We bought a washing machine for a friend that lives across the border in Mexico. She has had one of the old mechanical timer with cams and switches type of machines and we didn't think anything of buying a new machine and having it work.
One problem is - they don't have pressurized water in Matamoros Mexico unless they have a water tank and pump of their own. The water that comes from the city is at low pressure and often not even a trickle just 3 foot off the ground. SO - water at low delivery pressure and volume. And the new washing machine has a control with a micro-controller on board. One made by ST, but the number is impossible to read because of all the gunk sprayed on the PC board.
There are a bunch of wires going to sensors and a few pieces that are unusable (water solenoid valves, remember - no water pressure...) and the machine expects to run a complete cycle with no way to reset the cycle and if you abort the cycle it pumps all the water out.
Using the old, mechanical timer machine, she would stop the machine, remove the cloths from it and put some more in that need washing, reset the timer for the wash cycle and start it up again. The when she was done washing she would do a second rinse (first rinse was by hand in a wash tub) stopping and removing the cloths and then finally spin the cloths before she hangs them to dry.
So - First version Arduino based control - 3 buttons. 1 Stop - an interrupt routine that zeroes the InCycle Variable and all outputs get turned off. 2 Wash - Motor has 2 power wires, forward and reverse, 1.25 sec forward, 1.25 sec reverse, repeat until stopped. 3 Drain and Spin - Run the pump for 2 minutes to drain the water out and then spin until the Stop button is pressed. May need to modify the pump and spin cycle, but for now she is able to use her new machine in a way that makes sense for her conditions. The power is handled by some Crydom SSR's that I had from a previous salvage/scavenge operation.
Still want to find out what all the motor wires are supposed to do - Not able to find any documentation from Whirlpool as to how the machine is supposedly wired or how their control board is supposed to function.
The control board is about the minimum that I could build - Socket, Caps, Resonator and some female headers. Additional board on top with maching male headers and a 7805 and rlated caps. Made it easy to solder the needed wires to,the board, while still being able to separate the 2 boards and carry the processor to where I can swap the 328 into my Arduino board to program. Whole thing is 1.75" square by 3/4 inch thick. SSRs are monted on the back panel which can also act as a heat sink, though I doubt they will work that hard.
The most practical solution might be to dig a hole in the yard (or other low point) and put a 5 gal. bucket in and fill with water. In a low place, the bucket should fill quicker from the low pressure supply. Then fill the washing machine from the the bucket. The old mechanical timer machines work well in underdeveloped areas. When I was small, I helped my aunt wash clothes in her wringer washer on the back porch.
My washing machine is about 6 years old and has the mechanical timer. When I bought it,
the guy in the store said it was the last one.
When the EMP comes, I'll be laughing.
In relation to your problem, I'd suggest that the easiest solution is to get her a water
pressurising pump. Then you won't have to tinker with the washing machine, which
sound tedious and potentially hazardous. And it will solve the problem for any other
faucets in her house.
Will you ?
Because you will get on your bicycle and start peddling to get a dynamo running so you'll at least have some shiny clothes i guess :D.
The pressurising pump will need to be powered.
Is the power over there stable enough to run a pump like this, and will it be affordable even if the pump itself would be a gift ?
Ofcourse the washing machine needs power too so it doesn't matter if either one of those lost power.
Many homes in Mexico do have a pump and pressure tank so they can have pressurized water in the house. The problem becomes one of cost - both for the pump and the electricity. It is a real struggle to get electric at 220VAC so they have t use a 110V pump, and considering the number of houses on 1 transformer and the length of the lines in the neighborhood the life expectancy on pumps can be quite short.
One important idea when trying to help in the third world is supplying technology that can cope with poor or limited resources. Here in most places in the USA we have ample water supplies and running 20 gallons of water down the drain doing a load of wash doesn't even register on our water usage. And we have no problem with the water going into whatever sewer system and going away. 20 gallons of water is several hours of recovery time in the colonia (unincorprated comunity). So to do a single load of laundry means several hours waiting for the water holding tank to refill. And then there is the problem of dealing with the waste water. there are no public sewers. Some people will use the grey water to water plants or the water gets thrown out on the road to control dust.
The model for washing clothes is still based on the old washboard. A tub of soapy water and the clothes are all washed and rung out. Then the clothes are rinsed, maybe several times, and then rung out and hung to dry.
They have to use water conserving methods all the time because they can't get enough to be wasteful. Along with the income - an engineer - a college drgreed Mexican National working in Matamoros will earn maybe $120US a week. A typical worker will make $50US to $70US a week. They can't waste it because they can't afford to waste it.
That is exactly what i meant in my reply.
One shouldn't compare or reflect its own situation to that of other, less fortunate countries.
Did you have an actual question, or are you sharing your experiences so far ?
All the wires to the motor, are to enable different speeds, so the same motor can (and will) be used to spin.
I can't tell you exactly how this works, but it's unlikely that there's just an extra motor coil that will be added, as most machines have multiple spin speeds.
So there needs to be some logic to it.
If you do have questions, telling the model of the Whirlpool machine might come in handy, or tell us anything else you can find out about the controller board (like any stickers or other clues to the model).
zoomkat:
A couple of $ to a local fix-it guy in Mexico probably would have gotten the origional machine running again.
Nice of you to read the thread starter...
I did, and how is your "and we didn't think anything of buying a new machine and having it work." working for you?
Edit: Go on craig's list and look for the older mechanical washers. Locally they can be found for $60-$100 in decent working order. I recently got a good condition washer and drier just for removing it from an appartment that a friend was moving out of.
Washing machines often have pumps built in. Could you use the inbuilt pump to supply the water, instead of just draining it?
I remember an old washing machine my mum had used to have a "suds return" cycle, where it would pump out the washing water into the laundry trough, so that you could use it again by pumping it back in on the next cycle.
You could program the arduino to allow for that, to make getting the washing out easier.
, hand pump to get the pressure up and feed the water in with it.