iceblu3710
Member level 3
m looking to control a 1/5HP single phase motor, at rated speed it draws 3.3A so a cheep IBGT array around 50W should be up to the job. I have never seen or worked with a IGBT but they seem to just be high voltage/current transistors with a TTL input. Seems they have around 2-3V voltage drop across them while their on so even without constant PWM it stands to reason I only need say (6 times motor current x 3.3A x 3V drop = 60W)
I have found this on Mouser and it all seems to be in my specs but what else should I consider when choosing?
Another thing to consider is bias voltages for the gates, data sheet says 20V but its not to particular. Say I start with a nice test setup and use my 120/24V isolating transformer with grounded center tap to get +/-14V then to operate the low side I would need to give the array a low side bias of +6V? Once this scale up to +/-180VDC then high side would need +160V and low -160V right??
This is a pretty heavy project so I am using a AT90PWM3B and its application notes on constant V/F ac induction motor control to get me started. I have seen the pic's with PSC (Power Stage Controllers) and avr's seems pretty much the same setup. The app note covers everything except on actual sine wave creation. (I have never created a sine wave based on a lookup table...)
Anyways, Have I missed/misunderstood anything?
I have found this on Mouser and it all seems to be in my specs but what else should I consider when choosing?
Another thing to consider is bias voltages for the gates, data sheet says 20V but its not to particular. Say I start with a nice test setup and use my 120/24V isolating transformer with grounded center tap to get +/-14V then to operate the low side I would need to give the array a low side bias of +6V? Once this scale up to +/-180VDC then high side would need +160V and low -160V right??
This is a pretty heavy project so I am using a AT90PWM3B and its application notes on constant V/F ac induction motor control to get me started. I have seen the pic's with PSC (Power Stage Controllers) and avr's seems pretty much the same setup. The app note covers everything except on actual sine wave creation. (I have never created a sine wave based on a lookup table...)
Anyways, Have I missed/misunderstood anything?
