Page 1 of 2 12 LastLast
Results 1 to 15 of 21

Thread: Dust bin sensor to power down collector

  1. #1
    Join Date
    Nov 2018
    Location
    Eagle, WI
    Posts
    130

    Dust bin sensor to power down collector

    Others have described building a sensor that detects the level of dust collected in dust bin. https://sawmillcreek.org/showthread....nsor-Completed

    I plan to build such a sensor and am wondering about the feasibility/practicality of programming the sensor to not only turn on an alert light when the dust bin is full, but possibly to power down the collector. Has anyone tried this?

    Peter

  2. #2
    I am working in this direction - ever so slowly.

    I have a Pentz DC with 5hp 3ph motor, driven by Huanyang VFD. I use Eton remote for start/stop. It is a simple matter to insert a normally-closed contact in series with the Eton 'stop' circuit, and drive it open using a bin-full sensor.

    I looked at the bin-full sticky thread here (its been a month or 6), and recall the sensor is normally-open (::closes on high level, triggers light/buzzer). I would like to do both a warning and VFD stop, so need both NO & NC contacts. I set off on a search for the proper prox switch, equipped with both contacts - - and failed (so far). And then life intervened, and I have not gone back on the hunt.

    A simpler method would be to clone the bin-full system above, but drive a DPDT relay with the prox switch. Then the relay's NO contact drives the light/buzzer, and the NC contact drives the DC stop circuit. I would think the latter could be interfaced to any DC circuit - VFD/Starter/etc.

    I have not given up on the elegance of a prox switch doing it all. Never surrender.
    ******
    Adder - In my case, the prox could 'do it all' because the VFD 'stop' circuit is 5VDC - easily doable thru the prox. Depending on the starter coil a DC uses, a prox might be able to handle switching this coil load. But generally, a prox switch can't handle a 120VAC motor load - - so some interposing relay would be required.
    Last edited by Malcolm McLeod; 01-07-2021 at 11:54 AM.

  3. #3
    Join Date
    Jul 2007
    Location
    NE OH
    Posts
    2,612
    Quote Originally Posted by Malcolm McLeod View Post
    I am working in this direction - ever so slowly.

    I have a Pentz DC with 5hp 3ph motor, driven by Huanyang VFD. I use Eton remote for start/stop. It is a simple matter to insert a normally-closed contact in series with the Eton 'stop' circuit, and drive it open using a bin-full sensor.

    I looked at the bin-full sticky thread here (its been a month or 6), and recall the sensor is normally-open (::closes on high level, triggers light/buzzer). I would like to do both a warning and VFD stop, so need both NO & NC contacts. I set off on a search for the proper prox switch, equipped with both contacts - - and failed (so far). And then life intervened, and I have not gone back on the hunt.

    A simpler method would be to clone the bin-full system above, but drive a DPDT relay with the prox switch. Then the relay's NO contact drives the light/buzzer, and the NC contact drives the DC stop circuit. I would think the latter could be interfaced to any DC circuit - VFD/Starter/etc.

    I have not given up on the elegance of a prox switch doing it all. Never surrender.
    My kit from Oneida came with a Banner QS18vp6d sensor (which works well for me). It has both NO and NC outputs. The NC is not used in the standard setup but the wire is available. That sensor cannot handle a lot of current, but can easily drive a solid state relay. The QS18vp6d has pnp outputs. If you need npn outputs, the QS18vn6d is the one you want.

    But I think there is a bigger issue with controlling the collector directly from the sensor. Because you have all kinds of "stuff" flying around in the bin, it is common for the sensor to trip briefly when the bin is not full. You see short little flashes of the beacon, at random times and intervals as the bin fills up. If you stopped the blower every time the sensor did this, you would drive yourself mad, not to mention stressing the motor from all the frequent starts. You need some delay to filter out the short sensor pulses. Simple enough to do, and the thread you refer to (I believe) talks about one way to do this. But I wouldn't do it without a delay function.
    --I had my patience tested. I'm negative--

  4. #4
    Quote Originally Posted by Paul F Franklin View Post
    My kit from Oneida came with a Banner QS18vp6d sensor (which works well for me). It has both NO and NC outputs. The NC is not used in the standard setup but the wire is available. That sensor cannot handle a lot of current, but can easily drive a solid state relay. The QS18vp6d has pnp outputs. If you need npn outputs, the QS18vn6d is the one you want.

    But I think there is a bigger issue with controlling the collector directly from the sensor. Because you have all kinds of "stuff" flying around in the bin, it is common for the sensor to trip briefly when the bin is not full. You see short little flashes of the beacon, at random times and intervals as the bin fills up. If you stopped the blower every time the sensor did this, you would drive yourself mad, not to mention stressing the motor from all the frequent starts. You need some delay to filter out the short sensor pulses. Simple enough to do, and the thread you refer to (I believe) talks about one way to do this. But I wouldn't do it without a delay function.
    Excellent point. Spurious trips could REALLY degrade customer confidence. Still in the (mental) design stage, so will incorporate it - thanks.

    I am trying to talk myself into just grabbing a pile of current sensors, actuated blast gates, and AB MicroLogix 1400 to automate the whole thing. Next week?

  5. #5
    Join Date
    Nov 2006
    Location
    Northeastern OK
    Posts
    301
    I recently built a dust bin sensor using the Banner transducer device. I considered having it shutdown the collector fan but decided against that. Intermittent shutdowns could be avoided with a time delay circuit to keep the relay engaged or something similar using solid state electronics. The real problem in my opinion is having the dust collector shut down in mid operation. Imagine running a large board through a planer and having the fan die just as you engage the board. At minimum a mess is made. Worse case something plugs up. It is better to have the light flashing for a few minutes while you finish off whatever operation is in process.

  6. #6
    To me, worst case is the DC filters fill up and require cleaning. YMMV

    It is certainly possible to have the alarm function on zero delay, but have the stop function on a delay suitable to the user. It all depends on your tolerance for the complexity of the circuit & devices. ...now where did I put that MicroLogix?!

  7. #7
    Join Date
    Feb 2008
    Location
    E TN, near Knoxville
    Posts
    12,298
    I bought one from ClearVue that did just that: uses optical sensors (garage door sensors) to detect when the bin is full. The sensors look across a short length of 6" diameter clear flex hose connecting the bottom of the cyclone to the bin. When full, it cuts the power to the cyclone if desired - your choice. At the same time it sounds a loud alarm and flashes a bright white strobe to get your attention if you are wearing hearing protection and/or there is a lot of noise.

  8. #8
    Join Date
    Nov 2013
    Location
    Crozet, VA
    Posts
    638
    I have a more general question on these circuits as I’m troubleshooting mine that has flaked out on me. Given the choice between running them off a 12V or 24V power supply, which is preferred? I was thinking 24V would be better as it would in theory draw less current that could overload the delay/timer circuitry but this is not my area of expertise.
    There is a very fine line between “hobby” and “mental illness.” - Dave Barry

  9. #9
    Join Date
    Jul 2007
    Location
    NE OH
    Posts
    2,612
    The answer, of course, is it depends. It is mostly the case that a circuit *designed* to run on 24 volts will draw less current than a similar circuit *designed* to run on 12 volts. But it is not necessarily true that a circuit designed to run on a range of voltages, say 12-24 volts, will draw less current at 24 than at 12.

    If a circuit has been designed to work either at 12 volts or 24 volts, then in a electrically noisy setting, there is often an advantage to running at the higher voltage, but it really depends on how the circuit was designed.
    --I had my patience tested. I'm negative--

  10. #10
    Quote Originally Posted by Tom Bain View Post
    I have a more general question on these circuits as I’m troubleshooting mine that has flaked out on me. Given the choice between running them off a 12V or 24V power supply, which is preferred? I was thinking 24V would be better as it would in theory draw less current that could overload the delay/timer circuitry but this is not my area of expertise.
    I'm afraid I can only give you a general answer. Most newer (modern?) sensors, timers, and relays pertinent to this thread have a relatively wide voltage range - say 9-28VDC. So they will operate just fine on any of these voltages. Just make sure your supply voltage meets these limits - including AC or DC, and they will 'sense', 'time', or 'relay' (contacts will switch) as advertised. Ampere draw for these devices would rarely if ever exceed 1-2A total, even at the lowest voltages. Excluding the final motor load, of course. Also, make sure the power supply can supply the total amps required: all the devices together may only need 2A, but lots of the small wall-wart power supplies I see used are only rated for 0.5A.

    In my experience the most common problem with small logic controls like this is the switching of the final loads. This would be the blower motor itself in this case. If this load exceeds the ampere rating of the logic device relay contacts, they can be damaged and release the magic smoke.
    Last edited by Malcolm McLeod; 01-08-2021 at 10:06 AM.

  11. #11
    Join Date
    Feb 2008
    Location
    E TN, near Knoxville
    Posts
    12,298
    Quote Originally Posted by Tom Bain View Post
    I have a more general question on these circuits as I’m troubleshooting mine that has flaked out on me. Given the choice between running them off a 12V or 24V power supply, which is preferred? I was thinking 24V would be better as it would in theory draw less current that could overload the delay/timer circuitry but this is not my area of expertise.
    Tom, Most circuits like this draw very little current so I can't imagine the voltage difference you mention would make any difference. Mostly the voltage is decided by the designer when choosing components.

    What exactly is the problem, the symptoms?
    Did it fail suddenly, after some erratic behavior, ???
    Is this a circuit you built yourself or purchased?
    If purchased sometimes it's easier to buy a replacement board.

    I debug things like this in stages depending on the symptoms.
    - I first verify that the power supply is producing the proper voltage.
    - Visually inspect all wires, components, and PC boards for damage or suspected damage (does anything look overheated or smell burned?).
    - Unplug and reset every connector in the system - occasionally solves the problem, especially if the environment has temperature fluctuations or some humidity.
    - Test any cables.
    - Visually check the PC board for and remelt any suspected cold solder joints. (that fixed air conditioning circuits on two of our vehicles the same day!)
    - Test suspected diodes, capacitors, coils, transistors, etc. using a voltmeter or oscilloscope. (Sometimes have to unsolder components to isolate them from the circuit.) Mechanical things like switches are always suspect.

    Do you have a circuit diagram? If necessary and the circuit is not too complex I'll create a diagram and work from that. Circuits with custom ICs can be difficult to debug. I fixed the controller in my friend's old massage chair just last week with careful examination and some microscope surgery to repair a physical break in one leg of a mystery component.

    You can sometimes find electronics expertise at Maker clubs, sometimes free from enthusiasts.

    JKJ

  12. #12
    Join Date
    Nov 2013
    Location
    Crozet, VA
    Posts
    638
    John — That is very gracious of you. It’s just the dust bin sensor circuit that is described in the sticky thread. I suspect the delay/timer/relay module has gone haywire. For reasons unknown after it counts down it doesn’t actually trigger the relay/switch on. I’ve tried rebooting it, and it won’t go into programming mode. So, for $10 I’m just going to order a new one and hope it doesn’t fail again ... but what prompted my question is I was thinking of switching to the 24v version in the off chance that would provide some benefit ... which it sounds like it really won’t.
    There is a very fine line between “hobby” and “mental illness.” - Dave Barry

  13. #13
    Join Date
    Apr 2010
    Location
    Nashville, TN
    Posts
    1,544
    There are sensors available that already do this. They have multiple switches, delays, sensitivity adjustment etc, but they may be a lot more expensive than what you are looking to do. Babbitt is a brand we use a lot.

  14. #14
    Join Date
    Nov 2018
    Location
    Eagle, WI
    Posts
    130
    Thank you for your insights. I think my first step will be to build a ‘lights flashing’ sensor. If that doesn’t meet my needs, I’ll consider adding a shut-down function to the sensor. I appreciate your advice and willingness to share your experiences.

  15. #15
    Join Date
    Dec 2006
    Location
    Toronto Ontario
    Posts
    11,236
    Quote Originally Posted by Malcolm McLeod View Post
    Excellent point. Spurious trips could REALLY degrade customer confidence. Still in the (mental) design stage, so will incorporate it - thanks.

    I am trying to talk myself into just grabbing a pile of current sensors, actuated blast gates, and AB MicroLogix 1400 to automate the whole thing. Next week?
    Hi Malcolm, my design incorporates a 10 second time delay to avoid nuisance trips.

    I did have my detector shut down the cyclone however that resulted in plug up of all plug ups in my planer. Now I only use the flashing beacon, since the bin sensor triggers about 10cm before full it gives me lots of time to complete what I’m doing......Regards, Rod.

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •