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Timer for laundry machine

Discussion in 'General Electronics Discussion' started by Nucejoe, Oct 7, 2018.

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  1. Nucejoe


    Oct 7, 2018
    Hi all.
    I am completing design of a laundry machine to be mass produced.
    Need an electronic timer to turn the motor on/off four times (produced preset)
    Need advice from step one.
    Regards joe.
  2. Bluejets


    Oct 5, 2014
    I assume this is a washing machine..??

    The number of input/output requirements and different timing sequences normally involved, it really is a job for a small microcontroller.

    In years gone by it was done with cam switching but these are long since gone.

    I imagine there would be a manufacturer out there somewhere who does nothing BUT produce timers for laundry gear.
    Nucejoe likes this.
  3. Nucejoe


    Oct 7, 2018
    Thanks for your response and advice.
    Requirments are,

    1. run for period T.
    2. Turn off and stay off during perid T1
    3. Turn on and run for perid T2
    4.Stop turn off. Sound finish signal.
    Expectedly manufacturers flood in with claims to have or build just the right piece for the job,
    I am at point zero to select the right piece.
  4. Nucejoe


    Oct 7, 2018
    I am told this will be the simplest laundry washer produced in past three decade, compatible with regional culture and highly efficient.
    Rinsing keys are left at the users disposal manually to perform as desired.
    Will not spin dry either.
    It would have no electric valve.
    Some collaborators suggest the electronics can be designed and produced cheaper locally.
  5. Bluejets


    Oct 5, 2014
    I'd be inclined to go the Arduino way.
    Not only for ease of programming but cost also. Many clone devices at low cost.
    e.g. Pro Mini... I just bought 10 for $25.00 delivered to Aus from China.
    Going this way allows for ease of reprogramming when/if you decide on other input/outputs.
    Seems relatively simple program but you or whom ever would need to learn to program ( not difficult)
    In this instance look at ways of running timing sequences without using delays as it allows the micro to check timings and do other things simultaneously.
    If you look at the Arduino site it might be an eye opener for you.
    Plenty of professional help there also.
    Of course there will be other aux gear required such as power supplies and hardware switches etc.
    Last edited: Oct 7, 2018
  6. hevans1944

    hevans1944 Hop - AC8NS

    Jun 21, 2012
    The biggest problem is going to be finding an inexpensive way to turn the motor on and off using a low-level logic signal. Optically isolated AC switches are common and easy to interface with. Control inputs vary from about 2 V DC on up, depending on how you want to control the optical isolator input, which is usually just a light-emitting diode photo-coupled to a photo-transistor or a silicon controlled rectifier. Many have internal circuitry that inhibit triggering until the AC line voltage goes through zero, and then continuous conduction throughout the AC cycles after that until the control signal is removed. Such circuits are designed to minimize radiated and conducted radio frequency interference caused by the large current transient when the motor starts.

    If you want to build a really inexpensive washing machine, design an agitator mechanism that does not require gears, belts, or pulleys. Let the motor shaft directly drive the agitator and control the motor electronically. An Arduino microcontroller would seem to be ideal for this purpose. There is also a huge world-wide development community that you can turn to for help and advice. Try some of the links here for starters.
  7. AnalogKid


    Jun 10, 2015
    Are T, T1, T2, and the time the finish signal is on adjustable or fixed?

    I suggest renaming them T1 to T4.

  8. kellys_eye


    Jun 25, 2010
    Isn't this a KISS project? The mechanicals are, why can't the 'electronics' be? The good-old motorised microswitch/cam system worked very well for decades, don't require 'soft switches', PSU's, semiconductors, LEDs etc. Servicing would be simple.

    There are many mechanically operated timer switches on the market even now (for wall socket timing applications) that are reliable enough for commercial/public sale so why not KISS?
  9. Nucejoe


    Oct 7, 2018
    Thank you all,
    Production will be at facilities already making cheap washing machines, motor and most other parts will be the same, domestically made.
    Mechanical switches used already provides functioning up to about an hour, whilst for this design , longer time period is required at one stage. I think any longer period requires a movement of escapement mechanism, a pain.
    At this point I will work to understand what you are saying and to spell out the requiremnts logically. You gentleman are lucky to live with decipline of logic and math.
    Yes the mentioned periods will be fixed for each state of small, medium and large loads.
  10. Nucejoe


    Oct 7, 2018
    Yes mechanical switches gave less electric shocks too.
  11. Bluejets


    Oct 5, 2014
    There already has been for 20 odd years now....Fisher and Paykel .... Not exactly cheap though.
    Family in Thailand run a small laundry using a 14kg capacity twin tub made I think in Japan, National brand.
    Flog the absolute guts out of this thing day in day out for maybe 4 years at a time. Then replace with exact same thing. Cost $300 so going to be difficult to beat something like this. Mechanical tic tic timers for both spin and for/rev belt drive agitator, no pump just a mechanical bellows drain valve, 5 year warranty on motors but we cannot use warranty for over 12 months due to commercial use.
    Last edited: Oct 8, 2018
  12. hevans1944

    hevans1944 Hop - AC8NS

    Jun 21, 2012
    I have often wondered why so-called "white goods" are so expensive... washing machines, clothes dryers, cooking ranges, refrigerators, chest freezers... all are essentially painted or enameled sheet-steel enclosing some really basic (primitive, even) electrical and electro-mechanical parts. Still, I doubt that I could DIY build a washing machine for @Bluejets $300 target price, even using modern (21st Century) electronics to keep the cost of the human-machine-interface (HMI) down to a minimum at the sacrifice of simplicity. Maybe if I were to salvage the tub and enclosure from a defunct machine I could come close.

    The OP appears to want to eliminate the rinse-followed-by-spin cycle and have manual control of the agitator/washing/rinse cycles. This reminds me of Mother's old Maytag wringer washing machine with its "gear shift" lever on the side of the machine...


    Everything was TOTALLY manual, including feeding wet clothes through the top-mounted pair of wringer rollers to remove excess water before hanging the wet laundry on a clothes-line to dry in the sun. Water for washing was heated in a manually-filled cauldron set atop a natural-gas burner. A galvanized steel bucket was used to transfer hot (boiling) water from the cauldron to the washing machine tub. This was all "state-of-the-art" in the 1950s, and considered to be a "labor saving" boon for the housewife, who could now put her rippled washboard up on the fireplace mantle, reserved now for use only while playing country (folk) music with spoons and buckets for rhythm accompaniment.

    Well, actually, all this took place in Lake Charles, Louisiana circa 1952. We didn't have a fireplace or a mantle in our rented house, but Mom sang and played the violin, and she was quite familiar with the washboard from her childhood, being born and growing up on Bull Creek in Mohawk, WVA in the 1920s.


    I have never thought of Iran as a "third world" country (my cardiologist, the one who first saved my life eighteen years or so ago, is from Iran and is a graduate MD from Tehran University School of Medicine), so do the people in Iran really need a washing machine invented early in the previous century? No spin cycle? No pump to remove dirty rinse water? No solenoid valve to admit water to the tub? This is progress? Early sewing machines were foot-treadle operated. Gotta wonder if this would work for a washing machine...
  13. Minder


    Apr 24, 2015
    Picked one up at a Garage sale, in case of power outage!:p


    The current machine we just purchased has a rotary selector with 10 positions and 4 electronic switches each with 5 selections, so this is what you are competing on in the modern market! :eek:
    I suspect embedded μp controlled.
    Also has the latest Fisher-Paykel style outrunner motor, no gearbox.
  14. Nucejoe


    Oct 7, 2018

    Hello Sir, I imagine your surgery having had a profound effect on your view of life. I am speechless. Humanity is beautiful and you are showing the extents of it,s beauty.
    I promise to explain why a simple machine before long and am all ears if you just talk telling more about yourself.
    Regards joe
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