Controlling H_bridge with PIC16F1827

[jean12]

Hello there can anyone help me to control my H_Bridge switching at 20Khz and 50Hz,using 20Khz as carrier signal of 50Hz;
here below is my circuit but when I apply it to the MOSFET making an H_Bridge the MOSFET became very hot so they can be damaged.

please help.

 

[Fidelis Anyanti]

Hi, go here :

https://www.edaboard.com/threads/154618/

goodluck

 

[goldsmith]

Hello there can anyone help me to control my H_Bridge switching at 20Khz and 50Hz,using 20Khz as carrier signal of 50Hz;
here below is my circuit but when I apply it to the MOSFET making an H_Bridge the MOSFET became very hot so they can be damaged.

please help.

Hi jean12
The problem is so simple ! you didn't use any dead time for your SPWM signals . right ? just add a proper value of dead time in those signals then your mosfets won't event get heat !

Best Wishes
Goldsmith

 

[jean12]

can you please help me to add a dead time on the SPWM signal?

Thanks.

 

[goldsmith]

can you please help me to add a dead time on the SPWM signal?

Thanks.

Hi again
Yes of course .
use an schmitt trigger not gate IC like 40106 and use RCD network . is that clear ? if not , i can draw it's exact circuit for you . would you like this ?

Best Lucks
Goldsmith

 

[jean12]

Hello,can you please help me by giving a circuit for that?not gate and RCD network.

Thanks,please help.

 

[goldsmith]

Hello,can you please help me by giving a circuit for that?not gate and RCD network.

Thanks,please help.

Hi jean12

Certainly . have a look here please :



If your inlet signals are TTL ( 5 volt ) then replace the 40106 with 4049 .
how to calibrate it : use two potentiometers instead of those two 200 ohm resistors and then before connecting the signals into the driver , try to calibrate deadtime by viewing it via a 2 channel oscilloscope and be sure that dead time is enough . and for 2nd step get them into the driver and then don't turn the main power supply on and see voltages across the GS of each mosfet ( H side and L side of right arm and left arm ) and then investigate that if deadtimes are fine . then if they are , turn the main PSU on and enjoy your circuit ! ha ha !

Good Luck
Goldsmith