Hello,
I am trying to understand the effectiveness of filter capacitors on a 125A, 50V brushless DC motor controller circuit. Are they even doing anything?
The circuit contains two 470UF/63V electrolytic capacitors at the power input connector. The incoming power is 58.8V DC. For clarity, let's call these nodes BATT+ and GND. The three n-channel bridges are connected up to the same BATT+ and GND. There is about 3V pk-pk ripple on BAT+ at the motor switching frequency while the motors are turning. It's the capacitor's job to hold the 58.8V node steady during the sag, but it's obviously powerless against the size of the load. Therefore are the capacitors necessary? (see picture attached for glimpse at the schematic)
The problem is these capacitors are blowing up but the reason is unknown. Could it be the ripple current is exceeded or because the ambient temperature is high (70-80C ++?)
Any help understanding intuitively what these capacitors are good for would be appreciated.
Thanks, Roy
I am trying to understand the effectiveness of filter capacitors on a 125A, 50V brushless DC motor controller circuit. Are they even doing anything?
The circuit contains two 470UF/63V electrolytic capacitors at the power input connector. The incoming power is 58.8V DC. For clarity, let's call these nodes BATT+ and GND. The three n-channel bridges are connected up to the same BATT+ and GND. There is about 3V pk-pk ripple on BAT+ at the motor switching frequency while the motors are turning. It's the capacitor's job to hold the 58.8V node steady during the sag, but it's obviously powerless against the size of the load. Therefore are the capacitors necessary? (see picture attached for glimpse at the schematic)
The problem is these capacitors are blowing up but the reason is unknown. Could it be the ripple current is exceeded or because the ambient temperature is high (70-80C ++?)
Any help understanding intuitively what these capacitors are good for would be appreciated.
Thanks, Roy
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