Go to mount from mains!

[robmichael81]

I use a Baader outdoor telescope power supply from FLO. It is supposedly moisture resistant, though of course the extension reel I use isn't. Make sure it is all supplied through an RCD though.

Ian

Hi Ian,

What mount do you use with the above power supply. I like this idea however getting lots of comments about a 13.8V being more reliable. Do you just power the scope or anything else with it? I like things simple and this seems to fit the bill.

R

[ShrimpBoatSteve]

Sorry, but I think these 'astro' power supplies are a con. They are probably re-badged standard power supplies, maybe with a bit of sealing on the case which you could do yourself. £55 for a £12 PSU is silly. CCTV power supplies are made to be reliable and throw regulated voltages over reasonable distances, don't be fooled into buying snake oil ... it's just a power supply.

If you supply the mount with 13.8V the voltage regulator in the mount will reduce this to 12V, so supply it with a good regulated 12V. Or maybe I'm just tight with money

Sent from my Nexus 4 using Tapatalk

[The Admiral]

Hi Ian,

What mount do you use with the above power supply. I like this idea however getting lots of comments about a 13.8V being more reliable. Do you just power the scope or anything else with it? I like things simple and this seems to fit the bill.

R

It's only a Nexstar 6/8SE mount, which has a modest demand of ¾ amp, and I don't power anything else. It's only the 1.5 amp unit.

Sorry, but I think these 'astro' power supplies are a con. They are probably re-badged standard power supplies, maybe with a bit of sealing on the case which you could do yourself. £55 for a £12 PSU is silly. CCTV power supplies are made to be reliable and throw regulated voltages over reasonable distances, don't be fooled into buying snake oil ... it's just a power supply.

If you supply the mount with 13.8V the voltage regulator in the mount will reduce this to 12V, so supply it with a good regulated 12V. Or maybe I'm just tight with money

Sent from my Nexus 4 using Tapatalk

I'm sure that you are right, but mine was the version at half that price. I think if I needed significantly greater output I'd probably have looked around a bit further, but as it was, it was an easy purchase. In fact, the FLO website even recommends a Maplin unit for higher outputs (not that Maplin is as cheap as chips).

Ian

[Tinker1947]

This link shows the differences in Linear or Switch Mode, i would choose the Linear as the fixed output of 13.8v on like the maplin XM21X type this is 1.2 volts below the maximum and 2.8volts above the minimum, the Switched Mode on the other hand are 3 Volts below the maximum and 1 Volt above the Minimum this to me isn't enough a slight drop in voltage when the Mount slews and GoTo accuracy could suffer....

Maplin type

http://www.firstlightoptics.com/power-accessories/maplins-xm21x-7a-138v-regulated-mains-power-supply.html

Difference 

http://www.kele.com/keleblog/blog/ac-to-dc-linear-versus-switch-mode-power-supplies/

[The Admiral]

Thanks for that Tinker1947, I've wondered whether it makes much difference to the use with astro mounts whether a switched mode supply is OK. Does the 'cleaner' supply of the linear device make much difference in this use, ignoring the voltage characteristics?

The XM21X appears to have been replace by the XM20. At least that is what the picture shows, though the code remains XM21X! http://www.maplin.co.uk/p/maplin-97w-dc-fixed-voltage-bench-power-supply-xm21x

Ian

[Tommohawk]

Whatever else you do, a big ++ for the idea of RCD protection for any mains sections, and ideally fuse any low voltage supplies too.

I use RCD protected mains extension to garden - taking care to avoid fishponds etc but no other special precautions. Then a PC style "brick" converter bought from ebay. Mine has 7.5A capacity so I can run heaters etc. Its 12V, and this seems fine, whereas the power light on the HEQ5 used to flash occasionally when running from the "power tank" battery.

I meant to put an in-line fuse on the 12V line, but never got round to it. So if anything goes a bit dicky in the mount it will have 12V at 7.A to blow itself up with - not ideal.

Couple of other things to consider - if you want a simple "brick" solution such as mine be aware that the HEQ5 uses a 2.1mm jack, where some bricks such as mine have 2.5mm jack and need an adapter (Maplins)

Also, if you have a high ampage model, the output cable is quite think and can pull sideways on the HEQ power input socket.

[souls33k3r]

I bought one of these bad boys to power my mount (NEQ6 Pro) from the mains

https://www.widescreen-centre.co.uk/astronomy-power-supplies/power-adapters/baader-outdoor-telescope-power-supply

Then also RCD from Maplins. Run everything through a 4 ways power bar and cover it up with a plastic box so that no dew gets in.

Hope this helps.

[Skipper Billy]

Sorry to start this thread up again but will it matter if the PSU is >5A i.e. 13.8V DC 15A. I'm only planning to run the HEQ5 off it. Dew straps may come later.

I've also found one that is 13.8V DC 3-5A. 

Cheers,

R

It will only take what it needs - the >5a one will give some redundancy if you at some later point add more kit.

[Tommohawk]

It will only take what it needs - the >5a one will give some redundancy if you at some later point add more kit.

Agreed - but be aware the more current you have available the more important it is to protect your kit with fuses on the low voltage feed. In the event of a short circuit, !2V @ 15 amps would give 180W of power - plenty enough to fry your nice expensive gear. 

[robmichael81]

This link shows the differences in Linear or Switch Mode, i would choose the Linear as the fixed output of 13.8v on like the maplin XM21X type this is 1.2 volts below the maximum and 2.8volts above the minimum, the Switched Mode on the other hand are 3 Volts below the maximum and 1 Volt above the Minimum this to me isn't enough a slight drop in voltage when the Mount slews and GoTo accuracy could suffer....

Maplin type

http://www.firstlightoptics.com/power-accessories/maplins-xm21x-7a-138v-regulated-mains-power-supply.html

Difference 

http://www.kele.com/keleblog/blog/ac-to-dc-linear-versus-switch-mode-power-supplies/

Thanks for this Tinker1947,

With this in mind I've been looking round for a cheaper version than that sold by Maplins. Would either of these be ok? Realistically I am only going to be running the HEQ5 Pro Synscan off it at the moment but maybe one day I might add dew heaters.

http://www.rapidonline.com/Electrical-Power/Voltcraft-FSP-1136-Fixed-Voltage-Power-Supply-51-7498

13.8V 6(8)Amp

http://www.rapidonline.com/Electrical-Power/Voltcraft-FSP-1134-Fixed-Voltage-Power-Supply-51-7497

13.8V 4(6)Amp

Thanks again for everyone's help.

R

[Tinker1947]

I would go for the 20 Amp in there range so there's some future proofing, but the 6amp one would give you a bit more leeway......