My apologies to everyone that responded to my original thread. I had notifications turned off and forgot about this thread! Life took over and this project got benched for a year.
This was my original question
"I am building a dust collection cyclone for my wood shop and assembled a sawdust bin level shutoff circuit but I have a concern. A normally open 110 vac photoelectric switch energizes a dpdt relay and shuts off power to a 40amp motor relay when the sensor see's an object within four inches. My concern is the sawdust in the bin will be swirling around and might trigger the sensor before the bin is full. I dropped a handful of sawdust in front of the photoelectric switch and it rapidly switched the 40amp relay on and off. I do not want this happening to a 5hp compressor duty motor. My thoughts are to integrate a time delay relay that only shuts off the 40amp relay after it has a steady object sensed for at least :30 seconds and ignore intermittent object sensing."
The cyclone is nearly complete and I will soon be after a bin full sensing solution. When I get the cyclone up and running I will test the photoelectric switch with a light bulb to see how it reacts to air currents in the bin.
Thank you for the 555 suggestion. I looks plausible but I need to dust the cobwebs off the electronics knowledge first.
The weight sensing suggestion may not work. I have heard reports that when the cyclone is turned on it lifts the collection bin off the floor through the small section of flexible duct between the cone and the bin.
The capacitance and paddle solutions look like better solutions and are proven in industry. They are expensive through! The bin is plastic so I wonder if that would affect the capacitance type system.
Here's a couple of pictures to give you an idea of what we're talking about. 5hp motor, 16" material handling impeller, 8" inlet and 6" ducting to all the tools. I'm modifying all the dust collection hoods and ports to accept 6" ducting. This has been a monumental project.
This was my original question
"I am building a dust collection cyclone for my wood shop and assembled a sawdust bin level shutoff circuit but I have a concern. A normally open 110 vac photoelectric switch energizes a dpdt relay and shuts off power to a 40amp motor relay when the sensor see's an object within four inches. My concern is the sawdust in the bin will be swirling around and might trigger the sensor before the bin is full. I dropped a handful of sawdust in front of the photoelectric switch and it rapidly switched the 40amp relay on and off. I do not want this happening to a 5hp compressor duty motor. My thoughts are to integrate a time delay relay that only shuts off the 40amp relay after it has a steady object sensed for at least :30 seconds and ignore intermittent object sensing."
The cyclone is nearly complete and I will soon be after a bin full sensing solution. When I get the cyclone up and running I will test the photoelectric switch with a light bulb to see how it reacts to air currents in the bin.
Thank you for the 555 suggestion. I looks plausible but I need to dust the cobwebs off the electronics knowledge first.
The weight sensing suggestion may not work. I have heard reports that when the cyclone is turned on it lifts the collection bin off the floor through the small section of flexible duct between the cone and the bin.
The capacitance and paddle solutions look like better solutions and are proven in industry. They are expensive through! The bin is plastic so I wonder if that would affect the capacitance type system.
Here's a couple of pictures to give you an idea of what we're talking about. 5hp motor, 16" material handling impeller, 8" inlet and 6" ducting to all the tools. I'm modifying all the dust collection hoods and ports to accept 6" ducting. This has been a monumental project.

