Ok sourced and took Dans advice which was the easiest method to adopt
If you already have a AC/DC adapter for your Canon then buy a PowerTechPlus N287 12v to selectable V converter from Jaycar for $25
cut the supplied connector off (not the cigarette lighter plug end the other one) and splice the cable into the output power connectors on the MB of the Canon adapter, the lead is colour codes for positive/negative and marked on the plug you'll cut off so easy to follow (screws are under the label on the Canon adapter box to take it apart)
make sure you have all you + and - going to the right place and bobs you uncle, works a treat (no guarantees if you FIU though)
Well after a lot of soul searching...Martin (user Mill) gave me a Texas Instruments PTN78020WAH adjustable switching regulator to try/use.
This item is excellent and can supply up to 6 amps! I made up a small cct board (with eagle) and am running this at 1amp constant (to simulate the camera) and there is virtually no heat emitted from the regulator....aka it is efficient and damn stable.
In fact there is a quantum more heat dissipated in my load testing resistors, which was not the case with the old adjustable linear regulator I was trying!
These new switching regulators have much more inbuilt protection features than I could add to a std linear regulator so it's basically add a few resistors & capacitors & away you go.
So it's all going in a small box and will be powering my 450D soon.
I'll report back on how this progress but I must say a big thanks to martin for pointing me in this direction.
Last edited by wasyoungonce; 19-01-2010 at 11:15 PM.
I have just received one of these 6amp switching reguators from Texas Instruments and I am in the board design stage, using pencil, paper and a sharp knife so it going to be an "ugly board" construction. Hopefully will have it finished by tonight for my session with the scope. What software do you use to design the boards? Usually I would use Protel but my licence as run out and cannot justify the cost to reregister the software.
I have just received one of these 6amp switching reguators from Texas Instruments and I am in the board design stage, using pencil, paper and a sharp knife so it going to be an "ugly board" construction. Hopefully will have it finished by tonight for my session with the scope. What software do you use to design the boards? Usually I would use Protel but my licence as run out and cannot justify the cost to reregister the software.
Adrian
Adrian, why do you even bother with an circuit board?
I have mine in a small box with the components straight on the converter.
For only 4 components you don't need a board.
Adrian, why do you even bother with an circuit board?
I have mine in a small box with the components straight on the converter.
For only 4 components you don't need a board.
That is true but I like to complicate things and I find it easier to modify the circuit if I have a board to work with.
I have just completed the circuit board now all I got to do is find were SWMBO has put my soldering iron. I went away for a few days and now I can see the top of my desk, now how am I going tofind anything
Bugger, that you can see your desk is not good
The only thing i can see on my desk is my mouse pad
I have to share my desk(s) with 3 daughters....all who demand room for their UNI/Tafe/School stuff.
So I have little chance to proclaim "my desk". I'm relegated to a lower status than the dog!
But...I'm a bit anal as well...I like cct boards.
Adrian..I can send you my Board layout & Schematic I made in Eagle....if you use Eagle?
It's a bit oversized ..I was experimenting with ground planes...but "Meh"...it works. Main problem was I had to make a device layout for the PTN78020WAH (for the board pad layout) and getting 2.2 micro fard ceramic filter caps on input. I put caps in parallel to add up to the req'd value.
I have just received one of these 6amp switching reguators from Texas Instruments and I am in the board design stage, using pencil, paper and a sharp knife so it going to be an "ugly board" construction. Hopefully will have it finished by tonight for my session with the scope. What software do you use to design the boards? Usually I would use Protel but my licence as run out and cannot justify the cost to reregister the software.
Adrian
Sorry missed this part...I use Eagle. Its freeware for boards up to 100 x 80mm.
What? Brendan i hope you didn't follow the TI rules of design to the letter?
The only thing i used were the DC-DC converter, resistor and last but not least the capacitor on the output.
so three components in all.
How dare TI tell us how we have to use the component
PS: It works excellent with only an capacitor on the output
And when would you like to come over for processing lessons Brendan?
Call me call me now (i know you want to)
yes well...I'm admit I'm deficient in that area...by a long shot.
And I kinda followed the TI specs...well loosely that is.
Edit:
Martin...ATM I'm trying to locate what this is from...see attached! very nasty...from C8 on horsyhead one with camera at 90 degrees. I think it was something on the main corrector lens & have just cleaned it.
It appears to be a stray reflection from Alnitak?
edit 2:
Cleaning the corrector fixed the problem. A shot from last night in full moon...not the best but shows refraction is gone @F10.
Last edited by wasyoungonce; 28-01-2010 at 02:50 PM.
I have to share my desk(s) with 3 daughters....all who demand room for their UNI/Tafe/School stuff.
So I have little chance to proclaim "my desk". I'm relegated to a lower status than the dog!
But...I'm a bit anal as well...I like cct boards.
Adrian..I can send you my Board layout & Schematic I made in Eagle....if you use Eagle?
It's a bit oversized ..I was experimenting with ground planes...but "Meh"...it works. Main problem was I had to make a device layout for the PTN78020WAH (for the board pad layout) and getting 2.2 micro fard ceramic filter caps on input. I put caps in parallel to add up to the req'd value.
Anyway...my 2 cents worth.
Fortunately I have my own desk, so does my wife. At one stage we were both studying and working so we both needed a PC each. So we have one room with 2 desks and 2 PC's then we decided we both needed laptops as well. So we have 2 PC's 2 laptops and now my employer as thrown a laptop at me aswell. Now if I could find my Jornada PD I would look like a proper geek....
Brendan that is not Alnitak.
Alnitak is more to the left in your HH pic, it looks more like SAO132451.
This is a bright star more to the right and closer to the HH and the angle of the reflection looks more like originating from there.
See this picture Brendan.
You might have a thin film left on the corrector plate
As you can see the stray rays are ..."bad" to say the least.
Main mirror front is fine so it's not a major mirror quality issue.
I've cleaned this up/out & am hoping this was the problem as the stray off axis reflections are very prismatic in that the light has been broken into quite a diffraction pattern.
Anyway..thanks...if it continues I'll post a separate thread.
Last edited by wasyoungonce; 28-01-2010 at 02:51 PM.
ATM it's now in it's box & am waiting for the Canon DRE5 adaptor to arrive.
Most places are drop shipping so ....it's a waiting game.
Any way here are some pics. I added a switch that has an inbuilt LED but I didn't do a resistor on the cct board for this...silly me. Anyway...no problems as the cct board had a ground plane to drill into.
Soon...I'll be in "no battery heaven"!
I must again thank Martin for his most excellent help on this. This TI switching regulator is "a champ"! Something I was not looking at because of pre-conceived bias against switching regulators.
Looking the goods Brendan
You could also make that box a universal power supply, EG: 8.1V, 12V and 5V (usb hub).
I did all this in a plastic box and it is fitted to the scope so i can feed the camera, usb hub and everything 12V like mount, heaters etc.
This means that i have only two wires going to the scope that i don't even have to separate, usb and 12V DC.
The box with electronics is very light and this way the bulk of wires can be short and it all turns with the scope (so no wires get stuck).
If you have an old worn out battery then you can use that as an adapter, take batteries etc out and wire the + and -, then glue it back together.