TEC cooling QHY 8 with Maxim DL 5

[graham.hobart (Graham stevens)]

Greetings, having gone through a roller coaster ride with my QHY 8 acquired from PMRID, ( bought it, got it, plugged it in, plugged it in wrong, puff of blue smoke and smell of electronics doing novel things at high temps, sent back to QHY, got mended, back to me, certian gravitas with unpacking and plugging in this time with scrotum tightening pause before flicking the switch, Yoinks! it works!, so got it working in Nebulosity 3. Now here is the rub as they say, or in Hollywood, here's the hook...
I can get the TEC control in Neb 3 and set it (for example -10), but I have connected to the camera via ASCOM then the QHY 8 driver in Maxim DL 5 and there is a connection but there is no control over the cooler.
What gives? is it set automatically in Maxim?
Anyone got an older style QHY 8 OSC and using Maxim? with a TCF-S focuser/FocusMax?

Thanks for any tips
Graham

[Ross G]

Hi Graham,

Sorry to hear about your problems. Hope all goes well now.

I have a newer QHY8L which has temperature control. However, I think the older QHY8s did not have temperature control. The cooling was OFF or ON.

Ross.

[Poita (Peter)]

That is correct. The older QHY8 only has the cooling off or on, there is no temperature setting.

[marki]

On the original QHY8 there is no temp sensor on the chip so it is not possible to have a feedback loop thus the user being able to set the level of cooling is a waste of time. The sony chip when cooled was deemed clean enough to not require darks so they didn't bother with temp control and taking good darks is where you need this level of control particularly on the kodak chips. From memory the peltier is set to run at 80% capacity to prevent damage to the cooling unit. In MaximDL only camera's that have temp sensors are given the option to set cooling levels in the software. Basically the TEC on the old QHY8 is either off or running flatout (80%). Changing the TEC controller box will not help here as you need a sensor on the chip to make it work. Its not a problem in any case as the subs are pretty clean straight of the camera.

Mark