Power cable check

[aGreyarea]

Hi all,

Ridiculous question but I have to check before I fry another control box. Is the attached pic what I should be plugging into my mount? Or do I have the polarity wrong?

Many thanks in advance!

[Uplooker]

Hi aGreyarea,

First off what is on the end of the plug? What are you putting the plug into? Have you rewired the devise / plug? If you did rewire, did you make sure that the tip of the plug is positive(+)?

Hard to give an answer without further information.

Ian

[knobby]

It does look to be correct but i'd want to check it after frying one mount already. Go to maplin and buy a cheap multi meter (or borrow from someone)

Check the centre is positive.

Don't fry another mount

Also what is the volt / amp rating of the power pack you are using?

[gkec]

The photo shows that the tip is +ve, but as knobby says an inexpensive multimeter is an invaluable tool in these circumstances to ensure the voltage is the correct polarity AND the correct voltage..

[Steve Ward]

That's the correct way if your mount is 'tip positive' , most are but check the manual .

I found that the plugs with interchangeable tips can be a bit 'dangerous' in that it's all too easy to put it in the wrong way round by accident , they do have a knack of pulling out .

When you've established that it's correct give it a good wrapping with insulating tape to prevent it coming out unexpectedly.

[aGreyarea]

Guys,

Many thanks for your replies. I thought it was on the right way around... And that's what worries me. I havent changed it since before the mount stopped working. I heard a faint click/crackle when I connected the 12v mains adapter and assumed I had fried it.

The mount in question is an eq5 with a Synscan upgrade and normally, the control box should be stuck to one of the steel legs, to earth it I assume. What happens if it's not properly earthed? Mine sits on an ali pedestal.

[daz]

The EQ5 will be centre positive, so you just need to check that your supply and connector are delivering that.

If by control box you mean handset, then no, it is not there to earth the mount, its there for convenience. The mount does not require earthing.

[aGreyarea]

Hi Daz

Thanks for your message. The instructions explicitly state that the motor control box (that the hand controller, power cable and ra motor is connected to) should be placed in its holder and attached to a leg of the tripod. The holder has a contact point that connects the control box with the SS leg of the tripod. Since I want to leave the mount on a pillar permanently, I don't have a tripod leg to connect the motor control box to. When I set up the control box just hangs by the ra connection cable. What effect do you think this might have?

[hazegood]

Its a 12v DC adaptor, if you are running it from a mains supply, it will be double insulated so no electrical earth present at all,

if you running from a power tank the again no electrical earth is present.

Is it may be as is common confusion with DC power supply you are confusing the - (negative side of the supply with earth?

[hazegood]

also think about this, the tripod has plastic (or maybe rubber feet) there is no path to electrical earth through that, so its possible you are misunderstanding the manual, or something has been lsot in the translation of the manual,

either way, I don't think you need to worry about earthing through the mount

[knobby]

Maybe they are referring to earthing for static?

All sounds pretty unearthy to me though!

[aGreyarea]

Thanks again for your replies. I just looked at the instructions again and would you believe the point above is highlighted with a BOMB!! It seems this is about preventing electromagnetic interference, but still, what does that mean? Especially when highlighted with a bomb? I cant attach it but here's a link.

http://www.skywatcher.com/swtsupport/Instruction_Manuals/EQ5%20SynScan%20upgrade%20kit.pdf

Since I connect a laptop to the control box ( to use eqmod) and not the hand box, could this potentially cause 'electromagnetic interference' that results in the mount not working?

[Psychobilly]

It may be more for heatsinking the regulator inside the box rather than an electrical connection... I know I don't mount mine to the tripod (as its on a pier) and I just stick it to it with Velcro so there's no connection between the metal pad and the pier/tripod...

Peter...

[kerrylewis]

Knobby

did you repair the mount that you fried? I have a HEQ5 that I connected up wrong that's waiting for me to open up and try to repair

Kerry

[knobby]

Knobby

did you repair the mount that you fried? I have a HEQ5 that I connected up wrong that's waiting for me to open up and try to repair

Kerry

Haven't actually fried one Kerry... I have replied in your other thread, I sometimes repair (or try to) boards at work.

[kerrylewis]

Ah - I misunderstood the wording of your post. Thanks for your two replies - I'll have a look inside one day when I'm in the mood

[knobby]

Fingers crossed!