Slow down actuator with PWM controller?

[ozumo]

When trying to nudge the dish using my V-Box, each nudge is usually two pulses. Would using a PWM motor speed controller like this work to slow the actuator down (or rather reduce time the power is sent to the motor) and achieve a one pulse nudge?

https://www.amazon.co.uk/ARCELI-Upgraded-Controller-Regulator-Support/dp/B07MQ13ZGX/

My thinking is - if PWM is set to 50% the motor will only receive power for half the time, and only move around half as far - unless the V-Box is waiting for two pulses before stopping.

 

[ozumo]

Nevermind, it says do not reverse power supply

 

[Trust]

Its possible if you open the V-box and connect the PWM between the 36 V rectifier and the motor relais

 

[Channel Hopper]

I suspect it is either reed switch bounce in the actuator, or a lack of shielding in the cable.

Try reversing the magnetic wheel on the shaft in the first instance

 

[ozumo]

I don't think it's miscounting, I can nudge between stored positions without issue. Can I use a single run of coax for the sensor cable or would it need two? I have a surplus of WF100 after an incident with a strimmer

 

[s-band]

My nasty solution to a Uniden UST771 driving the jack too fast. A 22R resistor. The 771 puts out about 45V off-load and 40V driving a small jack.
As Trust said, doing something inside the box, before the switching, would be best but I was lazy.

 

[Channel Hopper]

I wouldn't run coax since one side is always going to be the outer shroud.

CAT6A external fit cable has good shielding properties, what's inside looks like the motorised ribbon cable of old.

 

[ozumo]

Does all the shielding need to be connected to ground?

 

[Channel Hopper]

No.

 

[Channel Hopper]

A picture of the elevation motor cable I use on most dual axis mounts.

For other sensor types I still use the same cable, by using the outer braid of the signal cable as the earth line ( eg Phillips/Fibo dish designs).

 

[jeallen01]

My nasty solution to a Uniden UST771 driving the jack too fast. A 22R resistor. The 771 puts out about 45V off-load and 40V driving a small jack.
As Trust said, doing something inside the box, before the switching, would be best but I was lazy.

Decades ago I had an NEC 5000 receiver/positioner that drove the NEC/Jaeger H-H mount with an 80cm dish on it at +/- 24V.

Later bought a more modern receiver/positioner that drove mounts at +/- 36V, but I didn't want to risk burning out the 24VH-H motor &/or turning too fast, so inserted a bank of w/wound resistors (in parallel) that brought the motor voltage back to around 24V - that worked happily for quite a few years.