Hey fellows, couple of questions. I have a led on my Fridge that lights up every six months telling me its time to change the water filter. I'm assuming its using a 555 chip or some timing circuit to turn this light on every six months. To turn this led off, you have to press a reset button. I actually change the filter every two years or when I noticed the water flow start slowing down. My Cuisinart coffee maker has a red light light come on when the maker supposedly needs cleaned. I havn't noticed any set time when this coffee maker decides that it needs cleaned. Here is my question. After I go through the cleaning routine with the white vinegar, the red light goes off by its self. I didn't unplug it or reset anything. this is a $50 coffee maker. How did it know if I actually cleaned it or not? What kind of sensor could determine this? Thanks!

 

It isn't using a timer. More than likely it is using a micro controller that is controlling most or all of the appliance. There may be multiple micro controllers in the appliance.

And chance are it is not watching time rather the number of uses,. It could be doing this by monitoring the total volume of water dispensed or simply the total amount of time the pump was on. Voulme could then be extrapolated from that with the assumption that water was actually flowing. And it could monitor supply water pressure so the timer won't start if the supply water is off.

 

It's likely the fridge has an internal clock. Though it's not displaying any time (some of them do) the clock is used for things like automatic defrost cycles (frost free fridge). It's a simple counter matter to trigger a filter alarm every six months.

As for the coffee maker: I couldn't begin to guess how they know you just cleaned it. To be honest, I'm not quite believing you the red light goes off when you put it through the cleaning cycle. Unless there's a different button or configuration you are required to follow for cleaning. I really don't think coffee makers have sensors that "Know" when you clean them. As for flow - from what I've seen on every coffee maker (cheap ones anyway) there's a heat element. When the water boils it flows through the tube into the carafe (pot). The only sensors I've seen in these cheap makers is the one that controls the boiler and one that controls the hot plate under the carafe. For thermal protection there's a fusible link that is designed to burn out at a certain temperature. If the system over heats the link burns out and shuts down the maker.

So to answer your question on how the coffee maker knows when you cleaned it - honestly, I can't imagine a way to do that without some sort of gas chromatography sensor. And those aren't cheap.

 

It's likely the fridge has an internal clock. Though it's not displaying any time (some of them do) the clock is used for things like automatic defrost cycles (frost free fridge). It's a simple counter matter to trigger a filter alarm every six months.

As for the coffee maker: I couldn't begin to guess how they know you just cleaned it. To be honest, I'm not quite believing you the red light goes off when you put it through the cleaning cycle. Unless there's a different button or configuration you are required to follow for cleaning. I really don't think coffee makers have sensors that "Know" when you clean them. As for flow - from what I've seen on every coffee maker (cheap ones anyway) there's a heat element. When the water boils it flows through the tube into the carafe (pot). The only sensors I've seen in these cheap makers is the one that controls the boiler and one that controls the hot plate under the carafe. For thermal protection there's a fusible link that is designed to burn out at a certain temperature. If the system over heats the link burns out and shuts down the maker.

So to answer your question on how the coffee maker knows when you cleaned it - honestly, I can't imagine a way to do that without some sort of gas chromatography sensor. And those aren't cheap.

Exactly! Just to recap, I come downstairs in the morning and the clean button is illuminated.
http://www.mediafire.com/convkey/03bd/c2si99047cz24eb6g.jpg
(can't attach picture here for some reason).
I press the clean button to turn off the light, then brew my pot of coffee, no problem. The clean light doesn't come back on.This routine happened a number of times.
Come downstairs yesterday, same thing. clean button lit up. I shut it off but this time I'm going to clean it. Run white vinegar through a couple of times then a couple of water pots to flush it. Come down the next morning and the clean light is not on. Somehow that coffee maker knew that I ran vinegar through it, ie, cleaned it and just didn't make a pot of coffee. Weird. It must have some sophisticated electronics in it. Just curious. Thanks for your input!

 

Exactly! Just to recap, I come downstairs in the morning and the clean button is illuminated.
http://www.mediafire.com/convkey/03bd/c2si99047cz24eb6g.jpg
(can't attach picture here for some reason).
I press the clean button to turn off the light, then brew my pot of coffee, no problem. The clean light doesn't come back on.This routine happened a number of times.
Come downstairs yesterday, same thing. clean button lit up. I shut it off but this time I'm going to clean it. Run white vinegar through a couple of times then a couple of water pots to flush it. Come down the next morning and the clean light is not on. Somehow that coffee maker knew that I ran vinegar through it, ie, cleaned it and just didn't make a pot of coffee. Weird. It must have some sophisticated electronics in it. Just curious. Thanks for your input!

It didn't know that you ran vinegar through it. All it knows is that a sensor is clear. Probably and optical sensor. Dryers have these for lint traps. It really isn't "ophisticated" electronics at all.

 

An optical sensor would sound great. However, both fresh water and clear vinegar are both - um - clear. And the water doesn't turn black until it runs through the grounds. From there it's into the carafe. Or cup. Or into whatever vessel you put under the spigot. While an optical sensor would sound logical at first glance, you have to consider that both the water and the vinegar are going to be clear.

However, I did just think of something: Vinegar is probably going to boil at a different rate than water. I'd think faster. Maybe not. Maybe by measuring boil time one could discern the difference between water and vinegar. However, my wife has a cleaner she mixes with water then runs through the maker. So again, water. And at my elevation water boils at 203.4˚F. (95.2˚C)

 

Just looked it up. Vinegar is basically water and some sort of acitic acid. Typical food grade (market) is around 4% whereas industrial vinegar is around 20%. So vinegar is not going to boil any faster or slower than water. There IS a difference, but so minor as to not be discriminable between the differences in boiling points. And given that water boils at different rates at different altitudes - unless the coffee pot has a barometer it's not going to be able to tell the difference. That'd be a whole lot of engineering work for a cheap coffee pot.

It must be something simple like you pushed the clean button then the brew button one time but another time you pushed the clean button but didn't press the brew button within a time window and the machine automatically reset. The next morning the "Clean" lamp was lit again. I think it's due to operator habit and nothing more.

 

Hey fellows, couple of questions. I have a led on my Fridge that lights up every six months telling me its time to change the water filter. I'm assuming its using a 555 chip or some timing circuit to turn this light on every six months. To turn this led off, you have to press a reset button. I actually change the filter every two years or when I noticed the water flow start slowing down. My Cuisinart coffee maker has a red light light come on when the maker supposedly needs cleaned. I havn't noticed any set time when this coffee maker decides that it needs cleaned. Here is my question. After I go through the cleaning routine with the white vinegar, the red light goes off by its self. I didn't unplug it or reset anything. this is a $50 coffee maker. How did it know if I actually cleaned it or not? What kind of sensor could determine this? Thanks!

The coffee makers use a simple current sensing resistor and a comparator to determine when the pump motor is working too hard to move the water. It assumes there carbonate/scale build up that needs to be removed to unclog the tubes and reduce current load.

About $0.25 worth of parts.

 

My single cup maker has a pump. But no "Clean" button or light. My 10 cup maker has no pumps. It relies on water boiling and rising from the boiler up to the drip coffee grinds. I've never scrapped a maker that had a pump and a clean button/light. What Gopher says makes sense. I've never seen it - but I've never seen an alien flying saucer either. Doesn't mean they don't exist. Never seen an angel or a demon either. Well, I take that back. My son was rather - um - not so much like an angel.

 

Unless there's a different button or configuration you are required to follow for cleaning. I really don't think coffee makers have sensors that "Know" when you clean them

Why? Santa always knows if you have been naughty or nice!

 

The coffee makers use a simple current sensing resistor and a comparator to determine when the pump motor is working too hard to move the water. It assumes there carbonate/scale build up that needs to be removed to unclog the tubes and reduce current load.

About $0.25 worth of parts.

Yeah, there are lots of different technologies in some of the newer coffee toys. A lot of the cool tech has trickled down from commercial coffee equipment (my line of work.) There could be impeller based flow meters, conductivity based level probes, and a variety of other things involved.

I'd be interested to know the make and model of the machine in question.

 

You clean your coffee maker? Shame, there goes the flavour! I think nearly all modern appliances have an internet connection and are secretly controlled by the Russian hackers. When the day comes they will turn off your fridge and spoil your apple pies and ruin your coffee. Just mark my words!

 

You clean your coffee maker? Shame, there goes the flavour! I think nearly all modern appliances have an internet connection and are secretly controlled by the Russian hackers. When the day comes they will turn off your fridge and spoil your apple pies and ruin your coffee. Just mark my words!

When I have to walk down to the corner store and pick up a new apple pie, I'll think about you. They guy who has been warning people to have an Apple-pie contingency plan all these years. The whole 3-minutes it takes me to walk to that store I'll be kicking myself for not following your advice and planning for the day the Russians try to spoil my pie.

 

Yeah, there are lots of different technologies in some of the newer coffee toys. A lot of the cool tech has trickled down from commercial coffee equipment (my line of work.) There could be impeller based flow meters, conductivity based level probes, and a variety of other things involved.

I'd be interested to know the make and model of the machine in question.

Hello. The machine is a Cuisinart model # CBC6400-PC. I paid around $50 for it on sale at Costco about a year ago.

 

Cuisinart model # CBC6400-PC

Wasn't that formerly the "Binford 6400" coffee maker? I think the Binford 6400 had more power.

 

Hello. The machine is a Cuisinart model # CBC6400-PC. I paid around $50 for it on sale at Costco about a year ago.

Thanks for sharing. Now I'm even more intrigued - I haven't found a parts list or service manual yet, but even just a cursory look at the features makes me think it's the usual, basic internals, nothing fancy. I wouldn't expect this model to even have a pump (per GopherT's suggestion, which would make perfect sense if there is a pump.) Anyway, I'm very curious now. I may do some more research cause I'm always wanting to know more about coffee machines at any level. If I learn anything more, I'll let you all know.

 

A person on another electronic message board said this :

"
its just a thermal switch on the boiler unit.
when it gets limed up it runs hotter since the heat transfer to the water is impaired.trips the sensor and turns on the light.nice and simple.and useful."

Seems the most logical.

 

A person on another electronic message board said this :

"
its just a thermal switch on the boiler unit.
when it gets limed up it runs hotter since the heat transfer to the water is impaired.trips the sensor and turns on the light.nice and simple.and useful."

Seems the most logical.

That makes a lot of sense. Thanks for sharing what you found!

 

I heard about this the other day and in my opinion its taking technology too far. In the wake of hurricane Harvey,
A family had to rebuild part of their house. It was an older home and code called for upgrading the smoke detectors. The new ones are networked, maybe bluetooth, and have to be able to sound the alert as well as announcing in which room is the fire.
In my mind, a loud, abrasive alarm is all that is needed.

 

its just a thermal switch on the boiler unit.
when it gets limed up it runs hotter since the heat transfer to the water is impaired.trips the sensor and turns on the light.nice and simple.and useful."

Seems the most logical.

But water boils at different temperatures. At my elevation water boils at 203.4˚ F. The sensor can not heat enough to make the pot think it needs to be cleaned. And if you consider the possibility of using a time base to measure how fast water boils, in America, some homes are running close to 110 VAC at the outlet while others (some of the places I've been) can measure 119 VAC. Given the difference in voltages, the wattages will vary enough to cause the so called sensors problems deciphering when it's time to be cleaned.

Sorry, just having a hard time believing there's a simple way for a pot to know when it's time to be cleaned.