Powering an HEQ5Pro

[Insane Climber]

Hi all. Some gronk stole my celestron power tank on the weekend:mad2:, so any way i have been wondering about otherways to power the unit. Has anyone out there got any suggestions. An Electrician friend suggested buying a $25 regulated power supply kit from Dick smiths.?

"Happy New Year"

Jason

[bmitchell82]

@#$@$# A55.... Depends if you want to run it in the field or at home close to 240V.

Option A, add all your current draws from all your equipment then x it by how many hours you want to run remembering to minus 20% buffer from the Amp-Hours and go get yourself a Deep cycle battery to suite.

something around the 100 A-h will see you for 8 hrs imaging with a normal setup.

Option B, yep get a 240-12V dc with about 5A current maby more depending on your equipment look for the highest peak power draw.

[NCRAW]

Done waste ur time at Dick Smith. Head straight to Jaycar.

[bmitchell82]

ahhhaaa, forgot that golden advice, :D yes dick smiths aint what it used to be.!

[NCRAW]

He's too busy making biscuits called Dickies!!

[Insane Climber]

? Ok sounds good a battery is heaps cheaper than a new powertank, but i was rather concerned when the salesman at andrews told me that some people have burnt there mounts out useing batteries with out regulators. Have you guys heard of this ?

[Karls48]

You cannot (for practical purpose) regulate voltage output from 13.8V battery to 12V. Such a regulators require at least 0.5V difference between input and output and would considerably reduce your battery capacity.
Damage to the mounts electronics is in most of cases done by reversing polarity or by using unregulated 240 to 12 Volts power supplies. You can protect your mount against accidental reversing polarity by wiring 3A diode (IN5404) in series in the lead that plugs in your mount. It will cause about 0.7V drop in voltage supplied to your mount when slewing, but if you accidentally connect your battery wrong way around - nothing will happen – no damage to electronics.

[mill]

Any HEQ5pro and HEQ6 pro have a inbuild voltage regulator that brings the voltage back to 12V DC internally.
This is the reason why you can connect the mount to the car thru the cigarette lighter (full battery is over 14V if you just stop the car).

[pjphilli]

Hi All

According to my HEQ5Pro handbook the SynScan should be powered by 11-15v DC power supply (TIP POSITIVE) minimun of 2 amps. Hence, operating from a a fully charged car battery is OK. The inclusion of a BLOCKING DIODE is very wise in case you connect the battery around the wrong way. Also the plug on the power lead (intended apparently to be plugged into a car "cigarette" lighter outlet - tip positive) has a small led which glows red when the polarity is correct, if the polarity is reversed the led does not light. So CHECK THIS FIRST before you plug the other end of the lead into the mount.
I operate my mount from a JayCar switchmode regulated power supply which supplies 12volts at 5amp max (Cat No: GH1379 cost $29-95). This works well and gives me plenty of extra power to operate other accessories. I bought a cigarette lighter in line socket from JayCar and connected it to the power supply so that the supplied HEQ5Pro lead will plug straight into it. Again MAKE VERY SURE that you have got the polarity correct before connecting to the mount.
Also, never be tempted to operate your mount from an UNREGULATED power supply such as a mains powered car battery charger as the peak voltage from these would certainly exceed the maximum voltage limit of the HEQ5Pro. I do not know whether the mount has an internal regulator but I would not take the chance that it has. Besides an unregulated mains power supply voltage typically has no filtering capacitors and the DC output voltage consists of raw rectified alternating current of half sine wave pulses that will vary in voltage from zero to about 1.4 times the rated DC output voltage - murder for electronic equipment!
Cheers Peter

[NCRAW]

I bought the 12V 2.5 amp one from JayCar but i was concerned to plug it in cause im not sure which direction is the polarity as the unit comes with multiple heads!! how do i know (without having the cigi adaptor) which way is tip positive? anyways what does Tip positive mean??

Many thanks

[NCRAW]

Did some quick search about the polarity and how to figure it out. Im sure many knows it but for the ones like me, here u go

http://www.bixnet.com/caradcpoadfo.html

[Sionnagh]

I use a laptop power supply to power from the mains. I've also built a voltage regulator unit which I now plug into before plugging into the mount.

The regulator doesn't regulate power from the laptop supply - I included a bypass from the input to an output with just a diode for polarity protection - but has also 2 outputs regulated at 12 VDC. Why? Because my Orion Starshoot also needs 12 V and this frees up a point on the powerboard. The same (12 V) lead can power the mirror fan while I'm messing around with setting up. I put the 2nd 12 V output in just as a spare.

Plus the regulator pack velcros onto the mount head so the leads don't all get wrapped around and caught on things during a slew. :)

;-)
Mick

[Insane Climber]

Cheers for the extra info there everyone. I feel like i know what im doing now.

[AdrianF]

When at home I power my EQ6 from a 40Amp regulated switch mode PS when I am lazy I power it from a Projecta 17AH jump starter which gives me about 8 hours+

Adrian

[bmitchell82]

Thats what i was kinda thinking as the output of a Laptop battery pack is rated for 12v @ 2-5 A, depending. Theres one at Jaycar 12V @5A, im thinking of just wiring it up with a few ciggi plugs and some fuses. easy done. HAZZAR;)

[AlexN]

I recently acquired a 13.8v 10A powersupply off the forums for $50 that powers my mount, dew control, a couple of fans (to cool the power unit and to cool the C11) etc perfectly at home/at star parties where 240v power is available..

I also have a 12v 110aH battery thats being built into a power unit.. A big box, it will have a 12v->240v inverter in it, with 2 external wall socket plugs to power the Laptop/QHY8, and a few 12v auto sockets for the mount/dew heaters etc...

I reckon 12v 110aH should EASILY see me through 2 nights with no power. If not, Im making sure there is room inside the box for a further 12v 60~70ah battery.. then the 110aH will be dedicated to 240v power supply ad the 60aH will power the 12v accessories...

Before getting the 240v supply, I ran my mount and heaters of a 12v 17aH battery that easily gave me 6~8 hrs of imaging time (depending on the heaters power level)

I do look forward to the day that my setup is power self sufficient, and can set up in the most remote of areas without worrying about a 3km long 240v extension lead :D

[ozstockman]

Hi Jason,

I was PMed the same question on how to power EQ6 Pro mount. I guess there should be no difference in term of power between EQ6 Pro and HEQ5 Pro so I hope my reply might help

[pjphilli]

Hi NCRAW

If you look at the socket on your HEQ5Pro mount ( I guess the HEQ6 will be similar) you will see a small diagram next to it which shows that the centre connection of the male socket indicated by a line ending in a dot is the positive and the outer surround of the socket indicated by a line ending in a semicircle is negative. I guess that the the term tip comes from an older type of coms switchboard plug where by the centre conductor of the plug was called the "tip" and the outer the "ring". Tip is a confusing term as sometimes it is applied to the whole multiple plugs that you have got with your power supply. In the case of the cigarette lighter end the tip is the centre conductor which is always positive on cars these days.
All this can be confusing and I would strongly recommend that if you are going to be playing around with power supplies, leads, batteries etc you should invest in a cheap electronic multimeter. I notice that JayCars have one for $7.95. This is indeed cheap for a device that can measure volts, amps, resistance (for continuity tests etc). With one of these you can then make your best guess regarding what is positive, wire it up and BEFORE you plug it into the mount put your multimeter on the 20volt scale, put the red positive lead into the centre hole in the female plug and touch the outer plug casing with the negative (black) multimeter lead (make sure you have plugged the leads into the multimeter properly in the first instance!). You should see the meter indicate about +12 volts, if you have got the lead connections to your power supply wrong the meter will show - (negative) 12 volts. If so you will need to reverse the supply leads in some way.

The suggestion of having a blocking diode in your lead means that in future
if you mix up the polarity to the lead (eg putting the crocodile clips on a battery the wrong way) then the diode will block the wrong current being
sent to your mount. A diode allows current to flow through it in one direction but not the other. A suitable blocking diode would be a type
1N5-404 (Page 103 JayCar catalogue - no I don't work for them, just have
their excellent catalogue!). This diode will cost you 25 cents. Current will flow through the diode when the banded end (cathode) of it is negative and the other end (anode) is positive. Current will not travel if the above polarities are reversed. However, a blocking diode does come with a small disadvantage as up to about 0.5 volts can be lost across it when conducting (ie instead of getting 12 volts to your mount you would get say about 11.5 volts but this should still be ok as the mount is rated for operating down to 11volts).
I hope this all helps and has not confused you further!
Cheers Peter

[bmitchell82]

Well i ended up at jaycar, dickies wanted 60 bucks for a small 2.5/3 A @12v DC and i thought that was a bit on the expensive side. So after viewing what jaycar had in stock, (the original 12v 5amp was there) for 29.95, but there was a regulated 12vdc @ 8amp switch mode psu for 10 rods more. 39.95.

Saturday night I got it all sorted out and running, using the hand controller to see what output was being fed to the mount it was a constant 13.7V mind you to set up where i was i was a good 10m away from the power outlet. when i tested it inside it held steady at 13.8V.

With 8amps it has bult room to load it up. All i will be doing is getting a little grey box from MM electricals or jaycar see who has what, lining it with a few ciggi lighters, a fuse box and what not so i can just plug in what i want when i want. HAZZAR.!

The next thing that ill end up getting is a decent battery to run it in the sticks.!

[NCRAW]

Thanks for all the great info PJ. I'm surprised the mount doesnt have built in polarity protection. Would have made life much easier. The power supply already got the + symbol and the tip word on it so it should be no probs but i do have a multi meter at home (I believe) so i'll also test it.

Many thanks

[AlexN]

Brendan.. If you're interested, PM me and I can show you what I've done for a solution for dew prevention and providing some external cigarette socket plugs...

I use mine to house my laptop power pack, the 13.8v 11A supply I use, the power box for the QHY8 CCD.. Due to all the power boxes in my big box 'o' power, I've installed some fans and some holes to promote airflow in the hottest areas of it etc.. Its quite fantastic really.. And really cheap too..

[pjphilli]

Hi Ncraw
I don't know what protection/regulation is contained inside the HEQ5Pro but it is best to assume they have none. The days when manufacturers include a circuit diagram with electronic equipment are long gone. Pity, as it would solve a lot of speculation. Incidentally, I do see that the HEQ5Pro contains good access to the primary motor gearing when the side plate is removed. I noticed that my DEC backlash seemed a bit excessive so yesterday it was a simple job of loosening the motor and primary gear screws so I could take up excessive slack. Now my PHD guiding should work even better!
Cheers Peter