Fan speed

[photon]

Dear community,

I noticed that the telescope fan connected to the DDM 60 Pro is running on full speed, no matter where the slider stays in Autoslew software.

The DC fan is connected to the fan port with only 2 wires. As far as I can remember this feature worked in the past, did anyone notice this too? 

There is also a 3rd pin on the FAN connector, but it seems to be only a dummy. Couldn't measure any PWM signal here and the other pins always have full power.

 

Best regards,

Gerald

[MarkS]

Gerald,

I can't answer you directly, as I don't have a DDM60 pro, but I do have a DDM85. I imagine that the fan control works the same.

There are only the two connections on the 3-pin fan plug. The fan is controlled by voltage variation (I don't know if it is done by mark-space ratio or DC voltage adjustment, and I can't get to my gear to check). In any event the variation occurs within Autoslew.

Have you tried re-installing Autoslew?

If that doesn't fix it send an email to ASA Support - response is usually prompt.

Mark

[photon]

Mark,

I can't detect any voltage change if I change the slider in Autoslew. Anyway, thank you for the response!

 

Gerald

[RamaSpaceShip]

Hi Gerald,

You need an oscilloscope to see the voltage change as it is probably a PWM (mark-space ratio).

Bernard

[MikePaling]

Hi Gerald ...

I have a DDM60Pro ..... I didn't know that I might have a fan controlled from Autoslew!

Can you explain where it is on your set-up? ... is it something on your scope or camera ???? Am I missing something?

I have a fan on my Moravian camera but this is controlled by MaximDL.

Cheers Mike

 

[photon]

@bernard I checked with an oscilloscope but got only a flat line at approx. the input voltage. If it was PWM, wouldn't we need at least 3 pins?

@MikePaling The DDM60Pro has a "Fan" labelled port on the RA axis. You can connect any 12V DC fan (i.e computer fan) to the outermost pins and control it directly from Autoslew. I use it for telescope cooldown and connected a DIY mirror fan.

Gerald

[MarkS]

Mike,

The Moravian camera fans are internally connected to the 12V power supply in the camera. That is, they are NOT externally controlable. The camera must run on FIXED 12V. It should never be connected via the ASA fan port, which is intended to run telescope fans only.

Mark

[MikePaling]

9 hours ago, MarkS said:

Mike,

The Moravian camera fans are internally connected to the 12V power supply in the camera. That is, they are NOT externally controlable. The camera must run on FIXED 12V. It should never be connected via the ASA fan port, which is intended to run telescope fans only.

Mark

Hi Mark ...

That makes sense .... I had forgotten that that the larger reflecting scopes have a fan !

Mike