Go Down

Topic: H-Bridge with High Current Transistors (Read 17286 times) previous topic - next topic

Domino60

Hi all,

  I searched on google many types of H-Bridge(HB) but most of them are for low current circuits,
as you all know h-bridge control a dc motor in 2 ways, I'd like if someone can give me a type of transistor that will be able to
handle high current like  12v to 24v and 5A to 10A, well at least I'm gonna use a 19v 4.7A power supply to control a dc motor.

   And one more question, how I'm able to control 2x DC Motors with the same H-Bridge in the same time and in the
opposite directions, or should I build (HB) for each motor ? Even if I need 2 HB for each motor I'm able at least to control
the 2 motors with diferent HB in the same time and opposite directions with the same arduino ?


Thanks, Hope someone will reply (noone lately reply to me).  =(
To be or not to be? Read a book and you will see.
Join Discord Free_World (Arduino_Room) Live chat
https://discord.gg/bBXEuKQ

vaj4088

If you have to ask these questions, I suspect that you are going to have great difficulties when you try to implement this yourself.  An H-bridge is the way to go, but there are many practical issues that you are probably not prepared to handle.  You have not specified N-FET, P-FET, IGBT, NPN bipolar, or PNP bipolar.   These are all types of transistors that could be used in an H-bridge.  Are you prepared to deal with issues such as shoot-through?  I suggest that you purchase a ready-made H-bridge motor driver.

You will need one H-bridge per motor.  Each H-bridge will require at leat two outputs from the Arduino.  Sometimes more than two outputs are needed, depending upon the functionality of the H-bridge.  For example, do you want to be able to perform braking as well?

You justed posted today.  All responses on this forum are unpaid.  You should expect to wai 0, 1, or even 2 days for responses here.

Good Luck!

Domino60

First of all thanks for reply,

  As I know about transistors I persoanly know 3 types, I learned more but I never needed them, NPN, PNP (bipolar ofc) so on.

1. Not sure if you know about the simple DC motor control that use a NPN Transistor and just control the motor in one way,
I done that a month ago with a 2n2222 and 2n3904 NPN type, about the practical issues not sure what are you talking about :D
I'm thinking to use a NPN Transistor but not sure what type because not sure where to find one with the (specification) I need.

2. I found about about H-Bridge  5~8 months ago but I never done one because I'd not needed one, but nowdays
I need, so I found out this video one youtube about how they work https://www.youtube.com/watch?v=Fjo7t_U59tY
so I thought If I need 4 Transistors to do that H-Bridge why should I not use the simple

 DC motor drive example : http://cdn.instructables.com/FN3/AGFE/H1HMDLS9/FN3AGFEH1HMDLS9.LARGE.jpg

But insted of 1 Transistor to put 4 and drive them in the same way at the youtube simulation example, ofc I will need 4 pins on the arduino.

Should that work ? I personaly think yes, but again not sure about what type of transistor to use and how I will protect
the arduino from high (Voltage and Current) ?
To be or not to be? Read a book and you will see.
Join Discord Free_World (Arduino_Room) Live chat
https://discord.gg/bBXEuKQ

knut_ny

Ny

Domino60

Hi knut_ny

    Yes I know that the transistors i refered are toys that's why I ask help to find the right transistors I need.
About the problems, I don't have problem to build my own circuits and thanks for the Ebay link
but I don't have time to wait 1 month till the comp. will arive to my location, I need to keep going my project
so for me It's easier to build a H-Bridge by buying components from local store.

I see many people buying several arduino circuits to build their project and in the end they have a huge
one on the top of the other (shileds) just for a simple project.

So what i need is
: To control a motor with a 19v - 4.7A power supply, Is anyone able to give me a push what kind
of transistor I need and how to protect the arduino or a microchip from the (PowerSupply)H-Bridge ?


Thanks.
To be or not to be? Read a book and you will see.
Join Discord Free_World (Arduino_Room) Live chat
https://discord.gg/bBXEuKQ

vaj4088

1.  If you don't know the practical issues, then you have some interesting leaarning experiences ahead of you.  One of many possible examples:  With an H-bridge, it is possible to turn on transistors in such a way that the current path is from the most positive voltage, through two transistors, and then to the most negative voltage.  If this doesn't damage your power supply, it is likely to permanently destroy two of your transistors, possibly explosively.  I hope that you have extra power supplies and extra transistors on hand.  Eye protection is also recommended.

2.  That example is great for a little motor running in one direction.  The moment you get a bigger motor or want to go in both directions, it won't work.

If you have to ask about types of transistors and about practical issues, you aren't ready for this.  In the United States, I would start with onsemi.com or digikey.com to look for transistors.  Wherever you are, there may be a better way to go about this.  You will need at least 8 (4 for each motor), plus SPARES!

Yes, you can control the four transistors of an H-bridge with four outputs from an Arduino.  But...  you had better think about the voltages you are going to use, the voltages needed to drive the transistors, the voltage limits of the Arduino, and what happens if the sequencing or timing of the Arduino outputs is wrong.

I still recommend that you purchase a commercial device to do provide this interface.

I can't look at the YouTube video right now, but knowing how something works and understanding the practical issues of why it might NOT work are different things.
I can well understand the interest in doing it yourself, but you are walking into dangerous territory without the appropriate precautions.

Good Luck!

vaj4088

You wrote that you want to buy components from your local store.  We didn't have this information before.  We still don't know what is available from your local store.  You are on your own, I guess.

Domino60

#7
Jun 20, 2014, 10:13 pm Last Edit: Jun 20, 2014, 10:18 pm by Domino60 Reason: 1
Well to be clear,

Let's take it from the beginning, I need to build a H-Bridge with transistors that will handle 5 to 10A and 12 to 24 volts.
I don't wanna buy anything from ebay like a really made HB Driver.
Because I don't have the time to wait_ I need the H-Bride in 1~2 weeks max.
I wanna build it on my own. To be more clear I have a local store that have mostly Transistors (any type), Resistors, switches, leds, capacitors (any type) ...etc They don't have at all microchips so Don't talk about a H-Bridge chip.

I need someone that know about "Home made" H-Brigdes and how they work.
I'm able to build circuits and I'm able to handle any future problems so If there is someone that wanna realy  help
then reply.
To be or not to be? Read a book and you will see.
Join Discord Free_World (Arduino_Room) Live chat
https://discord.gg/bBXEuKQ

Domino60

Well thay say that everyone can comment, but when you realy need something noone helps.


If anyone needs something like what I need just follow this tutorial :
http://www.pyroelectro.com/tutorials/h_bridge_4_transistor/

Thanks to myself.
To be or not to be? Read a book and you will see.
Join Discord Free_World (Arduino_Room) Live chat
https://discord.gg/bBXEuKQ

Grumpy_Mike

Quote
I need someone that know about "Home made" H-Brigdes and how they work.

You don't use transistors to make a high current H-bridge. Most power transistors have a Vsat of about 2V, that means with 10A current you have heat dissipation of 20W per transistor. So that is 40 W you are burning off at any time.

You are coming across a bit naive when you say:-
 
Quote
I have a local store that have mostly Transistors (any type)

Now I use Farnell and I just put transistor into their site and it said:-
Quote
27,241 Product results found for "transistor"

Farnell do not by any means have all the types of transistor, I suspect neither does your local shop.

What you need to use is a power FET. These have a very low turn on resistance and will be able to handle the current without dissipating vast amounts of heat.
If you want a recommendation how about this one:-
http://uk.farnell.com/nxp/buk755r4-100e/mosfet-n-ch-100v-120a-to220/dp/2215769?in_merch=New%20Products&in_merch=Featured%20New%20Products&MER=i-9b10-00002068

Next FETs need high voltages to switch them, normally 10V but there are logic level ones that will go at 5V. One way to do this is to use opto isolators to get over the DC shift problem, something like this:-
http://www.mcmanis.com/chuck/robotics/tutorial/h-bridge/bjt-circuit.html

I suspect you are looking for a design ready to build. What google searches have you done for this?

Grumpy_Mike

Quote
Well thay say that everyone can comment, but when you realy need something noone helps.

You waited all of 20 minutes before complaining. Your expectations are as unrealistic as your circuit building ambitions. 

Quote
If anyone needs something like what I need just follow this tutorial :
http://www.pyroelectro.com/tutorials/h_bridge_4_transistor/

A TIP147 is not going to be good enough for what you want. It will melt long before you can get 10A through it.

Domino60

Hi Grumpy_Mike Thanks for reply

Well I found this tutorial : http://www.pyroelectro.com/tutorials/h_bridge_4_transistor/index.html
and you said :
Quote
A TIP147 is not going to be good enough for what you want. It will melt long before you can get 10A through it.


Well I'm not gonna use 10A, max that I'm gonna use is 5A, and yes I know they gonna start heat up realy fast, but how about
if I put a transistor heat sink ? I need the H-Bridge at max 10A because I may upgrade my motors in the future.
But right now I'm gonna use only a 19v 4.7A  (90w) power supply, and to be more clear I'm not gonna run the motor
constantly but with some delays.

So what you think I'll be good with that circuit ?
To be or not to be? Read a book and you will see.
Join Discord Free_World (Arduino_Room) Live chat
https://discord.gg/bBXEuKQ

Grumpy_Mike

Quote
, but how about if I put a transistor heat sink

I am not sure that even an infinite heat sink will be enough.
For calculating the sort of sink you need see this:-
http://www.thebox.myzen.co.uk/Tutorial/Power.html
That package has a junction to case of 1.5 degrees C per watt and a Junction to ambient of 45 degrees C per watt.
With 4.7A ( lets call it 5A ) and a Vsat of 2V then that is 10W per transistor.

Quote
So what you think I'll be good with that circuit ?

I haven't done the sums on it but my gut feeling is that it will get too hot.

Domino60

#13
Jun 20, 2014, 11:42 pm Last Edit: Jun 20, 2014, 11:45 pm by Domino60 Reason: 1
So as you see I'm searching for a ready made circuit, can you suggest me a ready made HB circuit that will be good with my specifications of the power supply ? 5A 19v

I just wanna control a motor in 2 directions :D
and what you think should i spend some money to build that tutorial circuit or not ?
To be or not to be? Read a book and you will see.
Join Discord Free_World (Arduino_Room) Live chat
https://discord.gg/bBXEuKQ

Domino60


Can't I use this system instead of "H-Bridge" circuit ?

To chouse 2x High Voltage/A, and put them in that way as the Fig.1.
Instead of 2 swichis to put 2 transistors and connect the Base of the transistors on the arduino,
and to be more careful not burning the arduino to write a program that will have a delay between the swich time
about 200ms so there will not be posible way of "short circuit".
Ofc we need to add some resistors too and I think between that 2 Hight V/A transistors to put on the base of them
a smaler transistors that will save the arduino of something else.

Fig.1. Example of a simple HB.
https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSZAy4gACEa0pwInXzJhZaB7bT5zvNiC5eoBjfNthNf-BadxUrY

Just telling my opinion, trying to do it more simple. So is there any transistor that will handle 5A and 20 v ?
To be or not to be? Read a book and you will see.
Join Discord Free_World (Arduino_Room) Live chat
https://discord.gg/bBXEuKQ

Go Up