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Topic: sensor connectors for use outside (Read 1 time) previous topic - next topic

bobhawkens


bibre

#16
Apr 08, 2012, 03:08 am Last Edit: Apr 09, 2012, 08:47 pm by bibre Reason: 1
@woody_unreal

Those Radio Shack boards you suggest are great.

I've made 15 DPDT Latching DIP relay modules for my model railroad automatic signal control blocks using them.
Billy     http://www.z-world.com/operations/gbremer/

When you've eliminated the impossible,
whatever remains, however improbable, must be

roncoop


weather proof connections are possable , but the 3 sensors part makes it difficult. since your reducing your wire count run.


I agree.

OP, you ever consider a different sensor type?

How about an automotive fuel tank sending unit?

Fairly inexpensive, reliable, built to take the elements, don't need floating balls in your tank and you'd get a more acurate reading due to it being variable not stepped.

Just throwing it out there.

Good luck!

woody_unreal

agree  roncoop , even just 3 wires danging in the water at hight, but i think he said something about already having them- (didnt feel like rereading) :)  so i went with that possable solution - Even just a POT connected to a flowing arm would have worked :)

lemming

#19
Apr 09, 2012, 08:55 am Last Edit: Apr 09, 2012, 09:06 am by lemming Reason: 1
I use these on farms for measuring dam and tank levels:

http://www.sparkfun.com/products/639

The good thing is they only need three wires, they provide infinite measurement (not just three levels) and they have no moving parts and are not in contact with the water. i.e. no wear and tear, no corrosion or fouling of terminals.

For $26 they are simple to use and save you time and money over cheaper but less reliable systems.

bobhawkens

#20
Apr 24, 2012, 05:20 am Last Edit: Apr 24, 2012, 05:22 am by bobhawkens Reason: 1
Just to update everyone on what I decided to do. I bought some of these:
http://www.adafruit.com/products/266

I stick the pins of the hall sensor right into the female jumper wires, then wrap the whole thing in electrical tape, then tape that to the outside of the tank. On the inside, I have a pvc I sawed in half and duct taped to the wall of the tank (which in my case is just a plastic tote box). Inside of the half pvc, I have a simple float made of styrofoam with some rare earth magnets duct taped to the bottom. Put it all together and you have a cheap float sensor.

Originally, I wanted to wire several hall sensors together in series to eliminate the number of wires running a longish distance. There still isn't an elegant solution to this problem, but now I can at least try to wire in series away from the hall sensor pins. But it's such a hassle, so I'll probably just run redundant ground and 5v wires all the way out to the sensors. If I try again to wire in series, I will connect the other end of the female jumper cables to these:

http://www.adafruit.com/products/744



gravelbar

Shrink tubing with hot-melt adhesive inside is good for watertight connections.  You can find it at a lot of online suppliers and it's even showing up in hardware and automotive supply shops.

You can also put connections inside a watertight enclosure and use gland nuts for your cables to make something that is pretty much watertight.

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