Hi, I am new here, and hoping someone can help.
I am designing a motor controller for a 110v DC motor. The motor is 800 watts, and going to be used as a spindle in my custom-built CNC mill.
I have got it working with a PWM controller I built, so I feel confident that I have the switching side dialed in very nicely, but I'd like to improve the power supply.
I have a massive 2000 watt, 70 VAC transformer that rectifies to about 109 volts DC. From there, I'd like to filter the output and get a nice flat DC output. I am familiar with a basic full wave rectifier circuit, but I am not skilled enough to design a circuit that will minimize ripple, provide about 12 amps of max output (allowing some headroom), roughly 800 watts continuous, with low ripple that will supply a switching motor control circuit with clean power. Simplicity of the design and low-cost components are also a major concern, and since I already have the big transformer I'd like to use that rather than SMPS. I've looked at capacitance multiplier circuits to reduce ripple, but I can't figure out what transistors to use, or how to put them in parallel. I have some really powerful mosfets capable of 500V at 100A.
I looked at possibly using a low-current LC or RC filter to remove ripple on the rectified output, and then use the mosfets to amplify the current, but I can't figure out how to do it. Max threshold voltage of the mosfets is only 30V, so that's why I thought maybe I am stuck using transistors? Really hoping someone can suggest the most efficient path forward with both cost and complexity considered.
I am designing a motor controller for a 110v DC motor. The motor is 800 watts, and going to be used as a spindle in my custom-built CNC mill.
I have got it working with a PWM controller I built, so I feel confident that I have the switching side dialed in very nicely, but I'd like to improve the power supply.
I have a massive 2000 watt, 70 VAC transformer that rectifies to about 109 volts DC. From there, I'd like to filter the output and get a nice flat DC output. I am familiar with a basic full wave rectifier circuit, but I am not skilled enough to design a circuit that will minimize ripple, provide about 12 amps of max output (allowing some headroom), roughly 800 watts continuous, with low ripple that will supply a switching motor control circuit with clean power. Simplicity of the design and low-cost components are also a major concern, and since I already have the big transformer I'd like to use that rather than SMPS. I've looked at capacitance multiplier circuits to reduce ripple, but I can't figure out what transistors to use, or how to put them in parallel. I have some really powerful mosfets capable of 500V at 100A.
I looked at possibly using a low-current LC or RC filter to remove ripple on the rectified output, and then use the mosfets to amplify the current, but I can't figure out how to do it. Max threshold voltage of the mosfets is only 30V, so that's why I thought maybe I am stuck using transistors? Really hoping someone can suggest the most efficient path forward with both cost and complexity considered.