Bad servo, bad pouwer suppply, or something I did?


 

Tim Loftus

TVWBB Member
First, let me thank Bryan for dreaming up the HM and Tom Kole for the case and off-set valves. Also to all those who have put time an effort into this project. it is awesome. I have been following for years, but do to time, money and self doubt, have not built one until now.
I had so much fun building the HM, now I can't wait to start using it.
but I have run into a little problem. the servo seems to cause major issues..... I lose WiFi, the fan runs inconsistent, and sometimes the display even losses power.....

Let me say that it runs without issues with only the fan attached to it...I did an 8 hour test run last Sunday and was able to play around with it a little bit. I have an Ugly Drum Smoker and I was able to attach the fan to a 1 inch copper pipe and that pipe fit right into the outlet of my smoker. I started off at 245 for an hour then down to 235 for an hour then down to 225 for the rest of the time.....it worked perfectly.
However when I bring a servo into the mix everything starts going haywire. The first servo I used when you powered the HM on or connected the cat 5 cable (I am using Tom Koles off set rotery valve version1) the HM went nuts, wifi stopped working, The LCD went crazy, the fan ran, then stopped then ran, and the servo just made funny sounds.....
So I started testing....found out it works fine without the servo, I tried another servo ( I got the 4 pack of the Tower pro that Tom recommends)it that seemed to fix some of the problems, but now it seems lit the unit when you add the servo just does not have enough power.
So My question to the forum...what do I do test to pin point the issue?
 
John asked all the right questions... Sounds like the draw from the blower and servo are too much for your power supply to handle and the HM and/or rPi is browning out on you... Try a beefier 12V supply, you might even have one laying around the house. Lots of stuff use them, have any old cordless phones, answering machine, routers etc laying around? Check their PS for 12VDC output, TIP POSITIVE. You really want more than 1A current, but not all PS are created equal, so you may find one 12V 1A PS that browns out and the next works fine... Otherwise a 2A or better PS is pretty cheap on Amazon or Ebay etc.
 
Thanks for the response guys. Ralph I think you probably hit the nail on the head, with the power supply not being up to par! I was thinking that the PS was but wanted to run it through you guys first. Regardless if it is or not I need to get one with a longer cord. I didn't' want to order a more powerful one before I checked with you guys first. I might head to amazon and find a 2A with a longer cord.
But to answer your questions,
it is the stock blower that comes with the unit (the new blower with the blue tach wire) and the power supply is the recommended 12V DC Power Adapter Supply 2.1mm 1A
here is the link to the amazon page.
http://www.amazon.com/exec/obidos/ASIN/B00452YFZU/tvwb-20
and the specs from the page.

Technical Details

Brand Name: ZJchao
Model Number: LJY-186
Item Package Quantity: 1

Product Description

12VDC 1000mA (1A) Regulated Power Supply for CCTV Cameras SPECIFICATION: ü AC input voltage 100-240VAC 50/60Hz ü Output Voltage 12VDC (Regulated) ü Plug Tip size 5.5, 2.1mm (inside Hole) (see Photo) ü Working temperature 0-35℃@100%,50℃@70% load ü Safety standards CE, CCCs&e

Here is the link for the servos I have.
4pcs MG90S Gear Micro Servo for RC Helicopter Plane Boat Car + Horns
http://www.amazon.com/exec/obidos/ASIN/B006VRWV1W/tvwb-20
 
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All standard issue stuff... SHOULD work, does work for many people I guess... But I always suggest someone buy a larger power supply if you are going to use a servo and a blower or an extra large blower. On the initial purchase it cant cost more than a buck or two to get a 2A 12v PS instead of 1A.
BTW, on power supply selection, what you NEED to match is 12VDC output, TIP POSITIVE cord with the jack you refer to. For amperage you can really run anything rated higher than what you need. You can't over Amp your system, so extra amps just cost you extra bucks but give you more capacity to push current.
 
You mayt have another issue then. Your power supply should be fine.

Disconnect the blower and run the servo by itself and see what it is doing. you may have a short some where or you are not connecting the servo to the correct wires or your cat5 cable may have a short some where.
 
wow how times flies....so I was not able to work on this much over the last month, but over the weekend I finally got a chance to sit down and work with it. I got a new power supply
http://www.amazon.com/exec/obidos/ASIN/B00Q2E5IXW/tvwb-20
TMEZON 12 Volt 2 Amp Power Adapter AC to DC 2.1mm X 5.5mm Plug 12v 2a Power Supply Wall Plug Extra Long 8 Foot Cord
and switched out the servo.

now my heater meter fully works. I had it on my smoker for over 8 hours on Sunday. I was messing around with the temps a lot increasing and deceasing the pit temp. it worked like a charm. I was not having any of the issues that I was having before. I also made the best smoked chicken thighs I have ever had.
I do have one question.... it does not seem like the servo does anything. it never moved the entire time. is there something I need to adjust in the config or a setting change I need to make? I have not made any adjustments other than setting the name of the probes.
I was using Tom Koles 1st off set rotary damper.....
and again thanks to everyone! this has been an awesome project and is really helping my smoking out.
 

 

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