AVX mains power connection

[Adaaam75]

Members,

I'd prefer to use the connector for my mount that came with the car socket as it screws onto the mount and can't be pulled out accidentally but the connector that came with the mains plug for permanent power in my observatory has a connection that can just be pulled out (see photo). Can I swap these out using a suitable connection box or is this not as simple as that?

Please help!

 

[Cosmic Geoff]

I have not come across the screw retained connector before.  Shaky connectors are a general problem on GoTo mounts, and a proven solution is to run the cable through an anchor of some sort adjacent to the connector, so that the connector cannot twist around or pull out. I use a self-adhesive cable grip that has aluminum lugs that bend around the cable.

[Adaaam75]

2 minutes ago, Cosmic Geoff said:

I have not come across the screw retained connector before.  Shaky connectors are a general problem on GoTo mounts, and a proven solution is to run the cable through an anchor of some sort adjacent to the connector, so that the connector cannot twist around or pull out. I use a self-adhesive cable grip that has aluminum lugs that bend around the cable.

Any chance of a picture so I have an idea of what you are describing Geoff? I'm concerned my power may be cut off halfway through a session!

 

[RayD]

10 hours ago, Adaaam75 said:

 

Members,

I'd prefer to use the connector for my mount that came with the car socket as it screws onto the mount and can't be pulled out accidentally but the connector that came with the mains plug for permanent power in my observatory has a connection that can just be pulled out (see photo). Can I swap these out using a suitable connection box or is this not as simple as that?

Please help!

 

Yes you can swap them providing you make sure you retain the tip positive polarity.  The screw plugs are quite good and you can buy them separately if you don't want to chop up your original lead, or indeed FLO do some very nice silicone ones with variations on terminations.  I have the AVX one and it is very good.

[Cosmic Geoff]

32 minutes ago, Adaaam75 said:

Any chance of a picture so I have an idea of what you are describing Geoff? I'm concerned my power may be cut off halfway through a session!

I couldn't get a really clear picture, but in the upper one the bright square is a stick-on cable anchor that prevents the cable (with inline filter) dropping straight down. The other shows the cable plug entry and how the cable runs up through the anchor (unseen). This is a 6/8SE mount, and I did the same on my Nexstar SLT mount.  As the mount moves the anchor takes the strain of dragging the cable around.

[Adaaam75]

Thanks Geoff, that helps a lot!

[Adaaam75]

48 minutes ago, RayD said:

Yes you can swap them providing you make sure you retain the tip positive polarity.  The screw plugs are quite good and you can buy them separately if you don't want to chop up your original lead, or indeed FLO do some very nice silicone ones with variations on terminations.  I have the AVX one and it is very good.

How do I know which is positive and negative?

[RayD]

4 minutes ago, Adaaam75 said:

How do I know which is positive and negative?

You can use a meter to test each lead and then make a note of the cable going to the tip (the middle part of the plug).  Most wiring has a distinguishing mark, the most common being a colour (Blue, Brown etc.) or some may have a line or other marking on it.

Either way you really do need to make sure the polarity is right, and that the centre bit of the tip is +12V before you plug it in.

[Adaaam75]

Both cables are only 2 core cables but on the removable socket on the mains wire one connection is slightly bigger than the other indicating there is a difference in the cables. This is all above my head but I do understand there is a difference and a need to ensure it's done properly.

[Cosmic Geoff]

Buy a multi-test meter - they cost only a few pounds and are useful for all sorts of jobs, besides checking that your mains power pack delivers power the same way round as the car cigarette lighter lead. Much cheaper than a new board for your mount.

[Adaaam75]

Noob alert! So plug them both in and check to see if the readout is the same for one of the lead outputs and compare that to the other lead and if it's the same that's the way round the wires go?

[Grierson]

3 hours ago, Cosmic Geoff said:

Buy a multi-test meter - they cost only a few pounds and are useful for all sorts of jobs, besides checking that your mains power pack delivers power the same way round as the car cigarette lighter lead. Much cheaper than a new board for your mount.

Totally agree. Using a meter will take the guess work out of all manner of jobs.

I think you will need to explain your last post a little (for me anyway). What do you mean by the readout? Also, do you have some sort of power supply into which you fit the cigar lighter plug? Assuming the two items have come from reputable sources than my view would be that they will be interchangeable in terms of connections/voltage output polarity.

Probably unhelpful but you could make up a simple lead with a standard plug on one end and a captured plug on the other. Tape the non captured plug permanently into the socket on your mains adapter lead perhaps using some self amalgamating tape. However some soldering would be required and polarity checked.      

 

[The-MathMog]

Just a note. The mains power supply you posted, says that it delivers 1.5 amps. From the manual, the AVX mount states that it requires 3.5 amps. This could lead to tracking or alignment issues. I've heard about quite a bit of guys, who had issues with their mounts, which turned out to be insufficient power. Also to ensure that the power don't drop below that during cold weather, 5 amp adapters is often recommended.

[Adaaam75]

6 hours ago, Grierson said:

Totally agree. Using a meter will take the guess work out of all manner of jobs.

I think you will need to explain your last post a little (for me anyway). What do you mean by the readout? Also, do you have some sort of power supply into which you fit the cigar lighter plug? Assuming the two items have come from reputable sources than my view would be that they will be interchangeable in terms of connections/voltage output polarity.

Probably unhelpful but you could make up a simple lead with a standard plug on one end and a captured plug on the other. Tape the non captured plug permanently into the socket on your mains adapter lead perhaps using some self amalgamating tape. However some soldering would be required and polarity checked.      

 

I mean plug the cigarette lighter socket lead for the mount into a car socket and then test both connections for a reading on a voltmeter, then plug the mains socket lead for the mount into a mains socket and again using a voltmeter check the reading on both connectors and from these tests I'll be able to cut the decent screw end connector of the cigarette lead and fit it on the mains lead replacing the poor connector?

Does this make sense and sound correct?

[RayD]

You really need to do this in 2 stages.  You need to cut the plug off the power supply and strip the ends of the wires.  Please make sure you do this when it is unplugged.  You then need to use a meter on a DC Volts setting, with a probe on each wire end, making sure they do not touch, turn it on and look at the readout.  If it shows 12VDC (or similar) then the probes are the right way round, and the red probe is on the positive wire.  Put a piece of red tape or something on that wire to identify it.  If the reading is -12VDC, then the black probe is positive, so mark that wire with red tape.

Now you need to test the other lead with the meter on Buzzer or bleep setting.  You can put it on Ohms if it doesn't have a buzzer, but most do, and it's usually the same setting as diode test.

Cut the cigarette lighter end off and strip the ends of the wires.  With your meter on bleep, put one probe in the very end of the screw connector (down the middle of it, in the hole effectively).  With that probe in place, touch the other probe on the stripped ends of the cables sequentially until the metre bleeps, or shows something near to 0 Ohms (short circuit).  This wire is now your positive wire from your screw plug, so put a piece of red tape in that.

You now should have 4 cable ends, 2 from each item.  You now need to join together the 2 with the red tape, and then the 2 without, making sure they cannot touch once connected.  The best way to do this is solder and water resistant heat shrink, but any suitable and water tight connector should do.

Once you have done all this, make sure you put your meter back on VDC (probably the 20V range) and when switched on, your red probe down the hole of the screw plug, and your black probe on the bit around the outside should show you a 12VDC reading.  If it shows -12VDC then you've connected the wires back to front.

Hope this helps.

Note.  Please see earlier comment regarding supply size as you will need to make sure It can supply your mount.  The cigarette lighter plugs for the AVX are normally fused at 10A or so, so if your proposed supply is only 1.5A, it is very likely that it won't be big enough.

[Grierson]

13 hours ago, Adaaam75 said:

I mean plug the cigarette lighter socket lead for the mount into a car socket and then test both connections for a reading on a voltmeter, then plug the mains socket lead for the mount into a mains socket and again using a voltmeter check the reading on both connectors and from these tests I'll be able to cut the decent screw end connector of the cigarette lead and fit it on the mains lead replacing the poor connector?

Does this make sense and sound correct?

OK I gather that you do indeed have a meter. Rather than remove the captured (screw end) plug from the cigar lighter lead (it looks as if it is moulded on to the lead so presumably you are suggesting cutting the lead) and thus destroying its' use for any future need why not just get a new captured plug and fit that to the mains adapter (if you have and can use a soldering iron that is)? Or indeed follow the comprehensive instructions above.

[SteveA]

http://uk.rs-online.com/web/p/dc-power-plugs/0487820/

[Cosmic Geoff]

Adaam75 - If you are not used to working with electrics and joining wires, I suggest that (having acquired a test meter) you use it to check that the cigarette lighter lead and the mains PSU deliver the power in the same polarity (centre positive) and then devise an anchor to prevent the power lead pulling out or swiveling around.  If this topic is foreign to you, it would be wise not to try cutting wires and attaching connectors. I worked in the electronics industry for over 20 years, so this is all elementary to me, but it will not be for those whose contact with electronics ends with the On switch.

If you buy a mains PSU of adequate rating (at least 3.5 amps at 12v) sold for the purpose of powering a telescope mount, it should come with a moulded lead that delivers the power with the correct polarity, so all you have to do is devise a cable anchor to stop the plug pulling out or working around. Keep it simple!

I also wonder if there is a mount maker supplied mains PSU for the AVX that has the locking connector you desire, since they supply a car lead with locking connector. Or you could get a 12v power tank with cigarette lighter socket outlet (these devices are discussed at length elsewhere in the forum) and plug the car lead with the locking connector into it. 

In an idle moment I looked around on Cloudynights and found that some AVX owners do use power tanks and there is a Celestron 5 amp 12v mains PSU with locking connector.

 

[iapa]

On 13/05/2017 at 11:39, Adaaam75 said:

Members,

I'd prefer to use the connector for my mount that came with the car socket as it screws onto the mount and can't be pulled out accidentally but the connector that came with the mains plug for permanent power in my observatory has a connection that can just be pulled out (see photo). Can I swap these out using a suitable connection box or is this not as simple as that?

Please help!

 

I use 240v - 12V adapters from Maplin that have the 'cigarette lighter' socket on them.

http://www.maplin.co.uk/p/12v-5000ma-car-accessory-socket-ac-dc-power-supply-l25ay