Qhy8 heater muff

[pjphilli]

Hi

I have seen reference to a heater muff for a QHY8 camera to prevent
dewing of the imaging sensor. Where can these be obtained and how much
power do they require (ie volts and amps). Or in general, how much power
should be applied to such a device in case I decide to make one up myself.

Cheers Peter

[peter_4059]

You can purchase a heater ring from Theo
http://www.gamaelectronics.com.au/heater.html

They work on 12V and have a resistance of about 230 ohms.

You can also make one using resistors. The one I made has 48 ohms total resistance and works fine. I use a dew heater controller to adjust the temperature.

The Kendrick dew heater website lists the power ratings for al their dew heater straps and is a good starting point for sizing these things.
http://www.kendrickastro.com/astro/dew_premierheaters.html

[pjphilli]

Hi Peter
This is just the information I was looking for thanks. I see that the 230ohm one would use about 1 watt. However, your idea of using a lower resistance
and then adjusting as required through a controller is a good one and
the way I will go.
Cheers Peter