connecting an optical liquid level sensor

[davidnprop]

I have a prodject that requires a level of fuel to be maintained. Yet the chamber is to small for a float. As I was looking for something I came across an optical liquid sensor (www.fluidswitch.com). My knowlege of electronics is VERY BASIC. Electrition by trade we don't get that much traning in it. I've got model# OS-900B-12-0 and also a OMRON solidstate relay for a load. When the level is low the sensor pulls in the relay yet it never shuts off. If I pulse the power to the sensor as the level comes down it shuts off at the proper level.The relay is a G3PB-215B-VD the only info I have on it is that it's DC 12-24v and draws 7ma. I've tried putting R in series with the load and I get up to 4.61K and after that it just shuts down and it still operates the same. I've hopefully attached the info I have with the sensor. Thanks in advance, I know I'm over my head with this one!

DavidnProp

 

[jkmadsci]

If you post your entire circuit we might be able to help. Is your sensor the one that sinks power?

 

[mcs51mc]

It will never work by connecting both directly together.
Your sensor is an open collector output (sink current when dry, max 40mA).
Your relay needs 12 tot 24 V to operate.

You need something in between sensor and relay...

I suggest that you try both seperatly first so that you get familiar with both systems.

Put a 1K resistor and LED between sensor output and +12V. Led should be on when the sensor is dry, off otherwise. (Watch the led polarity)

To operate the raley you need at least 9.6V, it will release when the voltage drops below 1V. Connect a switch between your 12V supply and the input of the SSR. When you close the switch the SSR must operate.

Now you know how both systems works, try to find a way to put them together. If it fails, post it here and we can help you further.


Why using a SSR?
Do you need the 15A load current of the SSR?
Why not using a standard relay?

 

[davidnprop]

Sorry, about the photo. New to this and got orders to go to a birthday party. Maybe these might help? mcs51mc thanks, tomorow I'm going to get those parts and like you say get familiar with them. Sounds like a good place to start.

 

[blufke03]

I can't tell you how to set up the optical liquid level sensor, however if you visit Madison's website, they have a lot of useful information on **broken link removed**. Plus they can tell you exactly the sensor that you need.
Hope that this helps!