Recent content by tim9000

Thanks for the reply. I appreciate the derivation of your matrix in your post #62, however I failed to derive any intuitive understanding in a fault. Because it implies to me that as i1 and i2 increase, so will V2. Anyway putting this aside, in your post #42 you wrote a nice summary explanation...

Thanks for the reply but the OP is wrt a fault external to the transformer, with the assumption that the supply is an infinite bus. Cheers

Hi, I was having a discussion with a colleague today now I'm second guessing myself. My understanding of nameplate kVA is that it is based on 'ambient temperature, temperature rise, heat transfer, thermal mass, thermal time constant, materials used, and expected transformer life'. However...

Sorry, I just wasted your time. Thank you for not barrating me for asking a stupid question. I'm going to guess it was some sort of 10V power supply with a really low internal impedance. I'm guessing not battery though... possibly capacitor bank. Thanks, I'll post on here next time I have some...

Hi Tom, Very simple but effective way of calculating the charging time of the gate capacitance, thank you for showing me that. Out of interest, on the MOSFET datasheet Table 5 when they state: td(on) = 27 ns and tr Turn-on Delay Time Rise Time = 11 ns Using test: VDD = 30V, ID = 20A, RG =...

My mistake, if the integrated body diode is insufficient for the motor freewheeling current, I won't use a small signal diode, it will be a power fast recovery diode. I must have misinterpreted my component notes, the 1N4148 must have been for something else.

Hi All, I'm trying to get back on this horse, this thread hopefully isn't dead yet. To refresh you're memory this was a brushless DC motor to be run from 36V lithium batteries. The controller between the bldc hall sensors and MOSFET drivers was a raspberry pi. (So I've been getting smashed at...

Cool. Well, I'll probably be back on this thread in a couple months when I have an update. I am moving inter-state to start a new job, so don't hold your breath in wait. Cheers

My memory certainly failed in the interim of continuing this thread, so I just checked my purchases, and they are actually 1uF and 10uF "monolithic ceramic" capacitors, so I expect the coating is just superficially shiny like tantalum caps. And as I said, both the legs are equal in length, and...

Woops, I didn't even notice the IC sockets had a notch! Thanks for pointing this out. Also, apologies about the circuit diagram, it is out of date, are pins 3&4 Vcc and COM? (I don't have the datasheet on me at the moment). If so, this is a symptom of me needing to update the diagram, they are...

Update, I have finished soldiering the MOSFET driver. Can people please have a look at the attached pictures and offer thoughts. The circuit shown is the part of the circuit which interfaces between the micro-controller and the MOSFETS. So basically it houses the ICs and the digital outputs from...

I haven't read any more of this thread other than your post, but I agree, it is for a single frequency in the same way that jwL is a simple function of w. So I assume that if I divide: by: to get V/I, it would also be a function of 'w' in the same way, with the small difference being w = wo...

I am not up to date with this thread, but I had a spare 5 minutes and my eyes fell on your post. Wow, you say this isn't too complicated (and you are correct in the sense that what you have written is easy to follow) but I disagree in that it would have taken me a week to come up with what you...

Yes, no argument there, I can imagine integrating a square wave gives a ramp function, and there is an integral relationship between magnetic flux (a proxy for current) and applied square voltage over time, etc. To be honest, I don't know what to say here that won't incriminate myself as a...

Hi Charles, Great response. It's been too many years since I did Signals and Systems, it would probably take me a full day if I was to try and convolve something simple on paper. I should look into linear response theory when I can; I can't even really remember what a Bode plot is. You point out...