Going to have to turn back the controllers to DigiKey - apparently, I did not do enough research.
Texas Instruments also puts out a controller similar to the LM74610-Q1, which is the LM74670-Q1. However, the LM74670 is described in the datasheet as a rectifier diode controller specifically for car alternator rectifiers. There doesn't appear to be a whole lot of difference between the two chips, otherwise. Just in case, though, I ordered the LM74670s, and should get them about a day after I get the LM74610s.
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Originally Posted by serialk11r
Eager to see how this turns out. How does packaging look? (as in, how much more space do the MOSFETs take up?)
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Well, the MOSFETs are in a TO-220 package, so they should be able to fit between the two common rectifier plates. I'm going to screw the MOSFETs onto the rectifier plates, to use the plates as heatsinks. The B+ plate won't need any isolation, but the ground plates will. I'll probably also press out the existing rectifier diodes, since the MOSFETs themselves can also act as rectifier diodes if their controllers somehow fail.
The controllers themselves are about 1 mm thick, so maybe I can epoxy them directly onto the MOSFETs.
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Originally Posted by serialk11r
And yea, they are usually 1V drop not 0.7. I figured that out when searching through electronic component catalogs and found the high amperage diodes having higher voltage drop. It's kind of insane that car companies use something that wasteful to save a hundred bucks...but then again, belt driven power steering and water pumps are even worse, and barely save any money as well.
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It's engineering-by-accountant. If you can chop off a dollar for every vehicle you make, and you make 300,000 vehicles a year, you just saved $300,000. That's the thing that pretty much killed Chrysler after Mercedes bought it. Chrysler's 4th gen minivans are about the most visible example of this - rustbuckets that literally start to fall apart after 150K miles.
Quote:
Originally Posted by serialk11r
It's also crazy that without the 2V total voltage drop, the alternator pulley ratio or engine speed could be lowered while maintaining enough electrical power, or kept the same and avoiding flickering lights.
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If we can lower the alternator speed, we could realize even further gains. Alternators are said to be about 55% efficient. They're more in the 70% range at low speeds (say, at engine speeds from 700 to 1200 RPM)
