Dew heater band and ZWO ASI533 - Forums

Topic starter

Aug 6, 2023

I have a 5V 2A dew heater band, which is powerd by USB.
Do you guys think I can power the band with the USB hub on the back of my 533MC Pro/Laptop USB port?
Or is it better to power it through a power bank or phone charger?

Engaging

jewzaam

Aug 6, 2023

Probably worth giving a shot. It can be considered an unpowered hub. If it draws too much you might see problems with cooling not working on the ASI533MC.

Daniele Borsari

Topic starter

Aug 6, 2023 · Edited: Aug 6, 2023

@jewzaam I see that if i don't power the camera with the 12v dc the dew heater doesn't work, so I think it's a powered hub.

jewzaam

Aug 6, 2023

Great point, I have not run mine w/o power and didn't realize that. So, even better then. I'd go for it.

Daniele Borsari

Topic starter

Aug 6, 2023

Don't know why I didn't come up with this idea before as I don't have to use a powerbank anymore and cable managemnt is cleaner.

Jim Raskett

Aug 6, 2023

How do you power your guide camera?

If you have doubts about powering your dew heater through the 533's hub, you could install a one to two 12v splitter and power both with a single power supply (assuming it is up to snuff) and leave the 533's hub for other tasks (guide camera, focus motor).

Jim

Concise

Daniele Borsari

Topic starter

Aug 6, 2023

@Jim Raskett I don't have any guide camera, focuser or filter wheel and as said before the dew heater is 5V USB, so the 12V splitter would not work.

Damien Galanaud

Aug 6, 2023

Personally, I would not try that. On my 5V USB dew heater bands, it is clearly specified that you should not run them from a computer port. They draw a lot of current, are very rudimentary (just a resistor connected to +5V/GND) and may easily short and destroy your 1000 US$ camera.

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Jim Raskett

Aug 6, 2023

Daniele Borsari:
@Jim Raskett I don't have any guide camera, focuser or filter wheel and as said before the dew heater is 5V USB, so the 12V splitter would not work.

You sure did. Thanks for the correction.

If you haven’t imaged yet with this configuration yet, you could test it off-line by doing a simulated sequence or session with the camera cooled while powering the dew heater.
That way if there was a problem, it wouldn’t affect an actual session.

Jim

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DoctorJB

Aug 6, 2023

I powered mine off my ASIAir. Had no issues.

Daniele Borsari

Topic starter

Aug 6, 2023

@Jim Raskett Thank you. I've already imaged with this setup, but my cables were probably pulling the camera and the tracking was a bit inconsistent. I'm doing some cable management and powering the dew heater directly from the camera helps.

@DoctorJB Thank you for your opinion.

Daniele Borsari

Topic starter

Aug 6, 2023

Damien Galanaud:
They draw a lot of current, are very rudimentary (just a resistor connected to +5V/GND) and may easily short and destroy your 1000 US$ camera.

There is a controller between the heater and the USB connector, but don't know how it works.

MikeAstronomy

Aug 6, 2023

I have the Svbony dew heater and I can only use the low and medium setting. Once I go high the dew heater shuts off. I am cooling at -10c . My asiair powers the camera, Eaf, efw and Avx mount.

Tommy Blomqvist

Aug 6, 2023

Yes, It is possible to power a USB-dew heater from the 533 as long as the power consumption doesn't exceed the maximum rating for the USB-port or the total consumtion exceed the maximum rating for the setup.

Garanteed output for Usb 2.0 is max 500mA (x5V = 2,5W) and Usb 3.0 max 900mA (x5V = 4,5W) per port.
I've noticed that cheap cables simetimes have way to high resistance and creates power loss and unwanted heat ( in the wrong places 😀 )

But even if you can power the heater from the camera USB make sure that it is a quality heater as if it shortens the port isn't well protected and you may end up burning one or both ports (have happened to others).