DBennett63
New member
Hi, I need help designing a two channel complementary generator. This is basically two PWM channels that have opposite timing (when one channel is high the other one is low) plus there needs to be a little dead band time (at least 1 usec) between them. Such a circuit is typically used to drive MOSFET or IGBT half bridges. The dead band is needed to prevent conduction through both switches at the same time which would be a short. So obviously the two channels have to stay phased together as well. I built the circuit at the following link and it works fine, but the frequency and duty cycle have to be adjusted using potentiometers and I'd like them to be software adjustable:
http://www.edn.com/design/analog/4314069/Build-a-simple-complementary-bracket-pulse-generator
I'd like to adjust the frequency from about 1kHz to 30kHz. I'd like to adjust the duty cycle from 10% to 90%. A fixed dead band of 2usec would be fine. I came to this forum because I read some Ardunio forum comments from Paul about writing a function called analogwritefrequency() for the teensy board which seemed very close to what I was looking for. The update speed of changing the frequency etc is not important and doesn't happen often. As such an Arduino Uno board could talk serially to a teensy and it could output the desired dual channel pulse train.
This circuit needs to be developed in the next week or two and will be going on an industrial piece of equipment costing around $500K. So the hardware costs for these hobby boards is not a concern at all.
However, the solution does need to be reliable. We have written a lot of Arduino uno code which accepts serial commands from a PC and sets relays and power supply voltages among other tasks. We don't want to start over on this code so a device that programs in a manner similar to Arduino is very interesting. We have purchased a Due and a Mega board as well. We were considering trying to get the Due to output the dual channel signal but are having difficulty knowing how to do this.
I'd be glad to pay $2k for someone to help me figure this out. I don't know if looking to hire someone through a forum is appropriate. If not, I apologize, but I am getting a little desperate.
http://www.edn.com/design/analog/4314069/Build-a-simple-complementary-bracket-pulse-generator
I'd like to adjust the frequency from about 1kHz to 30kHz. I'd like to adjust the duty cycle from 10% to 90%. A fixed dead band of 2usec would be fine. I came to this forum because I read some Ardunio forum comments from Paul about writing a function called analogwritefrequency() for the teensy board which seemed very close to what I was looking for. The update speed of changing the frequency etc is not important and doesn't happen often. As such an Arduino Uno board could talk serially to a teensy and it could output the desired dual channel pulse train.
This circuit needs to be developed in the next week or two and will be going on an industrial piece of equipment costing around $500K. So the hardware costs for these hobby boards is not a concern at all.
However, the solution does need to be reliable. We have written a lot of Arduino uno code which accepts serial commands from a PC and sets relays and power supply voltages among other tasks. We don't want to start over on this code so a device that programs in a manner similar to Arduino is very interesting. We have purchased a Due and a Mega board as well. We were considering trying to get the Due to output the dual channel signal but are having difficulty knowing how to do this.
I'd be glad to pay $2k for someone to help me figure this out. I don't know if looking to hire someone through a forum is appropriate. If not, I apologize, but I am getting a little desperate.