Astrozap dew heater questions

[themos]

Do you know which Astrozap heater would be the right size for a 480/80 APO ( we have a Meade 5000 and a Revelation)?

And do you know what the Ohm rating of the heater is? I have a homemade regulator already but I am not sure of the wattage rating.

[Jessun]

Hello, I use this on my SW80ED with about an inch of the actual heating band overlapping. I believe the 80ED is rather large around the dewshield compared to other brands.

Astrozap Heating band for 4" telescope apertures

It's 12V and the optional regulator gives 1.25 amps per socket. (Four sockets on mine)

Hope that helps!

[themos]

Thanks. My regulator (essentially this) is good for 3 amps and it has two sockets.

[Jessun]

That gives you what you need, and a bit more. The Astrozap control box does 'pulse modulating' so it whacks 12V on and off at different intervals depending on how you adjust a knob. At full on it is on 95 percent of the time.

I wonder if this sollution is just a bit cheaper to manufacture than a volt regulator. Also perhaps it draws less amps over the course of a night.

[themos]

I am pretty sure my "motor regulator" does PWM as well. Haven't actually put an oscilloscope on it, though. Yes, it definitely saves on power.

[themos]

Maybe this 30A one is better value!

[Jessun]

Maybe for 24 lens elements :-)

Overkill IMHO, not sure how easy it is to fry the straps... Or when the lens expands through the dew shield :-)