Help please
LtDan
Posts: 10
I have trouble installing batteries correctly so I would appreciate help with
a project I'd like to complete.
I would like to replace a magnetic reed switch that is used to count
revolutions with an IR sensor/proximity sensor.
The counter is a Red Lion Cub3.
If anyone could provide the details for components and schematic
it would be greatly appreciated.
The reason I used the magnetic reed switch is probably obvious- the
problem using it is that it can't detect at rates over @ 840 rpm's.
Thanks for any help provided.
a project I'd like to complete.
I would like to replace a magnetic reed switch that is used to count
revolutions with an IR sensor/proximity sensor.
The counter is a Red Lion Cub3.
If anyone could provide the details for components and schematic
it would be greatly appreciated.
The reason I used the magnetic reed switch is probably obvious- the
problem using it is that it can't detect at rates over @ 840 rpm's.
Thanks for any help provided.
Comments
The hall effect detection exceeds the rpm range I'll be using.
Changing the polarity of the magnet currently in place is not a problem.
Although a reflective surface for the IR is not a problem there does seem to
be a spacing limitation to deal with that the hall effect will somewhat eliminate or
at least give a wider margin for adjustment.
Even so, I still face the ignorance problem preventing me from acquiring the correct components
I'm guessing the material list is:
1 capacitor - 10nf
1 resistor- 5.6
1 hall effect sensor
1 power supply ( not sure but guessing a 3.6V- 50mA "wall wart")
I appreciate your efforts kwinn.
http://www.redlion.net/Products/Groups/Archive/CUB3/3R/Docs/01008.pdf
Two wire, reset.
Should using the Hall Effect require using a power source
then upgrading the counter to a backlit 5 digit would be good. ?
I might be wrong about this, but it appears that the Hall Effect sensor that kwinn indicated requires a minimum of 3.5 volts to operate. but your Red Lion can only provide 3 volts. So it looks to me like you would need an external power supply to run the Hall Effect switch, and then the output of that Hall Effect switch would need to operate a transistor that switches the Red Lion's 3 volts. In other words, I don't think the Hall Effect sensor can directly switch your counter's input lines: you'll need an extra transistor.
As for upgrading to a 5 digit device... what exactly are you talking about with that?
You omitted the import part of ugrading the counter which is "backlit" as the Cub3 is a five digit
counter but not lighted. I can see that the counter is adding confusion so please disregard.
I'll be happy if I can get the Hall Effect information needed to work with the Cub3.
A simple material list of power supply and components needed to operate the Cub3 with a Hall Effect sensor would
be appreciated.
How many pulses per second (Hz) would you need to count? There are micro reed relays rated up to about 500 Hz which perhaps could replace the particular reed relay you are now using. See for example:
http://www.digikey.com/product-detail/en/ORD211-1015/374-1083-ND/2171060
http://www.meder.com/fileadmin/meder/pdf/en/Products/OKI_Switches-En/OKI_Switch_ORD211.pdf
For such a reed relay, you would not need any other components.
I do know that it stops triggering the counter at @ 890 rpm's.
If there is a better reed switch that will work up to @ 2,000 rpm's It would
be preferred, easier and I wouldn't have to deal with power and all this other
stuff I don't know about.
I guess the fastest that I could try would tell. Is that what you linked to?
I found that higher speed reed switch by searching on Digikey for a reed switch that could handle the smallest amount of current, and because your Red Lion counter does not pass much current through the sensor, I figured that would work out okay.
840 rpm works out to be 840/60 = 14 Hz.
For 2000 rpm, you have 2000/60 = about 34 Hz, which is well below 500 Hz if there is only a single magnet passing the reed switch on each revolution.
Do you know how many magnets are on the wheel or whatever is turning? Is it only one magnet or are there more?
Solving for N in (2000/60)N = 500, you could have up to about 14 magnets on the wheel (14 magnet-passes per revolution) on your system and still be below the 500 Hz max of the reed switch at 2000 rpm.
Only one magnet and others using the Cub3 can count much faster than 2,000 rpm's as it's rated
to handle 6,000 rpm's.
I've read they are using IR proximity sensors - that is why inquired seeking help with components
to do that.
Now you are saying I can save myself the hassle and use a faster magnetic reed switch.
Either way to achieve the desired result would be good.
I'd also like to thank you very much for helping me with this.
I can't speak from experience because I've never used that particular reed switch or a reed at those speeds, but that's how I interpret their data sheet.
I suppose you could order a couple of those reed switches and the Hall Effect switch and give them all a try. I would gladly help with the transistor design of the Hall Effect switch but I'm terrible when it comes to transistor design. Maybe kwinn or somebody else much smarter than I could suggest a complete design for that. kwinn???
Due to the reed switch stopping at relative low rpm's I thought it was simply the mechanical
properties hampering the performance.
I've ordered the reed switch you linked to, just to try.
I feel that the Hall Effect or IR proximity sensor will give 100 % accuracy.
I've seen it checked in YouTube video - that's what sent me in this direction.
Currently it's low rpm's with questionable accuracy.
I hope we can put together a material list for the Hall Effect. It would be appreciated
and I believe it's the solution for the accuracy desired.
That parts list is what you need provided you get a 5.6K resistor instead of 5.6 ohms (I assume that was a typo). You could use a 3.6 to 5V wall wart of 50mA or higher current rating. The output of the sensor is open collector so an external transistor should not be needed. After looking at the data sheet for the Cub3 it looks like it was designed to operate with a reed relay contact closure or an open collector transistor.
Thanks, kwinn. I'm glad you helped out with this.
Thank you both very much.
It wasn't a typo kwinn...I'm flying be the seat of my pants.
You're not alone! Welcome to the forums!
Yes, welcome LtDan. We're all flying by the seats of our pants at times so it's great to have all the forum members to help out when needed.
It seems like a great forum...but unfortunate when one such as myself, asks
for help and has nothing or little to offer back... well I do have appreciation.
It also seems that I'm not naturally wired for this so I'm not expecting
rapid progression on my part.
I don't plan on asking every little thing either. I did try and did search for
solutions/answers before asking. I just couldn't "get it" and needed to
solve this...now to try and resolve it.
Again, my thanks for the help and warm welcome.
It is a great forum with a lot of knowledgeable, helpful, and friendly members. Forum members do encourage folks to learn for themselves rather than provide all the answers, but are always willing to pitch in if you get stuck, so don't hesitate to ask for help.
that I'm aware of.
I'll be giving it my best shot when I receive them.
If I do send smoke signals...I survived at the least. Thanks kwinn
and I'll let you know how it goes- good or bad.