DIY Dew Heater

[Abernus]

Hi all,

Well on the back on my DIY Focuser I now fancy making a Dew Heater. But I know very little about them. So I am looking for advice.

I have seen the basic construction of a set of resistors set in parrallel and it looks easy enought to make. However with a constant flow of voltage through them they will get very hot, so I asume that the controllers for the commercial Dew heaters are a pulse module? as in they pulse the voltage on and off at a set interval to keep the temp constant?

Can someone who has knowledge of this advise me if I am correct.

[Bizibilder]

Does this site help?

Dew Heater

[Merlin66]

I built the dew heater for my 12" Lx200 from a couple of lengths of Chrome-Ni wire (Ex Jaycar) sewed into a length of velco (Thank's Sue) -works very well with the AstroZap controller.

Over three years now and still going strong...

[Demonperformer]

You don't say what size scope you are making it for. I made one for my 6" sct and have never used it because the dew-shield (rolled up piece of black cardboard) does the job admirably.