmtelescopes.com.au/shop/product_info.php?cPath=27&products_id=45), and my heater straps for the M102/M90/ST80/C11

Overall I think it was $330 for the heater unit, a 2" strap, 2x 3" straps, a 4" and the 12"...

Thats a bargain in my books..

[Starkler]

Looking at the photo it would seem that the orion unit is powered from AC :shrug:
That has to be a negative.

[Matty P]

Thanks for the link Alex. That looks like a very decent price for a dew heater but it says that they are out of stock.

Might send them an email. :)



I got this from the Bintel website,

"The Orion Dew Zapper Pro control module is powered by a 12-volt field battery and comes with a car lighter-style DC plug on a 12' cable."

That is a positive. (pun intended) :lol:

[leon]

I have to agree with Geoff, Matty battery powered can be a bit of a draw back, as these heater straps have to run sometimes all night and need a fairly steady supply of power.

Mine run from a Regulated power supply, which is dedicated only to the heaters.

But I might be wrong here, and I do suppose one can't have tem hooked up to DC out in the field :shrug:

Leon :thumbsup:

[Matty P]

Leon, I intend to use a regulated power supply to power the dew heaters inside my Obs. I am aware that they require a steady power supply and I understand that powering the heaters all night on battery power is less than ideal.

I just need to find a regulated power for the heaters and my mount. :)

:thumbsup:

[erick]

Dick Smith had a very good one - delivering 13.8Volts at 23 Amp. The output voltage can be adjusted - I brought mine down to 12V, no problem.

Cannot see it on their website at the moment. I got it on special for something like $89.

[Matty P]

Thanks for the heads up Erick. Will have to go have a look. :)

:thumbsup:

[Starkler]

23 amp? Thats huge!:eyepop:

Just to drive a mount and a few dew straps 5amp would be ample.

[Bassnut]

Matt. Ppl get fairly anal about dew heaters, the Orion looks fine.

I just have a Kendrick heater with no controller on my 12', works fine.

[AlexN]

Matt, I just found a few power supplies on ebay which may suit your needs very well... Im actually in conversation with one of them to find out about the suitability for semi-outdoor use.. if its all good I'll be buying it.. 13.8v 25A, $130. Australian made. :)

The problem with most of these power supplies, is that they are not suitable for outdoor use where they may be exposed to dew and moisture... If need be, I'd build a ventilated box for it..

there are more options for you obviously, being that it will be inside an observatory,.. just needs some basic cover and it would be fine.

[Matty P]

Sounds good Alex but the price doesn't. :sadeyes:

I might be worth having a look though. Could you post a link. :)

Thanks. :thumbsup:

[AlexN]

Err.. I was wrong about the price... Its $150...

http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&Item=350105299569&Category=30862

You'll be hard pressed to find a 12~13.8v PSU above 5 or 6A for less than $120 - $130.. I've been searching for quite some time.

[Starkler]

13.8v 5A psu for $30 (http://www.jaycar.com.au/productView.asp?ID=GH1379&CATID=27&keywords=&SPECIAL=&form=CAT&ProdCodeOnly=&Keyword1=&Keyword2=&pageNumber=&priceMin=&priceMax=&SUBCATID=381)

13.8v 8.5A psu for $40 (http://www.jaycar.com.au/productView.asp?ID=MP3470&CATID=27&keywords=&SPECIAL=&form=CAT&ProdCodeOnly=&Keyword1=&Keyword2=&pageNumber=&priceMin=&priceMax=&SUBCATID=381)

[bluescope]

Hi Matt

I have the Thousand Oaks controller and 2 x DewNot straps, 5" and 1.25" eyepiece .... $235 delivered.
The power supply I use is from Dick Smith ... 3 amp regulated $60 ... it comes with a cigarette lighter type adapter with banana style connectors that plug into the end of the screw type connectors, if you get what I mean. So the mount is connected with screw and heater with banana to same posts. Anyway as my FLT110 scope only weighs around 7kgs with SBIG camera the mount and dew heater run off the same power supply with no problems so far.
I hope all that came out as clear as mud ... I know what I mean !

Here's a link to heater and straps ....

http://www.sdmtelescopes.com.au/shop/index.php?cPath=27&osCsid=400be140dd4377444f2a579bf422 3469

power supply link ....

http://www.dse.com.au/cgi-bin/dse.storefront/48f09ade112ed9242740c0a87e0106df/Product/View/M9940

Keep the power supply dry .... it's not recommended for outdoor use .... mine lives under a foot stool under the mount on top of carpet tiles in my observatory.

:thumbsup:

[AlexN]

well well well.. dont I feel dumb :)

Guess who's going to Jaycar monday morning...

[Starkler]

Just pays to know where to look ;)
Its worth phoning them in advance as their hit rate on having items in stock isnt all that good :whistle:

[Matty P]

Which one would you recommend?

Does it matter?

:thumbsup:

[Matty P]

Thanks Steve,

I do understand what you are saying but not that clearly. :doh:

Do you think you could post some images. That would make it much easier. :)

Thanks :thumbsup:

[AlexN]

Matt, that all depends on your specific power requirements... Take a look at everything you intend to run off this power supply, find out their amp draw, add it all up, then add 1/3 of the total to the total....

Ie, if your equipment all totaled to 5A draw, add 1/3, making it 6.5A. That 1/3 allows for any surges by any of the gear etc, and gives you a little bit of head room should you want to power something else...

I know the EQ6 draws 2A, towards 4A during the start of a slew.... Dew heaters are power hungry, although I dont off the top of my head know their ratings.... Personally I'd lean towards the 8A one... Maybe buy a 5A as well just for posterity...

Alex.

[Matty P]

Thanks for the info Alex. The 8A sounds like the goods.

I was just wondering how I will power the mount and the dew heaters at the same time as there is only one cigarette lighter adapter available?

:thumbsup:

[AlexN]

bintel sell a double adapter... $15...
I have one to run my mount and heaters off my field battery...

[Matty P]

Thanks for your help Alex. ;)

:thumbsup:

[AlexN]

:) no probs mate.. All these things are things I wondered about a few months ago when I got serious about imaging.. So I've looked around a fair bit, and found most everything I've needed... Only thing I still NEEEEEEED is a HGM Titan or a Paramount... Sigh... cash issues.

[erick]

Much the same price in Dick Smith and Jaycar I think - check which store has one. I bought mine from the Dick

[peter_4059]

Are people having success powering the mount and dew heaters from the same supply? I've heard rumours of the dew heater PWM controller causing noise in the 12V supply which then affects the mount causing erratic slewing etc? I've got an independent supply for my dew heater as a precaution although I've not tried running everything from one supply.

[AlexN]

I've had no problems running them both of my 12v 17aH jump starter battery.. I've not tried powering them both off the same 240vac transformer though...

Will let you know later in the week.

[Starkler]

I would personally go for the 8A for $10 more just for the fact it has a cig lighter socket if thats whats needed.

[Matty P]

I've been browsing the Bintel website and I came across the Kendrick Digifire 7 dew heater controller and Kendrick Firefly heaters.

All together the Kendrick heaters are cheaper than the Orion heaters so it might be worth a look. The controller looks very high quality and so do the heaters.

What do you think? Has anyone had any experience with these?

Go to the 3rd page of Telescope Accessories on the Bintel website.

:thumbsup:

[Robbie]

I have a set up from bintel regulated power supply/orion dew heater with cig sockets, cost about $150 the lot made up and shipped, It works fine with no hiccups or glitches, the slewing pulls like a train no problem.

[shredder]

I looked into these a while back when I had my C8 and wanted to drive the dew heater.

What I found was the dew heater would consume a lot of power in a single night (especially if it was cold). On warmer night it still consumed a lot of power but wasnt always needed.

The solution, as is obvious from other commercial products, is to regulate the power, which in turn will extend your battery life. If you look at these simple transformer options from JCar/TrickyDicky etc they are generally without regulation. They will consume power, as will your dew heater and together will consume it even quicker...

There are some options in controlling the power usage, but you have to choose carefully. The simple and cheap option is to use essentially a voltage divider style circuit, thus limiting the voltage (and so power) to the dew heater. The problem with this approach is that the dew heater is designed to operate at a specific voltage level (which translates to current level), without that current it wont heat at all. So by using a voltage divider you essentially go from full power to off with only a minor change in the voltage. The other problem with the voltage divider is that in the other half of the divider you end up consuming the power not used by the dew heater, again saving you nothing.

This is not how the commercial units are built, hence their added cost and complexity.

However their cost is not justified by the complexity of the circuit needed. What you really need is a voltage regulator that doesnt divide the voltage but divides the time its on (there is a technical name for this but it escapes me today). For example for 3 out of 5 sec its on at 12v and for 2 out of 5 sec its off. This allows for full current while on and no current while off. This gives much better heat regulation (provided you dont have the setting on and off in terms of minutes) while achieveing the all important battery life. This is essentially how the better commercial units do it.

In terms of complexity its actually not that difficult to make, and if you are somewhat capable with soldering its something you might like to try making. What you end up developing is a 555 timer circuit that drives the on off state timing, and a transistor that controls the voltage throughput. There are some good circuits on the web specifically for it (and for astronomy uses). Well worth a look.

I built one and I am sure it was only a couple of dollars worth of parts. The other advantage of this approach is with the same circuit you can control multiple outputs at the same time (just like the commercial ones).

[Geoff45]

Yes, DYI is the way to go. Cheap and you can custom design it for your own gear. I built mine using the IIS articles http://www.iceinspace.com.au/63-285-0-0-1-0.html
and http://www.iceinspace.com.au/63-292-0-0-1-0.html
Geoff

[shredder]

Ahh, thats the name I was looking for "Pulse Width Modulation".... Dolt!

Anyway yes the make it yourself option is not bad if you are a little handy. Though I must say I was never so keen on the resistor dew heater, too many chances for problems, some form of resistance wire is a better solution.

[Gem]

According to Kendrick, the micro firelite controller can handle 7a. The Bintel site says 1.5a. Does anyone have this controller? I am looking for an economical system for dew control.

[Gem]

Ok, I should add that Kendrick has posted TWO specifications on the controller on their site. They post 1.5a http://www.kendrickastro.com/astro/dew_microfireliteheaters.html
and 7a http://www.kendrickastro.com/astro/dew_controllers.html#MicroControlle r

I hope someone can shed some light!

[wasyoungonce]

The 1.5A version is an older version designed to run one heater band only. The idea was to have the controller near the heater band.

The 7A version is a newer controller capable of much more I draw out. It is still single channel but with 2 outputs.

Why the change? Who knows..probably they save some $.:shrug:

[telemarker]

The 1.5A controller has outputs for 2 bands using the firelite plugs. The combined output cannot exceed 1.5A or you blow the fuse. I run a band for both an ED80 and 200mm SCT off the one controller (total of about 1.2A I think). I find these are enough for me during Canberra winters.

Regards
Keith