Author Topic: dc motor driver  (Read 2411 times)

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Offline yifei87Topic starter

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dc motor driver
« on: January 01, 2009, 09:15:35 AM »
hey guys,

i am now working on dc motor driver using H-bridge connection.
i am wondering designing a Bipolar transistor H-bridge motor driver is better or FET-tansistor H-bridge motor driver?
1 more question is bout TC4424. what else components can replace it but giving same or better performance?
thank you very much

Offline TrickyNekro

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Re: dc motor driver
« Reply #1 on: January 01, 2009, 12:09:12 PM »
The easiest way to go is a MOSFET bridge... bipolar has some maths you may want to avoid...
Now....

A good replacement is a L298, provided you have a heatsink you can do pretty things with it...


But if you don't really care about space, MOSFETs is the way to go!!!
For whom the interrupts toll...

Offline Soeren

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Re: dc motor driver
« Reply #2 on: January 01, 2009, 01:15:45 PM »
Hi,

Bipolar or MOSFET, they both need the math to get optimum results!
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
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Offline TrickyNekro

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Re: dc motor driver
« Reply #3 on: January 01, 2009, 01:29:52 PM »
MOSFET are like switches... far more simpler math...
no question about it... plus they can sink a lot of current and they don't need pre-amplification on Gate...
Big fat transistors need....
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Offline Webbot

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Re: dc motor driver
« Reply #4 on: January 01, 2009, 04:52:18 PM »
Webbot Home: http://webbot.org.uk/
WebbotLib online docs: http://webbot.org.uk/WebbotLibDocs
If your in the neighbourhood: http://www.hovinghamspa.co.uk

Offline Soeren

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Re: dc motor driver
« Reply #5 on: January 01, 2009, 05:33:41 PM »
Hi,

MOSFET's as well as BjT's can be used as switches as well as linear devices, but both has got parameters that you need to take into account, to get them to work as well as possible, whether used as linear or "digital" devices.

For a MOSFET, you need to consider things like the Miller plateau at some V_gs (and hence Q_g and Q_gd), V_gs(th). C_iss, C_oss, (in some apps even C_rss), for starters and if you ignore them, you can just as well ignore the equally important BjT parameters.

All kinds of transistors, whatever the type, needs math for well designed circuits and those that won't do the math are forever destined to just assemble puzzles allready solved by others - and in this case... There is probably several times as many allready designed BjT switches, since the BjT has existed for longer - MOSFET's has some advantages, BjT's some other and it's up to the designer to choose - the puzzlers just need to select from those designs various specs to get the problem solved.
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline TrickyNekro

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Re: dc motor driver
« Reply #6 on: January 02, 2009, 08:32:20 PM »
I don't argue about that... but, for a total beginner, mosfets are just plug and play, right?
Of course you need math and all that...

But, I've been in works for sometime both theoretical and practical...
And I truly believe MOSFETs is the way to go...
They offer superior protection both for themselves and the micros... compared to bipolars....

He isn't going to build an inverter, an H-bridge is trying to build....


Best Regards, Lefteris
Greece
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Offline yifei87Topic starter

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Re: dc motor driver
« Reply #7 on: January 05, 2009, 07:03:38 AM »
Thanks guys. it is really help

 


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