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16  Using Arduino / Project Guidance / Re: DC dimmer circuit on: July 20, 2012, 03:37:23 pm
Well, the new TC2249 is now exhibiting the same problem. The only thing I did was to set it to output a 32 μs pulse width. I was getting strange readings so I set it back to a simple digitalWrite HIGH.

Now I get a similar 11.7v on the TC2249 output instead of the expected 0v. I was careful to ground myself when working on it. Is it possible that 30kHz is burning something out?

Is there a more robust way to drive a mosfet?

TNX
17  Using Arduino / Project Guidance / Re: DC dimmer circuit on: July 19, 2012, 12:08:57 pm
Hooray! It works!

Replacing the TC2249 solved the problem.

Thanks, dc42 for helping me track this down.

(I'll add another one to your tab. smiley)
18  Using Arduino / Project Guidance / Re: DC dimmer circuit on: July 17, 2012, 08:40:22 pm
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Try disconnecting one end of the 47 ohm resistor and measuring the output from the TC4429 again

Okay, I tried that and I get the same result 11.99v when input is high and 11.65v when input is low.

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Also check that the ground pins of the TC4429 really are at 0v all the time, in case you have a bad joint.

It reads a perfect 0v.

Do you think the TC4429 is bad? Luckily I ordered two; I will try replacing it.

TNX
19  Using Arduino / Project Guidance / Re: DC dimmer circuit on: July 17, 2012, 03:42:21 pm
Thanks for your time dc42.

Here is the whole circuit. The violet wire from the top is 12v and the red wire (top-right) is ground, both from the power supply. There are several other things going on too, but i hope you can make out the connections for the mosfet.

I should note that the middle pin (pin 2, D) on the IRF5210 is bent forward a little, it is not attached to the resistor.
20  Using Arduino / Project Guidance / Re: DC dimmer circuit on: July 17, 2012, 11:31:23 am
Hello dc42!

Well, I have quintuple checked the connections multiple times. (My brain has involuntarily been going over every little detail for hours)

I wired the IR5210 according to the datasheet where pins 1, 2, and 3, are G, D, and S, respectively. (See attached)

WRT the TC4429, I have all the pins connected except for 3 which is supposed to be left unconnected. The chip is mounted upside down on my circuit (again see attached), so the pin numbering is clockwise from the top-right.

Even now my gut feeling is that something is "misconnected," but I can't see anything wrong.
21  Using Arduino / Project Guidance / Re: DC dimmer circuit on: July 17, 2012, 12:11:07 am
Well I FINALLY had a chance to get this circuit together. smiley-eek

Life is what happens to you when you are trying to work on electronics projects... smiley

The circuit is now set up as in the attached diagram. However something is not quite right. For testing, I am running the circuit on 11.9 volts. When D10 is high the output from the TC4429 reads 11.65 volts on my multimeter and 11.9 when D10 is low. Obviously, that is not enough to turn the IRF5210 on.

May I once again appeal to the experts for some advice?

Thank you for your patience.
22  Community / Bar Sport / Re: You know you are a tech geek when.... on: June 25, 2012, 12:17:41 pm
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When you need 3 separate circuits for one room of the house

I actually did have 3 separate circuits but it wasn't enough so I wired in one more!
23  Using Arduino / General Electronics / Re: Confused about multiple voltages in same circuit on: June 17, 2012, 02:59:04 pm
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I'm using a 6V power supply, which I need to drop to 5V,

Using a diode between your supply and the device will drop the voltage by 0.7 giving you 5.3v. Also a 1v zener could work too.
24  Community / Bar Sport / Re: What projects do you currently have in the idea phase? on: June 02, 2012, 02:01:58 pm
A laser gun to shoot mosquitos. I haven't quite figured out the details yet...
25  Community / Bar Sport / Re: Solar eclipse photos on: May 27, 2012, 03:27:15 pm
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How did you take the photos (without burning your eyes)

I used a DSLR with a neutral density filter, and I didn't look too long!
26  Community / Bar Sport / Re: Solar eclipse photos on: May 25, 2012, 11:55:55 am
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center.jpg has a really dark sky

The sky wasn't that dark to the naked eye. I had to use an 8x neutral density filter and -5 exposure compensation to make the ring visible in the photo.
27  Community / Bar Sport / Re: Solar eclipse photos on: May 24, 2012, 03:13:54 pm
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What does RPCoyle's picture show?

I'm guessing its the moon's shadow split over the horizon. smiley-roll

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I've seen 2 lunar eclipses.

That reminds me. I have a couple of shots of the 2010 lunar eclipse.

Also I should clarify; the composite solar shot (above) was a feeble attempt at HDR. Impossible with an infinite dynamic range like that!
28  Community / Bar Sport / Re: Solar eclipse photos on: May 22, 2012, 07:30:37 pm
18:24 PST for the centered shot. (second attachment)
29  Community / Bar Sport / Re: Solar eclipse photos on: May 22, 2012, 04:45:41 pm
Northern California. It is the only time in my lifetime that it it will be visible here.
30  Community / Bar Sport / Solar eclipse photos on: May 22, 2012, 03:45:57 pm
Here some photos I took of the recent solar eclipse. Not the best shots but it was fun...

Enjoy!
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