Hi All,

Thanks for your suggestion to my other posts and I am back looking for ideas again.

I have installed power window regulators from a 2018 Toyota Corolla into an old car. The window size and lift height are similar but the movement is too fast. It takes about 1.5 seconds 'UP" and 1 seconds "DOWN". I'm probably a bit off on the timing but it feels much faster than the Corolla they came out of. The other part is it is difficult to make small adjustment to the window travel because it moves quite fast and getting them fully closed without being over tensioned (too tightly closed or opened) is difficult. Or even making small adjustment to contol the air flow through the window is easy to over shoot the mark.

I think I can add One Touch power window modules (like AutoLoc One Touch Power Window modules) or install micro switches to help with controlling the limit of travel but I would like to slow the movement if possible.

I have considered resitors in the power supply but I am concerned about them getting too hot and causing a fire risk but then again windows are not usually used continuously so maybe that isn't really a concern. Then there is some sort of PWM motor controller but I think that is adding too much complexity.

Does anyone have a suggestion about how I can slow the speed of the power windows? The current I have measured is between about 2amps and 6 amps per window.

TIA.

 

A resistor in series is what comes to mind. If the fuse block is in the engine compartment and the windows fuse is there, then one resistor is all it will take. There should be some area where a 50 watt two ohm resistor can be mounted, At 2 amps that will drop 4 volts and produce 8 watts of heat.

 

In a contemporary automobile a power window has a data line between the solid state window control module
that senses armature position by means of a ripple counter in the motor assembly. The window wants to stop where it does.
The window is set to start and stop at very precise distance. The car company control systems department is not old school.
This makes it difficult to modify because surveys said that customers want fast and furious operation. The low cost of micro controllers
and solid state modules gave car manufacturers reason to use off shore engineers where fast is never fast enough.
If you go back far enough a domestic power window motor was simple. The average power window draws 20 Amps.
The window wiper motor speed can have different speeds.

 

Look for others there too.
PWM DC Motor Speed Controller - 9-60VDC, 1200W (mpja.com)

 

Really, the first step should be finding the actual specifications for the window motors you installed.
Of course, if they were installed on the same hardware gear as manually cranked windows, then the gear ratio will be different. So the specification will be useful. The logistics of adding a PWM controller for each power window will be quite a challenge because where can they be mounted??
THAT is why I suggested a single power resistor under the hood, where there may be more room in "an old car".

 

The car company control systems department is not old school.

Unlike me.
They definately have their work cut out for them with demanding consumer expectation and the world of instant gratification. Just OK doesn't cut it anymore.

Really, the first step should be finding the actual specifications for the window motors you installed.
Of course, if they were installed on the same hardware gear as manually cranked windows, then the gear ratio will be different. So the specification will be useful.

The existing cranked window regulator was a series of complicated cables and pulleys that were completly removed leaving a blank canvas with just the glass and chanels remaining. I grafted in the entire window regulator including arms, levers, motor etc from the Corolla into the 'Old Car' so there have been no changes to ratios of the Corolla regulator or motor - it is exactely how it was in the Corolla. I choose the Corolla regulator because A: they were free of charge as spares laying around at work, and B: they were similar glass size and lifing height to try to avoid exactely that problem of it being mismatched. I had actually tried adding motors to the original cranked regulator which worked ok but was too slow due to exactely what you mentioned - the ratios were way out. I know the motor specs would be helpful but this project doesn't warrant such detail or complexity. It looks like the simpliest solution will be resistors to slow the motor a little and probably an add on 'One Touch Power Windows' module/controller to limit travel by detecting motor stall (and cutting power) when the glass reaches the limits of travel. Both of those have relatively known results where as adding PWM will take a bit more working out and I still wouldn't have the limits of travel managed.

Another thought was adding some sort of soft start to the motor circuit to help with smaller movements not being so harsh and jolting but I haven't really looked into the possibilities of this yet.

Thanks for your thoughts and ideas.[/QUOTE]

 

OK, that was a serious project indeed. Actually very impressive. So all four windows are "new", and there is entirely new power wiring for them. So the really simple option will be a single power resistor near the main power fuse under the hood. The only compromise with that is that running multiple windows at the same time will be slower. Depending on how much speed reduction you want, the resistor would be in the two ohm to six ohm range, and probably rated at 50 watts or so.

 

OK, that was a serious project indeed

As it turned out it was suprisingly straight forward. Much easier than when I added the motors to the original cranked regulators. I just made a paper template for the mounting holes with it in the up position, took a few measurements to align, centralise and level the mechanism with the glass also in the up position and transfered the holes into the door. From there it was only 1x 10mm spacer on one bolt and I welded in a strip of metal for another bolt location and it worked first time. I was really just 'winging it' and it worked.

I have done a bit more testing over the weekend and I think the speed might actually be managable if I control the limits of travel beter; or maybe I am getting used to it. I'm first going to try 'One Touch' power window modules as I want that feature and if the speed or limits are still not great I can add a resistor to slow movement and/or micro switches to cut power at the limits.

Thanks I appreciate your input.


Off topic back story.
It is a Holden Gemini 3 door station wagon so there are only the 2 front doors with moving glass, but yes it's all 'new'. I first repaired and refurbished the complete electrical system including wiring loom. Then set up the complete functioning electrical system on the bench for testing, so I knew I had a good starting point. The wiring is only good for 70's/80's tech and power demands, so I ran an additional 'accessories power' feed from the battery to the fusebox in the drivers footwell and upgraded the alternator. That has allowed me to use the spare/added fuse locations with the new circuit for additional accessories like these electric windows, driving lights, central locking, remote tailgate/boot release, heated seats, better sound system, and all integrated into the original style and design of the car. Along the way, I have also upgraded and changed the original wiring to modernise it with headlight relays, dome light delays, USB power outlets instead of cigarette lighter plugs and little things like that. I'm not going for a factory finish rebuild. My plan is for a modernised version that will look like it came that way from factory, even though these weren't available options. You won't see additional wires, fuses or any of the other usual nasty electrical work that is so common with old cars. Everything is neat, tidy, properly secured and organised and; I have also documented all the changes and additions if I (or someone else) need to go back through it at some stage it won't be too dificult to work out. Should be good but it's a long way off, Electrical is the first step, with Mechanical, Suspension Body/Paint and Trim to go and I am doing it all my self ( I work in the automotive repair industry).

 

Oh WOW!!! Certainly not an average level project. And certainly an above average skill set!!
My big project in years past was dropping a new complete drive line into a car. THAT was a fair sized back-yard undertaking. Quite an achievement for a beginner in vehicle remodeling, really.

Given that your entire electrical system is new, and that you are quite familiar with it, adding a single dropping resistor would not be such a huge effort, though. Fast windows can sometimes be inconvenient if you just want to make a small adjustment, however.

 

Welcome to AAC.

How much investment in learning are you willing to make? Incorporating an embedded MCU (microcontroller) would involve a learning curve, though thanks to the Arduino environment, certainly nothing like the sheer cliff of the past. The added bonus is that one you have the skill set associated with the Arduino platform (which encompasses far more the the few boards actually designed and sold by the Arduino foundation) you will be master of a tool with limitless possibilities. It’s akin to learning to weld, and probably about the same degree of difficulty if by “welding” you don’t stop at globby piles of stick welder poop.

In your current case, for example it would be trivial to arrange it so a single activation of the switch delivers “fine” operation offering precise adjustment while a double activation (or perhaps better, long press) produces a maximum speed (whatever you choose that to be) operation for quickly opening or closing. Another possibility is to mimic the operation of my BMW windows where double activation operates the window at full speed, bypassing all safety controls—intended to deal with a threat. (And given the reputation of BMW drivers, and prevalence of road rage incidents, might just be an essential function if you live in some cities.)

You could also use it just to implement your soft start idea—and something I haven’t thought of... automatic venting based on temperature? Automatic closing against rain, snow, or simply forgetting to close a window? It’s incredibly cheap, easy (once you’ve learned some fundamentals) and satisfying.

Whatever you choose, good luck and have fun with it.

 

And certainly an above average skill set!!

I’m not there yet and have plenty of learning to do. There will be mistakes and failures but that is just part of learning. My back ground is as a panel beater and am still in the game but have been off the tools for years. I have a good general understanding of all the elements required but don’t know all the detailed processes and tasks yet but I will learn as I go. I’m happy to put 20 hours in to learn and complete a task where a qualified tech may only take a couple. I enjoy learning by doing and seeing the end results of the hard work and challenges.

 

Incorporating an embedded MCU (microcontroller) would involve a learning curve

I have seen a few power window controller projects using an Arduino and they sound good but I don’t think it is for me. The hardware part seems fine but don’t like the idea of working through the coding. I know I’m adding complexity already but I think an Arduino is a bit of a stretch and I don’t think I could get it to function stable enough.

Thanks for your suggestion.

 

I have seen a few power window controller projects using an Arduino and they sound good but I don’t think it is for me. The hardware part seems fine but don’t like the idea of working through the coding. I know I’m adding complexity already but I think an Arduino is a bit of a stretch and I don’t think I could get it to function stable enough.

Thanks for your suggestion.

Obviously you should choose what is best for you but a suggestion before you reject the idea fully: get an Arduino starter kit and work through the tutorials a bit. I know that when one is unfamiliar with programming it can seem daunting be the complexity is really a matter of a bunch of very simple things interacting. Breaking it down to parts makes it much simpler and with a limited number of basic building blocks and the huge number of libraries that hide the heavy lifting, things might turn out to be simpler in practice than you are thinking.

As far as “stability” goes, if you approach things systematically and don’t make the mistake of cargo cult programming you won’t encounter the sort of problems that plague any project that lacks a solid foundation.

 

I see an unanticipated problem with using a micro for controlling the window, which is the FEATURE BLOAT syndrome hitting it. (see post #10 for a start of the list).

 

I see an unanticipated problem with using a micro for controlling the window, which is the FEATURE BLOAT syndrome hitting it. (see post #10 for a start of the list).

Feature creep is a problem of design. To use a less capable technology to compensate for bad design practices is… silly. There’s a lot more I could say but I will leave it at this.