IF it were on 100% of the time, thenĢ5 * 100% duty cycle = 25 Watts average power.īut, mosfets in switching power supplies are almost never on 100% of the time. Let's take a 1 ohm mosfet in a system with a 5 amp average current. Otherwise, you need to calculate the power dissipated when it's on, then factor the duty cycle. You can't use the average current through a switching mosfet to calculate it's power dissipation, unless the duty cycle is 100%. If we did get lucky the equation would match the simulation results, but it would be pure luck as there is no physical theory that i know of that says that should be true. We could easily do a simulation and compare results. So that equation is a very very vague approximation at best. With just a resistive load, the current peak follows the sine shape and so we might use an approximation like we see in that equation, but when we add a capacitor what happens is the diode does not conduct at all for some parts of the cycle, then suddenly the current jumps up creating as current surge that is hard to calculate without a good spice model.
#Diode bridge rectifier calculator simulator
In fact, the best bet if you are not heavy into the math is to use a simulator and measure the power in one diode and then go from there. The capacitor makes it very hard to calculate the voltage drop of the diode(s) without doing a complete analysis and using something like a spice model of the diode. With no inductor and an output filter cap the diode waveshape is very peaked and narrow. That equation would be "somewhat" true if there was a resistive load only or perhaps an inductor input filter. I really need a confirmation of this soon.
If I had multiplying with 1, I would obtain half of the power losses (which would be for a half-diode bridge).
What I understand from this equation, this gives total power losses for a whole bridge, by multiplying with 2. 1 is:Ġ.6 V = Typical voltage drop for one conducting rectifier diode" For example, power dissipation of the diode bridge in Fig. However, diodes in low voltage, high power rectification applications dissipate significant power and the inherent diode drops take a significant bite out of the operating voltage. At typical AC power line voltages, the drop across the diodes has little impact on the rectified output voltage and diode power dissipation. Full-wave diode bridges are found in many electronic systems ( Fig.
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