Extending or Modifying Wireless sensor for Tstat

kilosos2 · 04-04-2012, 01:55 PM

Hey Guys

I got a S1-THSU32HP7S source1 LX series thermostat. I have a few of these thermostats. I was exploring into the wireless accessories for this thermostat to help install one in a friends home. It has a wireless RF module you add on to it and a wireless sensor that can be used for indoor or outdoor temperature readings. Well I bought the wireless RF module model S1-LXRFM and the wireless sensor model S1-LXRFTS. I hooked them up and installed them but the signal strength is not that great. I mean after I install them the signal first says its 10 and if I move the sensor away like 30-40 ft it goes down quickly to 3 or 2 out of 10. Sometimes it goes down to 0. LOL , So I just had a idea. What if I were to extend the Antenna? I mean just make it bigger? Now one thing I do want to say, I believe the wireless sensor are working but I was wondering if I could improve the signal so I can move the sensor a bit farther. Also another question for you guys. The wireless sensor uses 2 AAA batteries, is there anyway I can hook this up to some sort of permanent source of power so I never have to change the batteries and tamper with the sensor? Because when you change the battery , you have to reprogram/relink the sensor to the wireless RF module. I mean this is all just a idea and I am saying if its possible. I may post this on the electrical forum area also.

I have some pics of the sensor and RF module for you guys to look at.

So what you guys think?

kilosos2 · 04-05-2012, 04:29 AM

Any idea's?

bobinphx · 04-05-2012, 09:37 AM

yes you can extend the antenna, both transmitting and receiving. Its a very complicated subject, but it can be done. Look up Helictical antennas. I would also suggest that you look at the radiation pattern for this type antenna. Short of adding more antenna, you might want to try and move the outdoor sensor around. Try to visualize the path the wireless has to travel. If you can move the sensor to a location that has fewer walls etc between the recieiver and transmitter, that would be better. Also try moving the sensor from a vertical to horizontal plane. that might help also.

To answer your question about powering the sensor with 110volts, yes you can do it, but you would have to interface a 3volt transfomer to the sensor. This can be done, but be aware of national electical code, fire dangers and insurance regulations reqarding this, if something bad happens.

now, it if was me,,, I would hack out the thyristor that does the actual temp sensing and extend that outside, keeping the rest of the sensor inside and fairly close to the receiver.. I would also take a 3 volt wall transformer and solder it on to the battery connections and power it from a close by indoor outlet, but thats just me.

good luck.

kilosos2 · 04-05-2012, 11:12 AM

Ok alot of info to gobble down here. The sensor will be used for indoor only. The problem for my friend he has 2 AC units that pretty much share a open space between a primary area of his home and an extended living room area. The extended area has a 1.5 ton AC unit that cools the extended area plus one bedroom. We are thinking of throwing the sensor into the bedroom to kinda of isolate the temperature control for that extended area's zone. The thermostat also has a option to make a average between the sensor and the thermostat. The problem occurs is the 2 AC unit's thermostats battle each other and they have to turn one thermostat up and the other down to make the units keep running. Its weird and annoying to them. I really like your transister idea but loll that would defeat the purpose of wireless because we were trying to avoid running any wires. The 3 volt transformer, where can I buy something like that? I am a HVAC student so I know how transformers work. I am wondering what the antenna is made out of? LOL I was thinking of even using wifi antenna's but it seems like this is an Helictical antenna as you are saying. I know this can be done because just like wifi on routers or wireless cards you can attach a bigger antenna and increase range. The only other thing I want to know will there require a increase in any power? And is that only controlled by the microchip of the sensor and RF module? Or just making the Antenna bigger will do the job. I just really want this to be working well and stable and maintenance free because it's for my friend and I don't want him to be going back and forward with any connection problems or battery issues.

thanks for your replies. this is kickass!

kilosos2 · 04-15-2012, 02:17 PM

Well here's a little update. HAHA. After tweaking around with my RF wireless Module model S1-LXRFM. I make this retrofit Antenna. HAHA I got it off a wifi Antenna of a wireless card and taped it with some UL-181 silver tape. I tested it and placed the sensor far away and it tested out ok. Very weird , it kinda does jump around in signal but I still saw a great improvement from signal strength as 1 to all the way to 9. ( Maybe cuz I was moving it sometimes) I think onces I have it installed and it won't jump around in signal strength.

Anyways my second part of my project was to put my the indoor sensor on to some sort of permanent power source so we never have to change the batteries and mess around reinstalling it after changing batteries. I got from Radio Shack a AC to DC converter. Now the batteries in the sensor take 2 AAA batteries which gives it 3 Volts total. I got a converter that does as low as 1.5 to 12 VDC at 300mah or .3 amps. I don't know if the .3 Amps is too much!?! It's the lowest I saw. Is there a way to figure out how many amps this sensor really needs? Or watts? Because with Watts I can calculate the amps. Any idea's ? I just don't want to fry this sensor you know! Also after I figure that out, how would I wire this to the sensor? I was thinking just solder Plus with Plus and Negative to Negative. That should be right since this is DC voltage. See the pictures of the RF module and the AC to DC converter . LOL this has been a fun project.