Has anybody ever

[ubtripn]

considered installing a potentiometer in where the windshield wiper switch his? Something like what we use to dim lights in our home. So turning the knob to the right starts the windshield wipers and the farther you turn it the faster they go.

I know there are after market wiper delyas out there but this would allow me to keep it hidden and adjust the wipers to meet conditions exactly rather than have 2 speeds. There would be no delay just a range from very slow to max.

Has anybody done this?

[Tinkermc]

Sounds like a super idea

[CST10]

I'm interested. Sounds like it would work.

[cleszkie]

How would you activate the winshield wiper fluid pump with a potentiometer in place of the stock switch? You would have to install a second switch for it! Then you are in the same position as you would be if you just bought one of the wiper delay kits with the remote potentiometer.

[specks70]

What resistance would you be using? I think a pot. would work but only for a brief amount of time. I feel the current draw from the wiper motor would probably smoke it.
I built a wiper delay circuit for my 1977 ford mustang back in the mid 80's. I'll look and see if I can locate a circuit schematic and post it. It was actually quite simple to construct.

[lousyflyer]

Allow me to be the "Voice of Doom" here.

I would not recommend operating a DC wiper motor through a potentiometer.

First off, the potentiometer would have to be rated for the amount of current that the wiper motor would draw. Such a potentiometer would be rather large and prohibitively expensive. (About the size of a tennis ball and well over 100 dollars) The tiny potentiometer used on a wiper delay is merely the trigger for a timer based switching circuit that controls the high amperage required to run the wiper motor.

Second, when you operate a direct current motor at voltages that are lower than they are designed for (like when you try to slow the motor down) they develop very little torque and may not run at all, creating a "stalled" situation where current is still flowing through the windings but the motor isn't rotating. The motor will then overheat and burn the insulation off it's internal windings.

This is why windshield wiper motors usually have two speeds for operation - the lower setting is calculated to be as slow as possible without stalling the motor.

[lousyflyer]

Not really sure that I would want a slow windshield wiper crawling across my field of vision either.

[TrkEnvy]

I think it sounds like a great idea, but my question is.. what good is a wiper inching across the windshield? if we think about how wipers work they are always moving rather quickly but they have a pause in between each fast pulse. A potentiometer is going to slowly increase voltage but wont it be worthless in the first full turn?? the wipers will not be moving fast enough to sheet water. Not trying to pee in anyones cornflakes, but im just questioning if it will work as intended.

Lousy beat me to the punch..

[specks70]

This is one very similar to the one that I had built. Very simple circuit and should work very well for what you are trying to do.
Check out the link . . . http://circuitforfree.blogspot.com/2...by-2n4401.html

[lousyflyer]

Yeah, I had a 53 Bel Air with vacuum operated wipers. Anytime it went uphill the vacuum would drop and the wipers would slow to a crawl if not stop entirely. Going up any bridge in rainy weather was a real PITA.

Once the wipers slow down to a certain speed it becomes a distraction to the eyes.

I suppose one could substitute our typical DC wiper motor with a brushless AC motor with a speed controller to vary the speed. Not sure if it would be worth the cost.

On a different note, If you could install a static generator to repel the water droplets before they hit the windshield, you could sell that little system to the world. (Insert maniacal laughter here)

[ubtripn]

Wow, thanks everybody for the info, I am going to go for it. I want to be able to adjust to exactly what the conditions are demanding. For me I already lost the standard push fluid function so I installed a fluid tank with an integrated pump out of a Subaru and then put a button on the dash and plumbed it to the existing tubes so I can squirt the windshield when needed. (That's too easy to make a joke, let's leave the low hanging fruit alone

I am going to use the schematic and see if I can find a servo motor that will run on very low current. I won't have it on the lowest setting most of the time. I expect a range between semi-slow to max. I just want to get around 2 speeds and the delay option.