Quote:
Originally Posted by lutach
Lets assume you have a quad power board R1, would that make less then the 3.2W of dynamic loss? The controller will have more FETs and each one would be working less to make the same amount of power that a single or double power board controller would be. Another example which is completely off topic would be in car audio. I had a 4 woofer set up in my car and it was loud (Load enough to have neighbors complain that things were falling from their furniture's  ), but then I went up 4 more for a total of 8 woofer wired for the same load to the same amp and it was blistering loud. Each woofer was getting less power from the amp, but they were putting out higher db at the same time. The design that I have in mind (Artur I will send you 2 examples via e-mail) will be a total of 240 small FETs with a datasheet rating of 10A each and they come in 30V and 60V. Each power board will have 80 FETs so 40 in the H-Bridge you mentioned in another post. I'm just throwing out ideas basically to see a rock solid controller that is better then a Schulze 40.160, but a tad smaller for around the same price. |
We will continue next week-end, need to go.
Dynamic loss is fixed with fet, each fet has a capacitance in the gate (value dependant on temp, load...) to charge and discharge this capacitor requires energy, so more fet's more energy.
Conduction loss would be related to Rdon and more fet's lower value, so good thing, but as you can see you need to keep balance...
I will check e-mail later, and let you know.
Keep in mind TO-220's and D-Pak's are huge packages and can easily absorb ~1W without heatsink, but they are not as fast as smaller, tuned fet's.
Your Amp has a pretty sized heatsink, right :)