[Tesseract]

No worries. I wasn't annoyed, just a little surprised at your interpretation of my earlier advice on RPM sensors and targets. Now back to your initial questions:

A PNP proximity sensor (just called a 'prox' for short) requires a resistor from TACH to SGND to operate correctly. This resistor is often called a pulldown because it pulls the output down to ground whenever the transistor is off. A pullup resistor, which is used with NPN output sensors, pulls the output up to the positive supply voltage (ie - S12V on the Soliton controllers) whenever the transistor is off. Whether you use a pullup or pulldown resistor, then, depends only on the polarity of the output transistor.

I'm not familiar with the Siemens prox you selected, but if it has 1-2mm sensing distance, is an "inductive" type (that is, it detects any change in metal, and not just ferrous or magnetized metals), runs on 10-30VDC and has a PNP open collector output then it should work fine.

Finally, I concur with the suggestion that you use shorter bolts as a sensing target, not only because it will increase the output pulse width from the sensor, but also because you really want the bolt head to be tightened up against a surface (preferably with a toothed lockwasher underneath it) so that it won't loosen up from vibration over time.

[TTmartin]

Originally Posted by Tesseract

No worries. I wasn't annoyed, just a little surprised at your interpretation of my earlier advice on RPM sensors and targets. Now back to your initial questions:

A PNP proximity sensor (just called a 'prox' for short) requires a resistor from TACH to SGND to operate correctly. This resistor is often called a pulldown because it pulls the output down to ground whenever the transistor is off. A pullup resistor, which is used with NPN output sensors, pulls the output up to the positive supply voltage (ie - S12V on the Soliton controllers) whenever the transistor is off. Whether you use a pullup or pulldown resistor, then, depends only on the polarity of the output transistor.

I'm not familiar with the Siemens prox you selected, but if it has 1-2mm sensing distance, is an "inductive" type (that is, it detects any change in metal, and not just ferrous or magnetized metals), runs on 10-30VDC and has a PNP open collector output then it should work fine.

Finally, I concur with the suggestion that you use shorter bolts as a sensing target, not only because it will increase the output pulse width from the sensor, but also because you really want the bolt head to be tightened up against a surface (preferably with a toothed lockwasher underneath it) so that it won't loosen up from vibration over time.

Thank you for suffering a fool gladly
I think I must of latched on to the pulse width thing, meaning longer between pulses, not longer pulses.
The reason I used long bolts was to create a larger diameter with out increasing the collar size, so as to give a longer time between pulses, (stupid me)
But as regards the security of the bolts, they are actually screwed into drill dimples in the motor shaft locking the collar and the bolts , they were going to be locked with stud, Loctite fluid.
Anyway, slight modification required (SHORTER BOLTS WITH LARGER DIAMETER HEADS)
Really appreciate your advice/guidance
Thank you.
Oh, if Ruckus and Malcomb are around sorry for sounding like I new what I was talking about, I clearly didn't. I got it wrong big time, thank you for your input also.
On a positive note, I'm learning

[MalcolmB]

No problem Martin. Glad you got it straightened out. Most of us are still learning here, and that definitely includes me

[PStechPaul]

You could make a speed sensor from a shaft collar, machining two sides so that the on/off periods will be about equal. Like this:

[TTmartin]

Originally Posted by PStechPaul

You could make a speed sensor from a shaft collar, machining two sides so that the on/off periods will be about equal. Like this:

That's nice and simple, looks good.
I've nearly finished modifying the one I already have but if it gives any problems, I think your suggestion will my be plan B

Thanks

Martin.

[teoami]

Not to go too far off topic, or beat a dead horse, but I just wanted to clear something up. (Being a math nerd and all)

The diameter of a circle (in this case, created by the bolts) does not affect the frequency of said circle.

Two long bolts vs two short bolts placed at equal intervals will yield the same number of pulses. The only thing that would increase the number of pulses is to add more bolts or increase the RPM.

Two circles of different diameters spinning at the same RPM will give you the exact same speed (or number of pulses).

However, I do agree that the bolts need to be locked in somehow and the shorter bolts with lock washers suit that need better.
Also, the width of the bolt head will affect the pulse so you do need to follow the formula from Tesseract.

[skooler]

Originally Posted by teoami

Not to go too far off topic, or beat a dead horse, but I just wanted to clear something up. (Being a math nerd and all)

The diameter of a circle (in this case, created by the bolts) does not affect the frequency of said circle.

Two long bolts vs two short bolts placed at equal intervals will yield the same number of pulses. The only thing that would increase the number of pulses is to add more bolts or increase the RPM.

Two circles of different diameters spinning at the same RPM will give you the exact same speed (or number of pulses).

However, I do agree that the bolts need to be locked in somehow and the shorter bolts with lock washers suit that need better.
Also, the width of the bolt head will affect the pulse so you do need to follow the formula from Tesseract.

Yes you are correct.

The point that was being made was not about frequency. It was about the width of the pulse generated.

By reducing the rotating circumference of the target (by shortening the bolts), the pulse width is increased (the bolt head is the same size but travel less per rotation). Therefore, the bolt head spends longer in an area where it can be picked up by the proximity sensor to generate the pulse.

Make sense?

Cheers,

Mike

[Hyatt]

Hello Ruckus,

I am about to buy my sensor and thought I would just buy one I know is working with a Soliton controller. Can you give me the part number of your sensor? I can see the "E2E" in the picture, but that's all.

Thanks,

Hyatt

[Tesseract]

Originally Posted by Hyatt

Hello Ruckus,

I am about to buy my sensor and thought I would just buy one I know is working with a Soliton controller. Can you give me the part number of your sensor? I can see the "E2E" in the picture, but that's all.
...

Ruckus doesn't have a Soliton controller and this question is very Frequently Asked, hence there is a FAQ entry about it on our website:

http://www.evnetics.com/support/faq/

Lots of good info in this thread as well.

[Hyatt]

Thanks Tesseract! I had already been planning on buying from Automation Direct, it was a pleasant surprise to see that this is your recommendation.

Hyatt