Black Lives Matter - Action and Equality. ... Adafruit joins the Stop Hate for Profit campaign.
0

Ice tube clock low boost voltage
Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.

Ice tube clock low boost voltage

by jeff01 on Sat Oct 03, 2015 8:20 pm

Hello,

I have been trouble with my ice tube clock kit. The first check was fine. Voltage was right where it was supposed to be at 5v. The second test with the beep also tested out fine. When testing the boost converter it is only showing about 11V. I checked component placement a few times and can't see anything. Are there any suggestions on things I can check? This is the first board that I have assembled so I don't have a lot of experience with these things.

IMG_2197 (1).JPG
IMG_2197 (1).JPG (88.87 KiB) Viewed 826 times

IMG_2196 (1).JPG
IMG_2196 (1).JPG (95.98 KiB) Viewed 826 times


Thanks a lot!

jeff01
 
Posts: 5
Joined: Sat Oct 03, 2015 7:59 pm

Re: Ice tube clock low boost voltage

by adafruit_support_bill on Sun Oct 04, 2015 6:11 am

The assembly looks good so-far. Are you still getting a good 5v reading and a beep?

adafruit_support_bill
 
Posts: 77819
Joined: Sat Feb 07, 2009 10:11 am

Re: Ice tube clock low boost voltage

by jeff01 on Sun Oct 04, 2015 11:55 am

Yeah. Still beeps and has 5v. Any ideas on what or where to test next?
Thanks

jeff01
 
Posts: 5
Joined: Sat Oct 03, 2015 7:59 pm

Re: Ice tube clock low boost voltage

by adafruit_support_bill on Sun Oct 04, 2015 12:18 pm

What is the voltage on the positive leg of C7?
And measure the boost voltage again - it sounds like you may be getting a partial boost.

If you can post a close-up photo of the area around Q2, we can take a closer look for any suspicious solder joints.

adafruit_support_bill
 
Posts: 77819
Joined: Sat Feb 07, 2009 10:11 am

Re: Ice tube clock low boost voltage

by jeff01 on Sun Oct 04, 2015 3:55 pm

This is the closest my camera would focus, hopefully it works. Touched up C6 and didnt seem to make a difference
IMG_2199.JPG
IMG_2199.JPG (90.03 KiB) Viewed 774 times
IMG_2198.JPG
IMG_2198.JPG (95.95 KiB) Viewed 774 times


Voltage at the striped end of D3 shows 10.9V.
C7 is showing 8.8V
L1 is showing 4.2 ohms.
D3 and D5 check out.

I installed C5 and it didn't seem to make any difference.

jeff01
 
Posts: 5
Joined: Sat Oct 03, 2015 7:59 pm

Re: Ice tube clock low boost voltage

by adafruit_support_bill on Mon Oct 05, 2015 3:55 pm

So you are getting a slight boost. But not enough to light up the display.
Do you have access to an oscilloscope so we can see what is happening in the circuit?

adafruit_support_bill
 
Posts: 77819
Joined: Sat Feb 07, 2009 10:11 am

Re: Ice tube clock low boost voltage

by jeff01 on Sat Oct 10, 2015 6:26 pm

Unfortunately I don't. I just have a mulitmeter.

jeff01
 
Posts: 5
Joined: Sat Oct 03, 2015 7:59 pm

Re: Ice tube clock low boost voltage

by adafruit_support_bill on Sun Oct 11, 2015 6:57 am

Let me check with the designer and see if she has any suggestions on how to best troubleshoot this without a scope.

adafruit_support_bill
 
Posts: 77819
Joined: Sat Feb 07, 2009 10:11 am

Re: Ice tube clock low boost voltage

by adafruit2 on Sun Oct 11, 2015 9:08 pm

ooof without an oscilloscope its really challenging, its a frequency based thing, yknow? :)
you could just keep going...but i'd really try to get a hold of a maker space or friend with a 'scope

adafruit2
Site Admin
 
Posts: 19217
Joined: Fri Mar 11, 2005 7:36 pm

Re: Ice tube clock low boost voltage

by Russell 27 on Mon Oct 12, 2015 12:12 pm

Does your meter have a frequency setting. You could always use that.
Russell 27
 
Posts: 240
Joined: Thu Sep 12, 2013 3:59 pm

Re: Ice tube clock low boost voltage

by jeff01 on Thu Oct 15, 2015 9:43 pm

My meter doesn't have that function. Hmm. Ok well I guess not much that can be done then. Guess ill finish it and see what happens. If all the components are installed right the only things left are IC1 and the high voltage transistor. It sounds like there is no way to know if something is wrong without an o scope?

jeff01
 
Posts: 5
Joined: Sat Oct 03, 2015 7:59 pm

Re: Ice tube clock low boost voltage

by adafruit_support_bill on Fri Oct 16, 2015 5:44 am

The boot circuit works by having the microprocessor generate pulses to the input of the transistor which switches current into the inductor/capaciitor circuit. These get transformed in to higher voltage pulses on the output. There are several ways that can go wrong.

A frequency meter would let us know whether pulses of the right frequency were being generated. An oscilloscope would let us see what the pulses look like in various parts of the circuit to help understand which component or components are not working right.

adafruit_support_bill
 
Posts: 77819
Joined: Sat Feb 07, 2009 10:11 am

Re: Ice tube clock low boost voltage

by peokuk on Mon Feb 15, 2016 5:04 pm

I know it's an old thread, but I'm having the same issue and can have someone take a look at my board with an oscilloscope. Where should I be checking?

peokuk
 
Posts: 3
Joined: Mon Feb 15, 2016 5:02 pm

Re: Ice tube clock low boost voltage

by adafruit_support_bill on Mon Feb 15, 2016 5:36 pm

Let's start with some nice clear photos of the front and back of the main board. If you have access to an oscilloscope, traces from pin 12 of the processor and the cathode of D3 would be a good place to start.

adafruit_support_bill
 
Posts: 77819
Joined: Sat Feb 07, 2009 10:11 am

Re: Ice tube clock low boost voltage

by peokuk on Tue Feb 16, 2016 1:49 am

Thanks for the quick reply! It'll be a few days before I can get it under a scope, but here are some pictures--

Front:
IMG_3554.jpg
Front
IMG_3554.jpg (318.8 KiB) Viewed 495 times

and back:
IMG_3553.jpg
Back
IMG_3553.jpg (317.59 KiB) Viewed 495 times

peokuk
 
Posts: 3
Joined: Mon Feb 15, 2016 5:02 pm

Please be positive and constructive with your questions and comments.