Hi there,
I am trying to understand how a half bridge works. Here is a picture of one.
View attachment 61790
I am hoping someone might comment either tell me I am wrong or tell me I have the basic operation understood. I then have a four questions below that would help me understand as well...
As I see it there are essentially two circuits one on top of the other so to speak. When the top circuit is turned on it sends current from right to left (red arrow) as there is a voltage difference of V and V/2. This happens when the top Mosfet is turned on. In this case the Mosfet is above the transformers primary.
When the top Mosfet is turned off and then the bottom Mosfet is turned on the current is sent from left to right (black arrow) with the Mosfet below the transformer's primary.
- Given this can I assume that the 120k bridge divider is what creates a mid point from the bridge rectifier?
- What do the small 3μ capacitors next to the 120k resistors do? they seem to be quite small for filter caps.
- Shouldn't the gate drive input into the Mosfets have some resistance? What should the gate drives have in this instance... nothing but a straight wire to the mosfet?
- Finally, would you anchor ground to the bottom of the bridge as is shown? or can you have it floating?
Kind regards
Simon
I am trying to understand how a half bridge works. Here is a picture of one.
View attachment 61790
I am hoping someone might comment either tell me I am wrong or tell me I have the basic operation understood. I then have a four questions below that would help me understand as well...
As I see it there are essentially two circuits one on top of the other so to speak. When the top circuit is turned on it sends current from right to left (red arrow) as there is a voltage difference of V and V/2. This happens when the top Mosfet is turned on. In this case the Mosfet is above the transformers primary.
When the top Mosfet is turned off and then the bottom Mosfet is turned on the current is sent from left to right (black arrow) with the Mosfet below the transformer's primary.
- Given this can I assume that the 120k bridge divider is what creates a mid point from the bridge rectifier?
- What do the small 3μ capacitors next to the 120k resistors do? they seem to be quite small for filter caps.
- Shouldn't the gate drive input into the Mosfets have some resistance? What should the gate drives have in this instance... nothing but a straight wire to the mosfet?
- Finally, would you anchor ground to the bottom of the bridge as is shown? or can you have it floating?
Kind regards
Simon
