"D from BC" schrieb im Newsbeitrag news: snipped-for-privacy@4ax.com... | On Sun, 11 Feb 2007 12:20:12 +0100, "Henry Kiefer" | wrote: | | >Sounds not so bad. Generally spoken, newer devices have lower losses (=smaller chip inside). | >
| >I use LTspice to run efficiency calcs. It's easy. Use digikey to find what is buyable. | >
| >I don't understand how Mot comes to the 50:50 rule. | >
| >- Henry | | I know...The rule is strange.. | 50% heat due to switching and 50% of heat due to Rds(on). | It shouldn't matter what combo...2%, 98%....40% 60%...20%80%.... | I just want lowest mosfet heat. (Neglecting mosfet driver dissipation) | | I could create a table of Rds(on) and gate capacitances based on | mosfets available at digikey.. Then run multiple simulations in | LTspice to find the coolest mosfet.. | Something just seems wrong about this...
At least the rule must have a function of duty-cycle!
- Henry
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