Power supplies

[Neo_uk]

Hi I have these two power supplies from my days in amateur radio ..would either of them be suitable for running my astro gear ...ie mount (heq5 pro) , cameras, dew heaters etc .

Many thanks chris.

[dodgerroger]

Not sure how they would handle been outside with dew etc. 

[SimM]

My dew controller (actually the dew heaters) is limited to 12V. A higher voltage also means higher wattage. It's one thing to heat the scope, but turn it up too much and it might be an issue too.

The problem of being outside is that you really need a sealed "efficient" PSU e.g. a modern regulated PSU with over/under current and good regulation. If the unit is not terribly efficient then it gives off heat - so you can't really put it in a box to keep out moisture. Does it get hot in operation?

A second issue might be the degree of regulation it offers. It might offer 13.8V but still be a "dirty" supply e.g. lots of ripple or poor regulation.

Realising that PSU noise rejection is best managed by having more than one PSU e.g. for keeping motors and cameras on separate PSU, a one PSU might not be the best option.

Of course if you have an observatory, and the unit is electrically OK then you can put it "inside" and moisture is not a concern. 

PS what works for a radio ham might not work for astronomy equipment. For some radio ham users, it doesn't work for them either e.g. read: https://www.eham.net/reviews/view-product?id=8380

NB if you are feeling brave, then you can open it up and adjust the voltage down to exactly 12V. One issue is with the operation and specs (see the link).

If you do intend to try it out, get ring connectors and not spade connectors or banana plugs. Most equipment is not too forgiving of applying the opposite polarity and it would be easy in the dark to attach flying leads the wrong way around - permanently screwed on ring connectors avoid this.

Edited November 30, 2020 by SimM

[malc-c]

13.8v is fine for running an HEQ5.  There would be no need to open it and start messing with the internals.  Both would have ample amperage to run the mount, camera and dew heaters.  The only concern would be to prevent moisture getting inside them as they are not IP rated for external use.  You could however place them inside a shed or from the house and run the low voltage supply out to the mount.

[TerryMcK]

+1 with Malc-c comment. 13.8 volts is a nominal output of a regulated power supply like the ham radio ones you have. In fact I use one outside but have it inside a plastic lidded 42 litre storage box  https://www.amazon.co.uk/gp/product/B001O3PG6A along with a few more electrical devices to keep dew free. The minimal amount of heat generated inside the box keeps it dry and does not overheat. I drilled a couple of holes in mine to let cables in and out.

In use I bung up the holes with some bubble wrap to stop creatures getting in. So reuse your old amateur gear and you will be fine.

[fifeskies]

These should be fine, I use 13.8v for all my gear.

I would however recommend some inline fuse protection or build a splitter box with some fuse protected outlets. I use a small ABS box near the mount for my fuses.

If you need to drop the voltage (dew heaters) you can get some small circuit boards that do that for you that can fit in a small box, these work fine on 13.8v in with a regulated 12v out.

 

 

[StevieDvd]

Are the ones shown by the original poster switched and not the more preferable regulated type?

[fifeskies]

Looks like OP has switch mode type, for the first smaller unit , other one is hard to tell but could be linear given the big case.

Personally I have (and prefer) the heavy linear type and if sourcing new would probably advocate a linear.

However a great many on this site use and recommend the switch mode style.

 

A linear is particularly the choice if you want to locate the unit indoors and run a long cable out to your mount (10s of metres).

The high frequency ripple on a switch mode would generate a bit of RF interference using a long output cable as an antenna, though should be supressed with a decent quality switch mode anyway.

Both types seem to give good service.

Edited December 1, 2020 by fifeskies

[malc-c]

24 minutes ago, StevieDvd said:

Are the ones shown by the original poster switched and not the more preferable regulated type?

Hi Steve,

A quick google and both are switch mode supplies  https://www.dxengineering.com/parts/asr-ss-30

Spec for the SS30

* Short circuit and over-voltage protection
* Automatic over-temperature shutdown
* Output current rated at continuous service
* Dual backlit meters on the SS-25M, SS-30M and SS-50M models
* Precision regulation of output voltage
* Most are designed to house specific LMR radios
* Fully EMI filtered
* Internal fuse access
* Switchable 120/220V input voltage (auto-select with power cord change)

Edited December 1, 2020 by malc-c

[Neo_uk]

Thank you all for your input ! ...

I can keep the power supply in a shed as it is very close to where I intend to setup the mount ...and at the moment that is all i wanted to run ...just wanted to make sure they wouldn't damage anything ...unless of course you reverse the polarity as pointed out ...

God I miss my obs I used to have ...maybe a project for next year building a new one ...

Thanks again .

[billhinge]

I used a 30A nevada clone  switch mode supply with out issue but have just  replaced it with a nevada 30A  linear supply. (from nevada web site)

I use one of  those orange camping leads with commando sockets  (plus heavy 2.5mm thick cable version, not the cheaper 1.5mm). I just put the psu in an IP66 box,  quite a lot of dew where  I live.

I use an external rcd on the house side