Hi
The Project:
I am building a system that works with CNC machine centres.
I am adding a 4th and 5th indexing axis to my machines and have succeeded in having the machine control send commands to my board, the motors indexing rotary tables and then the board triggering an input in the machine to let it know it has reached its position.
I have not setup homing and limit switches as of yet but will use the industry standard of 24v switches.
My Issue:
The project requires 48v dc, 24v dc and 5v dc power.
The 48v dc must supply 6-8 amps to 2 motors (288w-384w).
It's not an exact number since the motors are rated for 8 amps each (stepper motors) but will not need full amperage as only 1 will run at a time and never under large loads.
Then I will need 24v dc running to limit switches that in turn run to a reed relay or HF relay (3ms switch time, 140mA draw) to trigger microcontroller pin.
24v is needed since other technicians will be working on systems, need the same standard and reliability as most industrial CNC systems.
Lastly the 5v needed for the circuit board and peripherals (LCD, switches etc. Estimate 2A to have wiggle room for upgrades).
Total current draw with overhead room = 10-11 amps
My Solutions:
I have a few options of doing this..
Option 1 = Multiple transformers where I then rectify and filter voltage, however transformers will make system large, heavy and expensive, especially with higher current draw at 48v.
Option 2 = Switchmode power supply feeding 48v dc @ 10.5 amps (can get them at good price), use linear regulators with monsterous heat sinks to bring down to 24v dc and 5v dc. Currently this is where my experience ends. Linear regulators is what I have used in low voltage regulation in the past. I am aware this particular option will be highly inefficient and believe the regulators will not survive long with so much heat, if they survive at all. Unless I use regulators stepping down slowly ie...37v...24v...12v...5v. Still highly inefficient.
Option 3 = Switchmode power supply feeding 48v dc @ 10.5 amps (can get them at good price), use buck converters to bring down to 24v dc and 5v dc (using LM2576HVT-ADJ/LF03).
Looking for assistance:
- If anyone has any better ideas about this project or comments that might assist me.
- Which option would be best or if there are better options?
- Someone to guide me and teach me, or send me to a resource on how to do the heat calculations for the LM2576HVT-ADJ/LF03 chip. My brain turns to Jelly with all those formula options.
Thank you in advance
Clauds
The Project:
I am building a system that works with CNC machine centres.
I am adding a 4th and 5th indexing axis to my machines and have succeeded in having the machine control send commands to my board, the motors indexing rotary tables and then the board triggering an input in the machine to let it know it has reached its position.
I have not setup homing and limit switches as of yet but will use the industry standard of 24v switches.
My Issue:
The project requires 48v dc, 24v dc and 5v dc power.
The 48v dc must supply 6-8 amps to 2 motors (288w-384w).
It's not an exact number since the motors are rated for 8 amps each (stepper motors) but will not need full amperage as only 1 will run at a time and never under large loads.
Then I will need 24v dc running to limit switches that in turn run to a reed relay or HF relay (3ms switch time, 140mA draw) to trigger microcontroller pin.
24v is needed since other technicians will be working on systems, need the same standard and reliability as most industrial CNC systems.
Lastly the 5v needed for the circuit board and peripherals (LCD, switches etc. Estimate 2A to have wiggle room for upgrades).
Total current draw with overhead room = 10-11 amps
My Solutions:
I have a few options of doing this..
Option 1 = Multiple transformers where I then rectify and filter voltage, however transformers will make system large, heavy and expensive, especially with higher current draw at 48v.
Option 2 = Switchmode power supply feeding 48v dc @ 10.5 amps (can get them at good price), use linear regulators with monsterous heat sinks to bring down to 24v dc and 5v dc. Currently this is where my experience ends. Linear regulators is what I have used in low voltage regulation in the past. I am aware this particular option will be highly inefficient and believe the regulators will not survive long with so much heat, if they survive at all. Unless I use regulators stepping down slowly ie...37v...24v...12v...5v. Still highly inefficient.
Option 3 = Switchmode power supply feeding 48v dc @ 10.5 amps (can get them at good price), use buck converters to bring down to 24v dc and 5v dc (using LM2576HVT-ADJ/LF03).
Looking for assistance:
- If anyone has any better ideas about this project or comments that might assist me.
- Which option would be best or if there are better options?
- Someone to guide me and teach me, or send me to a resource on how to do the heat calculations for the LM2576HVT-ADJ/LF03 chip. My brain turns to Jelly with all those formula options.
Thank you in advance
Clauds