Recent content by ShamilaWije

Thanks guys. Will do as advised. :-)

Thanks for the replies. Well the thing is I can read the rate data from the sensor without any problem. Some other points are, 1) Tested with several clock speeds ranging from 250kHz to 1.5Mhz with the same results. 2) You have to write values to the configuration registers to configure the...

Hi I've been testing the Analog devices high precision rate sensor ADIS16130AMLZ and got some doubtful results..... I tested 4 sensors from 2 batches, 1) The self test value -- I got 54 deg/sec on all 4 sensors but the datasheet says it should be between 65-85. 2) Cant seem to get a valid...

I thought voltage spikes are the result of higher recovery time. Anyway I'm using a IPM from IRF IRAMY20UP60. This should be able to go upto 15kHz without any problem.

Thanks for the star sreid. By the way I measured the capacitance of each phase of our BLDC motor with a LRC meter and found out that there was about 200nF of capacitance in each phase. By looking at the current wave form going in to each phase I could see two spikes one when the PWM swithes...

I agree with blacksea. There are 2 main variations how you can do PWM switching Bipolar and Unipolar. In bipolar mode you switch from +V to -V and then again to +V. If your duty cycle is 50% then the average voltage would be 0. Since we are changing the voltage by 2*V the there is a higher...

what is exactly meant by 'current loop'? Is it the feedback loop created by taking the current sensor output? I guess sreid you are referring to self commutation when you say soft switching am I right? If so I'm planing to do hard switching. I am planing to use a IGBT module. Also a constant...

I thought your first equation is the correct one. If the 3 phases are Y connected you just have to apply KCL to the point right?

Thanks for the info. I'm already using avago opto-isolators and LEM current transducers. So I seem to be on the rught track. :-)

Thanks sreid. I'll see if I can get some actual measurements on the motor I'm working on.

Thanks guys for the info. Can you give me some guidance on either measuring or estimating these capacitances and permiability effects. Also how do I choose the required series inductance assuming I know the above data.

Thanks guys for the response. electricuwe 2. The IPM you mentioned contain driver circuits, but they do not contain the signal isolation and the driver power supply to SELV level. Yes i understand that the signal isolation is not provided. But if need be I can optically couple the signals as...

itsmoked IXSY has CBI IGBT modules but they do not integrate the gate drive ICs. I was looking to see if IPMs are available with the HV gate drive ICs integrated as well

Blacksea, I considered that option but 2 points The motor is a custom design and run at a very low speed generating high torque and short operating time. Couldn't find a suitable controller. Ultimately the drive and the motor will be packaged as a single unit. So I thought it's better to...

Hi, I'm designing a 3 phase motor drive for a 3 phase BLDC drive. The drive should operate from a 440V 3 phase system and should be capable of handling 5kW to 7kW. I've been looking for a package which integrates all the IGBTs and the drive electronics from manufacturers such as IOR and...