12V Power supply otions....

In my quest to have the LX200 and DSI set up outside but controlled from
inside, I am looking for a decent 240V AC to 12V DC power supply. I would
ideally like one with two or three 12V cigarette lighter style outlets so I
can power the scope itself, the DewBuster and possible any 12V ancilliary
bits and pieces I might aquire over time.

So far, all I can find are the small units that plug into the mains and just
give a single socket that give 800mA, or a bigger much more expensive single
socket unit from Telescop House that doesn't seem to have a maximum current
specified.

I presume that 800mA will be OK for the scope itself, but the DewBuster spec
says it needs a 3A rated supply.

Does anyone know of a supplier that makes the kind of thing I am looking for
off the shelf ? I guess alteratively, a fairly beefy 12V power supply
without the lighter sockets would work and I could make up a breakout panel
with the actual sockets on that.....

I ideally want to make up a single "umbilical" type ccable that will run
from the house to the scope itself - it would consist of power (240V AC),
USB2.0 and the LX200 communications cable itself. This would probably be
buried in a conduit in my garden and run to a breakout box where the 240V
would be converted to the DC outputs.

adm wrote:

In my quest to have the LX200 and DSI set up outside but controlled from
inside, I am looking for a decent 240V AC to 12V DC power supply. I would
ideally like one with two or three 12V cigarette lighter style outlets so I
can power the scope itself, the DewBuster and possible any 12V ancilliary
bits and pieces I might aquire over time.

I use a nominally 13.8v ham radio PSU (the sort that Maplins and others
stock with two banana plug terminals on). Easily meaty enough at 4A for
my dewheater and fullrate slew to object.

So far, all I can find are the small units that plug into the mains and just
give a single socket that give 800mA, or a bigger much more expensive single
socket unit from Telescop House that doesn't seem to have a maximum current
specified.

I presume that 800mA will be OK for the scope itself, but the DewBuster spec
says it needs a 3A rated supply.

800mA will be marginal for the LX200 and may well blow its fuse on fast
slew if the thing momentarily stalls (and on 12v this is not uncommon).
Meade upped the voltage spec to nominal 18v to avoid motor stall issues.
But it is noisy on 18v so I find 14v PSU (or a charged lead acid battery
about right). Halfords do a self contained charger and battery too.

Check MAPUG threads for additional details.

Does anyone know of a supplier that makes the kind of thing I am looking for
off the shelf ? I guess alteratively, a fairly beefy 12V power supply
without the lighter sockets would work and I could make up a breakout panel
with the actual sockets on that.....

I ideally want to make up a single "umbilical" type ccable that will run
from the house to the scope itself - it would consist of power (240V AC),
USB2.0 and the LX200 communications cable itself. This would probably be
buried in a conduit in my garden and run to a breakout box where the 240V
would be converted to the DC outputs.

BTW I would not run signal cables parallel to 240v mains wiring.
And USB 2.0 will not like running very far and working either.

Regards,
Martin Brown

"Martin Brown" wrote in message
...
adm wrote:

In my quest to have the LX200 and DSI set up outside but controlled from
inside, I am looking for a decent 240V AC to 12V DC power supply. I would
ideally like one with two or three 12V cigarette lighter style outlets so
I can power the scope itself, the DewBuster and possible any 12V
ancilliary bits and pieces I might aquire over time.

I use a nominally 13.8v ham radio PSU (the sort that Maplins and others
stock with two banana plug terminals on). Easily meaty enough at 4A for my
dewheater and fullrate slew to object.

Yeah - I saw one of those for £34 or something....but......isn't 13.8V too
high for the LX200GPS ? I though I read soemwhere (MAPUG ?) that it needs to
be 12V, not 13.8 and that it was the non GPS LX200s that used 13.8V

So far, all I can find are the small units that plug into the mains and
just give a single socket that give 800mA, or a bigger much more
expensive single socket unit from Telescop House that doesn't seem to
have a maximum current specified.

I presume that 800mA will be OK for the scope itself, but the DewBuster
spec says it needs a 3A rated supply.

800mA will be marginal for the LX200 and may well blow its fuse on fast
slew if the thing momentarily stalls (and on 12v this is not uncommon).
Meade upped the voltage spec to nominal 18v to avoid motor stall issues.
But it is noisy on 18v so I find 14v PSU (or a charged lead acid battery
about right). Halfords do a self contained charger and battery too.

I have one of those already ! I want to get away from lugging it outside all
the time, and especially being frustrated when I realise the damn thing
isn't charged up and needs to be charged for hours before I can power my
scope !!!!

Check MAPUG threads for additional details.

Does anyone know of a supplier that makes the kind of thing I am looking
for off the shelf ? I guess alteratively, a fairly beefy 12V power supply
without the lighter sockets would work and I could make up a breakout
panel with the actual sockets on that.....

I ideally want to make up a single "umbilical" type ccable that will run
from the house to the scope itself - it would consist of power (240V AC),
USB2.0 and the LX200 communications cable itself. This would probably be
buried in a conduit in my garden and run to a breakout box where the 240V
would be converted to the DC outputs.

BTW I would not run signal cables parallel to 240v mains wiring.

It's non-optimal, I know ! I could run the data cables in a separate conduit
though - the distance is only around 10M or so.

And USB 2.0 will not like running very far and working either.

I know - but then again it isn't very far.... I wish I could find a single
15m USB2.0 active extension cable rather than having to daisy chain several
together.

Top posted, but.....

In reply to my own post, I just took another look at the Maplin website, and
found a 12V, 5A supply with ciggy lighter socket for £19.99 inc VAT. That
plus a 4 way ciggy socket adaptor should do the trick nicely !!

In case anyone wants something similar, the link is:

http://www.maplin.co.uk/Module.aspx?...42702&doy=10m8


"adm" wrote in message
...

"Martin Brown" wrote in message
...
adm wrote:

In my quest to have the LX200 and DSI set up outside but controlled from
inside, I am looking for a decent 240V AC to 12V DC power supply. I
would ideally like one with two or three 12V cigarette lighter style
outlets so I can power the scope itself, the DewBuster and possible any
12V ancilliary bits and pieces I might aquire over time.

I use a nominally 13.8v ham radio PSU (the sort that Maplins and others
stock with two banana plug terminals on). Easily meaty enough at 4A for
my dewheater and fullrate slew to object.

Yeah - I saw one of those for £34 or something....but......isn't 13.8V too
high for the LX200GPS ? I though I read soemwhere (MAPUG ?) that it needs
to be 12V, not 13.8 and that it was the non GPS LX200s that used 13.8V

So far, all I can find are the small units that plug into the mains and
just give a single socket that give 800mA, or a bigger much more
expensive single socket unit from Telescop House that doesn't seem to
have a maximum current specified.

I presume that 800mA will be OK for the scope itself, but the DewBuster
spec says it needs a 3A rated supply.

800mA will be marginal for the LX200 and may well blow its fuse on fast
slew if the thing momentarily stalls (and on 12v this is not uncommon).
Meade upped the voltage spec to nominal 18v to avoid motor stall issues.
But it is noisy on 18v so I find 14v PSU (or a charged lead acid battery
about right). Halfords do a self contained charger and battery too.

I have one of those already ! I want to get away from lugging it outside
all the time, and especially being frustrated when I realise the damn
thing isn't charged up and needs to be charged for hours before I can
power my scope !!!!

Check MAPUG threads for additional details.

Does anyone know of a supplier that makes the kind of thing I am looking
for off the shelf ? I guess alteratively, a fairly beefy 12V power
supply without the lighter sockets would work and I could make up a
breakout panel with the actual sockets on that.....

I ideally want to make up a single "umbilical" type ccable that will run
from the house to the scope itself - it would consist of power (240V
AC), USB2.0 and the LX200 communications cable itself. This would
probably be buried in a conduit in my garden and run to a breakout box
where the 240V would be converted to the DC outputs.

BTW I would not run signal cables parallel to 240v mains wiring.

It's non-optimal, I know ! I could run the data cables in a separate
conduit though - the distance is only around 10M or so.

And USB 2.0 will not like running very far and working either.

I know - but then again it isn't very far.... I wish I could find a single
15m USB2.0 active extension cable rather than having to daisy chain
several together.

"adm" said

In my quest to have the LX200 and DSI set up outside but controlled from
inside, I am looking for a decent 240V AC to 12V DC power supply. I would
ideally like one with two or three 12V cigarette lighter style outlets so I
can power the scope itself, the DewBuster and possible any 12V ancilliary
bits and pieces I might aquire over time.

So far, all I can find are the small units that plug into the mains
and just
give a single socket that give 800mA, or a bigger much more expensive
single
socket unit from Telescop House that doesn't seem to have a maximum current
specified.

I presume that 800mA will be OK for the scope itself, but the
DewBuster spec
says it needs a 3A rated supply.

Does anyone know of a supplier that makes the kind of thing I am
looking for
off the shelf ? I guess alteratively, a fairly beefy 12V power supply
without the lighter sockets would work and I could make up a breakout panel
with the actual sockets on that.....

Lateral thinking here - if you are happy making up a breakout panel then
why not use a standard 400W Computer PSU? The +12V rail on that has at
least 4 outlets and is rated at 22A it also has +5V at 34A. The cost is
something like £10-12 retail. You would need to provide a method of
triggering the 'Power OK' signal though.

I ideally want to make up a single "umbilical" type ccable that will run
from the house to the scope itself - it would consist of power (240V AC),
USB2.0 and the LX200 communications cable itself. This would probably be
buried in a conduit in my garden

As Martin has already said - not a good idea.


and run to a breakout box where the 240V would be converted to the DC
outputs.

That's OK though.

JG

"JG" wrote in message
news:313030303331393042FA38AA83@crescentcomputing. co.uk...

"adm" said

In my quest to have the LX200 and DSI set up outside but controlled from
inside, I am looking for a decent 240V AC to 12V DC power supply. I would
ideally like one with two or three 12V cigarette lighter style outlets so
I
can power the scope itself, the DewBuster and possible any 12V ancilliary
bits and pieces I might aquire over time.

So far, all I can find are the small units that plug into the mains
and just
give a single socket that give 800mA, or a bigger much more expensive
single
socket unit from Telescop House that doesn't seem to have a maximum
current
specified.

I presume that 800mA will be OK for the scope itself, but the
DewBuster spec
says it needs a 3A rated supply.

Does anyone know of a supplier that makes the kind of thing I am
looking for
off the shelf ? I guess alteratively, a fairly beefy 12V power supply
without the lighter sockets would work and I could make up a breakout
panel
with the actual sockets on that.....

Lateral thinking here - if you are happy making up a breakout panel then
why not use a standard 400W Computer PSU? The +12V rail on that has at
least 4 outlets and is rated at 22A it also has +5V at 34A. The cost is
something like £10-12 retail. You would need to provide a method of
triggering the 'Power OK' signal though.

I ideally want to make up a single "umbilical" type ccable that will run
from the house to the scope itself - it would consist of power (240V AC),
USB2.0 and the LX200 communications cable itself. This would probably be
buried in a conduit in my garden

As Martin has already said - not a good idea.


and run to a breakout box where the 240V would be converted to the DC
outputs.

That's OK though.

JG


Rigging up a system to do this won't be difficult, there's plenty of
websites which show how to do this. Normally, electronics hobbiests do this
as a cheap bench power supply. So you'll get some pretty good and safe ways
to do this.

I'd suggest that you place the power supply and scope as close as possible
to the scope. 12v DC doesn't tend to travel too well. Something to do with
resistance in power cables.

Regards

Colin Dawson
www.cjdawson.com

"JG" wrote in message
news:313030303331393042FA38AA83@crescentcomputing. co.uk...

"adm" said

In my quest to have the LX200 and DSI set up outside but controlled from
inside, I am looking for a decent 240V AC to 12V DC power supply. I would
ideally like one with two or three 12V cigarette lighter style outlets so
I
can power the scope itself, the DewBuster and possible any 12V ancilliary
bits and pieces I might aquire over time.

So far, all I can find are the small units that plug into the mains
and just
give a single socket that give 800mA, or a bigger much more expensive
single
socket unit from Telescop House that doesn't seem to have a maximum
current
specified.

I presume that 800mA will be OK for the scope itself, but the
DewBuster spec
says it needs a 3A rated supply.

Does anyone know of a supplier that makes the kind of thing I am
looking for
off the shelf ? I guess alteratively, a fairly beefy 12V power supply
without the lighter sockets would work and I could make up a breakout
panel
with the actual sockets on that.....

Lateral thinking here - if you are happy making up a breakout panel then
why not use a standard 400W Computer PSU? The +12V rail on that has at
least 4 outlets and is rated at 22A it also has +5V at 34A. The cost is
something like £10-12 retail. You would need to provide a method of
triggering the 'Power OK' signal though.

Possible. I would eventually also like to put a permanent pier in this same
location, so a bit of infrastructure creation is OK with me. Using a PC
power supply means you might as well have a small (weatherproofed) computer
there as well, which kind of negates the need for the long USB run as you
can then just use ethernet from the embedded PC at the scope.....

(i'd actually like to knock down my garage, rebuild it eslewhere and then
build a small domed obeseravatory where the garage was....but that's a
different story)

I ideally want to make up a single "umbilical" type ccable that will run
from the house to the scope itself - it would consist of power (240V AC),
USB2.0 and the LX200 communications cable itself. This would probably be
buried in a conduit in my garden

As Martin has already said - not a good idea.

Taking power there is no problem. Data is more of a pin. It would need to be
Cat 5 cabled ethernet or wireless, long term.

Short term though, a few USB2 active cables daisy chained together will have
to do.


and run to a breakout box where the 240V would be converted to the DC
outputs.

That's OK though.

JG

"adm" wrote:
"Martin Brown" wrote in message
...
adm wrote:

In my quest to have the LX200 and DSI set up outside but controlled from
inside, I am looking for a decent 240V AC to 12V DC power supply. I would
ideally like one with two or three 12V cigarette lighter style outlets so
I can power the scope itself, the DewBuster and possible any 12V
ancilliary bits and pieces I might aquire over time.

I use a nominally 13.8v ham radio PSU (the sort that Maplins and others
stock with two banana plug terminals on). Easily meaty enough at 4A for my
dewheater and fullrate slew to object.

Yeah - I saw one of those for £34 or something....but......isn't 13.8V too
high for the LX200GPS ? I though I read soemwhere (MAPUG ?) that it needs to
be 12V, not 13.8 and that it was the non GPS LX200s that used 13.8V

13.8V is what you get from a fully charged lead-acid battery, dropping
to around 11V when discharged. Anything designed to run from a 12V
battery supply really ought to be fine with between 11 and 13.8V.

I've got a 20A 13.8V supply, made by Pro Peak and available from model
shops for £35 or so (it's targeted for use by RC enthusiasts for
battery charging). No built-in cigarette lighter plugs though, just
two banana plug / screw terminals on the front.


Tim
--
Today's message was brought to you by Mary, Jane and a big number two.

adm wrote:

"Martin Brown" wrote in message
...

adm wrote:

In my quest to have the LX200 and DSI set up outside but controlled from
inside, I am looking for a decent 240V AC to 12V DC power supply.

I use a nominally 13.8v ham radio PSU (the sort that Maplins and others
stock with two banana plug terminals on). Easily meaty enough at 4A for my
dewheater and fullrate slew to object.

Yeah - I saw one of those for £34 or something....but......isn't 13.8V too
high for the LX200GPS ? I though I read soemwhere (MAPUG ?) that it needs to
be 12V, not 13.8 and that it was the non GPS LX200s that used 13.8V

I don't know offhand what the voltage spec for the GPS LX200 is. The
original LX200 was *designed* for 12v nominal and "upgraded" to 18v with
no actual thought about the consequences. Several components are
stressed if it is run at full 18v (and the official Meade 12-18v DC
converter is one of the worst self-immolating pieces of shi^d^d^d bad
design you are ever likely to see).

I presume that 800mA will be OK for the scope itself, but the DewBuster
spec says it needs a 3A rated supply.

800mA will be marginal for the LX200 and may well blow its fuse on fast
slew if the thing momentarily stalls (and on 12v this is not uncommon).
Meade upped the voltage spec to nominal 18v to avoid motor stall issues.

If the GPS really is specced for 12v then they have changed the motors.
I would have thought they would make it so it could tolerate a nominal
12v lead acid battery though since they are regularly used that way.

But it is noisy on 18v so I find 14v PSU (or a charged lead acid battery
about right). Halfords do a self contained charger and battery too.

I have one of those already ! I want to get away from lugging it outside all
the time, and especially being frustrated when I realise the damn thing
isn't charged up and needs to be charged for hours before I can power my
scope !!!!

Recharge it immediately after using (and once a month otherwise).

Check MAPUG threads for additional details.

BTW I would not run signal cables parallel to 240v mains wiring.

It's non-optimal, I know ! I could run the data cables in a separate conduit
though - the distance is only around 10M or so.

And USB 2.0 will not like running very far and working either.

I know - but then again it isn't very far.... I wish I could find a single
15m USB2.0 active extension cable rather than having to daisy chain several
together.

I think the longest I have ever seen are around 16' but I haven't really
looked very hard.

Regards,
Martin Brown

Colin Dawson wrote:
"JG" wrote in message
news:313030303331393042FA38AA83@crescentcomputing. co.uk...

"adm" said

In my quest to have the LX200 and DSI set up outside but controlled from
inside, I am looking for a decent 240V AC to 12V DC power supply. I would
ideally like one with two or three 12V cigarette lighter style outlets

Lateral thinking here - if you are happy making up a breakout panel then
why not use a standard 400W Computer PSU? The +12V rail on that has at
least 4 outlets and is rated at 22A it also has +5V at 34A. The cost is
something like £10-12 retail. You would need to provide a method of
triggering the 'Power OK' signal though.

Some of them do not like having no load on the 5v rail though.

I ideally want to make up a single "umbilical" type ccable that will run
from the house to the scope itself - it would consist of power (240V AC),
USB2.0 and the LX200 communications cable itself. This would probably be
buried in a conduit in my garden

As Martin has already said - not a good idea.

Rigging up a system to do this won't be difficult, there's plenty of
websites which show how to do this. Normally, electronics hobbiests do this
as a cheap bench power supply. So you'll get some pretty good and safe ways
to do this.

Though bear in mind that the new regulations require you to have an
electrician install all new mains wiring and for oudoors with ELCB.

I'd suggest that you place the power supply and scope as close as possible
to the scope. 12v DC doesn't tend to travel too well. Something to do with
resistance in power cables.

Although this is true, one option would be to have a nominal 13.8 5A
supply indoors and run the rough DC supply out to the scope and heater,
if necessary regulating down the scopes feed to a true 12v. A hundred
feet of cheapest solid copper core 20A house wiring cable will not drop
too much voltage (check this, but a back of the envelope gives 0.6
ohm/100'). Use all the conductors in the cable 2 for + 1 for -.

(Negative DC cables always rot away electrolytically in the damp)

At 4A max load it should drop about 2.4v - perhaps a bit marginal so a
thicker grade of cable might be advisable. At least with low voltage DC
you don't have to worry about armoured cable and deep trench burial.

You would need to do the sums a bit more carefully and put a couple of
capacitors at the far end to decouple the supply but it should be
workable over short distances (and certainly over longer distances than
USB2).

Regars,
Martin Brown