Most dishwashers come equipped with an indicator that lets people know when the dishes have gone through a complete washing cycle. Some people will open the dishwasher and get some clean dishes, but they won't unload it completely. The "clean" indicator will turn off, but people might not know whether the dishes are clean.
This gadget uses a flashing green LED to let people know the dishes are clean. An infrared proximity sensor detects the presence of a person near the dishwasher and turns on the LED circuit. The LED state remains set until someone completely empties the dishwasher. Even after you open the door and take out only a few dishes, the green LED will flash when people approach the dishwasher, so they see a reminder to unload it completely.
After the dishwasher is emptied, a red LED starts flashing, and people can start to load it with dirty dishes. Now no one will have any doubt about whether the dishwasher is full of dirty or clean dishes. The indicator tells it all.
Jitendra Tailor's gadget uses a proximity sensor and a flashing LED to alert his family members when to unload clean dishes from the dishwasher or load it with dirty dishes.
Here are the mounting positions of the LEDs and the infrared proximity sensor on the outside of the diskwasher's kick plate.
I love this project - it solves what is usually a nightly drama in our house, "Hey Josh - are the dishes in the dishwasher clean or dirty?" I used to use a refrigerator magnet that had clean and dirty printed on it and you would rotate it 180 degrees depending on the state of the dishes - but I would always forget to rotate it. Having a hands-free solution is sweet and I agree - very well documented. Now we just need something to tell us how long the leftovers have been in the refrigerator...
I like the red LED idea. In my house, with as many as six people using the dishwasher, I'm never sure if I'm loading dirty dishes in with clean ones that never got removed. I end up pulling the dishes out to examine them and then I decide if they're clean or dirty.
Or the water check, Charles - you know where you take your finger and touch to see if any water pooled on the bottom of the coffee cups that are placed upside down in the top rack...of course if its been long enough the water would have evaporated so its not always an accurate test.
I agree, Rob - it is surprising that it hasn't been implemented since its such a universal problem for those of us with dishwashers. Our old dishwasher just gave out last month and Hubby and I went dishwasher shopping. It's amazing the vast array of options that exist but not that one...I would definitely consider this gadget to be a value-added feature that would influence my buying decision.
Nancy, I agree this gadget would be a value-add for a dishwasher. How did the magnet work out? In my house, my kids (teenagers now) would forget to flip the magnet. I would end up washing the same dishes two or three times. I just know it.
My kids would forget to flip the magnet, Rob - but I couldn't really get upset with them. More times than not, I forgot too and it's not getting any better the older I get! My son made me some coffee earlier today and I forgot to pour some out of the coffee maker when it was ready until I heard the beep announcing the auto-shutoff two hours later! I think we need these types of gadgets on all of our appliances, especially for folks like me who get easily distracted...
I definitely agree, Nancy. It's a good idea for big families. When five or six or seven or more people use the dishwasher, it's almost impossible to keep everyone on the same page, especially when you have people running it late at night.
Nancy, I agree. The audible and visual indicators on consumer appliances reminds me of Tom's Igoe Make book, Making Things Talk. The book describes through Maker projects how to add sensors, microcontrollers, LEDs, speakers, and other audible/visual indicators to present information. This Dishwater Indicator is just an example of making things talk or communicate information: in this case when the diswasher needs to be unloaded. Cool Gadget Freak device!!!.
The indicator on our dishwasher resets only when you fully close the door after the wash cycle. So you can take dishes out all you want as long as the door doesn't latch closed and the clean dish indicator stays lit. Once you've emptied the dishwasher, you latch the door and the light goes out.
Since we only fully close the door when we run the wash cycle, this works very well. Unless you accidently bump the door closed, of course!
We had the same problem. I mounted a tag next to the dishwasher, black on one side (dirty) and white on the other (clean). While loading we keep the black side out. When we start the machine we flip the tag. I apologize to my fellow gadget freaks that we were unable to incorporate at least a thousand triode sections in this solution.
We used to have a fridge magnet, black on one side, and white on the other, to indicate clean or dirty dishes in the dishwasher. It worked perfectly until we got a new dishwasher with a stainless-steel front panel that, curiously, isn't magnetic...
We tried all the magnets, cup, etc routines as well and of course - we forget to rotate, etc the device.
Our solution is to fill the detergent container when we empty the washer. That way we can continue to load dirty dishes until filled (may be a few days) if there is detergent present. If no detergent, we just keep taking dishes out until empty - then fill w/dtergent.
The vision system is the operator. The first one to the dish washer empties so it's ready for the next dirty item. No excuses.
What I would like to see is a condensing unit added to dish washers to condense the steam and allow it to be drained with the other water. Thus, when the "I'm done" light comes on and you open the door you don't get a blast of steam on your glasses and add humidity to your house, especially in the summer when you're paying the air conditioner to remove heat and humidity. It would also eliminate the water that has re-condensed into the depressions in cups, etc. Seems lke a compressor, agitation fan, and a condensing coil that would fit in your hand would do the job. Then when the "I'm done" light comes on it would indicate the humidity is gone the dishes are safe to transport . . .Simple. Still the first one to need something from the dish washer empties it.
Those are really valid things when you have responsible people that utilize the dishes. Try telling that to a 2 year old, a 6 year old and an autistic adult that works on the level of about 4 years old. Unfortunately that is not real life so you try and find the solutions that will make life easier. Hey which is the reason we are engineers in the first place...imagine that!
In reading the article, that was also my immediate first question. My mind went to a pressure sensor on the rack rails, to gauge the extra weight of the dishes. But I like the vision sensor idea too --
JimT, The pressure sensor is a cool way to detect when the dishwasher is full or empty because of the absence or presence of weight from the dishes. I guess the only concerns in using the device are to ensure the sensor is tolerant to water while being in the dishwasher and not voiding the product's warranty by the install of the sensing unit. Nice idea though!
Mrdon - I guess a mechanical engineer thinks "Pressure-sensor" while (perhaps) an Optics Engineer thinks "vision sensor"-? Vision is probably a more waterproof solution ,,, I honestly don't have direct experience with either type sensor – Just thinking out loud.
Kevin, according to the instructions provided, the system doesn't know directly if you have taken some or all of the clean dishes out. It has a timer programmed such that if the door is 4.65 minutes in the horizontal position, the dishwasher has been fully unloaded, and less time indicates that only a few dishes have been removed. You can program the system to a different duration, if desired.
The build instructions explain that a 4.65 minute timer is used. The assumption is that it takes about that long to unload the DW. If you just open to grab a cup, the timer won't run long enough to set the red LED.
This is actually a pretty good and patentable project.
Cadman, we raise our kids with a very strong work ethic and laziness is not tolerated in our home (although relaxing is and there is a difference). That said, busy families can have hectic schedules which means running the dishwasher and going on to other things - or asking the kids not to run it because its too late at night or I am trying to work on something at the kitchen table and need quiet. I see your point, but for some families it really does make sense to have some type of indicator without encouraging laziness...the wash cycle can take quite awhile so its not a case of just doing the dishes and putting them away...
Cadman-LT, Sometimes our world can get really busy and we tend to forget the little household chores for example unloading the dishwasher. A little electronic reminder sometimes help to keep us on task and orderly.
mrdon, I agree. If you have a house full of people(kids) with chores to do, how do you know they actually did them. Maybe more devices are needed? Maybe one to see if someone lifted the trashcan lid to take the trash out...was the vaccuum actually used.....was the cat litter changed? the list goes on. I know it does. :)
Your are so correct, the list does go on. I think the key to the wireless concept is to have receivers attached to all household items family engaged with related to chores. The household chore monitoring system will send tweets to a smartphone when the item has been touched by a family member.
That is similar to the method (a sign) we use at home except we have 2 Post-It notes (Clean & Dirty). If I only take out a few dishes I leave the sign up. When the dishwasher is empty there is no sign and when we put in any dirty dishes the dirty post-it note goes up. Easy.
While this idea is nice it is in no way foolproof. First the sensor is a proximity sensor therefore as someone noted the software is programmed such that if the door is opened some duration of time (I think it was ~4.65 minutes) then the program would assume that all the dishes have been emptied otherwise it would detect whenever someone was in the proximity of the DW. Well if one thinks about this, it isn't very robust. Lets say your teenager is unloading the dishes and his/her iPhone rings just when they start unloading, well of course they will answer. They talk to their buddy for 5 minutes then come back and shut the DW door because they are in a hurry leaving a partially loaded dishwasher with the system now saying it is fully empty. The next person comes along with a dirty glass and sees that the DW can accept dirty dishes so they put the glass in. Now you have a DW with some clean and some dirty dishes.
If the designer did a DFMEA on his system he/she would have caught this and not used a proximity sensor with a time feature because it has a very high probability of failure. A better way to do this might be to use load sensors on the legs of the dishwasher (as someone noted) with a program that sets the weight of the DW with no dishes but it must also be after a wash cycle because there is always some residual water in the sump that adds some mass. Knowing that value, the program could then determine when the DW is empty of dishware. Of course even this isn't foolproof because the sensors have some tolerance which could make the system inaccurate to some degree, however I believe this would be a more precise way to accomplish this task. The other real question that must be asked is what is the cost of said system and is it something the consumer would be willing to pay for. Some thoughts from a DW engineer.
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