What size DC plug for a Sky-watcher 127 GOTO

[jerry12x]

I went and lost it.

I then bought the wrong one on ebay and just want the plug I can solder on.

 

[Cosmic Geoff]

The size is noted in my GoTo Faq

[jerry12x]

Thank you very much for that. It is the size I bought.

It  must have been changed somewhere along the way as the center pin is slightly larger than 2.1mm.

That is a really good faq by the way.

[Geoff Lister]

This is what I use with my Skywatcher and Celestron Az-Alt mounts (tripod & Dobsonian):-

http://www.maplin.co.uk/p/maplin-21-x-55-long-dc-power-plug-hh61r

The longer barrel (14mm instead of the shorter 9.5mm) ensures good contact with all depths of 2.1mm sockets. A 2.5mm ID plug will fit in the 2.1mm socket on the mount, but makes poorer contact with the socket's centre pin.

Note, a 2.1mm plug will not fit in a socket with a 2.5mm centre pin.

I always check with a voltmeter, to ensure that the +12V is in the centre, before plugging a newly-soldered lead.

Afterthought:-

Has a previous owner substituted a 2.5mm ID socket for the 2.1mm original? If so, go for

http://www.maplin.co.uk/p/maplin-25-x-55mm-long-dc-power-plug-hh63t

Geoff

[johnha]

On 30/05/2017 at 11:47, Geoff Lister said:

I always check with a voltmeter, to ensure that the +12V is in the centre, before plugging a newly-soldered lead.

Good point - I'd also check there are no shorts across the soldered connections - I once had a PSU fuse pop due to a very thin 'solder bridge' across the connections. I had checked for no continuity with my multi-meter but it must have been higher resistance than the <200 Ohm continuity check on the meter. Since then I always also check using a higher resistance range.