Mains power supply for AZ EQ6 GT mount

[Baffa]

Yeah, it's a reason why skywatcher don't offer power adapters, only cigarette adapters. 

Hehe, washing machines don't run on switched AC adapters though! If they are tingling - nuke it from orbit, only way to be sure no one is harmed 

All and all, it depends where you have your scope, if your main obs site is on a damp lawn, yes, use a battery or a proper earthed power supply. If you are in a semi dry, like an observatory a switched, maplin type, power supply should work without any problem. The tingling shouldn't be harmful to your health, but, better safe than sorry I suppose.

[IanH]

I think I'm OK with the Maplin/Flo unit. The tripod to ground measures as average 0.6v - which is like holding an AA battery. We're allowed to do that, so I guess it is safe. The 12v battery had a strange tripod reading, a small voltage alternating + to -. Presumably, that is safe.

I went over to a power supply because with the battery I regularly got the flashing light and motors complaining - for low power, and there is supposed to be the potential for damage if the power fails. Maybe with no dew heaters and perfect balance the battery would be OK. Also, this is a well loaded C11 sct, lighter scopes may mean the motor draws less power and the battery is sufficient.

it's hard to know what's best.

[jam1e1]

Did a quick indoors test using a multimeter between my maplin 12v power supply -ve terminal and earth unconnected to mount, also then when supply connected to AZ EQ6 and measured between mount to earth.

In either case did not measure or detect anything noticeable or of concern, although was a brief test (was indoors and earth being a nearby copper water pipe).

In summary no issue detected so far.

Note as this was an indoor test, did not fully recreate conditions i normally set up with (I use a different house plug socket with RCD and a 10m extension cable, also path to earth is longer - i.e. earth would be the grass in garden). There could be a number of factors due my setup causing an unusual effect i.e. long cable induce currents, voltage drop, length of cables creating an earth loop etc 

Will look to retest using actual 'field' conditions when get a chance.

[nucleardwarf]

Did a quick indoors test using a multimeter between my maplin 12v power supply -ve terminal and earth unconnected to mount, also then when supply connected to AZ EQ6 and measured between mount to earth.

In either case did not measure or detect anything noticeable or of concern, although was a brief test (was indoors and earth being a nearby copper water pipe).

In summary no issue detected so far.

Note as this was an indoor test, did not fully recreate conditions i normally set up with (I use a different house plug socket with RCD and a 10m extension cable, also path to earth is longer - i.e. earth would be the grass in garden). There could be a number of factors due my setup causing an unusual effect i.e. long cable induce currents, voltage drop, length of cables creating an earth loop etc 

Will look to retest using actual 'field' conditions when get a chance.

This is very good news, thank you for the report.

[Alien 13]

I find this all a bit disconcerting.

 

Imagine buying a washing machine or some other appliance and find that it "tingles" when touched, I don't think anyone should have to consider attempting home made grounding methods to resolve the issue, how many users are knowledgeable enough to firstly recognize the fault and then have the necessary ability to repair it?

 

As I am considering buying the Maplins power supply from FLO, am I going to experience this problem or is it wiser to stick with a battery supply which the thread on CN implies is the safest bet?

 

The tingling problem happens with almost all Switch mode PSU adapters (and pretty much all consumer electronics these days)it is normally between 70 and 90 volts and is caused by the complete lack of an earth so everything floats why manufacturers consider it safe to make them without a means of earthing is beyond me.

I have had so many shocks off TVs, blue ray players etc when connecting up that i now modify at least one item in the system with an earth.

Alan

[IanH]

I think my conclusion is that with a medium powers - eg up to 13.8v the issue is too small to worry about. The 15.25v power supply was a bit disconcerting though. Skywatcher themselves suggest a if using a laptop supply it should be switched mode 15v - rather them than me.

[nucleardwarf]

Well - I finally bit the bullet.  Ordered and received the Maplins power supply and lead, along with the 12v four socket adapter from FLO (who were very helpful in their recommendations)  and all is well.

The only "tingle" I got was the pleasure in it all working perfectly, thanks to all for the replies.  One happy astronomer!

[IanH]

With 12v I'm sure you'll be fine. An RCD (or 2) at the mains end is key, for safety. It's certainly nice not to have to worry about the battery running out.

The whole setup seemed happier with the mains power - now we just need how to work out powering the clouds away!

[jam1e1]

Well - I finally bit the bullet.  Ordered and received the Maplins power supply and lead, along with the 12v four socket adapter from FLO (who were very helpful in their recommendations)  and all is well.

The only "tingle" I got was the pleasure in it all working perfectly, thanks to all for the replies.  One happy astronomer!

worth checking the output current on the 4x way - one i was going to buy from maplin was rated at 1A max on each output

[nucleardwarf]

worth checking the output current on the 4x way - one i was going to buy from maplin was rated at 1A max on each output

As I still believe that lektrik is caused by crickets rubbing their legs together, can you explain what impact this has?

[jambouk]

Your mount may need to draw 4amps when doing the most energy consuming manoeuvres; if the max output of the socket is 1amp, the mount won't "get enough energy" and won't work, however hard the crickets in the national grid (or inside your battery) rub their legs together, as the maplin splitter would be a bottle neck. My maplin splitter is 4-5amp max per socket so not a problem for me.

[nucleardwarf]

Cricket now understands Master.

[brancusi]

My setup uses a trusty Maplin XM19V regulated PSU 13.8V at 7A continuous, 12A surge which I then feed through one of these to keep an eye on current drain and helps if I transfer to a battery powered setup. I then use a 15A twin cigar adapter to feed the AZ-EQ6 on one socket and reserve the other for the Kendrick Dew system and the secondary cooler of the SBIG ST-8E etc - lots of etc. I have a fuse of last resort feeding the cigar adapter fitted with a 10A blade fuse and run the PSU from an IP55 protected socket on the outside wall of the house with an RCD on the inside.

Love the Maplin PSU, it's built like a tank