15 replies to this topic

[Purritolover]

Hey all, just purchased a Dew Not dew heater strap for my 60mm refractor. Very good deal at 35 bucks, but now i’m faced with an issue. It seems like it’s impossible to get any sort of dew heater controller for under 150 bucks or so. I just need to control one strap, it has an RCA plug, and ideally I could get this controller for relatively cheap. Something like the Pegasus Pocket Power Box is appealing except for the fact it costs over 300 dollars for 4 DC outs and 2 dew heater controllers. There’s manual controllers like the ones from DewBusters that seem like they should be relatively cheap, but the only one I can find is 250 dollars. Is there any way around this or am I just SOL and need to buy a controller costing hundreds for a strap that I only spent 35 bucks on?

Somewhat of a secondary question, I’m going from powering just my mount on DC and then a battery DSLR to needing to power a 533MC, my mount, a dew heater, and mini pc. I could buy 2 more AC/DC plugs and a power strip, but I imagine there has to be a simpler way. So if you have any input on DC power hubs and/or places to buy good cables, I’m open to that too

[Walter T]

Make a manual one with a PWM controller and an RCA pigtail.  Total less than $20.

 

https://www.amazon.c...e?ie=UTF8&psc=1

 

https://www.amazon.c...3013167&sr=8-19

 

Edit:  Seems like the PMW I've used is unavailable.  Here is a similar one:

 

https://www.amazon.c...ools,102&sr=1-2

Edited by Walter T, 30 November 2024 - 07:37 PM.

[spaceoddity]

The pegasus 2 channel dew controller is $90 and the one from kendrick astro is about the same price with 4 outputs. You will have to also buy a 2.1 mm male to male cable to power it from a talent cell or similar power device. You can also use a cigarette plug type cable if you have an older lead acid celestron power tank or something similar. 

[Leafus]

4Tronix 4 channel works great and is £54. Also do a 2 channel.
It’s small and well built. And cheap.

[ButterFly]

Make a manual one with a PWM controller and an RCA pigtail.

You do want female RCA leads though.  Dew heaters typically have male RCA.  I would also use a much lower fuse than that provided.

 

PWM LED dimmers are another option as well.

 

In either case, make some sort of casing to prevent dew forming on the controller.

[Brian Carter]

An alternative is a USB dew strip like the Amazon link below.  If you are running everything off AC power anyways, just put a little USB charger on your power strip and plug these in.

 

The downside is that these are not very power efficient.  With a nice dew controller you can get pulsed power and keep the dew away without using a lot of electricity.  These USB ones are energy hogs, but they work and they are cheap.  

 

https://www.amazon.c...,aps,121&sr=8-3

[randcpoll]

Here is another approach. I used a three color version to make a three channel dew controller and it works great. $6 bucks from Amazon plus input/output cables.

 

https://a.co/d/c9OJS6h

Edited by randcpoll, 30 November 2024 - 08:18 PM.

[ButterFly]

Dew heating strips also aren't that hard to make yourself.  If you do, you can also ditch the RCA leads and just use regular 5.5x2.1mm leads as well.  If the draw is under 2A, that lets you use an inline dimmer such as this.  I would add an inline fuse to this, or if using several, then before the split to the individual controllers.  It's neater, not too much more, and doesn't need a separate casing.

[ButterFly]

Here is another approach. I used a three color version to make a three channel dew controller and it works great. $6 bucks from Amazon plus input/output cables.

 

https://a.co/d/c9OJS6h

Don't forget the fuse.  Can't be stated enough.

[Robert7980]

You get what you pay for… some of the prices seem high, most of them aren’t for what you’re getting… I probably put 300 or 400 into alternatives to the Pegasus, something that just works and automatically adjusts its output power for conditions is not nothing. 
 

I wouldn’t recommend most that are just power supplies, they’ll either be not enough or more that likely way too much power… the last thing you want is no dew but hot optics, at that point you’re better off just taking a hairdryer to it when it dews up and go again until it needs another round… 

 

I can say that once I setup the dew-nots on the Pegasus I’ve not even thought about dew control since and it’s worked flawlessly unattended… So there’s return on the investment even if it’s quite pricey initially… It just works… 

 

I thought there should be at least one advocate for going for the stuff that performs… I did the cheap thing for a long time and tried a dozen different low cost options so I won’t knock it because I did it too… 

 

This hobby is painfully expensive under all circumstances, it gets even more expensive when we start throwing good money after bad… That’s the harshest lesson I’ve learned, I learned it again every time I look in the junk box of now unused parts and accessories… 

 

-R 

Edited by Robert7980, 30 November 2024 - 08:31 PM.

[PIEJr]

I'm just glad I live in a warmer climate.

 

You guys might melt here in the summer, But I'm a native and a lizard.

 

I do have a heating pad under my laptop, so it runs its best.

I put it in a 1/4 sheet baking flat pan and set my laptop on the pans bottom (inverted).

It's set to 68 degrees. Has worked for several years for me.

[Andrea Salati]

I paid $13 for mine. Sure, it is not beautiful to look at and I cannot control it via a dashboard on the computer but I also do not want to do that anymore (I used to and I got tired).
It does exactly what I need it to do and I am happy with it.

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[ayadai]

I integrated this PWM controller into my home-made power supply (multiple internal fuses; 16 Amps total output). I added a digital volt meter connected to the output of the PWM controller to allow for precise, repeatable settings. This particular meter has a USB outlet and a switch to turn the meter off when not in use. Heater output is standard RCA; total cost was ~US$22.
 

 

I'm just glad I live in a warmer climate.

Hafa Adai from the Northern Mariana Islands, where it's always 80F and 80% RH and dew heaters and/or a sail shield on larger objectives (read: 8" SCT) are a definitive necessity.

Edited by ayadai, 30 November 2024 - 10:15 PM.

[limeyx]

An alternative is a USB dew strip like the Amazon link below.  If you are running everything off AC power anyways, just put a little USB charger on your power strip and plug these in.

 

The downside is that these are not very power efficient.  With a nice dew controller you can get pulsed power and keep the dew away without using a lot of electricity.  These USB ones are energy hogs, but they work and they are cheap.  

 

https://www.amazon.c...,aps,121&sr=8-3

I use those and they work well. They don't seem to suck too much power on my system (I use a hub with charging ports and a LiFe battery to supply power)

[spaceoddity]

I use those and they work well. They don't seem to suck too much power on my system (I use a hub with charging ports and a LiFe battery to supply power)

The svbony is a little cheaper. https://www.amazon.c...asin_title&th=1

[SteveL42]

A simple Pulse Width Modulated (PWM) controller is a great DIY project, and uses only a few dollars worth of parts. If you want to learn more, and Arduino can drive a PWM output device (like a MOSFET) and read the temperature - managing the power to keep it above ambient.  

 

Google "Arduino pwm dew heater" and you'll find lots.  It's a great place to start if you're willing learn.