I just finished building a K2639 Liquid Level Controller. I followed the diagram on page 12, my problem is that the low alarm does not come on, and the high level alarm works fine. but I have a small speaker connected to NO and C this is a small speaker that came out of an old PC. I get no sound at all, just the lights at high level no lights at low level. Can someone give me some direction. Thank you in advance.
A speaker between contacts of a relay won’t produce any sound … so that is very normal.
For the rest: check everything. Sometimes it helps when you send us a link here to a VERY sharp and HIGH resolution picture of the PCB (both sites).
Here is a link to some pictures of my build : onedrive.live.com/redir?resid=8 … =folder%2c
What I am looking to do is have a warning system for our AC air conditioner that is upstairs in our office. The pan is defective and we are on our second one in a year. The only warning system that we have now is when water comes through the ceiling, It would be a lot of work to run wires from upstairs to downstairs we we mostly work. So I thought the setup on page 12 with the alarm would be the best option. I went and purchased some Piezo buzzers today in hopes of getting a sound warning when liquid is detected. Can someone please tell me if this will work. If not how can I get it to work. Thank You in advance.
Basically, you need to wire the piezo in such a way that the relay interrupts the current to the piezo buzzer.
The way you wired it does not work as the relay does not put out any voltage.
Are there any instructions on how to do that ?
OK:
The (+) of the piezo sounder power supply goes to the COM of the K2639 relay.
The NO of the K2639 relay goes to the (+) of the piezo sounder.*
The (-) of the piezo sounder goes to the (-) of the piezo sounder power supply.
If the piezo sounder can handle the same voltage as the K2639, then you can use a single supply for both items.
*It is possible that you need to use the NC instead of the NO
Could part of my problem be that I am only using 11.87V I just ordered a bench power supply, but this is all I have right now. Switching to NC also did not set off the Piezo.
Does the relay on the K2639 click when the water reaches a certain level?
Does the piezo sounder work when you hook it up directly to a power supply?
Yes the relay clicks the lights go on, but no sound from the buzzer. Also when I put a meeter to NO I don’t see any power getting to it when the relay clicks. And yes the Piezo works fine when connected to power.
If all this is correct, then we must assume that there is a wiring issue.
Can you provide a link to a picture of your hook-up, so that we can take a look?
I am very happy to report that all is working correctly. My problem was that I did not have any power to the Piezo, I thought the pins were connected but they are not. So I connected Negative post to common, then Piezo neg to NO, Positive Piezo to Positive post 1. here is a link to the finished product ready to catch a leak in our office AC pan which is defective from the manufacture.
onedrive.live.com/redir?resid=8 … =folder%2c
Thanks to everyone for the support.
Hi Kid,
You might want to look at the engineering notes that Velleman made.
It might help to understand relays.
http://www.vellemanusa.com/downloads/EngineeringNote-enu.pdf
Just a thought you could also connect a small pump to it to pump the water out of the pan and into a drain.
Some helpful info, Thanks
The AC unit is upstairs and we would have to tap into the line in order to pump out the temp pan. hopefully it won’t leak again. But my friend who has a 44’ sailboat wants me to make one of these units for his forward bilge. So I just ordered another one from Amazon. Does anyone know of any issues dealing with saltwater?
We’d recommend to replace the PCB sensor with two stainless probes.
We will start looking, any recemdations .
Any two ‘probe-like’ stainless steel parts will do the job…