Component identification on driver board

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ecotack
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Component identification on driver board

I’ve just received a driver from FastTech and I was wondering what the little 3 pin SMD component was. Sorry for the bad picture. The IC number is C733.

DavidEF
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I’m not saying I know, but I’ll speculate, from a little bit of personal experience, that it’s a small, cheap FET. If so, those have a maximum throughput of around an amp or so. You could then stack another on top for an increase in output.

If you want a better “analysis” than that, maybe you could link the driver, so we can look at specs. Wink

Edit: I just looked it up in Google. It’s a transistor.

Edit II: I looked a bit more. It’s not at all clear to me. Sorry. I still think it’s a FET or transistor, but I have no proof that it is.

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ecotack
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Thanks. I’ll trace it later to see if I can figure out what its there for. The board has 8 x AMC7135, so I’m not sure why it needs a transistor. The image on FastTech has the transistor missing (here).

DavidEF
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That’s interesting, that they would have the board made for it, but have the space unpopulated. It would indicate that the part is optional to the circuit, which makes it more mysterious. I’d really like to know what it is now.

Edit: It appears that the two legs on the outside interrupt the ground. The leg on the left connects to pin4 of the MCU (assuming it’s ATtiny13) and the other leg connects to the ground ring. What does the third leg on the inside connect to?

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ecotack
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It appears to connect to pin 6 on the MCU. Still none the wiser.

Rufusbduck
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Could be acting in place of the reverse polarity diode for the mcu.

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ecotack
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Don’t think so, there is a diode to the side. It looks like it gives the MCU the ability to turn itself off. Why you would need that I’m not sure. I was going to zener mod it, but I used a different one.

DavidEF
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ecotack wrote:
Don’t think so, there is a diode to the side. It looks like it gives the MCU the ability to turn itself off. Why you would need that I’m not sure. I was going to zener mod it, but I used a different one.


Yeah, since it interrupts the ground, it makes sense that it may let the MCU shut itself off, except that doesn’t a transistor need power to turn ON? Maybe it’s not actually interrupting the ground path? The driver in the picture on the site doesn’t have that component populated, so it has to still have a ground path somewhere. Maybe it is dumping some power to ground from pin_6 for some reason? I dunno. Maybe this thread will draw the interest of somebody that understands electronics circuits. I’m not really one of those guys. Facepalm

Reason is not automatic. Those who deny it cannot be conquered by it. Do not count on them. Leave them alone.
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hank
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Maybe this thread will draw the interest of somebody that understands electronics circuits. I’m not really one of those guys. Facepalm

I’d contribute toward a tip jar for such a person if one emerges. We could all use the help understanding this stuff.

tterev3
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Can you tell where the third pin connects to? Also, the microcontroller pin connected to pin 1 on this component has another trace that goes somewhere else, can you see where?