ice tube clock - boost converter voltage < 10 volts

[twistdroach]

As the subject says...too low. Figured I'd try to figure it out before soldering everything else on there. I was missing the 22 ohm resistor, so I went and grabbed one from RadioShack ($1 for a bunch, so I figured why not).

[twistdroach]

Here are some pics of the board...

IMG_5684 - Copy.JPG (879.98 KiB) Viewed 1024 times

IMG_5683 - Copy.JPG (841.04 KiB) Viewed 1024 times

[twistdroach]

Also - should mention - it does beep and first test passed just fine....

[twistdroach]

Voltage on pin 12 matches the pin on the transistor closest to s3 and is at about .13 volts. pin farther from s3 on the transistor is at ground.

[adafruit_support_bill]

the pin on the transistor closest to s3 and is at about .13 volts

Looks like a clean build so far. The gate on Q2 (pin closest to S3) should be oscillating. Do you have any access to an oscilloscope to check it?

[twistdroach]

Unfortunately no - just a multimeter at this point...this is my first foray back into the hardware side of things since college, so i'm still building out my toolset...

[adafruit_support_bill]

Double check the value of R5. What is the resistance between pin 12 and GND?

[twistdroach]

21.9ohms to the ground tab on the voltage regulator from pin 12... hmmmm...

[twistdroach]

OK - so I tested C6 and C5, neither are shorting, C7 is not shorted either. The coil is neither open or shorted (measured a couple ohms), D3 was behaving properly showing ~130 ohms forward and no conductivity in reverse. Only thing left is either the microcontroller not pulsing pin 12 (wish I could verify that, but seems unlikely to me), or Q2 is having trouble. I need to look at the schematic - all i've looked at so far was the design page...

Any other ideas?

[twistdroach]

Wooooops - well that explains it. I put a 22 ohm resistor in R5 instead of the 10k resistor. Didn't notice until I looked at the full schematic. Thought R5 was the last one on the parts list, but it was the first. Haste makes waste. Thanks for pointing me in the right direction. Let me see how we do once I replace R5. Thanks again!

[twistdroach]

Yep that did it. Thanks again!

[adafruit_support_bill]

Good job!