Hi.
I’m looking for brushless, sensorless motor controller chip.
As soon as I need high current- 20-40 amp, the power
stage(6 transistors) should be outside this chip. Supply
voltages – 5-/-7 v. Could anybody recommend not expensive
chip?
Many companies have DSP chips, which they recommend for
such applications, but I’d like to use something almost ready.
Well, that may not be the best idea, but at a web forum I once saw a thread where a guy got that chip from a trahsed CDROM dirve abd found the docs on the semiconductor verndors site. CDROM dirves spin with brushless motors, you know...
Well here is something 'ready' for 3 phase DC brushless. I garantee that it does works as I buiilt it. Currently it drives a 250 Watts brushless motor from MAXON, but simply by adjusting the current sensing and the output FETS it will drive almost any loads.
Yes you are right. I went and search with google the data sheet (AN-42004) and curiously enough it seems that Fairchild own now this part.
It does seems like a nice alternative, I do agree. Did you used this part?
(On a DC 3 phase brushless motor?)
The nice thing about the onsemi solution is that there is virtually no hunting at very low RPM. Can you tell me if the same apply to the Microlinear part?
Hi.
I’m looking for brushless, sensorless motor controller chip.
As soon as I need high current- 20-40 amp, the power
stage(6 transistors) should be outside this chip. Supply
voltages – 5-/-7 v. Could anybody recommend not expensive
chip?
Many companies have DSP chips, which they recommend for
such applications, but I’d like to use something almost ready.
Hi.. for people who is reading this message now)
I used ML4425 chip in my master thesis in 2000, when it was produced by microlinear before it was owned by Fairchild..
Main problems were the startup and speed regulation.. Starting was not smooth, so this is an analog chip.. the performances is optimized by some R,C s.. Because of the frequency characteristics of RC, this chip can not give you optimum performance for a wide speed range.. So the speedregulation may get worse ..If you have a respectively narrower range.. this chip could be optimum..
I have seen that in the past some of you have tryed to build an BLDC controller using ML4425.
I would like to build such a controller for an PCB drilling motor. This motor has to run at 60 000 rpm's and I'm not shure that with this ic I can reach this speed.
Can you please tell me what was the maximum speed wich you have achieved with ML4425-based controller ?
If you have any other recomandations are wellcome.
dear all
I am using Texas'S UC3625 to control bldc motor in open loop configuration. but i have problem with that. as soon as i am varying the spped POT the motor Gets locked. so please suggest solution for that. or give me circuit connection diagram if any one have.