Water Level Sensor for HHO cell

MW383 · November 03, 2009, 02:08:25 PM

Quote from: Draco Rylos on November 03, 2009, 01:23:24 PM
Float type switches probably wouldn't work as well in the tightly cramped space of a HHO cell. I should have made it clear when I first posted. I only want just a little section of the sensor to actually be within the cell. I know modifications will have to be made to the sensor for it to work like I want it.

OK, staying with float concept for now, only build your own.... Mount 2 magnetic reed switches on outer surface of your vessel at desired heights. In this case the vessel would have to be a non-magnetic material. Within the vessel itself have a small diameter vertical rod. Attached to the rod are small floats that have a very small and light weight permanent magnet mounted to them. Magnet size tuned to activate reed switch on outside of vessel. This could be made quite small in size. I still recommend trying to get this stye of switch to work. This home made one would also eliminate the need for sealed bulkhead fittings (like in purchased item I posted a picture of).

You can brave into contuinity based switching. In this case you literally have 2 automotive style spark plugs. They are mounted externally having the electrodes positioned to be in contact with your liquid. Thus only a very little bit of interior tank real estate is consumed. You get back into hacing the need for bulkhead sealing though. Word of warning on continuity based scheme, be prepared for erratic behavior and probably more so in your hydrogen generating environment. No-switching when it should be and Switching when it shouldn't be. I have used these before too and have totally abandoned them due to poor reliability. I really cannot reccommend doing this with a good conscience.

Best of luck,

MW383

Draco Rylos · November 03, 2009, 02:35:23 PM

That sounds pretty interesting. I was planning on using a Sched 40 PVC pipe for the cell, so that would be non-conductive. You would have to go through the body of the cell to mount the floats on small rods that would support the floats. I would need 2 because one would be the upper limit and the second would be my lower limit. Where is the best place to put the lower sensor that would not have the risk of a random spark which would cause ignition of the generated hydrogen in the cell?
I've posted my source code at pastebin here pastebin - HHO Control Circuit Control Prog - post number 1644595

MW383 · November 03, 2009, 03:09:41 PM

Quote from: Draco Rylos on November 03, 2009, 02:35:23 PM
Where is the best place to put the lower sensor that would not have the risk of a random spark which would cause ignition of the generated hydrogen in the cell?

Since all electrical switching done on exterior of your vessel, random sparking not an issue. All you are doing inside the vessel is floating a couple of magnets so this in itself will not do anything.

Magnetic reed switches I am familiar with are small in nature (if bare switches). They remind me of the small style lights one would put on a Christmas tree. Basically it is just two contacts inside a small glass bulb, with small wire leads coming out the end. One contact does not move, other does. One that does, moves via magnetic field being applied to its vicinity which is your case the magnet on the other side of the PVC container.

Note, magnetic reed switches typically not rated for high currents. So you may have to use the reed switch to fire coil on a relay, and have the relay switching contacts do actual switching of heavier loads. (I'm not sure of your full setup yet)

Hope this helps,

MW383

Draco Rylos · November 03, 2009, 03:16:13 PM

What I meant when I said random spark is, that occasionally something may occur within the cell which could cause a small arc between the plates of the cell. Something like a piece of metallic debris that may enter the cell at any time but remain suspended until something happens like the fluid level going down to a level where the debris may cause a reduced gap between the plates causing an arc to occur. With the various voltages and amperages that are utilized in a HHO cell, a spark may occur if that does happen causing possible failure of the cell body and damage to the vehicle if the explosion is large enough.

MW383 · November 03, 2009, 04:11:29 PM

I'm no hydrogen fuel cell expert but do know their principals. Regarding floating debris, could this scenerio be prevented by using a battery grade polypropylene seperator paper wrapped around your metallic plates? (assuming you are using 304 or 316L stainless) Such paper should not interfere with anything nor prevent H gas from exiting as it is a pourous material. The theory here is to prevent possible floating debris scenerio.

As far as arcing, I am in the dark. I am assuming plate to plate distances are being minimized in order to get more plates into the system, thus more H gas generated. I would also venture to guess that smaller distance between plates increases chances of arcing if said plates were not submerged in water. Again all guesses on my part as I have no practical experience with these devices.