Reservoir Waterlevel Schematic - Page 3

wymjym · 05-06-2003, 07:04 PM

I went for a bike ride and while pedaling up the killer hill I thought, WTF...I am looking for a solution for folks and others are looking for something to discuss. My bad!

For those that are not interested in discussing............
place this small magnet, encased in a bit of epoxy and attach it to the TOP of a floatie. Place the reed switches accordingly...the only time those ions are going to coat the magnet is when they break down the epoxy and for some reason the floatie...quits (floating).
wj

Arcturius · 05-06-2003, 10:36 PM

What about making the res opaque (or just part of it) to block ambient light, and then put an LED at the top, and a photo-resistor at the bottom, and add some dye to your coolant?

As the water level drops, the photo resistor receives more light and becomes less resistive (if I recall correctly). You may need a high-intensity LED to make this work; I'm not good with optics.

photo resistor for $0.50

TerraMex · 05-07-2003, 12:59 PM

@Arcturius

Someone hasnt read the previous posts... we already stated that ideia.

@Alchemy

Same. You didnt read properly (imo).

Were in hell did i say that it would go armaggedon on you?

>Usually having a relatively strong magnetic field in water is a big
>"no no". It will eventually interact with the ions in the water and
>create a nice layer of magnetized compound around the magnet,
>twisting its fields . The way to prevent this is a electromagnet
>with an AC signal. And we'd be back to the electric current inside
>water.

Like, powerful. Not a pretty small magnet. As stated after :

> Using distilled water, and with a small magnet.

>However, as i said, distilled water with a low ions count (edit:
>just in case), a magnet with a light field, and those reed
>switches , in theory, they WILL work. The whole issue is the
>remaining ions in the water, and the long term effects on the
>magnet .

Again, i fail to see what's the problem. Can you garantee that it wont have any considerable effects in a large time delta? I cant, because i havent tested. I felt like giving fair warning to certain effects, even if they dont really have a considerable interferance. And as i said , in theory, it would work (translated: it would probably be negligable).

>How strong a magnet are you using, for god's sake?

It was an industrial setting , very large diameters . All the sensing was with electromagnetic displacement.

Arcturius · 05-07-2003, 01:31 PM

Quote:

Originally posted by TerraMex
@Arcturius

Someone hasnt read the previous posts... we already stated that ideia.

Nevermind; I just skimmed your posts quick, and missed the part where you were talking about an LDR resistor, I just expected you to stay stuck on the IR idea.

Although, I must say that I think it would be the easiest to implement, since there will be no moving parts, and there will be an analog output, which is really handy for doing lots of different things.

bigben2k · 05-07-2003, 01:32 PM

Here's a draft of what I mentionned earlier:

Arcturius · 05-07-2003, 01:36 PM

Does anyone know how it is done in car's gas tank? That should be fairly easy to leverage...

I know on older snowmobiles/motorcycles, there is a float with a 'screw' going through it, that turns as the gas level changes, and the turning points the needle which is part of a guage in the gas cap.

Perhaps a similar method with the needle dragging across a rotary switch would work; or turning a potentiometer?

TerraMex · 05-07-2003, 02:12 PM

@BigBen2k.

With that system you could connect directly to a variable resistance (turning potentiometer) and get a linear output without any complicated schematic , just the variable resistance and resistive divisor connected to the 12v. Cant get any simpler than that . I've got a similar one in a process simulator . I'll get some pictures tomorrow if i have the time.

@Acturius

Something like this? :

http://clientes.netvisao.pt/carlo001/06.jpg

wymjym · 05-07-2003, 02:50 PM

I must ask what type of float are you going to use to have enough pull on that pulley+ wiper pot?
I'm sure they exist but then the friction becomes the problem.

fuel tanks with electrical gauge outputs by their very nature are generally larger than the res in a computer so there is more area available for the mechanism.
wj

Arcturius · 05-07-2003, 04:28 PM

@TerraMex:
Yes, that is what I'm talking about, except the ones I'm familiar with don't have a simple lever, they have a double-helix that the float slides on and forced the float to rotate as it changes position vertically, and a keyed rod that allows the float to move on it vertically, but not rotate.

So...as the float moves up and down, the rod turns. I'm not sure my pic will help much after that explanation, but I spent some time on it, and want to share with everybody.

ph34r /\/\y /\/\5p41|\|7 5k1llz!!!

TerraMex · 05-07-2003, 05:52 PM

@Acturius.

The picture's fine

. I get the general idea. Interesting, i havent seen one of those . Looks pretty functional thou.

But doesnt the float need to have some weight or the helix can block the movement (due to the nature of the movement and friction)? Or even if the rod (endless screw type?) can prevent the float to move if there's enought friction between them ... or a stiff rotating potentiometer connected to the rod?

Arcturius · 05-08-2003, 09:19 AM

@TerraMex:

Where the double-helix passes through the float, the openings in the float are fairly oversized to prevent binding.
The rod is not an endless screw--that would cause a great deal of resistance. Rather, it is more like a hexagonal rod, or a round rod with a single flat side, or really any shape that is 'keyed' and has the same cross-section over its entire length. It is meant for the float to move freely in the vertical direction, but it needs to have a shape that allows it to be 'locked' to the float, in the sense of rotation.

Lastly, the float has to have some weight to it, but not much. Just enough for gravity to be able to pull it down over the double-helix, and overcome the resistance of rotational friction, and whatever the guage imposes. Usually the double-helix is quite steep, with maybe only 90-100 degrees of rotation over its entire length (~8" in my experience), so those forces are pretty minimal.

Also, in the application I've seen these used (gas tanks for snowmobiles) all parts are constantly washed in a gasoline/2-stroke motor oil mixture, so everything is quite well lubricated, and free to move.

Even though, I think it could effectively be scaled down, if someone still wanted to use a mechanical level indicator.
Actually...it could make for a very nice indicator to be installed in a tall cylindrical res...

TerraMex · 05-08-2003, 01:48 PM

@Arturius.

I see. Seems pretty simple for a DIY to do.

Anyway , some pics (as i promised) , to whoever is interested

. Sorry about the crappy quality, but i dont have a very good camera, its a 1.3Mpixel one , it was dirty cheap

. Its just some testing equiment, nothing fancy.

http://clientes.netvisao.pt/carlo001/index.html

05-07-2003, 12:59 PM	#53
TerraMex Cooling Savant Join Date: Nov 2002 Location: Portugal, Europe Posts: 870	@Arcturius Someone hasnt read the previous posts... we already stated that ideia. @Alchemy Same. You didnt read properly (imo). Were in hell did i say that it would go armaggedon on you? >Usually having a relatively strong magnetic field in water is a big >"no no". It will eventually interact with the ions in the water and >create a nice layer of magnetized compound around the magnet, >twisting its fields . The way to prevent this is a electromagnet >with an AC signal. And we'd be back to the electric current inside >water. Like, powerful. Not a pretty small magnet. As stated after : > Using distilled water, and with a small magnet. >However, as i said, distilled water with a low ions count (edit: >just in case), a magnet with a light field, and those reed >switches , in theory, they WILL work. The whole issue is the >remaining ions in the water, and the long term effects on the >magnet . Again, i fail to see what's the problem. Can you garantee that it wont have any considerable effects in a large time delta? I cant, because i havent tested. I felt like giving fair warning to certain effects, even if they dont really have a considerable interferance. And as i said , in theory, it would work (translated: it would probably be negligable). >How strong a magnet are you using, for god's sake? It was an industrial setting , very large diameters . All the sensing was with electromagnetic displacement. __________________ "we need more cowbell."

05-07-2003, 02:12 PM	#57
TerraMex Cooling Savant Join Date: Nov 2002 Location: Portugal, Europe Posts: 870	@BigBen2k. With that system you could connect directly to a variable resistance (turning potentiometer) and get a linear output without any complicated schematic , just the variable resistance and resistive divisor connected to the 12v. Cant get any simpler than that . I've got a similar one in a process simulator . I'll get some pictures tomorrow if i have the time. @Acturius Something like this? : http://clientes.netvisao.pt/carlo001/06.jpg __________________ "we need more cowbell."

05-07-2003, 05:52 PM	#60
TerraMex Cooling Savant Join Date: Nov 2002 Location: Portugal, Europe Posts: 870	@Acturius. The picture's fine . I get the general idea. Interesting, i havent seen one of those . Looks pretty functional thou. But doesnt the float need to have some weight or the helix can block the movement (due to the nature of the movement and friction)? Or even if the rod (endless screw type?) can prevent the float to move if there's enought friction between them ... or a stiff rotating potentiometer connected to the rod? __________________ "we need more cowbell."

05-08-2003, 01:48 PM	#62
TerraMex Cooling Savant Join Date: Nov 2002 Location: Portugal, Europe Posts: 870	@Arturius. I see. Seems pretty simple for a DIY to do. Anyway , some pics (as i promised) , to whoever is interested . Sorry about the crappy quality, but i dont have a very good camera, its a 1.3Mpixel one , it was dirty cheap . Its just some testing equiment, nothing fancy. http://clientes.netvisao.pt/carlo001/index.html __________________ "we need more cowbell." Last edited by TerraMex; 05-08-2003 at 01:53 PM.

05-06-2003, 07:04 PM	#51
wymjym Cooling Neophyte Join Date: Sep 2002 Location: near Austin Posts: 96	I went for a bike ride and while pedaling up the killer hill I thought, WTF...I am looking for a solution for folks and others are looking for something to discuss. My bad! For those that are not interested in discussing............ place this small magnet, encased in a bit of epoxy and attach it to the TOP of a floatie. Place the reed switches accordingly...the only time those ions are going to coat the magnet is when they break down the epoxy and for some reason the floatie...quits (floating). wj

05-06-2003, 10:36 PM	#52
Arcturius Cooling Savant Join Date: Aug 2001 Location: Chippewa Falls, Wisconsin Posts: 294	What about making the res opaque (or just part of it) to block ambient light, and then put an LED at the top, and a photo-resistor at the bottom, and add some dye to your coolant? As the water level drops, the photo resistor receives more light and becomes less resistive (if I recall correctly). You may need a high-intensity LED to make this work; I'm not good with optics. photo resistor for $0.50

05-07-2003, 01:36 PM	#56
Arcturius Cooling Savant Join Date: Aug 2001 Location: Chippewa Falls, Wisconsin Posts: 294	Does anyone know how it is done in car's gas tank? That should be fairly easy to leverage... I know on older snowmobiles/motorcycles, there is a float with a 'screw' going through it, that turns as the gas level changes, and the turning points the needle which is part of a guage in the gas cap. Perhaps a similar method with the needle dragging across a rotary switch would work; or turning a potentiometer?

05-07-2003, 02:50 PM	#58
wymjym Cooling Neophyte Join Date: Sep 2002 Location: near Austin Posts: 96	I must ask what type of float are you going to use to have enough pull on that pulley+ wiper pot? I'm sure they exist but then the friction becomes the problem. fuel tanks with electrical gauge outputs by their very nature are generally larger than the res in a computer so there is more area available for the mechanism. wj

05-08-2003, 09:19 AM	#61
Arcturius Cooling Savant Join Date: Aug 2001 Location: Chippewa Falls, Wisconsin Posts: 294	@TerraMex: Where the double-helix passes through the float, the openings in the float are fairly oversized to prevent binding. The rod is not an endless screw--that would cause a great deal of resistance. Rather, it is more like a hexagonal rod, or a round rod with a single flat side, or really any shape that is 'keyed' and has the same cross-section over its entire length. It is meant for the float to move freely in the vertical direction, but it needs to have a shape that allows it to be 'locked' to the float, in the sense of rotation. Lastly, the float has to have some weight to it, but not much. Just enough for gravity to be able to pull it down over the double-helix, and overcome the resistance of rotational friction, and whatever the guage imposes. Usually the double-helix is quite steep, with maybe only 90-100 degrees of rotation over its entire length (~8" in my experience), so those forces are pretty minimal. Also, in the application I've seen these used (gas tanks for snowmobiles) all parts are constantly washed in a gasoline/2-stroke motor oil mixture, so everything is quite well lubricated, and free to move. Even though, I think it could effectively be scaled down, if someone still wanted to use a mechanical level indicator. Actually...it could make for a very nice indicator to be installed in a tall cylindrical res...

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