Arduino Forum

Using Arduino => General Electronics => Topic started by: Domino60 on Jun 20, 2014, 07:39 pm

Title: H-Bridge with High Current Transistors
Post by: Domino60 on Jun 20, 2014, 07:39 pm
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).  =(
Title: Re: H-Bridge with High Current Transistors
Post by: vaj4088 on Jun 20, 2014, 08:43 pm
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!
Title: Re: H-Bridge with High Current Transistors
Post by: Domino60 on Jun 20, 2014, 09:37 pm
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 (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 (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) ?
Title: Re: H-Bridge with High Current Transistors
Post by: knut_ny on Jun 20, 2014, 09:50 pm
..dont walk in thin ice.  The transistors you refer to are 'toys' compared to what you will need for your task
Save yourself problems:
this is one example
http://www.ebay.com/itm/1pcs-miniIBT-Motor-Drive-Module-H-bridge-PWM-0-100-Control-12V-48V-5A-/301216849450?pt=LH_DefaultDomain_0&hash=item4621ec5e2a (http://www.ebay.com/itm/1pcs-miniIBT-Motor-Drive-Module-H-bridge-PWM-0-100-Control-12V-48V-5A-/301216849450?pt=LH_DefaultDomain_0&hash=item4621ec5e2a)
..or even better
http://www.ebay.com/itm/Dual-Motor-Driver-Module-board-H-bridge-DC-MOSFET-IRF3205-3-36V-10A-Peak-30A-/121220271322?pt=LH_DefaultDomain_0&hash=item1c394a8cda (http://www.ebay.com/itm/Dual-Motor-Driver-Module-board-H-bridge-DC-MOSFET-IRF3205-3-36V-10A-Peak-30A-/121220271322?pt=LH_DefaultDomain_0&hash=item1c394a8cda)
Title: Re: H-Bridge with High Current Transistors
Post by: Domino60 on Jun 20, 2014, 10:01 pm
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.
Title: Re: H-Bridge with High Current Transistors
Post by: vaj4088 on Jun 20, 2014, 10:02 pm
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!
Title: Re: H-Bridge with High Current Transistors
Post by: vaj4088 on Jun 20, 2014, 10:03 pm
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.
Title: Re: H-Bridge with High Current Transistors
Post by: Domino60 on Jun 20, 2014, 10:13 pm
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.
Title: Re: H-Bridge with High Current Transistors
Post by: Domino60 on Jun 20, 2014, 10:33 pm
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/ (http://www.pyroelectro.com/tutorials/h_bridge_4_transistor/)

Thanks to myself.
Title: Re: H-Bridge with High Current Transistors
Post by: Grumpy_Mike on Jun 20, 2014, 10:40 pm
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 (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 (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?
Title: Re: H-Bridge with High Current Transistors
Post by: Grumpy_Mike on Jun 20, 2014, 10:46 pm
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.
Title: Re: H-Bridge with High Current Transistors
Post by: Domino60 on Jun 20, 2014, 10:51 pm
Hi Grumpy_Mike Thanks for reply

Well I found this tutorial : http://www.pyroelectro.com/tutorials/h_bridge_4_transistor/index.html (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 ?
Title: Re: H-Bridge with High Current Transistors
Post by: Grumpy_Mike on Jun 20, 2014, 11:35 pm
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 (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.
Title: Re: H-Bridge with High Current Transistors
Post by: Domino60 on Jun 20, 2014, 11:42 pm
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 ?
Title: Re: H-Bridge with High Current Transistors
Post by: Domino60 on Jun 21, 2014, 12:08 am

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 (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 ?
Title: Re: H-Bridge with High Current Transistors
Post by: zoomkat on Jun 21, 2014, 12:42 am
Below are some high current transistors, a good read on a DIY H-bridge project, and a high current H-bridge that might meet your needs when your DIY project most likely fails.

https://www.sparkfun.com/products/10213

https://www.sparkfun.com/products/10349

http://forum.arduino.cc/index.php?topic=53425.0

http://www.ebay.com/sch/i.html?_sacat=0&_from=R40&_nkw=BTS7960B+driver&_sop=15
Title: Re: H-Bridge with High Current Transistors
Post by: MarkT on Jun 21, 2014, 12:45 am
Perhaps the easiest way to build an H-bridge from discrete components is to start with
good MOSFET H-bridge or half-H-bridge driver chips(*), add 4 n-channel MOSFETS
well up to the power and current and voltage ratings, and follow the suggested circuits
in the driver datasheets.  If you have a supply of limited current-sourcing ability
that will help prevent expensive mistakes (lead-acid and lithium batteries are not
forgiving).

(*) Ones with shoot-through prevention preferably - look at the datasheet for
the HIP4081A for a start.

Alternatively the VNH5019 does it all in one package:
http://www.pololu.com/product/1451 (http://www.pololu.com/product/1451)

(Its actually 4 MOSFETs and a driver chip packaged together)
Title: Re: H-Bridge with High Current Transistors
Post by: Domino60 on Jun 21, 2014, 01:30 pm
Well because I will anyway gonna turn the polarity of the motor manualy, I'm gonna use a Transistor to control
the voltage of the motor when I need it to be ON and OFF and I'm gonna rivers the polarity of the motor with a
DPDT switch. So I'm gonna put a button to control the motor state (ON/OFF) and a DPDT switch to control the
rotation of the motor (Right/Left).

That's what I'm thinking, so I'm gonna spend about 2~4$ for each motor system.
Title: Re: H-Bridge with High Current Transistors
Post by: keeper63 on Jun 21, 2014, 06:08 pm

Perhaps the easiest way to build an H-bridge from discrete components is to start with
good MOSFET H-bridge or half-H-bridge driver chips(*), add 4 n-channel MOSFETS
well up to the power and current and voltage ratings, and follow the suggested circuits
in the driver datasheets.  If you have a supply of limited current-sourcing ability
that will help prevent expensive mistakes (lead-acid and lithium batteries are not
forgiving).


I'm going to second this, with the following extra bit: Size the FETs 4 or 5 times larger than your current needs (so you want 10A - pick 50A n-channel FETs). That will give you plenty of breathing room, and it won't be that much extra to spend. You likely won't need heatsinks for a FET h-bridge (with the larger FETs and the smaller current needs), but you might want to leave room for them just in case (or if you want to use it with even larger motors later).

That said - you would still likely to be better off purchasing an h-bridge; since you don't want to go down this route, purchase plenty of spare FETs for the inevitable destruction as you test and play with the h-bridge you do build.
Title: Re: H-Bridge with High Current Transistors
Post by: dave-in-nj on Jun 21, 2014, 06:27 pm


Perhaps the easiest way to build an H-bridge from discrete components is to start with
good MOSFET H-bridge or half-H-bridge driver chips(*), add 4 n-channel MOSFETS
well up to the power and current and voltage ratings, and follow the suggested circuits
in the driver datasheets.  If you have a supply of limited current-sourcing ability
that will help prevent expensive mistakes (lead-acid and lithium batteries are not
forgiving).


I'm going to second this, with the following extra bit: Size the FETs 4 or 5 times larger than your current needs (so you want 10A - pick 50A n-channel FETs). That will give you plenty of breathing room, and it won't be that much extra to spend. You likely won't need heatsinks for a FET h-bridge (with the larger FETs and the smaller current needs), but you might want to leave room for them just in case (or if you want to use it with even larger motors later).

That said - you would still likely to be better off purchasing an h-bridge; since you don't want to go down this route, purchase plenty of spare FETs for the inevitable destruction as you test and play with the h-bridge you do build.


I would go along with this with a caveat.   READ THE DATA SHEET
many FET's are advertised as 50 amp, and then you find out that is good for pulsed operation with a 10% duty cycle. and the FET is rated for 8 amps at 100% duty cycle.   Many are being advertised as the 100% duty cycle, but this only takes a few seconds to verify before purchase.

Title: Re: H-Bridge with High Current Transistors
Post by: Grumpy_Mike on Jun 21, 2014, 09:39 pm
You can always use a relay to reverse the direction and a transistor to turn it on and off.
Have you seen this:-
http://www.thebox.myzen.co.uk/Workshop/Motors_1.html (http://www.thebox.myzen.co.uk/Workshop/Motors_1.html)
Title: Re: H-Bridge with High Current Transistors
Post by: luisilva on Jun 21, 2014, 11:11 pm
Grumpy_Mike, I don't like the option of relay to substitutes of transistors or for H bridges. You can't control the velocity (with PWM, for example) of the motors.
Title: Re: H-Bridge with High Current Transistors
Post by: Grumpy_Mike on Jun 21, 2014, 11:14 pm
Quote
You can't control the velocity (with PWM, for example) of the motors.

Of course you can. I said:-
Quote
You can always use a relay to reverse the direction and a transistor to turn it on and off.

You apply the PWM to the transistor turning the motor on an off and the relay for the direction.

Quote
I don't like the option of .......

Yes but it is not your thread so I care little about what you like or don't. Any real valid reasons?
Title: Re: H-Bridge with High Current Transistors
Post by: knut_ny on Jun 22, 2014, 02:03 am
..and there is now a small problem:
What voltage will be suitable for controlling base-inputs when motor run from e.g. 12V ?
(I guess additional components adds to the bill..)
Title: Re: H-Bridge with High Current Transistors
Post by: runaway_pancake on Jun 22, 2014, 02:11 am

Grumpy_Mike, I don't like the option of relay to substitutes of transistors or for H bridges. You can't control the velocity (with PWM, for example) of the motors.


Au contraire.

In the dwg (attached), I show an NPN, but that could be a "logic-level FET".

> > > 1A and 1B would be on together, 2A and 2B would be on together.  Steady on.
Title: Re: H-Bridge with High Current Transistors
Post by: luisilva on Jun 22, 2014, 02:36 am
After see the picture of Runaway Pancake, I must say that it seams that both of you ARE RIGHT! I didn't get it.
But I still don't like it for the other reasons that I point, and because I think that is "catching a fly with a hammer". That is, if you only need 4 switches why you should use 5? Is a assembly so important, so useful, and so well known that I don't remember of saw it ever. But yes, I shall admit that is possible.

@knut_ny: any voltage that can produce enough current in the base capable of put the transistor in the saturation. That is you must "play" with the voltage that you have in the base (constant) and the base resistor (that can be variable until you reach the current you want). If your base source cant source that current, yes, you need to add more components (more transistor in, for example, a Darlington pair)
Title: Re: H-Bridge with High Current Transistors
Post by: knut_ny on Jun 22, 2014, 03:12 am
..we are far off target now..but:
the "simple solution" may not be suited for arduinos digital outputs..
-----------
reading OPs problem.. I believe I'd go for a prebuilt, advanced soulutionfor moto control..  (the end)
Title: Re: H-Bridge with High Current Transistors
Post by: runaway_pancake on Jun 22, 2014, 03:51 am
http://www.rambal.com/descargas/libros/Nuts%20and%20Volts/2/Stamp%20Controlled%20High%20Power%20H-Bridge.pdf

Title: Re: H-Bridge with High Current Transistors
Post by: westfw on Jun 22, 2014, 04:36 am
Quote
that is 10W per transistor.

There are surely bipolar transistors that will run a 10W dissipation with a suitable heat-sink.   You just have to be prepared for the heatsink to be significantly large.   After all, I have a lab-style power supply that claims to deliver 5A, and I'm pretty sure it operates its output transistor at more than 2V Vce a lot of the time.

It'll depend on how much you're willing to experiment :-)

grab a couple 2n2955 (PNP) and 2n3055 (NPN) transistors (or the more modernly-packaged equivalents) (these are ancient and have rather poor performance, but they should be very common), set them up about like here: http://www.pocketmagic.net/2009/03/a-simple-h-bridge-design/
And use a smaller H-bridge chip (293L or whatever) to drive them instead of the 2n5551s (as per MarkT)

Quote
I don't like the option of relay to substitutes of transistors or for H bridges. You can't control the velocity

You use the relay to reverse direction, and a conventional (single) transistor or MOSFET to do the PWM.  This requires that you don't need to reverse directions quickly or often (like in an RC car, but NOT like for a stepper.)  This simplifies the circuit complexity and reduces the power waste by at least a factor of two.
Title: Re: H-Bridge with High Current Transistors
Post by: zoomkat on Jun 22, 2014, 05:31 am
You could get a log level MOSFET to control the PWM, A dual relay board like below to reverse motor direction, and wire the relays like in the pix for a simple setup.

http://www.ebay.com/sch/i.html?_sacat=0&_from=R40&LH_BIN=1&_nkw=arduino+relay+2&_sop=15

(http://web.comporium.net/~shb/pix/reversemotor.jpg)
Title: Re: H-Bridge with High Current Transistors
Post by: Grumpy_Mike on Jun 22, 2014, 06:57 am
Quote
That is, if you only need 4 switches why you should use 5?

Because those extra 4 switches are very much simpler and cheaper to implement as a realy than as a transistor. so while there is an extra switch the design is not complicated and there is no danger of shoot through.
Title: Re: H-Bridge with High Current Transistors
Post by: westfw on Jun 23, 2014, 03:31 am
Quote
if you only need 4 switches why you should use 5?

Note that four of those switches are typically contained in a SINGLE (DPDT) relay.  So it's one relay and one transistor...
Title: Re: H-Bridge with High Current Transistors
Post by: michinyon on Jun 23, 2014, 09:41 am
The problem the OP will run into,  is that it is easy to drive the bottom two transistors in the H bridge,  but hard to drive the top two transistors in the H bridge,  which he will need to be able to control the gate voltage around 17-19 volts.    cannot do with arduino output.
Title: Re: H-Bridge with High Current Transistors
Post by: MarkT on Jun 23, 2014, 10:40 am

I would go along with this with a caveat.   READ THE DATA SHEET
many FET's are advertised as 50 amp, and then you find out that is good for pulsed operation with a 10% duty cycle. and the FET is rated for 8 amps at 100% duty cycle.   Many are being advertised as the 100% duty cycle, but this only takes a few seconds to verify before purchase.


You would never choose a MOSFET by its current rating ever.  That's just noise in
the datasheet, since the key parameter is the on-resistance.

If the on-resistance is low enough for the power dissipation of the package, the
current is automatically within spec (the current limit is thermal in a power MOSFET).

The only caveat is check the package current limit - this is the current where the
pins and bonding wires of the packaging will start to fail.  For instance IR sell
a whole raft of TO220 MOSFETs with a ~240A rating, but admit in a footnote that
the package is limited to 75A (which is also a dodgy assertion, 30A is more reasonable).

So they claim the specs for the bare silicon die, despite not packaging it in a manner
that can carry anything like the current....

The other check you maybe should make (other than I-squared-R power dissipation) is
the Vsat (I-times-R), which needs to be well below the gate drive voltage.  So for instance
a 0.03 ohm MOSFET with 35A would have Vsat of 1.05V, which is OK if the gate
drive is 10V, but not with a 3.3V logic-level MOSFET since the you're in danger
of entering the linear region.  Normally a glance at the curves on the datasheet is
enough to confirm you are OK with Vsat

A 0.03ohm MOSFET with 35A would need to be in a package / heatsink able to
deal with 40W or so of course...
Title: Re: H-Bridge with High Current Transistors
Post by: tetris911 on Jun 23, 2014, 03:06 pm
I have 6 of these they seem to work really well.
http://www.ebay.com/itm/Semiconductor-BTS7960B-Stepper-Motor-Driver-43A-H-Bridge-Drive-PWM-For-Arduino-/131077219871?ssPageName=ADME:L:OC:CA:3160
Title: Re: H-Bridge with High Current Transistors
Post by: Domino60 on Jun 24, 2014, 10:05 am
Hi all and  thanks for reply,

Sorry If I interrupt your conversation but nowadays I had really bad day when I found out that I burned my arduino so even If I wanna build a H-Bridge with transistors I will not be able to control it with arduino because I don't have any arduino devices now.

What I decided to do as I replied that few days ago is to take a transistor, DC Motor and DPDT Switch.
If you think about the transistor state, because as I replaied that, I'm  gonna use about 5A and 15v to 30v I found out
this transistor :
Pdf. 2n3055. Datasheet :
http://html.alldatasheet.com/html-pdf/21680/STMICROELECTRONICS/2N3055/1620/1/2N3055.html (http://html.alldatasheet.com/html-pdf/21680/STMICROELECTRONICS/2N3055/1620/1/2N3055.html)

Fig 1. 2n3055 Transistor
(http://sigma.octopart.com/17594287/image/STMicroelectronics-2N3055.jpg)

I tested it Personally, I tested it and it's working really well and it's not burning at all, even if it will I have a huge heatsink for it, but as i tested it for about 5~10 min the transistor was really cold.


About the DPDT Swich not use if you all know about it.
It's a swich that can change the polarity of a motor or led or anything you wanna change.
Fig 2. DPDT Swich
(http://cdn.instructables.com/F6R/QQB3/HGU2LLE0/F6RQQB3HGU2LLE0.MEDIUM.jpg)

I realy feel bad that my arduino burned so that's the only way to control a motor in my case.

I see many people suggesting to buy H-Bridge from ebay or different sites, thanks alot for help but I'm not the type of guy that buy everything, I wanna have the experience to build something on my own. To upgrade my skill lvl and to be able in future to build the same stuff easy and fast because i will know that it's working, and if someone ask me for help I will be able to answer many questions because I will know that I didn't bought that ready circuit from Ebay or other websites but I builded on my own.

Thanks a lot all, I got many ideas searching for different ways to control a motor and reverse the polarities.
But I have one more question about the transistor that I posted :
a) What's the needed voltage and amperage I need to apply at the base of the transistor to activate and run the motor
         at full power of the powersupply ?

(It's maybe a silly question because I already learned about transistors but I'm not sure how you calculate that in different types of a transistor.)
Title: Re: H-Bridge with High Current Transistors
Post by: knut_ny on Jun 24, 2014, 06:51 pm
The datasheet says you may need up to 4A  to base to get a safe saturation when collectorcurrent is 10A.
This 'problem' is why mosfets often replaces it as a switching transistor
Title: Re: H-Bridge with High Current Transistors
Post by: Domino60 on Jun 25, 2014, 02:04 pm
I done few experiments with the transistor and I find out that a PC_USB 5v_400mA (I think it is) it's the best
Base Voltage/Current from the transistor to release all the power supply voltage and current to pass thru the
transistor.

Best way to find something is to test it on your own :)  Btw I runned the Transistor with a power supply of
5A and 30V for 10min without stop and the transistor was realy cold, no heat at all :) that's nice results for me.

I will try to record a video about the transistor, power supply, DPDT Swich and how they work with a motor :)
Title: Re: H-Bridge with High Current Transistors
Post by: Grumpy_Mike on Jun 25, 2014, 02:17 pm
Quote
Best way to find something is to test it on your own

Yes but only if you test it correctly.

Quote
Btw I runned the Transistor with a power supply of 5A and 30V for 10min without stop

Yes the power supply was that but what was the actual load. The value of the resistance between the supply and collector.

Quote
and the transistor was realy cold,

Which suggests that you had only an insignificant load and your test was a bit useless. If you did run it at 5A and it was cold then it was not actually working.

Quote
I done few experiments with the transistor and I find out that a PC_USB 5v_400mA (I think it is) it's the best
Base Voltage/Current from the transistor to release all the power supply voltage and current to pass thru the
transistor.

OK the real words for this are "to drive the transistor into saturation" and you did not do that with 400mA and a 5A load. You are going to have to drive that transistor with an arduino, you can only get 40mA out of an arduino so you need another transistor in front of this one to get the base current to what you want.

No one suggested using a DPDT switch. It was a relay with DPDT contacts that was suggested so you could control the diesction with the arduino.
Title: Re: H-Bridge with High Current Transistors
Post by: Domino60 on Jun 25, 2014, 02:53 pm
Quote
Which suggests that you had only an insignificant load and your test was a bit useless. If you did run it at 5A and it was cold then it was not actually working.


Ok, I didn't ment that was cold cold, was about from 15 to 30 celcius and i don't think that was a fail test because I
tested in diferent ways and the tongue of the motor was same with or without the transistor.

Quote
OK the real words for this are "to drive the transistor into saturation" and you did not do that with 400mA and a 5A load. You are going to have to drive that transistor with an arduino, you can only get 40mA out of an arduino so you need another transistor in front of this one to get the base current to what you want.

No one suggested using a DPDT switch. It was a relay with DPDT contacts that was suggested so you could control the diesction with the arduino.


As I said few days ago my arduino burned, so I'm not gonna use arduino at all.
About the DPDT Switch i found about it on the internet I suggested it

That's the Switch that I bought and soldered few jumper wires to be easier to test.
Fig 1. DPDT Switch.
(http://pumpshooter.com/zRTdfS76)

About all that system I'm trying to make, you said that I done useless test.
Quote
your test was a bit useless

I don't think so I tested it I saw it with my own eyes that it's working without problems and the tongue of the motor is the same as I expected.
I'm gonna do a video in the following days.
Title: Re: H-Bridge with High Current Transistors
Post by: Grumpy_Mike on Jun 25, 2014, 06:17 pm
What is :-
Quote
the tongue of the motor

?

Quote
was about from 15 to 30 celcius and i don't think that was a fail test because Itested in diferent ways

If a 2n3055 transistor did not get mad jumping hot with 5A flowing through it something is very wrong. You might think you have done a test but those results simply do not make sense. You should have nearly 5W of energy to burn off as heat, because you did not then I suspect you did not test it at 5A and so your tests do not show what you think they show.

Still if you will not give details of the test you did it is hard to say where you are going wrong, but wrong you are going somewhere. I suspect you did not test it at anything like 5A.
Title: Re: H-Bridge with High Current Transistors
Post by: MarkT on Jun 26, 2014, 12:20 pm
About 2.3W with 2N3055 in saturation at 5A with 300mA base drive, Vsat = 0.4V, I make it...
Given the large metal TO3 package that would take a little while to heat up.
Title: Re: H-Bridge with High Current Transistors
Post by: Grumpy_Mike on Jun 26, 2014, 03:07 pm

About 2.3W with 2N3055 in saturation at 5A with 300mA base drive, Vsat = 0.4V, I make it...
Given the large metal TO3 package that would take a little while to heat up.

The data sheet I read did not give such a tiny value for Vsat it was between 1 and 2V.
Have you used those transistors? There is no appreciable "time to warm up" with them.