Single, half, full-bridge PWM...

[dtvonly]

Hi. Could someone please explain the differences between half and full-bridge (reverse and non-reverse) PWM? The single is easy. If possible, please include waveforms. Thank you.

 

[Gryd3]

Hi. Could someone please explain the differences between half and full-bridge (reverse and non-reverse) PWM? The single is easy. If possible, please include waveforms. Thank you.

Where did you learn of these different types?
PWM is pulse width modulation... in that for any given frequency configured by the equipment or user, you define the ratio that the line is high to low.
So a 30% duty cycle will be high 30% of the time, and low for 70%.

It sounds as though you are confusing two different items... Bridge rectification is usually used in power supplies for converting AC to DC. There is a full and half bridge, I am not familiar with reverse and non-reverse though.

 

[dtvonly]

Where did you learn of these different types?
PWM is pulse width modulation... in that for any given frequency configured by the equipment or user, you define the ratio that the line is high to low.
So a 30% duty cycle will be high 30% of the time, and low for 70%.

It sounds as though you are confusing two different items... Bridge rectification is usually used in power supplies for converting AC to DC. There is a full and half bridge, I am not familiar with reverse and non-reverse though.

Hi. Please see short insert from the PIC18F14K22 microchip's Microcontroller - on Enhanced PWM section (P.115)


Thanks.

 

[Gryd3]

Hi. Please see short insert from the PIC18F14K22 microchip's Microcontroller - on Enhanced PWM section (P.115)
Thanks.

This would be a gap in my experiences, but it just seems like different configurations to drive different bridge topologies, not necessarily changing the PWM output.
I can't think of any reason why a PWM signal would be any different, but you may need to concern yourself with two opposing parts of a bridge being enabled at the same time. This function may help resolve that.

Please take this as an observed possibility, and wait for someone to confirm or correct me.

 

[BobK]

Half bridge and full bridge PWM on a PIC ECCP are means of driving a half-bridge or full H-bridge, typically for motor control. These allow either 2 or 4 outputs to control each of the switches in your half (2) or full (4) bridge. It also allows you to insert dead-time between the switching of the different switches so that you do not get shoot-though, which is when the top and bottom switches of a half bridge are both on at the same time.

The waveforms should be there in the datasheet.

Bob