spectro-aras.com

Hi Keith,

There is a bit of a discussion on this on spectro-l currently. I went for a minimalist approach with my ALPY which needs the same interface, partly as a bit of fun to see how simple I could make it
http://www.threehillsobservatory.co.uk/ ... opy_22.htm
but even easier would be to use a USB controlled relay board eg
https://www.pc-control.co.uk/control/pr ... laybee.php
I use their motor-bee board to control the current LHIRES lamp and the telescope focusser
http://www.threehillsobservatory.co.uk/ ... copy_9.htm
They come with simple demo software which can be used if you dont want to write your own

Robin

Hi Paul,

Thanks for that good information. I am somewhat electronically challenged although I have dabbled in some minor electronic projects. After I wrote this message, I remembered that Robin Leadbeater had some info on his website. I am now looking at the Mini Relay-Bee as that has a 12v output (so apparently no need for a 5v to 12v converter). I downloaded the manual and it all looks like it would be within my knowledge of electronics. But I cannot find that board as being sold in the US. I will look into your suggestion of the Arduino board to see if there is one similar to the Mini Relay-Bee.

Thanks,

Keith

Hi Robin,

Just saw your reply on p.2. As I mentioned in my reply to Paul, I did check out your website. That is where I saw the Mini Relay-Bee card. That card has the software, and it appears to be an easy adaptation for the new Lhires upgade. I cannot find this board in the States, so I am hoping I can order one from the UK (the shipping may be more than the cost of the board).

There is one part that has me a bit confused. In reading the manual, that Main Sequence Display Window has my head spinning. I figured the software was ready to go and once the wiring was complete the lamps could be turned on and off via an on-screen display. Looks like I may need to do something within that window first, but I do not know what. Any hints?

Cheers,

Keith

Hi all! In my experience with long integrations I have also seen that there is poor linearity in the spectrum shifts due to thermoelastic effects. I think the best way to solve (ignoring the shift during each of the individual subexposure frames) is to use the ISIS wavelength registration function that re-sync on first profile every following subexposure profiles on the basis of spectral lines. I use it often but it requires the presence of well visible lines in the spectrum. Follows an example (every sub lasts 15 mins). Note the non-linearity of shifting trend. Around frame #7 the target was close the meridian (values are about symmetrical around this point):

Registration of individual spectra...
File #1 -> 0.000 A
File #2 -> -0.230 A
File #3 -> -0.342 A
File #4 -> -0.430 A
File #5 -> -0.485 A
File #6 -> -0.497 A
File #7 -> -0.653 A
File #8 -> -0.576 A
File #9 -> -0.455 A
File #10 -> -0.382 A
File #11 -> -0.309 A

What I wonder, concerning the new calibration module, is if it would be possibile (would be directed to Christian!) and useful to implement a feature that use a series of intermediate lamp spectra to calibrate individual sub-exposure profiles (or find a trend with which register them) before combining. Indeed, with an automated control, it is easy to take a lamp spectrum between every sub-exposure. This would help to properly reduce all spectra (including those that do not show strong enough lines, faint targets, etc...).

May be we are becoming too demanding...

Paolo

Hi Keith,

I dont have a relay bee board but it looks like the simple demo program they use to show how to write programs would do what you are looking for
https://www.pc-control.co.uk/control/pr ... e_prog.php
(The mini bee and mini relay bee use the same instructions)

USB relay boards are pretty common though and there are probably local solutions if you can some simple software for them.

Robin

A bit of googling and looking on ebay suggests most come with some simple software.
This one for example is almost free
http://www.ebay.com/itm/Hot-2-Channel-P ... 1222007990?
though according to the info there it may only work on 32 bit windows systems
I think I might get one to just play with

Robin

Hi Robin,

Thanks for the link. I will read through and hopefully find what I need.

I did check the many made in China boards on Ebay. They all seem to be 5 volt except for 1 RS232 board that was 12v. I believe we need 12v boards for the LHires upgrade. Paul gave a reply earlier that suggested the 5v boards could be made in to 12v models with some additional electronics, but that appeared to be beyond my capabilities.

Cheers,

Keith

Hi Keith,

If you use a relay board, the 5v to power the board comes from the computer USB port and you can put any voltage (within reason - in this case 12v) on the relay contacts which are completely isolated from the computer side

Robin

duplicated post removed

OH, OK. That is good to know, Robin. I figured the 12v meant the input voltage from the power supply. Thanks for the clarification.

Cheers,

Keith