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Hmm. That's strange. | by Longfist | 2014-12-31 07:35:09 |
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Looks like I'll end up paralleling a *BUNCH* of | by LongFist | 2015-02-02 07:57:30 |
| Discussion Forward -> In Board Discussion |
by LongFist |
2015-02-03 06:42:45 |
<* SUMMARY *
On Monday 2015.02.02 we discussed this (above) method - and it's problems - fairly thoroughly. In that discussion ideur explained (and reinforced) why a resistive voltage divider would be a bad idea. "Remember that you have up to 350 Watts of heat to dissipate!" ... "That is way more that a seat warmer and two VERY bright headlamps!" ... "(And about 25% of the energy from the batteries wasted!)"
Also in that discussion wwill pointed me *directly* to an elegant solution - which I will draft/build "on faith" until I can figure out how/why it works. "Use whatever bridge or the like to supply the 40 or so volts to the regulator network, change the LM7812 to the LMZ36, and (even though it's a 10A chip) use all six pass transistors. The regulation will be TIGHT, the transistors will be running cool and ought to be able to buck about ANY load you hand them." ... "Though LMZ chips aren't cheap, but they aren't -all- that expensive, you might do with an LMZ3608 (8A version) for a substantial cost savings (five bucks per unit). If you go down to a 3A regulator such as the TPS5430MDDAREP (still a TI product) you ought to be able to get the current out you need, but I'd double up on the TIP2955's to maintain the tight regulation and the longevity / ruggedness. Just parallel more of them and their associated resistors." ... "Oh, and for the different voltage than that schematic on the web page, be aware that the R7 size (they use "R" for "Ohms" for some reason) might need to be adjusted. And I'd use a five-watter there, or larger, not a half-watt resistor."
* This is the thread that I use to contain the research on this particular issue. Since it is important (for science!) to keep these notes (somewhat!) in a single location, I concocted this summary and included the links - for further study as I continue to learn these techniques and (hopefully) to grow. Time will tell... * |
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[ Reply ] |
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I wonder what happens when a power supply rated | by Longfist | 2015-02-08 17:45:48 |
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UPDATE - NEW PART FROM MAXIM | by wwill | 2015-02-15 08:42:02 |
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THAT'S IT! THAT'S WHAT I NEEDED!!! | by Longfist | 2015-02-15 16:38:17 |
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