DiSEqC Motor is not Moving when horizontal Polarization is selected

[mohanaprakash]

Hi


I am having SG2100 DiSEqC motor, When i select Horizontal polarization in my box i am getting 18.4V in the output.

When i try to move my motor it starts moving and stops immediately.

I tested the voltage at that time and i found my output voltage is going to 0v and it is coming back to 18v.

For me it seems that when motor stats moving the box may be overloaded, so the output voltage is cut off.


So i remove the LNB cable from the motor then it is moving fine.


I am not facing this problem when the polarization is vertical(13V).


If any one has any input on this please share it to me.


regards
Mohanaprakash T

 

[Anole]

Try a different receiver, if you have one.
I suspect the voltage regulator in the receiver is overloaded, and may be shutting down.
The clue, was that the motor worked if you removed the LNB.
I suppose you could use a different LNB...
Is the motor moving an unusually large dish...?
Have you checked your mains power (110 volts AC or 220 volts AC, as appropriate)?

A while back, we had a discussion of replacing the voltage regulator in a receiver, to handle more power to the motor/LNB.
I will look for that thread and add it to this post when I find it.

edit: here you go. SatelliteAV described replacing the regulator with a more robust one.
Do you have the experience to take out the old and install a new part?

 

[mohanaprakash]

Thanks for your reply

Actually i didn't attach any dish to motor shaft , also i removed the LNB cable and connect a 100ohm 13W resistor instead of that , then also i am facing the same problem.


I checked the mains there is not voltage drop.



Regards
Mohanaprakash T

 

[AcWxRadar]

Thanks for your reply

Actually i didn't attach any dish to motor shaft , also i removed the LNB cable and connect a 100ohm 13W resistor instead of that , then also i am facing the same problem.


I checked the mains there is not voltage drop.



Regards
Mohanaprakash T

Mohanaprakash,

You appear to have sufficient background in electronics. Do you have a digital volt/ohm/ammeter that is capable of recording max/min current? If so, install the ammeter in line and when the motor is commanded to move to a H TP and stalls like this, see what the peak current was.

Then, we will need to know what the current limit of the receiver is supposed to be. If your dish motor and LNBF current is exceeding that by more than 50%, then I would assume that the receiver is working properly and shutting down according to its design. This would also mean that either there is something wrong with the motor or LNBF and causing it to draw more current than necessary or it is over sized for the receiver that you are using.

If the peak current detected is not over the rated limit of the receiver, but well within an acceptable limit, then the overcurrent protection circuit within the receiver is defective or at least not properly calibrated.

Just for an example, I have a Coolsat 5000 receiver which is rated at 500mA and I can pull at least 780mA continuously without it going into shut down mode. Possibly more during short momentary bursts of inrush current. Hope some of this helps, beyond the acquisition of this information, I don't know if I could identify the actual cause of the problem. It is just a place to start.

RADAR

 

[mohanaprakash]

Thanks for your input

These are my observation during the test

18 V: RF port ---> DiSEqC dish positioner ---> LNB: motor moves a slight amount, then stops (no measurements)
13 V: RF port ---> DiSEqC dish positioner ---> LNB: motor moves properly (no measurements)

18 V: RF port ---> DiSEqC dish positioner: current 110 - 160 mA when motor is moving
13 V: RF port ---> DiSEqC dish positioner ---> 100 ohm load resistor: current 240 - 270 mA when motor is moving


18 V: RF port ---> DiSEqC dish positioner ---> 100 ohm load resistor: motor moves a slight amount, then stops. I am not able to measure the peak current.


My receivers current limit ratting is 350mA mil and 600 mA max.

Motor(SG 2100) current ratting is 350mA

Regards
Mohanaprakash T