pulse sensor

[dreambox1959]

i m looking for pictures or advice for improve pulse per inch on actuator (opto coupler or something else)

 

[s-band]

Here are pics of the pulse mod that I did to a Pelco pan & tilt. It works fine with an RC2000 but I've now added absolute encoders for an accurate read out. The optical sensors are combined IR LED and optotransistor parts.

 

[Trust]

i m looking for pictures or advice for improve pulse per inch on actuator (opto coupler or something else)

 

[Channel Hopper]

i m looking for pictures or advice for improve pulse per inch on actuator (opto coupler or something else)

What size dish and motor are you using and is the current set up using the full travel ?

 

[dreambox1959]

I have Chinese actuators (old echostar?) even some with potentiometer,
they have 2 4 or 6 pole magnetic wheels, I would like to increase the PPI. It is quite easy to build or find optical fork sensors but do you have a source for the cogwheel?

 

[s-band]

I cut the disk using a Starrett hole saw and hand crafted the blades. If you want many slots, @Trust photo shows that. It should be possible to use saw cuts to do something similar.

Be careful that you don't exceed the counting rate of your controller. I only have 2 slots due to the gearing of the motors on the Pelco. Even now I have to run the Pelco at <60% full speed to keep within the range of the RC2k. I wonder if it's worth having the extra resolution for a standard jack given the play in many systems.

This is the opto switch that I used: Optoelectronics | Products | OPB620

 

[Channel Hopper]

I have Chinese actuators (old echostar?) even some with potentiometer,
they have 2 4 or 6 pole magnetic wheels, I would like to increase the PPI. It is quite easy to build or find optical fork sensors but do you have a source for the cogwheel?

Yes, but what is the actuator length and are you using the full travel on the dish ?

 

[Trust]

I made those “cogwheels” from simple plastic . No need to make extra electronics with That Crowtail device , its a 3 wire device giving nice pulses

 

[dreambox1959]

Yes, but what is the actuator length and are you using the full travel on the dish ?

I am looking for information on the opto detector, I have several actuators, one of them (Qarl3624) is a 48ppi on a UN8 screw (6 pulses each turn) with my software I count each change so I have 96 values per inch (that's good) but the duty cycle is not 50-50 but 20%-80%.

 

[Channel Hopper]

I am looking for information on the opto detector, I have several actuators, one of them (Qarl3624) is a 48ppi on a UN8 screw (6 pulses each turn) with my software I count each change so I have 96 values per inch (that's good) but the duty cycle is not 50-50 but 20%-80%.

OK, you have the 24" worm drive. How far does it extend on the polarmount from one extreme to the other ?

 

[dreambox1959]

the useful stroke for me is 575mm. why did you want this info?

 

[Channel Hopper]

the useful stroke for me is 575mm. why did you want this info?

Which is about the maximum.

To get a better accuracy you could upgrade to a QARL3636 and adapt the polarmount to maximise the full arc (850mm or thereabouts) which would improve your pulse count accuracy by 50%.