sergiosparks
Apprentice
Philippines
132 Posts |
Posted - Nov 05 2012 : 07:54:29 AM
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I made an astable circuit using 555 timer to output pulses for the LTC1155 MOSFET driver to variably drive a 100 w 12 v blower .The MOSFET is 50N06 and the data sheet says that its On resistance is about .023 Ohm ,50 A,60 V.I paralled 2 of them to even get lower resistance I can measure about 11 amps of current going to the motor at full speed...how come its still generating a lot of heat even at lower speed even though I installed heatsink about 1" by 2" on each Mosfet? I'm imagining that each pulse is still 12v in amplitude though..the heat is like a fresh hot coffee..I don't have a measuring device for it..with out the heat sink the solder from the power supply would melt away..that must be a lot of degrees F or C..right now its working tested for about 15 min. but I'm still worried about the heat..my power supply aggress with the mosfets.. |
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