Hello,
I'm new to the list & fairly new to electronics in general. I have a hobby machine shop and have been involved in building new servo drives for the axis servos on a CNC horz. milling machine for over a year. I understand a little about circuits (very little) and can build using a PCB, list of parts & directions. my mill has fairly large servos and I've been having one heck of a time blowing up drives when applying power to the drives when coming out of E stop. many, many things have been tried to stop the problem without success... my question to the group is double ended:
first, is it possible to build a device (?) that would be in the circuit between the transformer output, two taps, 100vac each, and the servo power supply that converts the above voltage to 135vdc. the 135vdc feeds the three axis drive amplifiers which control & power the axis servos. the function of this device would to be to prevent the surge thats killing the drive output power sections, specifically the IRFP264N,s and surrounding components. we're dealing with 135vdc / 50 amp servos (85amp locked spindle melt down) on each of the three axis. normal amp loads are more likely 22 amps at the start of a rapid travel move & 5 to 35 amp during feed moves i.e. removing metal with drill bits, end mills, face mills, etc. the wires between the transformer & power supply are 16gauge so I'm guessing 25 amps max on each tap into the power supply? what I envision is: and this needs your input, something that, when the relay is energized, would slow the inrush of voltage so that the dc voltage ramp up from 0 to 135vdc out of the power supply would occur over a time period of ??? 2 seconds or what is recommended ?
The second part of this question is, if the above is possible? would you people help me design the above device or point me to an existing design that I could build with your help? or?
sorry for the long post, I'm trying to put forth sufficient information for my query to have meaning when read. hope this isn't too long and/or in the wrong place.
Thanks
Paul
I'm new to the list & fairly new to electronics in general. I have a hobby machine shop and have been involved in building new servo drives for the axis servos on a CNC horz. milling machine for over a year. I understand a little about circuits (very little) and can build using a PCB, list of parts & directions. my mill has fairly large servos and I've been having one heck of a time blowing up drives when applying power to the drives when coming out of E stop. many, many things have been tried to stop the problem without success... my question to the group is double ended:
first, is it possible to build a device (?) that would be in the circuit between the transformer output, two taps, 100vac each, and the servo power supply that converts the above voltage to 135vdc. the 135vdc feeds the three axis drive amplifiers which control & power the axis servos. the function of this device would to be to prevent the surge thats killing the drive output power sections, specifically the IRFP264N,s and surrounding components. we're dealing with 135vdc / 50 amp servos (85amp locked spindle melt down) on each of the three axis. normal amp loads are more likely 22 amps at the start of a rapid travel move & 5 to 35 amp during feed moves i.e. removing metal with drill bits, end mills, face mills, etc. the wires between the transformer & power supply are 16gauge so I'm guessing 25 amps max on each tap into the power supply? what I envision is: and this needs your input, something that, when the relay is energized, would slow the inrush of voltage so that the dc voltage ramp up from 0 to 135vdc out of the power supply would occur over a time period of ??? 2 seconds or what is recommended ?
The second part of this question is, if the above is possible? would you people help me design the above device or point me to an existing design that I could build with your help? or?
sorry for the long post, I'm trying to put forth sufficient information for my query to have meaning when read. hope this isn't too long and/or in the wrong place.
Thanks
Paul