Go Down

Topic: Does a prebuilt H-bridge still need dead-time ?? (Read 229 times) previous topic - next topic

ydkm

I'm using this prebuilt H-bridge for my wireless power project.

https://www.alibaba.com/product-detail/50A-IMS-2B-Single-H-Bridge_60654344233.html?spm=a2700.8443308.0.0.20083e5forToQV


and im using arduino mega2560 as pwm to supply 150khz.

Now i'm wondering if i still need to implement the "dead-time" into the pwm code ?? Or i don't have to since its pre-built ??


Thankyou

jremington

#1
Sep 24, 2019, 05:05 am Last Edit: Sep 24, 2019, 06:09 am by jremington
What do you mean by "dead time"?

If the H-bridge is properly designed, "shoot through" will not be an issue.

But you should never attempt to rapidly reverse a spinning motor, as it will briefly draw twice the stall current.

Consult the H-bridge documentation for operational details.

It seems unlikely that the H-bridge will function properly at 150 kHz. Why did you choose this value?

JohnRob

Looking at the link you posted it appears the drive for the output MosFets is built in, so the deadband you refer to (that eliminates shoot through) should also be built in.

However I would look closely at the specifications before I ran this module at 150Khz.  If there are no specifications I would look at the part numbers on the driver IC's and see what the mfg suggest the drivers are capable of.

Please do not PM me with thread based messages.  If your thoughts are worth responding,  the group should benefit from your insight.

MarkT

If the H-bridge is properly designed, "shoot through" will not be an issue.
Doesn't follow at all.  An H-bridge can be just 4 switches, individually controlled, in which case whatever's
controlling it has to do the dead-time and shoot-through prevention.

Whether a bridge has timing constraints is part of its documentation, and strongly depends on which
chip is used.

If an H-bridge doesn't have good documentation, don't buy it!
[ I will NOT respond to personal messages, I WILL delete them, use the forum please ]

Go Up