EQ6 r Pro fried ..

[Cameranova]

4 minutes ago, Cameranova said:

Can you send a pic of this 12v /5a buck converter please .. 

I’m guessing this would work ? 

[DaveL59]

sure, here you go

I've a LiPo car starter pack and using the Cigar-plug output it was showing too much volts so I put this together. On my EQ5 SynScan the connector is a regular 2.1mm plug just as my CCTV modules use. Bought the plugs with tails and the buck converter off amazon and soldered some eyelets on at the converter end, heat-shrink sleeving to keep things isolated. It works well, gets only slightly warm but the draw is only 2A max when slewing on this mount and much less when just tracking.

 

[DaveL59]

11 minutes ago, Cameranova said:

I’m guessing this would work ? 

yeah that'd work if 4A is enough to drive everything, you'd just need the relevant connectors to wire it in between the power source and the mount.

[DaveL59]

25 minutes ago, Cameranova said:

Yes there was nothing loose at all when I opened her up , all looked hunky dory apart from the cooked bit .. 

I meant outside the mount, as in trailing 2.1mm plugs that aren't in use but might contact the metal casing and cause an alternate discharge path  

Edited April 20, 2020 by DaveL59

[Cameranova]

10 hours ago, DaveL59 said:

I meant outside the mount, as in trailing 2.1mm plugs that aren't in use but might contact the metal casing and cause an alternate discharge path  

Ah yes ok brill and thanks for your help 👍🏻 Much appreciated.. 

[Cameranova]

10 hours ago, DaveL59 said:

sure, here you go

I've a LiPo car starter pack and using the Cigar-plug output it was showing too much volts so I put this together. On my EQ5 SynScan the connector is a regular 2.1mm plug just as my CCTV modules use. Bought the plugs with tails and the buck converter off amazon and soldered some eyelets on at the converter end, heat-shrink sleeving to keep things isolated. It works well, gets only slightly warm but the draw is only 2A max when slewing on this mount and much less when just tracking.

 

Ok brill , I will definitely put one of these in the mount power train , fear of loosing a clear night and a motherboard for a little money well spent has got to be worth it .. thanks for the info 👍🏻🙏

[Waldemar]

Don't forget that these things fry your mount as well if/when not connected correctly...

[Waldemar]

Here is a way to protect your mount against wrong polarity mishaps at very low costs
You do not need to be a tech wizard to make a simple protection like this: 
https://provideyourown.com/2012/reverse-polarity-protection-circuits/

 

[DaveL59]

50 minutes ago, Waldemar said:

Here is a way to protect your mount against wrong polarity mishaps at very low costs
You do not need to be a tech wizard to make a simple protection like this: 
https://provideyourown.com/2012/reverse-polarity-protection-circuits/

 

does make it important to ensure there's no alternate path via the case tho, else the protection can end up bypassed. I recall but can't find the post where it was found that one of the pads the screw goes into was actually at Vcc (+12v) hence suggesting that this is checked and insulated if necessary etc. A simple nylon hat washer/bushing type as used for heatsinks might do this if you can source a suitable size
https://uk.rs-online.com/web/p/heatsink-mounting-accessories/7128225/

Some moisture protection at the mounting points might also be advisable given these things sit out in cold conditions where condensation can add to the fun.

[SimM]

I noticed that the pin out of the 12V connector has the cut-out on LHS on the panel drawing and on the RHS in the schematic. So the 12V is up for one and down for the other.

I was making up a 5.5 x 2.1 connector cable to GX-12 to use an existing PSU - done successfully. But I'm sure many will have been tripped up by this apparent reversal. I used a GX-12 socket to expose the 12v and ground and a multimeter to confirm that both panel and schematic (in their own way) are as expected e.g. using the supplied car adapter I may be buying a conversion cable from FLO - I would still check the pinout before use - mistakes have been known to happen.

One issue with electronics is grounding loops - two independent PSU will float and not cause problems with each other. This can be a problem when sharing PSU across several devices if they touch. It's also one of the reasons cars shouldn't touch when giving a jump start. Both PSU pins and the socket are not connected e.g. the chassis is not grounded on the (my) EQ6-r Pro.

Simon

[Luis Calle Rosasco]

On 20/04/2020 at 08:25, Cameranova said:

Thanks folks , it’s not the Polarity as suggested above it’s always been connected the same , you can’t change the polarity,  it’s quite possibly a power surge as suggested above but can’t understand why it wouldn’t blow the 5a fuse in the lighter socket .. 

 

 

Hello,
I am really sorry to be able to read this experience just to know. As you will see from myattached files, I had a very similar awful experience.

The motherboard of my EQ6R-Pro (with USB port) was burned too. However, luckily everything else works except for the RJ45 port and the Handcontroller, unfortunately.

I contacted Skywatcher USA and although they didn't openly admit it, the answer lies in the poor EQ6R-Pro mainboard build quality . Nominally, SW technicians say, that board works at 10.6 volts, however it has a sort of "tolerance" to work at 12v 5amps. To achieve the reduced operational voltage, it becomes obvious that mainboard includes a few resistors and a transistor that reduces the voltage to those 10.6v, which were precisely burned by a voltage spike. By not having a voltage regulator and ground connections in those 2000USD mounts, these mainboards are really bad and susceptible to damage. That's how it happened to me.

The only alternative was buying a spare motherboard from Skywatcher USA (also in First Light Optics, Ebay and Teleskope.de)  and taking it, along with the damaged motherboard, to an electronics service for repairs. It shouldn't be too hard, considering the specifical damaged components (3 resistors and 1 transistor). After repairs, you'll have a new board and a spare part, just in case.

Regards,

Luis 

(Lima, Peru)

 

[DaveL59]

makes you wonder if its possible to throw a buck converter in behind the power socket to at least flatten a spike?

I power my EQ5 SynScan via a buck converter when its on either mains 12v5A switch-mode PSU or the car starter LiPo pack. Might not prevent loss but I figure any level of extra safety is worth it.

[wulfrun]

On 21/04/2020 at 09:02, Waldemar said:

Here is a way to protect your mount against wrong polarity mishaps at very low costs
You do not need to be a tech wizard to make a simple protection like this: 
https://provideyourown.com/2012/reverse-polarity-protection-circuits/

 

A bit late but since this thread has been resurrected...

There's an often overlooked and fundamental flaw in one of the circuits shown - the one that shows a PNP transistor. It's unsuitable where the supply exceeds the transistor's base-emitter breakdown voltage (which is often no more than 5V or so). A reverse supply may cause the junction to fail, resulting in transistor failure as short-circuit and circumventing the protection entirely. I feel it's necessary to point this out to anyone contemplating this circuit, it's very unwise for a 12V supply.

Edited August 3, 2022 by wulfrun

[MartinsB]

Hello! I have the same burnt part, but i think I know how it happened.

The burnt part is choke throu which is fed +12v to hand controller. I did it by accidentally in the dark sticking a usb plug in hand controllers socket and shortened +12 to ground.

The inductance/choke L5 worked as a fuse and burned. Maybe someone can measure that component and tell its nominal, please?!

[MartinsB]

Problem solved! I replaced that induction with a random one  the same size from old PC motherboard and everything works!!! Maybe it was like a fuse for idiots like me sticking wrong plugs in wrong holes:)