I'm trying to design a motor driver for control motor speed with PWM.
The driver must have these specifications:
-Capable of driving motor in two direction
-Maximum voltage of 24V
-Maximum current of 10A
-Maximum PWM frequency of 1kHz
I decided to use a H-bridge, but i don't know how to choose the component (specially MOSFETs)
Now to questions arise:
1-Which NMOS & CMOS suit my condition?
2-How could i generally choose component for my devices, is there any site or catalog for those who know what the specification is but dont know the name of component? (or any kind of advise for someone like me to how to chose a special component?)
I'm trying to design a motor driver for control motor speed with PWM.
The best advice you will get is to buy an h-bridge like below instead of trying to make one.
zoomkat:
I'm trying to design a motor driver for control motor speed with PWM.
The best advice you will get is to buy an h-bridge like below instead of trying to make one.
Thank you for responssing .
The matter here is not to have a driver but to learn how to design a driver.
Any solution ?
salman_71:
Any solution ?
By "driver", are you meaning or wanting to design a discrete component system (ie - using individual mosfets for the h-bridge, etc) - or are you looking for a "single chip" solution (plus any extra parts) - and how to design the circuit for that?
If the latter - then you would do best to see what current driver boards are using (such as the one posted on Ebay), and find out what chip they use, then get the datasheets, etc for that chip - and become familiar with the reference design, etc contained in those documents so that you can lay out such a board.
If the former, though - then you will have a long row to hoe, so to speak. You need to become intimately familiar with a whole host of topics and parts for creating such a driver: Understanding p-channel vs. n-channel mosfets, more generally how to implement an all-n-channel mosfet bridge, high-side drivers (how they work, how they can be implemented, that or use of IC high-side driver chips for all n-channel designs), how to properly size the mosfets (and potentially any heatsinks - though your current requirements are low enough that if you can obtain n-channels with a very low Rds(on) value, they could be mostly eliminated - but if you didn't understand what I just said - well, again, more learning); then there is the actually software controls, other interfacing, elimination or prevention (or protection) against shoot-thru, etc.
In short - if you really wish to learn discrete h-bridge design, at the current levels you are wanting you will need to be prepared to spend some money, because you may be blowing FETs left and right. If you do go down that route, I would personally try to find and use FETs that are smaller with a small motor (maybe 12 volts at 1 amp or so) - that way, as you blow parts, you won't blow a budget, plus you'll still get the design experience and knowledge needed for implementing the larger bridge in the future (hopefully, with fewer costly mistakes).
Oh - you're also going to want to invest in a good oscilloscope and power supply, if you haven't already got these tools - if you insist on going down the discrete component design path.
I'm not trying to discourage you here; you've stated this is for learning, and there is nothing wrong with that. I'm just wanting to make sure you understand that it won't be an easy or inexpensive route to take. If you are good with that, then - go for it. Beyond that, I don't have any specific design knowledge or experience to impart.
Good luck.
Before thinking about building your own H-bridge I'd recommend reading
and understanding the HIP4081A datasheet - once you've done that you'll
both have more of a feeling for the issues and you'll realise that n-channel
MOSFETs with proper driver chips are needed.
With a battery supply you'll have to have fast current sensing to disable
the H-bridge on over-current since typical traction batteries will deliver
enough current to explode most MOSFETs if there's a fault or you reverse
instantly on full speed and pull twice the stall current from the motor.
Stall currents tend to be 10 to 20 times the rated current for a DC motor,
life is much simpler if your supply is current-limited already because of
this. But a current limited supply will simply brown-out if there's stall
current, so you'll need another supply to keep your circuit working for
the duration.
DIY H-bridge project from about a week ago, and an older H-bridge project.
http://forum.arduino.cc/index.php?topic=248204.msg1773713#msg1773713
cr0sh:
salman_71:
Any solution ?If the former, though - then you will have a long row to hoe, so to speak. You need to become intimately familiar with a whole host of topics and parts for creating such a driver: Understanding p-channel vs. n-channel mosfets, more generally how to implement an all-n-channel mosfet bridge, high-side drivers (how they work, how they can be implemented, that or use of IC high-side driver chips for all n-channel designs), how to properly size the mosfets (and potentially any heatsinks - though your current requirements are low enough that if you can obtain n-channels with a very low Rds(on) value, they could be mostly eliminated - but if you didn't understand what I just said - well, again, more learning); then there is the actually software controls, other interfacing, elimination or prevention (or protection) against shoot-thru, etc.
I already know about H-bridge. I also know enough to how to use p channel or n channel MOSFETs. The only things that i need is which MOSFETs could work in my condition & what is the process to pick such a MOSFET.
MarkT:
Before thinking about building your own H-bridge I'd recommend reading
and understanding the HIP4081A datasheet - once you've done that you'll
both have more of a feeling for the issues and you'll realise that n-channel
MOSFETs with proper driver chips are needed.
The motor driver is already designed and i almost know how to build a H-bridge . i just need a pair of n channel and a pair of p channel MOSFETs that suit my necessity.
zoomkat:
DIY H-bridge project from about a week ago, and an older H-bridge project.H-Bridge with High Current Transistors - General Electronics - Arduino Forum
Custom H Bridge Design - Motors, Mechanics, Power and CNC - Arduino Forum
Thank you. They will be helpful .
salman_71:
MarkT:
Before thinking about building your own H-bridge I'd recommend reading
and understanding the HIP4081A datasheet - once you've done that you'll
both have more of a feeling for the issues and you'll realise that n-channel
MOSFETs with proper driver chips are needed.The motor driver is already designed and i almost know how to build a H-bridge . i just need a pair of n channel and a pair of p channel MOSFETs that suit my necessity.
OK the usual scheme is level shift with NPN to drive non-logic-level p-channel
MOSFETs via a high current voltage divider, and use logic-level n--channel on the
low side driven direct from Arduino via 150 ohm gate resistors.
Something like:
(half the H-bridge shown - be sure to never activate both high and low switches on the
same side at the same time or bang go the MOSFETs.
The matter here is not to have a driver but to learn how to design a driver.
Any solution ?
If you want to learn how to do, surely you need to devise a solution yourself ?
The only things that i need is which MOSFETs could work in my condition & what is the process to pick such a MOSFET.
Is google broken in your country ?
Decide what voltage you need.
Decide what current you need.
Consult table.....
It's not rocket science.
michinyon:
The only things that i need is which MOSFETs could work in my condition & what is the process to pick such a MOSFET.
Is google broken in your country ?
Decide what voltage you need.
Decide what current you need.
Consult table.....
http://www.irf.com/product-info/fact_sheet/farnell/10527.pdf
It's not rocket science.
Tnx
This table is all i need.
My specialty is not electronics and i find out all i know about it by searching but sometimes there is a simple point like this that couldn't be find easily by person like me. So the things that obvious in your point of view may sometimes be more helpful than what you think .