Chausson electric bed problems.........solution ??? (1 Viewer)

[Sandancers]

Like a few others I got a bit sick of the Project 2000 electric bed needing to be re-programmed way too often.

So last week I started ripping out the old control system with a view to fitting a simple up - down switch system, albeit with a couple of end of travel switches.

What did I find in the existing system ? A power control relay without a flywheel diode !! Now this is not on the electronics board itself, but does supply power to the board, so maybe, just maybe the lack of the diode COULD cause enough interference to reset the board memory now and then.

As I had bought all the components to convert the system to manual I am going ahead with that, but if you have a project 2000 bed which is giving you problems as a first call I'd fit a flywheel diode to the power relay coil. The relay is situated under the big plastic cover which shields the motor and winding system, it's by itself fixed to a rail, you can't miss it. The diode could be a n4001 or something from the same series and will cost a couple of pennies from Maplin. Just make sure you fit it correct way round on the coil connections.

For more info on the flywheel diode look at the link below.

https://resources.altium.com/bill-o...-to-prevent-electrical-noise-in-your-circuits

 

[Podney]

A power control relay without a flywheel diode.
Appalling!!

 

[hilldweller]

As I had bought all the components to convert the system to manual I am going ahead with that

I like KISS. But you may be removing current monitoring to cover a jammed drive.

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[tonyidle]

I use this instead of limit switches. Not that there are limit switches on the step!! Ever used it? Trips out on jams as well.

 

[Sandancers]

I like KISS. But you may be removing current monitoring to cover a jammed drive.

True, but I have an LED to show when power is applied to the motor, so if the LED is glowing and the motor is not turning I'll just remove my hand from the momentary switch which controls the up and down.

I use this instead of limit switches. Not that there are limit switches on the step!! Ever used it? Trips out on jams as well.

I see what your doing, but the bed does present different problems. If the bed is going down and "hangs up" then the motor will keep turning and eventually start winding the straps in the wrong direction, ie up. Which would be a very bad thing as the up limit switch would then try and turn off a motor which is going down !!

 

[hilldweller]

True, but I have an LED to show when power is applied to the motor, so if the LED is glowing and the motor is not turning I'll just remove my hand from the momentary switch which controls the up and down.

No problem for you but the designer will have bee told to design something to cope with a numpty who would just keep their finger on the button until the flames hinted they had better stop.

Our FIAT MH windows are like this, the motor current is calibrated and monitored and once the window would not open because it had not been used for while and was a bit sticky. Some PTFE spray sorted that for good. There is a calibration routine an owner can use if they can find the details.

This rampant technology so to plausible in isolation but over the last ten years it's created technological monsters that no-one, except a few techies that they keep locked up, can understand. This week's FUN gripes has been cruise control software not coping with hills, probably it was programmed by a Dutch person.

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