# Dishwasher

Hello

I write here in the forum because I should start a project with Arduino about a dishwasher and there are parts that I never have used.

• the door closure sensor: could you please suggest one?

• The electrical resistance for heating the water and how it works

• how it is possible to vary motor's angular velocity for increasing the wather from the pump.

Are there any electric valves?

Thank you in advance for any answer.

the door closure sensor: could you please suggest one? A microswitch is simplest.

the electrical resistance for heating the water and how it works Electric goes through. It gets hot. Just accept it.

how it is possible to vary motor's angular velocity for increasing the wather from the pump. Why bother, just put Electric through the pump. Water comes out. Just accept it.

Are there any electric valves? Yes plenty.

I think you're in over your head.

THANKS FOR THE ANSWER. Yes I am doing another work meanwhile :(

What's the idea there? You want to design and build a dishwasher from scratch?

Hi

no , only to create a program where to use some sensors, timer, a menu, a motor (i don't know if possible) electrovalves...try to simulate it somehow...... :cold_sweat:

OK if you're interested in building an emulator, perhaps you could tell us what hardware you have available. Do you have an arduino? if so which flavour?

For the switch you could use a reed switch, a hall sensor or a electromechnical switch. I might be an idea to sense the hatch instead of the door.

It takes a certain amount of energy to heat a body. For a homogeneous body it s mass*specific heat capacity. In SI units Water has a specific heat capacity of 4,2 kJ/kg/K meaning it takes 4,2kJ of energy to heat 1kg (or 1 liter) of water 1K (or 1C). Since 1j = 1Ws heating power directly corresponds to heating rate. A heater with a power of 4,2kW will heat 1kg of water 1K in 1s. Or a 1kW will rise the temperature in 1 kg with 0,238K each second or 1K in 4,2s. A resistor converts electrical energy to heat with 100% efficiency. Electrical power is P=U*I. Combining this with Ohms law yields P=U^2/R or R=P/U^2.

It is possible to vary the rpm of the motor to alter the pressure and the flow rate in the pump. A PM DC motor can be regulated by varying the voltage or using PWM. A AC motor driving a pump must be regulated using a frequency converter.

Solenoid valves for these types of applications are quite common an easily available. These are on/off valves with no flow regulation.

Dishwashers and washing machines and similar appliances are most commonly modeled using state machines.

thanks for answering

As well as some leds, few other components have to be added to simulate the functioning.....I don't know what is [u]simpler[/u] ....Thus

• sensor for hatch (??!)

• Solenoid valves to charge the water

• motor with two speed to activate the pump

• electrical resistance proportional to power

• washing and addition of soap step

• rinsing step - open again solenoid for rinsing from the top

• drain pump

Heaters are generally run at full power (ie they’re either ON or OFF). A temperature sensor should be included, then you can turn the heater on or off to keep it within a specified temperature range.

Attempting to run heaters on anything, other than their optimal working current is not the normal arrangement.

As soon as I will have a bit of time ! I will attempt to write something to have a more concrete idea of what it is possible to be done....

For the sake of building your "emulator" all you need is some LEDs so you can see what the outputs are doing. A reed switch could be included to stand in for the actual door switch. You'll also need a small magnet that you'll have to place next to the switch (to simulate the door being closed).

I'd also suggest a 16x2 LCD display. These are cheep as chips but give you the means to provide a nice user interface.

belinda: I will attempt to write something to have a more concrete idea of what it is possible to be done....

This project is crying out to be treated as a state machine, about which forum members have written at least as follows:

You might find my turnstile example useful.

I know It's an old topic, but I think I could help you with it. I did dishwasher project with Arduino for this specific Thermador dwhd640jfp dishwasher. So if you are interested please let me know, I could help you.

It would interest people if you posted your project somewhere.