New build, blower running full speed.


 
R

Rick Loewen

New member
Just completed a new build, everything went well and looked great on first look. After configuring and setup, I connected the blower for a bench test, and it runs at full speed all of the time in spite of the correct functions displaying on the LCD and Config page. I have a scope meter connected to the blower leads and it is showing 222Hz @ 11.69V constantly.

Where should I begin troubleshooting and what are the test points with values I should check?

Rick
 
Solder looks real good on Q3

Voltages to gnd on Q3:

Blower G D S
0% 0.635V 11.82V 11.85V
100% 0.655V 11.82V 11.85V

Checked solder joints on related BS170 and pin 5 of ATmega, also looks good.
Noticed that blower comes on on immediately when powering up. Getting same results with either pulse or voltage on fan output config setting.
 
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Are you changing the 'startup max' value to test?

When I was testing it didn't seem to matter what min% max% were but the startup max% allows me to fluxuate fan speed.
 
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It's not a software thing, the blower shouldn't run at all with no pit probe connected (at least in auto mode).

The circuit here is uncomplicated, looking from the top:
-- Rightmost pin is connected directly to the 12V input, that looks good
-- Middle pin should be floating when it is off
-- Leftmost pin is pulled up to the right pin through the 2.2 resistor. The Q1 MOSFET there can pull this down and it looks like it is for some reason. I'd say maybe try removing Q1 and seeing if the blower turns off. Also check to make sure you've got the right part here because ~0.6V is pretty high. It should be able to pull it down a lot lower than that.
 
I tried a number of methods to set the blower speed, usually using the set temp of either 60 or 160 and the home page indicated either 0 or 100% and the LEDs confirmed.

I also tried various values in the startup max.

J. Rican, I find 'startup max' to be a 3-character max % field. Test?


Pics
solder.jpg


component.jpg


Bryan,
Just about to post above when I saw your response. I'll check the part and remove next, hanks. When I started building, I realized that I somehow used the 4.1 component parts list, and caught the different MOSFET and had to reorder, so I should be the right one. I'll check.
 
v4.1 uses BC337 NPN transistors for Q1, Q2, Q4. In v4.2, those were switched to the BS170 N-Channel MOSFETs for Q1, Q2, Q4 & Q5.
 
Bryan, good catch. When I re-ordered I must have only gotten 3 BS170s and somehow plugged in a MCP1700-33 in the trouble spot. Is the BS170 a Radio Shack item? It is tough finding components in Orlando. We do have one cool place for parts, but it is hit or miss on anything popular and current. It is always that $.44 item that gets you!


Steve, figured that out digging through the development evolution notes. I noticed it when I started running out of parts and had some extras. Too much clicking around during ordering.

Thanks to everybody on this project. It is soooooo cool (Or should I say hot!)

Rick
 
I can't check the Radio Shack website but you should be able to use a 2 N 7000 except the pins are reversed so just rotated 180 degrees when you install it
 
Rick Loewen said:
Bryan, good catch. When I re-ordered I must have only gotten 3 BS170s and somehow plugged in a MCP1700-33 in the trouble spot. Is the BS170 a Radio Shack item? It is tough finding components in Orlando. We do have one cool place for parts, but it is hit or miss on anything popular and current. It is always that $.44 item that gets you!


Steve, figured that out digging through the development evolution notes. I noticed it when I started running out of parts and had some extras. Too much clicking around during ordering.

Thanks to everybody on this project. It is soooooo cool (Or should I say hot!)

Rick
Click to expand...

I have Accidently made the same mistake, ordering parts. Byran should start to add the older builds into an obsolete area on GitHub and only show the current board where you can order the parts.
 
John Bostwick said:
I have Accidently made the same mistake, ordering parts. Byran should start to add the older builds into an obsolete area on GitHub and only show the current board where you can order the parts.
Click to expand...

+1 on that. I was ordering some extra parts, so by the time I found everything I opened up another Mouser window starting with the pages index for a fresh page, that's when it happened. I have gotten back to the old builds several other times this way. I was thinking 4.x Hardware (kind of like 4.x Software is) needing 4.3 Hardware and it is on the expanded pages index.

There are a couple other things I took a few side trips to figure out.

  • Leaving out the 10K resistor on the thermocouple option is easy to miss.

  • It was hard to find ordering info and specs for an RC servo.

  • The link is nice at the bottom of the 4.2 Assembly page taking you to the next step. If all the build pages had such links it would make the build flow a little smoother without going to the home page between steps.

  • I am starting on the blower mount and servo installation next. Is anyone offering printed blower/damper cases? I have some ideas of what I might do for my BGE, but I haven't seen anything on printed parts offerings.

I must say, this Wiki is so well documented and detailed. I am very impressed. Don't get me wrong, the items above are quite minuscule in the overall picture, but I just wanted to give a little feedback.

Rick
 
Rick Loewen said:
+1 on that. I was ordering some extra parts, so by the time I found everything I opened up another Mouser window starting with the pages index for a fresh page, that's when it happened. I have gotten back to the old builds several other times this way. I was thinking 4.x Hardware (kind of like 4.x Software is) needing 4.3 Hardware and it is on the expanded pages index.

There are a couple other things I took a few side trips to figure out.

  • Leaving out the 10K resistor on the thermocouple option is easy to miss.

  • It was hard to find ordering info and specs for an RC servo.

  • The link is nice at the bottom of the 4.2 Assembly page taking you to the next step. If all the build pages had such links it would make the build flow a little smoother without going to the home page between steps.

  • I am starting on the blower mount and servo installation next. Is anyone offering printed blower/damper cases? I have some ideas of what I might do for my BGE, but I haven't seen anything on printed parts offerings.

I must say, this Wiki is so well documented and detailed. I am very impressed. Don't get me wrong, the items above are quite minuscule in the overall picture, but I just wanted to give a little feedback.

Rick
Click to expand...

Yeah the Navigation is a little tricky for those not used to Github and that's most people. I think having a Sticky, here on the forums, that had the Step-by-Step with links to github. That way it could be updated easier.

look for the Rotodamper, by Ralph.
 
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