LX90 First Light (longish)

Well, I'll see how it goes with the car starter for a while, but I
suspect I'll give in and start on the rest anywy, just because it will
be fun to put it all together !.

Thanks for the tips on etching - think I'll give the laser printer
method a go.

Regards,

Andrew

Colin Dawson wrote:

Hi all



I haven't done any electronics since I were a lad (this is a great
reason to get back intot it!) - In those days I made PCBs using
transfers and etch resist pens. Is the photo-etching expensive to get
setup ? I bet the results are a lot better .. I'll do a little surfing
and see I think.


If you've got access to a lazer printer, there's a much cheaper solution
than photo etching.
If you take a look on the maplin website, take a look at the Press'N'Peel
transfer system.
You should get really good results from it. I used the photo-etching
method, because I like to do things that hardway.
also I only have an InkJet Printer.


At the very least it removes the urgency and lets me think about it in
more detail.
In all my vast experience of using the scope (1 night !) I haven't dewed
up yet, but
as soon as I do I know I'll wish I had the dew-heater handy so I'll
probably plug on
and get it going anyway. which means I also need to do the power thingy.


I've not really used the heater all that often, but it's been a godsend when
it's been needed.
The power thingy, isn't needed straight away either. You'll be able to tell
when the battery is wearing out
as the scope will start slow down and start to sound laboured long before
the battery gives out.


Good luck with that ! If I can't find the right kind of toolbox I may be
forced to do the same. I've got a mate who could help though, so maybe
for the price of a few beers I can get one together.


lol, sounds like my approach. I've got a mate who does alot of DIY, I'm
beggining to get a rought idea
of how the box will fit together, it's turning out to be a little more
complex, than I thought, but it should be
worth it in the end.

Regards

Colin Dawson
www.cjdawson.com

Got my starter so power is sorted for the time being :-)

Now I have time to think about the main power project since there hasn't
been a break in the clouds for days :-(

Andrew

Colin Dawson wrote:

"Chris Taylor" wrote in message
news:[email protected]

Hi Colin

I own 2 GOTO scopes and both have their own 1.2Ah batteries. I've not
noticed any difference between the beginning of the evenings battery's
performance (slewing speed or sound), or the end of the session on either

of

them. I do spend more time tracking with the LX90 given that the LPI get's
used. Nonetheless, I've not had the battery go flat, or appear to be
labouring on the LX yet and I've spent from 8pm to 2am observing. The C
Cells are an expensive way to do things so I bought the Lead Acid before
they could go flat. On the Celestron GOTO the batteries (AA's!) used to go
flat in a few hours and were a waste of time and money; lesson learned.



hmm, you're lucky. I think it's partly because I'm such a pickky little
blank (insert bad word of your own choice)
but I've noticed that about 1/2 way through the session my scope starts to
sound a less perky than at the beginning of the session. It doesn't seem
to affect the performance though, but I'm definatly not making it up.

I've just checked the Duracell web site, and they rekon that the LR14's will
work for 11 hours at 0.5 amp current.



There's also no reason not to get a 7.2AH and I'd have probably bought one
if the closest shop i could find with a solution (B&Q) had sold them. The
other alternative was a 45 Minute journey to Maplin, or a few day wait for
an internet purchase to arrive.



From the information that you've provided, I think that the only need to a
bigger battery it to help power more toys.
Can't have too many toys.

Regards

Colin Dawson
www.cjdawson.com

Cool.

Rather than spending time thinking about your main power project, it might
be worth getting the dew heater built up and running. I remember that it
took me about a week to of evenings to get the main ring and K8004 running.
You could also put a power lead to your scope from this box, or do something
similar to my new box that I'm working on. Then have a single plug into
your start's socket.

Once you've got the K8004 working properly, there shouldn't be a problem
moving the circuit into your master project once it's ready. ;-)


I've got next week off work, so hopefully I'll be able to get my power box
finished. It's taken a little thinking out, but I've got a rough plan for
how the box is going to fit together. Fingser crossed that it works.

Regards

Colin Dawson
www.cjdawson.com


"Andrew Cockburn" wrote in message
-service-com...
Got my starter so power is sorted for the time being :-)

Now I have time to think about the main power project since there hasn't
been a break in the clouds for days :-(

Andrew

Colin Dawson wrote:

"Chris Taylor" wrote in message
news:[email protected]

Hi Colin

I own 2 GOTO scopes and both have their own 1.2Ah batteries. I've not
noticed any difference between the beginning of the evenings battery's
performance (slewing speed or sound), or the end of the session on
either

of

them. I do spend more time tracking with the LX90 given that the LPI
get's
used. Nonetheless, I've not had the battery go flat, or appear to be
labouring on the LX yet and I've spent from 8pm to 2am observing. The C
Cells are an expensive way to do things so I bought the Lead Acid before
they could go flat. On the Celestron GOTO the batteries (AA's!) used to
go
flat in a few hours and were a waste of time and money; lesson learned.



hmm, you're lucky. I think it's partly because I'm such a pickky
little
blank (insert bad word of your own choice)
but I've noticed that about 1/2 way through the session my scope starts
to
sound a less perky than at the beginning of the session. It doesn't
seem
to affect the performance though, but I'm definatly not making it up.

I've just checked the Duracell web site, and they rekon that the LR14's
will
work for 11 hours at 0.5 amp current.



There's also no reason not to get a 7.2AH and I'd have probably bought
one
if the closest shop i could find with a solution (B&Q) had sold them.
The
other alternative was a 45 Minute journey to Maplin, or a few day wait
for
an internet purchase to arrive.



From the information that you've provided, I think that the only need to
a
bigger battery it to help power more toys.
Can't have too many toys.

Regards

Colin Dawson
www.cjdawson.com

You're right, I'll make the dew heater, then I have a reason to make the
master project :-)

Problem is, work is looking sucky for the next 3 weeks - lots of
travelling so no time to do anything at all astro related except bug you
all with my posts !

The only plus is that I will be spending a week in the states so might
get a chance to pick up some cheap astro bits or components for the dew
heater - I'll be in Silicon Valley, and they have electronics shops
there you just wouldn't believe ;-)

Andrew

Colin Dawson wrote:

Cool.

Rather than spending time thinking about your main power project, it might
be worth getting the dew heater built up and running. I remember that it
took me about a week to of evenings to get the main ring and K8004 running.
You could also put a power lead to your scope from this box, or do something
similar to my new box that I'm working on. Then have a single plug into
your start's socket.

Once you've got the K8004 working properly, there shouldn't be a problem
moving the circuit into your master project once it's ready. ;-)


I've got next week off work, so hopefully I'll be able to get my power box
finished. It's taken a little thinking out, but I've got a rough plan for
how the box is going to fit together. Fingser crossed that it works.

Regards

Colin Dawson
www.cjdawson.com


"Andrew Cockburn" wrote in message
-service-com...

Got my starter so power is sorted for the time being :-)

Now I have time to think about the main power project since there hasn't
been a break in the clouds for days :-(

Andrew

Colin Dawson wrote:


"Chris Taylor" wrote in message
news:[email protected]


Hi Colin

I own 2 GOTO scopes and both have their own 1.2Ah batteries. I've not
noticed any difference between the beginning of the evenings battery's
performance (slewing speed or sound), or the end of the session on

either

of


them. I do spend more time tracking with the LX90 given that the LPI

get's

used. Nonetheless, I've not had the battery go flat, or appear to be
labouring on the LX yet and I've spent from 8pm to 2am observing. The C
Cells are an expensive way to do things so I bought the Lead Acid before
they could go flat. On the Celestron GOTO the batteries (AA's!) used to

go

flat in a few hours and were a waste of time and money; lesson learned.



hmm, you're lucky. I think it's partly because I'm such a pickky

little

blank (insert bad word of your own choice)
but I've noticed that about 1/2 way through the session my scope starts

to

sound a less perky than at the beginning of the session. It doesn't

seem

to affect the performance though, but I'm definatly not making it up.

I've just checked the Duracell web site, and they rekon that the LR14's

will

work for 11 hours at 0.5 amp current.




There's also no reason not to get a 7.2AH and I'd have probably bought

one

if the closest shop i could find with a solution (B&Q) had sold them.

The

other alternative was a 45 Minute journey to Maplin, or a few day wait

for

an internet purchase to arrive.



From the information that you've provided, I think that the only need to

a

bigger battery it to help power more toys.
Can't have too many toys.

Regards

Colin Dawson
www.cjdawson.com

If you start looking about for astro bits in the states. I think that I
should point out the Kendrick Dew system.

I've never seen this device directly, but it also has setting for how much
power is being used. The dew heater project on my website, uses a pulse
width modulator that pulses at about 2.5 Khz (down to about 1.5Khz I think).
The kendrick system, depending on it's settings, turns the heater on for 15
seconds, then off for 15 seconds. It's basically the same as doing it as
sub second pulsewidths BUT, and yes it's a big but, if you try to run your
scope and the heater off the same battery there's a voltage issue. Whenever
the Kendrick heater turns on there's a huge power drain on the battery (just
the same as a homemade heater), then when the kendrick turns off this stops.
This causes the battery voltage to drop when the heater is on, Then come
back up. I've heard from a posting on a NG a while back, that this can
cause the scope to do strange things (reset, motor faliure, autostar goes
haywire, not track properly). Using a Khz frequency for the pulse width,
means that the battery voltage will not fluctuate as much as the load
changes, in fact it's so quick that I'm not even sure if it will be noticed.

I've been given a circuit diagram by a very helpful poster from another NG,
which will monitor the load on the heater. I've not investigated this, but
decided to keep it for a later date, then try it out and retro fit it to my
power box.

Regards

Colin Dawson
www.cjdawson.com


"Andrew Cockburn" wrote in message
-service-com...
You're right, I'll make the dew heater, then I have a reason to make the
master project :-)

Problem is, work is looking sucky for the next 3 weeks - lots of
travelling so no time to do anything at all astro related except bug you
all with my posts !

The only plus is that I will be spending a week in the states so might
get a chance to pick up some cheap astro bits or components for the dew
heater - I'll be in Silicon Valley, and they have electronics shops
there you just wouldn't believe ;-)

Andrew

Colin Dawson wrote:

Cool.

Rather than spending time thinking about your main power project, it
might
be worth getting the dew heater built up and running. I remember that
it
took me about a week to of evenings to get the main ring and K8004
running.
You could also put a power lead to your scope from this box, or do
something
similar to my new box that I'm working on. Then have a single plug into
your start's socket.

Once you've got the K8004 working properly, there shouldn't be a problem
moving the circuit into your master project once it's ready. ;-)


I've got next week off work, so hopefully I'll be able to get my power
box
finished. It's taken a little thinking out, but I've got a rough plan
for
how the box is going to fit together. Fingser crossed that it works.

Regards

Colin Dawson
www.cjdawson.com


"Andrew Cockburn" wrote in message
-service-com...

Got my starter so power is sorted for the time being :-)

Now I have time to think about the main power project since there hasn't
been a break in the clouds for days :-(

Andrew

Colin Dawson wrote:


"Chris Taylor" wrote in message
news:[email protected]


Hi Colin

I own 2 GOTO scopes and both have their own 1.2Ah batteries. I've not
noticed any difference between the beginning of the evenings battery's
performance (slewing speed or sound), or the end of the session on

either

of


them. I do spend more time tracking with the LX90 given that the LPI

get's

used. Nonetheless, I've not had the battery go flat, or appear to be
labouring on the LX yet and I've spent from 8pm to 2am observing. The
C
Cells are an expensive way to do things so I bought the Lead Acid
before
they could go flat. On the Celestron GOTO the batteries (AA's!) used
to

go

flat in a few hours and were a waste of time and money; lesson
learned.



hmm, you're lucky. I think it's partly because I'm such a pickky

little

blank (insert bad word of your own choice)
but I've noticed that about 1/2 way through the session my scope starts

to

sound a less perky than at the beginning of the session. It doesn't

seem

to affect the performance though, but I'm definatly not making it up.

I've just checked the Duracell web site, and they rekon that the LR14's

will

work for 11 hours at 0.5 amp current.




There's also no reason not to get a 7.2AH and I'd have probably bought

one

if the closest shop i could find with a solution (B&Q) had sold them.

The

other alternative was a 45 Minute journey to Maplin, or a few day wait

for

an internet purchase to arrive.



From the information that you've provided, I think that the only need
to

a

bigger battery it to help power more toys.
Can't have too many toys.

Regards

Colin Dawson
www.cjdawson.com

I saw that post as well, and came to the same conclusion - a high
frequency PWM design should give a roughly constant load that won't
trouble the scope at all, so I am sticking with your design and planning
for one big battery rather than 2 separate ones. Same should be true of
the laptop inverter - I assume that it will be working roughly at
50hz, which again is near enough a constant load, especially when you
factor in the smoothing effect of the battery. Worst case I can add a
regulator to the scope supply.

Andrew

Colin Dawson wrote:
If you start looking about for astro bits in the states. I think that I
should point out the Kendrick Dew system.

I've never seen this device directly, but it also has setting for how much
power is being used. The dew heater project on my website, uses a pulse
width modulator that pulses at about 2.5 Khz (down to about 1.5Khz I think).
The kendrick system, depending on it's settings, turns the heater on for 15
seconds, then off for 15 seconds. It's basically the same as doing it as
sub second pulsewidths BUT, and yes it's a big but, if you try to run your
scope and the heater off the same battery there's a voltage issue. Whenever
the Kendrick heater turns on there's a huge power drain on the battery (just
the same as a homemade heater), then when the kendrick turns off this stops.
This causes the battery voltage to drop when the heater is on, Then come
back up. I've heard from a posting on a NG a while back, that this can
cause the scope to do strange things (reset, motor faliure, autostar goes
haywire, not track properly). Using a Khz frequency for the pulse width,
means that the battery voltage will not fluctuate as much as the load
changes, in fact it's so quick that I'm not even sure if it will be noticed.

I've been given a circuit diagram by a very helpful poster from another NG,
which will monitor the load on the heater. I've not investigated this, but
decided to keep it for a later date, then try it out and retro fit it to my
power box.

Regards

Colin Dawson
www.cjdawson.com


"Andrew Cockburn" wrote in message
-service-com...

You're right, I'll make the dew heater, then I have a reason to make the
master project :-)

Problem is, work is looking sucky for the next 3 weeks - lots of
travelling so no time to do anything at all astro related except bug you
all with my posts !

The only plus is that I will be spending a week in the states so might
get a chance to pick up some cheap astro bits or components for the dew
heater - I'll be in Silicon Valley, and they have electronics shops
there you just wouldn't believe ;-)

Andrew

Colin Dawson wrote:


Cool.

Rather than spending time thinking about your main power project, it

might

be worth getting the dew heater built up and running. I remember that

it

took me about a week to of evenings to get the main ring and K8004

running.

You could also put a power lead to your scope from this box, or do

something

similar to my new box that I'm working on. Then have a single plug into
your start's socket.

Once you've got the K8004 working properly, there shouldn't be a problem
moving the circuit into your master project once it's ready. ;-)


I've got next week off work, so hopefully I'll be able to get my power

box

finished. It's taken a little thinking out, but I've got a rough plan

for

how the box is going to fit together. Fingser crossed that it works.

Regards

Colin Dawson
www.cjdawson.com


"Andrew Cockburn" wrote in message
-service-com...


Got my starter so power is sorted for the time being :-)

Now I have time to think about the main power project since there hasn't
been a break in the clouds for days :-(

Andrew

Colin Dawson wrote:



"Chris Taylor" wrote in message
news:[email protected]



Hi Colin

I own 2 GOTO scopes and both have their own 1.2Ah batteries. I've not
noticed any difference between the beginning of the evenings battery's
performance (slewing speed or sound), or the end of the session on

either


of



them. I do spend more time tracking with the LX90 given that the LPI

get's


used. Nonetheless, I've not had the battery go flat, or appear to be
labouring on the LX yet and I've spent from 8pm to 2am observing. The

C

Cells are an expensive way to do things so I bought the Lead Acid

before

they could go flat. On the Celestron GOTO the batteries (AA's!) used

to

go


flat in a few hours and were a waste of time and money; lesson

learned.


hmm, you're lucky. I think it's partly because I'm such a pickky

little


blank (insert bad word of your own choice)
but I've noticed that about 1/2 way through the session my scope starts

to


sound a less perky than at the beginning of the session. It doesn't

seem


to affect the performance though, but I'm definatly not making it up.

I've just checked the Duracell web site, and they rekon that the LR14's

will


work for 11 hours at 0.5 amp current.





There's also no reason not to get a 7.2AH and I'd have probably bought

one


if the closest shop i could find with a solution (B&Q) had sold them.

The


other alternative was a 45 Minute journey to Maplin, or a few day wait

for


an internet purchase to arrive.



From the information that you've provided, I think that the only need

to

a


bigger battery it to help power more toys.
Can't have too many toys.

Regards

Colin Dawson
www.cjdawson.com

I don't think that there's going to be any problems with power spiking.
I've had the heater, battery and 12v laptop converter all running at the
same time. Everything worked perfectly.

Colin Dawson
www.cjdawson.com


"Andrew Cockburn" wrote in message
-service-com...
I saw that post as well, and came to the same conclusion - a high
frequency PWM design should give a roughly constant load that won't
trouble the scope at all, so I am sticking with your design and planning
for one big battery rather than 2 separate ones. Same should be true of
the laptop inverter - I assume that it will be working roughly at
50hz, which again is near enough a constant load, especially when you
factor in the smoothing effect of the battery. Worst case I can add a
regulator to the scope supply.

Andrew