We have a bean to cup machine with an odd fault or feature, I’m not quite sure which.
Whenever it makes a cup of coffee it spits out a compressed cake of used coffee-grounds into an internal bin. After a while a light come on to tell you the bin is full and it need emptying.
The thing is, sometimes it happens when there are only a couple of “cakes”, other times it may take up to ten cakes. There seems little rhyme or reason to when the “full bin” light comes on.
I can’t see any internal mechanism to determine the state of fullness of the bin. There is a simple micro switch to ensure that the machine won’t operate without the bin but beyond that there’s absolutely nothing visible.
I did wonder about some sort of ultrasonic level detector but there’s nothing in the plastic mouldings above or around the bin that suggests that there’s a hidden sensor. There’s no sign of anything optical either.
It did occur to me that it might simply count the number of operations between bin removals but replacing a full bin doesn’t reset it.
Any thoughts on how it works? Any other indirect means that it might be using that could be completely hidden?
Tim