Running off the mains?.

[LukeSkywatcher]

Hi all. I'm wondering if if it's OK to run a 8Se, and or a Quark Chromosphere off house mains via an extension cord (not at the same time). My newish (hardly used) 7Ah tank is dead as a Dodo and I don't want to buy a new one if possible because they are not cheap. I also don't really want to start using leisure battery because might be too heavy for me.

TIA.

[scotty38]

I run all my gear off a single plug, mount, cooled camera, laptop, EAF and not a problem at all. I’ve not added it up but at full load I still don’t think it would exceed 13A and certainly not constantly.

[LukeSkywatcher]

8 minutes ago, scotty38 said:

I run all my gear off a single plug, mount, cooled camera, laptop, EAF and not a problem at all. I’ve not added it up but at full load I still don’t think it would exceed 13A and certainly not constantly.

Thanks. So the mains are whatever volt,amp etc and I believe the scope and even Quark run on 12 volt?. I'm not likely to fry the electronics in either?. 

I'm rubbish with technical stuff. 

[Carbon Brush]

The power consumption of astronomy gear is generally negligible.

In round figures, a 13 amp socket will give you up to 3000W. For the pedantic 240V x 13A = 3120W.

Things like mounts, cameras, etc take from a few watts to maybe more than 10 watts.

A laptop may take a few tens of watts if working and charging. OK 100 watts for a go faster sup screen model.

Dew heaters tend to take in the tens of watts. You might take up to 100 watts with a serious setup.

A hair dryer anti dew will take maybe 1000 watts for the few minutes it gets used.

All of the above figures are approximate. Yu might have a 1500W head burner hairdryer, or a 500W travel model. You get the idea.
But at the end of the day night you are using a fraction of what a domestic mains socket will provide.

Two cautionary notes.
If your house wiring does not include an RCD  (sometimes incorrectly referred to as an earth leakage breaker) then put one into the wall socket before your extension lead.
Then the extension lead. If you are going to run a hairdryer, make sure the lead is uncoiled.
Some extension reel manufacturers are very economical about cable size and you get significant heating.
For small loads, don't worry.

[rl]

Yes, it's fine but common sense applies..

I power all my gear off the mains when doing photography at home. Everything is powered through one extension lead which has a safety Residual Current Detector (RCD) plug. This will trip automatically if the current in the live is not the same as the current in the neutral because current is leaking out to ground (potentially through you!).

You want all the exposed metalwork either grounded or double insulated. Commercial stuff that comes with 2-pin mains connections should already be double insulated. 

I can't see how even a big setup will take more than a couple of amps at 240v (500 watts) unless you're using a hairdryer for dew prevention. 

Edited May 13, 2021 by rl

[Stu]

27 minutes ago, LukeSkywatcher said:

Hi all. I'm wondering if if it's OK to run a 8Se, and or a Quark Chromosphere off house mains via an extension cord (not at the same time). My newish (hardly used) 7Ah tank is dead as a Dodo and I don't want to buy a new one if possible because they are not cheap. I also don't really want to start using leisure battery because might be too heavy for me.

TIA.

You will obviously need the correct transformer to convert from mains to the input voltage of the mount. Do you have this?

The Quark can be powered from a USB cable from a 5V supply.

[LukeSkywatcher]

2 minutes ago, Stu said:

You will obviously need the correct transformer to convert from mains to the input voltage of the mount. Do you have this?

The Quark can be powered from a USB cable from a 5V supply.

I was thinking that I'd need some kind transformer/converter to convert the power going into the mount from mains. I have no idea what I need. 

[tonylumley]

LukeSkywatcher first, and not teaching you how to suck eggs, you will need to reduce 240 volt ac power to 12 volt d/c power,  have you looked on the First light optics web site under "accessories and power supplies" Also Martin and his colleagues are very approachable if you are not sure what you need,  all the best, Lum  Essex. finally, I'm hoping Iv got your name right, 3rd attempt!!!!

Edited May 13, 2021 by tonylumley
still hadn't got the name right ! 3rd time lucky!!

[LukeSkywatcher]

35 minutes ago, rl said:

Yes, it's fine but common sense applies..

I power all my gear off the mains when doing photography at home. Everything is powered through one extension lead which has a safety Residual Current Detector (RCD) plug. This will trip automatically if the current in the live is not the same as the current in the neutral because current is leaking out to ground (potentially through you!).

You want all the exposed metalwork either grounded or double insulated. Commercial stuff that comes with 2-pin mains connections should already be double insulated. 

I can't see how even a big setup will take more than a couple of amps at 240v (500 watts) unless you're using a hairdryer for dew prevention. 

The 15ft extension lead I have does have an automatic circuit breaker.

[The Lazy Astronomer]

 

14 minutes ago, LukeSkywatcher said:

I was thinking that I'd need some kind transformer/converter to convert the power going into the mount from mains. I have no idea what I need. 

There are a few options, I think the simplest is to get an extension lead and a weatherproof enclosure, to bring the mains sockets outside, then plug in a 12v brick type transformer (keeping the 240v side inside the enclosure), and have the 12v side cable coming out from the enclosure and into whatever you're powering

[rl]

The mount needs a clean source of DC from 12 to 14 volts, called a power supply. You need to choose its current rating; add up all the 12 loads like the mount (use the slew current..it's a lot higher than the tracking current), dew heaters, cameras, whatever else. 10-12 amps is a typical total number if you don't have access to all the individual numbers. If in doubt, go higher. Then you're in a position to buy the power supply from someone like Nevada. 

The power supply needs 12v connectors to suit. The car cigarette lighter plugs have become standard..personally I hate them because they can come loose easily

I use a Farnell 0 to 30v supply but I'm not sure I'd recommend it just in case a spot of finger trouble in the dark turns the voltage up. A specialist 12v supply or 13.8v supply is better. A modified 12v 10 amp laptop power supply is another option; they are small, don't generate much heat and are cheaply available on ebay. But you need to be certain what you're doing changing the 12v connector so possibly not the best bet if you have no electrical experience. 

Battery chargers are not a good idea since the output 12v is not always clean. 

You can get mains to USB chargers that should be ok for the quark. 

If you add up all the bills buying proper new stuff you might find the costs are not that far short of a new battery...

[Stu]

26 minutes ago, LukeSkywatcher said:

I was thinking that I'd need some kind transformer/converter to convert the power going into the mount from mains. I have no idea what I need. 

Yes, don’t go sticking mains wires into the mount!! 😱😱😱

The Quark draws 1.5A, so a decent phone charger will supply that via the USB cable.

This one looks suitable for the 8SE:

https://www.firstlightoptics.com/power-accessories/lynx-astro-12v-dc-5amp-low-noise-mains-power-supply.html

[LukeSkywatcher]

38 minutes ago, Stu said:

Yes, don’t go sticking mains wires into the mount!! 😱😱😱

The Quark draws 1.5A, so a decent phone charger will supply that via the USB cable.

This one looks suitable for the 8SE:

https://www.firstlightoptics.com/power-accessories/lynx-astro-12v-dc-5amp-low-noise-mains-power-supply.html

I wasn't planning on sticking mains into the mount. That would blow the electronics. 

Unfortunately this item doesn't ship to Ireland. It gives me a starting point to search for in Ireland. I'm amazed FLO can't ship a simple 12v dc to Ireland. 

Maybe I don't need a new one, as I have a couple of 12 volt cables kicking around that came with scope. It's only the battery pack that's dead. The cables are fine.

 

Edited May 13, 2021 by LukeSkywatcher

[Mr Spock]

Most small items ship by air freight with companies like DHL. Power supplies are on the prohibited list for air freight.

[scotty38]

1 hour ago, LukeSkywatcher said:

I wasn't planning on sticking mains into the mount. That would blow the electronics. 

Unfortunately this item doesn't ship to Ireland. It gives me a starting point to search for in Ireland. I'm amazed FLO can't ship a simple 12v dc to Ireland. 

Maybe I don't need a new one, as I have a couple of 12 volt cables kicking around that came with scope. It's only the battery pack that's dead. The cables are fine.

 

You can pick up that sort of thing from Amazon for less than a tenner. I have a 10A version with cigarette lighter connector that works just fine.

[Shimrod]

1 hour ago, LukeSkywatcher said:

I wasn't planning on sticking mains into the mount. That would blow the electronics. 

Unfortunately this item doesn't ship to Ireland. It gives me a starting point to search for in Ireland. I'm amazed FLO can't ship a simple 12v dc to Ireland. 

Maybe I don't need a new one, as I have a couple of 12 volt cables kicking around that came with scope. It's only the battery pack that's dead. The cables are fine.

 

If the budget allows, maybe consider a LifePO4 battery like a tracer or the Celestron battery (Celestron PowerTank Lithium Pro) I have the latter and it is much lighter than a traditional lead acid battery and does not degrade between charges.  I'm assuming your 7Ah powerback was a lead acid battery that has gone too long between charges. Alternatively, have a look inside your powertank, as you can probably buy a replacement battery much cheaper than a new powertank - I've done that in the past  as well.

[Carbon Brush]

14 hours ago, LukeSkywatcher said:

The 15ft extension lead I have does have an automatic circuit breaker.

Don't read too much into the capability of circuit breakers in extension reels.

If you run something like a power saw, and the blade gets stuck in the wood, the breaker will trip.
It may trip before the 13A fuse in the plug blows, depending on the power toll, breaker rating and more.
Apart from that sort of fault protection, it doesn't really do anything.

[Carbon Brush]

Going back to buying items.

There is no technical or regulatory reason why you can't have a mains to 12V power supply (no battery) shipped. Freight cost should not be prohibitive.
Whether a particular supplier wants to jump through the hoops associated with the UK no longer being in the EU is another matter.
Things I have bought for work from the EU, for years without question, now generate enough paper to deforest a small country.
Someone has to pay for the time involved in handling the paperwork.

Shipping lithium batteries involves the paper trail above - and more.
There are safety regulations regarding shipping lithium batteries.
If your battery pack has not been approved and the lithium amount exceeds an electrical capability/lithium content, it doesn't go.
The approvals process costs a few thousand pounds so it is the equipment manufacture who does it, provided he sees enough potential business.

However, some carriers are ill informed about lithium batteries. They just reject on the basis of the word being encountered.
I once had a carrier refuse a 50Kg machine consignment because it contained a little coin cell like you have in a remote control.
The sort of thing that presents no danger unless swallowed.

Right now a good option is for you to talk to someone locally who has the necessary technical skills to source the parts individually and put them together.
As an example, I use a lithium pack on a scope. It is a car jump start. Potentially very dangerous in it's native form, but after a few changes, quite safe.

HTH, David.

 

 

[Zummerzet_Leveller]

16 hours ago, LukeSkywatcher said:

My newish (hardly used) 7Ah tank is dead as a Dodo and I don't want to buy a new one if possible because they are not cheap.

Depending on the tank you have I would also recommend popping a proper charger on your tank.  The trickle chargers supplied tend not to have enough oomph to boost the battery properly.  I charge mine (7ah Celestron powertank) with a 12v car charger by the +ve -ve terminals on the back.  When I am doing a longer imaging session I leave the charger attached (probably not great practice but the battery is a buffer) it powers my AVX mount and ASIAir really well, and is a cost effective solution.

[Cosmic Geoff]

You should always make sure you are charging a lead-acid battery (the kind used in astro powertanks and car engine starters) with the correct type of charger.  This will be one that will charge it to about 13.8 or 14 volts but no higher.  The final voltage chosen may depend on the application. A charger with an unregulated output voltage will charge the battery quickly but should be disconnected once it has done its job, as leaving it connected could damage the battery.

Powertanks and engine starters should be supplied with a charger which, in the case of the one I have, is a low-power charger that has a regulated output and can be left permanently connected.  Such chargers are generally marked with the output voltage and current capacity.

Note that a lead-acid battery that has gone completely flat may have suffered permanent damage. Also, a charger with clever built-in protection circuitry may refuse to charge it. (This definitely happens with laptop batteries).

[LukeSkywatcher]

Well it turns out that I'm an idiot. When I tested my pack the other night, I just flicked the on/off button on top. Then it occurred to me that that button is for the 2 torches on the front. Hidden away on the side is the actual on/off buttons along with a charging button and indicator lights when charging.

24hr later, I now have a fully functioning 7Ah (could be 14Ah) battery pack.

[LukeSkywatcher]

This is the Celestron tank in question. It even has an AM/FM radio and a siren. It's 14Ah.

Edited May 15, 2021 by LukeSkywatcher