M-series integrated HH Electronics

Has anybody looked inside the printed circuit board of the m-series hh humidifier? There is a place for a humidity sensor on the pc board, but that place is empty on my unit. I wonder if this is how they left it intentionally on all units or I have something missing.

Even with the settings at 1, I get too much humidity; by that measure I would like to have a setting of 0.25, and 0.5 before the 1.0 setting

If anybody has looked inside, I would like to hear from them. I am looking into how to modify it to reduce the heating ...

feeling_better wrote: I am looking into how to modify it to reduce the heating ...

You can take the scholarly and honorable route and modify the electronics... or you can take the common man's route and just pull out the good old duct tape!

Easily-reversible gasket material or even properly heat-rated tape to make that thermal transfer less efficient (at the lowest setting of one) shouldn't cause significant heat buildup the circuitry wasn't designed to handle. You can even allow for gasket-material/tape on the ends (either thermal insulator/conductor, based on complementary air gap properties) and an air pass-through gap for heat redirection/transfer in the vast center of that mechanical plate coupling----that is assuming your M-Series thermal plate-coupling is similar to thermal-plate mating on my tank model.

Being inherently lazy and not overly concerned with honor, my last choice would be to re-bias any triac input, switched output, nor even insert a high-current rheostat/resistor in series with any heating element. I've never looked to see what circuitry is really in there, though. Duct tape is the true man's man solution! And if you refer to is as "thermal insulator" or "thermal conductor", duct tape becomes the thinking man's solution as well!

Good luck!

-SWS wrote:

feeling_better wrote: I am looking into how to modify it to reduce the heating ...

You can take the scholarly and honorable route and modify the electronics... or you can take the common man's route and just pull out the good old duct tape!

Easily-reversible gasket material or even heat-rated tape to make that thermal transfer less efficient (at the lowest setting of one) shouldn't cause significant heat buildup the circuitry wasn't designed to handle. You can even allow for gasket-material/tape on the ends (your thermal insulation) and an air pass-through gap for heat redirection/transfer in the vast center of that mechanical plate coupling----that is assuming your M-Series thermal plate-coupling is similar to thermal-plate mating on my tank model.

Being inherently lazy and not overly concerned with honor, my last choice would be to re-bias any triac input, switched output, nor even insert a high-current rheostat/resistor in series with any heating element. I've never looked to see what circuitry is really in there, though. Duct tape is the true man's man solution! Good luck!

-SWS, I love your reply!! Some people think alike I just came to the computer after spending a few minutes looking at it. All the ones you mentioned are excellent, all went thru my mind in the reverse order!!!

There is one more method, my second choice was: There is a thermistor sensor, which I just measured at about 3.3 ohm when it was luke warm (my guess is it would go to about 5 ohm when cold). All I have to do is add parallel resistor to the thermistor to make the feedback think it is already a bit warmer.

But then I said, yes duct tape, to my wife!!! And that was choice one!!! I could not believe my eyes when I came back and looked at your msg. Since there is a thermistor, there is not much risk at all of overheating with some tape in between, assuming their temp control works . The way it behaves with rather high humidity at setting 1, I am not ruling out their circuitry does work, at least in my machine. So duct tape it is tonight! And I can do all the fine tuning from outside without taking it apart!! There is even a spring loading between the hot plate and the bottom metal of the water container, so any tape will not make it harder to insert, etc.

Good thinking style!

Let us know how your experiment works out!


P.S. Just a reminder to make sure the tape you use is properly heat rated for that heat plate's worst-case thermal transfer setting of three (or whatever your M-series highest humidity setting happens to be).



shown above: yet another
"worst-case-scenario neglected"
energy transfer design

When I looked at mine after it shorted out it seemed to reminded me of my toaster oven on a small scale. I did not see a humidity sensor either. According to Respirionics it is not supposed to go above 145 degrees at the highest setting (5). I noticed I kept switching from 0 to 1 and back to 0 trying to find the right spot. You might make it back off the temp by putting some little buttons on the heating plate on the chamber to stop direct contact. That might lower the temperature in the chamber.

Jerry

-SWS wrote:Good thinking style!

Let us know how your experiment works out!

Well, the duct tape did reduce the humidity. An unwanted side effect: there is more friction from the tape than the original metal surface when you slide in the hh chamber. Remember the hot plate is spring loaded from the bottom and pushing against the hh chamber. Also the humidity reduction was not sufficient for me, I probably got my 0.5 setting (1 being the orignial), but I wanted to lower this more. So the second night I applied another layer of mylar tape. This also reduced the friction. Last night was ok; I might reduce it even further with another layer. After all I can easily increase it by going to the second setting on the knob any time.

There is one other side effect, if you interfere with the normal heat transfer to the water, it will be the same as running low on water. the heater element won't be cooled as much, so it will run hotter. It's best not to fool mother nature unless you are very smart. I'd turn it down or off with the knob if it was too much for me. jim

Goofproof wrote:There is one other side effect, if you interfere with the normal heat transfer to the water, it will be the same as running low on water. the heater element won't be cooled as much, so it will run hotter. It's best not to fool mother nature unless you are very smart. I'd turn it down or off with the knob if it was too much for me. jim

So, jim, is this a guess on your part or you have determined the thermistor controlled heating does not work for this model? I know you do not like to fool Mother Nature... But this unit is from Uncle Respironics.

I haven't seen inside the HH, I just know I use Artic Silver 3, on my computer processors, because I want to suck all the heat off them I can, they have thermal protection built in them too. But I have a need for speed... so I must keep them cool. Jim

Hello,

I'm very glad having found this forum. I have a M-Series with the M-Series heated humidifier wich I use when traveling. Looking in german forums, rainout does'nt seem to be a real problem. It occours rarely (sleeping with open window in winter) and normally is caused by a too high humidifier setting - so to fix it its enough to lower the humidifier heating and seldom a hose cover is needed. But there is a small group of people having really problems with rainout - and that's the people using the M-Series. The lowest setting of the M-Series heated humidifier is simply too strong - even stronger as the highest setting of the SOMNOclick 300 heated humidifier of my german SOMNOsoft+ CPAP by Weinmann.

As I noticed now, in the US rainout seems to be a common problem - and there also are different solutions. What I also came up with is to put some tape on the heating plate or modify the electronics of the humidifier. Other solution would be a heated hose, but these are relatively expensive.

Does anyone here have long-term experiences with either a taped heatplate or modified temperature sensor?

Regards,

Fabian

Awesome!! It’s just what I need!! Thanks!..............

6 ave electronics

I would love to explore.

very nice...

Davis Micro