You should run with the highest amperage power supply you can. A lower rating of power supply current has no impact on your circuit. The current rating of the power supply is only an indicator of how much it is ABLE to supply not how much it DOES supply. Your circuit will draw however much current it needs. Your logic is like saying a lower horsepower car will make you drive slower. It's rby pmarcus - Controllers
Sorry you are having trouble. Couple of things to look at: Is your current setpoint correct? Too high or too low can cause issues. Are you sure you have the motor windings connected right. I had a situation with windings crossed and it acted similarly to what you are describing. Motor controllers got hot fast in this situation. Another thing you could look at is the decay mode that the steby pmarcus - Controllers
I concur with the loading the 5V. I've played with a few different PC power supplies and some of them required as much as 10W of draw on the 5V line to keep them from shutting themselves off. My associate Nathan had issues similar to yours in that he could never figure out what was tripping out the power supply, even with a good load on the 5V it would shut down on occasion.by pmarcus - Controllers
In case anyone was wondering, we've finished initial evaluation of the stepper electronics. The A4988 at full current (2A) runs at an acceptable temperature. We didn't get a thermocouple on it but to the touch it is hot and slightly uncomfortable so it is likely in the 50 to 60 C range. When everything else it turned on I expect that it will get hotter but will still perfectly acceptable for aby pmarcus - Controllers
I did a little reading(and rereading of my previous posts) and realize I wasn't very clear on some things. When I was addressing the capabilities of ARM cores I was specifically talking about the module that yngndrw suggested. I realize that there are a lot of ARM based processors that are comparable in cost and capability to the dsPICs (though I didn't know until Nathan did some looking). Tby pmarcus - Controllers
bobc Wrote: > > Huh? That is nearly all nonsense! Have you > actually used anything apart from PIC? > > Obviously you have already a fixed idea of your > design decisions, and are not going to change > anything, which is fine, but don't back them up > with misinformation. > > Makes me wonder how reliable the rest of your info > is. This is great, if you haveby pmarcus - Controllers
Thanks for the compliment. I've been designing embedded systems, power electronics, industrial automation and medical instrumentation for a while. I'm certainly no grey hair and I still make mistakes. I think I'm getting pretty good at it but there's ALWAYS something to learn! Unfortunately for the heater MOSFETs there is a tradeoff between gate capacitance, Rdson and voltage rating. The MOSby pmarcus - Controllers
Okay I understand what you mean by a charge pump. No I don't have plans for that in this design. It would be a mistake for a user to have the current level of the steppers set high enough to cause damage if the motor ran into a physical stop. On a CNC it is more of an issue since the torques are so high. I've used what you call a charge pump before in medical devices. I'd not think it was neby pmarcus - Controllers
almost any glue, as long as it is thin should be okay. Remember that the heat you are able to dump through the top of an epoxy chip is pretty small. The added thermal resistance of a thin layer of almost any glue is going to be pretty minimal compared to the epoxy. This isn't like a CPU where you are dumping 100W. This is on the order of single watts.by pmarcus - Controllers
Interesting questions. No there are no plans for an even higher voltage version. 24V will be suitable for a long time on larger platforms in my opinion. Remember that power in resistive loads is V^2/R so you get a LOT of margin from moving the supply voltage from 12V to 24V. I'd be interested in what your thoughts on the value of a 48V system might be. The layout is not final yet but shouldby pmarcus - Controllers
reserved 3by pmarcus - Controllers
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24V or 12V Shifting from the accepted use of 12V power was another difficult choice but we believe was the right one. Increasing overall power and operational headroom for large heated beds, multiple extruders, and hot ends pushed the design to a level where the higher power at 12V made the circuit board layout expensive due to high copper thickness, larger board area, and more costly connectorsby pmarcus - Controllers
Introducing the Watson 3d printer electronics package. The Watson electronics were designed to address the specific needs of the Watson 3d printer as well as creating a platform for future printer development including larger format printers with higher deposition rates. Note that it will take us some time to get all the posts up related to the Watson 3d Printer so please hold tight while we gby pmarcus - Controllers
Cyberwizzard Wrote: ------------------------------------------------------- > I'm adding a MOSFET driver to see if I can keep > the MOSFET cool when its being driven with 12V > instead of 5. > > Now I have 2 questions: > - Without looking at the code, I assume inverting > the PWM is a simple flag somewhere, right? > - How fast does Teacup drive the PWM? Because the > Mby pmarcus - Next Wave Electronics Working Group