Need information to build a new Chip-Controller for my Mach I

[phobos]

Hello!

I'm about to make my own chip controller for my prometeia since I have that reset problem with the original controller.

I am planning to use a µC with an additional 2 or 4 line LCD and no additional power supply and propably a serial connection to configure it or to make software updates.

Does anybody have got a complete circuit diagram of the mach I controller?
I see some temperature probes installed at several places and don't really know what they are doing. Ok, I could find it out myself, but the Prommy-PC is my only PC so I don't want and don't have the time to remove or disassemble everything at the moment.
So if anybody has a complete circuit diagram or can at least tell me what these probes do it would be great if you could share these informations.

If I really start and finish that project I will of course share all my informations so that everybody with a little bit experiences in electronics can do it him- / herself.

[Marci]

The prommi controller is a stock Carel controller that can be bought off the shelf, so no-one will have the PCB Diagrams. If you serach for the MkI's controller by model number on google it'll bring up a few results, one of which should show each logic diagram for each of the controllers' states, but tbh, making your own is a lot of effort when u can just buy a different controller and hook that up instead. There are a few threads in ehre on suitable substitute controllers

[phobos]

I'm sure that nobody will have PCB diagrams, I just would like to know what the different temperature probes are measuring and how they are wired up to the controller.

I know that will be a lot of effort to make my own controller but I just heard some lectures about programming microcontrollers and designing circuits for it. And now I just want a little bit practise :)

And I also want a controller wich is compatible to all motherboards.

[Marci]

You have one thermocouple measuring EVAP head temp. Controller makes all it's decisions based on that single probe.

At w temp, fans are given 12v (0 to -29)
At x temp, fans are given 7v (-30)
At y temp, alarm sounds (+30)
At -y temp, alarm sounds (-50 usually but recommend setting to -65)
At z temp unit switches off (+35)

Controller holds reset until x temp is reached. Board fires up. That's it. They're wired to the controller by putting two wires into the necessary holes on the controller and tightening the screws. Resistors can be used to offset the temp probe and make it falsify a higher temp, but that's only to get round the problem that the stock controller whines at ya when u 404/507 mod yer rig so that it gets colder than -50.

[phobos]

Ok Marci, thank you for the informations but what I would like to know it what these are doing:

http://www.korthoff.com/images/xtreme/prommy1.jpg

http://www.korthoff.com/images/xtreme/prommy2.jpg

I also wonder why there are 4 wires going into the evaporator hose insulation.
Ok, 2 wires for the temp-probe but the other two? is there a heating element in the microfreezer or what?

[Marci]

Yes there's a heater in the evap head as well as a temp probe. The resistors shown are only necessary with that particular controller. Change the controller and you'll have to change those too as whether those are needed or not is entirely down to how you build your own controller. Only reason they are where they are is for handy grounding.

And here ends my input as I know ZERO about electronics. All the info I know above is from reading the manual that comes with the prommi.

[phobos]

Thank you marci. (And yes....I'll download the prommy manual.... ;) )

I also thought that the resistor on top of the condenser is a multiplier. But I wonder why it is getting so hot....

I also found out now that the black thing on the copper tube of the condenser ( 2nd picture ) is a AIRPAX 67L070 thermostat. It just opens a contact at 70°C.
I think it is used for a safety power-off for the prommy. I don't know anything about refrigeration so I don't know how important the temperature is there.

[phobos]

Does anybody know how the Mach II chipcontroller manages the motherboard no to start up before the evaporator reaches the right temperature?
Is it right that there are only connections from the reset button, power button and a standard molex to the Mach II chipcontroller?

[phobos]

I just got a thought: Maybe it's possible to clock the reset signal and they do it on the chipcontroller?