Best choice of motor driver?

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rubem
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Best choice of motor driver?

Beitrag von rubem » 26 Mär 2021, 19:43

I was doing some tests with motor drivers and arrived to some interesting results. I have just very basic equipment (i.e. an old digital multimeter), but I made several measurements and the results seem to be consistent. For the power source I'm using a no-brand 9V 3A switching power adapter which I've been using it to drive my fischertechnik models for years. So here is what I got:

The 9V adapter gives 9.5 V with no load. When it is used to power a TXT controller, it drops just around 5 mV. The "9 V Out" pin, on the other hand, gives around 8.5 V. When an encoder motor (part # 153422) is connected to it and turned on with Robo Pro, the "9 V Out" pin drops just a little bit: 8.4 V. The tension is around 7.7 V across the motor terminals.

On the other hand, an L298N module connected to an Arduino Nano gives 8.1 V across the motor pins. That's a bit of a surprise, because this module is considered antiquated by many people because it uses bipolar transistors.

In the end I don't want to use the L298N's because they are quite bulky. I have some other drivers like the BA6418N and the L293D. I also have a pair of L9110 modules, but as far as I know they don't have a brake function (important for encoder motors), and they also get super hot. I suspect none of them would be the recommended choice for today. I was thinking about a FET driver, but I'm not sure at all. (I'm familiar with electronics, but just as a hobby.)

So here's my question: which would be the best motor driver for ft motors?

Thanks in advance for any answers.

P.S. Sorry for no German translation this time. I'm pretty sure Google will think I mean a "motorcar driver" :D
Zuletzt geändert von rubem am 01 Apr 2021, 01:34, insgesamt 1-mal geändert.
Rubem

juh
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Re: Best choice of motor driver?

Beitrag von juh » 26 Mär 2021, 21:19

Hi Rubem,

the L9110 (aka HG7881) are also quite bulky, as each chip only drives one channel.

I see the TB6612 being used in a lot of projects, I also used them, I think they are well proven, drive up to 1,2A and have short brake.

Recently I've been testing the DRV8833, which (nominally) can drive up to 1,5A. I like it, as It has some additional features such as overcurrent protection, current limiting, and a fault signaling pin.

I found out the hard way to pay attention to two different ways these drivers are controlled by the µC in Arduino projects. Some like the TB6612 or L2298 need only one PWM pin (and one direction pin), some like the L9110 and the DRV8833 need two PWM pins, so in larger projects one has to watch out to have enough PWM pins.

Jan
Meine fischertechnik Designs für den 3D-Druck: https://www.thingiverse.com/juh/designs

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rubem
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Re: Best choice of motor driver?

Beitrag von rubem » 26 Mär 2021, 21:44

@Jan: Thanks for the advice! The DRV8833 keeps popping up in my searches, but I see its max operating voltage is 10.8 V. Isn't this too close to 9V to be safe? The TB6612 is rated at 15 V max, isn't this chip a safer bet?
Rubem

juh
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Re: Best choice of motor driver?

Beitrag von juh » 27 Mär 2021, 00:00

All I can say is that it tested fine with ft motors at 9V. I'm far from being an expert, but personally I'd be worried getting close to the current limit, but not so much with the voltage. Also, 10.8V is the recommended value, the maximum supply voltage is 11.8V, so there's still some extra safety margin.

Jan
Meine fischertechnik Designs für den 3D-Druck: https://www.thingiverse.com/juh/designs

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rubem
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Re: Best choice of motor driver?

Beitrag von rubem » 27 Mär 2021, 00:06

juh hat geschrieben:
27 Mär 2021, 00:00
All I can say is that it tested fine with ft motors at 9V. I'm far from being an expert, but personally I'd be worried getting close to the current limit, but not so much with the voltage. Also, 10.8V is the recommended value, the maximum supply voltage is 11.8V, so there's still some extra safety margin.

Jan
I didn't know that, that's good. I'll probably order a pair of DRV8833 modules and make some tests. Thanks again, much appreciated!!!
Rubem

juh
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Registriert: 23 Jan 2012, 13:48

Re: Best choice of motor driver?

Beitrag von juh » 27 Mär 2021, 01:22

rubem hat geschrieben:
27 Mär 2021, 00:06
I didn't know that, that's good. I'll probably order a pair of DRV8833 modules and make some tests. Thanks again, much appreciated!!!
In case you did'nt notice, there's at least three different modules with this chip, Adafruit, Pololu, and noname Chinese ones, and not all make all of the features of the chip available. Particularly the cheap ones from ebay omit the current control pins, but for testing purposes it probably doesn't make a lot of difference.

Jan
Meine fischertechnik Designs für den 3D-Druck: https://www.thingiverse.com/juh/designs

vleeuwen
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Re: Best choice of motor driver?

Beitrag von vleeuwen » 27 Mär 2021, 09:07

Maybe this could help:
The auto motive industry produce a lot of different types of full bridge motor drivers.
From low power up to heavy power.
Search key: "full bridge brushed motor driver"

For example:
https://www.allegromicro.com/en/Product ... escription
https://nl.rs-online.com/web/p/motor-dr ... s/7147715/

Most of the time the break out prints are very cheap from china (Alibaba)
Search to start with: "full bridge brushed motor drive (IC)"

Karl
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Re: Best choice of motor driver?

Beitrag von Karl » 27 Mär 2021, 09:31

Hallo,
den L298 würde ich, wenn möglich, nicht mehr einsetzen. Das IC ist schon mehr als 35 Jahre alt.
Effektiv als Schrittmotor-Treiber arbeitet dieser Baustein mit dem L297 zusammen welcher auch die
Stromsteuerung übernimmt. Neben den Sensor-Widerständen sind auch Freilaufdioden extra
erforderlich.
Habe selbst um 1985/1986 mit den Kombinationen L297 / L298 Schrittmotorsteuerungen gebaut. Leider
war damals die Auswahl an ICs sehr beschränkt und teuer waren diese ICs auch noch.
Die "modernen" Motor-Treiber-ICs bieten viel mehr Vorteile. Einfacher in der Ansteuerung, Verlustleistung
sowie oft die Freilaufdioden schon "On Board".

Hello,
I would no longer use the L298, if possible. The IC is already more than 35 years old.
Effectively as a stepper motor driver, this component works together with the L297 which also takes over the current control.
current control. Besides the sensor resistors, free-wheeling diodes are also extra
required.
I built stepper motor controllers myself around 1985/1986 with the L297 / L298 combinations. Unfortunately
the choice of ICs was very limited at that time and these ICs were also expensive.
The "modern" motor driver ICs offer many more advantages. Easier to control, lower power dissipation
and often the free-wheeling diodes are already "on board".

The standard circuit at that time was: https://electronics.stackexchange.com/q ... ot-working

Translated with www.DeepL.com/Translator (free version)
Grüße von
Karl

Es gibt immer viel mehr Lösungen als Probleme.

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elektrofuzzis
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Re: Best choice of motor driver?

Beitrag von elektrofuzzis » 27 Mär 2021, 13:06

Hi Rubem,

there are big differences between the old L296 simple transistor drivers and modern Bridges like A4988 or DRV88xx drivers. Since the modern drivers need some analogues stuff, the easiest way is to use a pololu breakout board (or a chinese clone).

With the modern drivers, voltage is not a problem. They are working in regulating the current. 9V with enough power (take a power supply with more power than needed).

If you don't want to think about at all, just get a ftPwrDrive from www.gundermann.org.

Best regards,

Stefan

vleeuwen
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Re: Best choice of motor driver?

Beitrag von vleeuwen » 27 Mär 2021, 15:16

Some additional information about flyback diodes or freewheeling diodes.
(Motor driver: Motor, stepper or relay are inductif loads.)
-) What is their function?
-) Internal or external?
-) What type of diode can serve as flyback diode?

See for example:
https://www.electronicshub.org/flyback- ... ing-diode/
https://en.wikipedia.org/wiki/Flyback_diode#Design
This diode is known by many other names, such as snubber diode, commutating diode, freewheeling diode, suppressor diode, clamp diode, or catch diode
Often the question is: when you will need external diodes for Flyback reasons or are internal diodes sufficient?

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rubem
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Re: Best choice of motor driver?

Beitrag von rubem » 27 Mär 2021, 15:17

juh hat geschrieben:
27 Mär 2021, 01:22
In case you did'nt notice, there's at least three different modules with this chip, Adafruit, Pololu, and noname Chinese ones, and not all make all of the features of the chip available. Particularly the cheap ones from ebay omit the current control pins, but for testing purposes it probably doesn't make a lot of difference.
elektrofuzzis hat geschrieben:
27 Mär 2021, 13:06
there are big differences between the old L296 simple transistor drivers and modern Bridges like A4988 or DRV88xx drivers. Since the modern drivers need some analogues stuff, the easiest way is to use a pololu breakout board (or a chinese clone).

With the modern drivers, voltage is not a problem. They are working in regulating the current. 9V with enough power (take a power supply with more power than needed).

If you don't want to think about at all, just get a ftPwrDrive from www.gundermann.org.
vleeuwen hat geschrieben:
27 Mär 2021, 09:07
Maybe this could help:
The auto motive industry produce a lot of different types of full bridge motor drivers.
From low power up to heavy power.
Search key: "full bridge brushed motor driver"

For example:
https://www.allegromicro.com/en/Product ... escription
https://nl.rs-online.com/web/p/motor-dr ... s/7147715/

Most of the time the break out prints are very cheap from china (Alibaba)
Search to start with: "full bridge brushed motor drive (IC)"
No-brand products are imported in bulk and therefore quite affordable here in South America, but unfortunately the same cannot be said about Polulu, Adafruit and the like, at least most of the time (there are exceptions). As most hobbyists, I tend to go for the less expensive options, and this means Chinese clones. As for the differences between modules using the same chip, I must admit I didn't even realize there were any, so now I'll keep a closer eye at the specs before making a purchase decision.

Meanwhile, thanks a lot for your insights, I'm always amazed at the interest these technical questions arise at this forum :)
Rubem

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rubem
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Re: Best choice of motor driver?

Beitrag von rubem » 29 Mär 2021, 22:54

juh hat geschrieben:
26 Mär 2021, 21:19
Recently I've been testing the DRV8833, which (nominally) can drive up to 1,5A. I like it, as It has some additional features such as overcurrent protection, current limiting, and a fault signaling pin.
A little off-topic, but still about chips: The Didacta board included in the ft Starter Set for micro:bit uses two L293Ds (https://www.fischertechnik.de/en/produc ... -micro-bit). The Kitronic micro:bit board, however, uses the same chip you are testing, the DRV8833. It's easy to see it from the photo (https://kitronik.co.uk/products/5656-in ... hertechnik). The Kitronik board is cheaper, but it can control only 2 motors, only one DRV8833 is used. I didn't even realize there were two options to interface fischertechnik to the micro:bit! Kitronik's is now on offer, just £6.96 excl. VAT. The form factors and the fixing are different, and the micro:bit is positioned at 90°.

I used a micro:bit to control a small buggy with 2 servos, here: viewtopic.php?f=6&t=6572.
Rubem

Karl
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Re: Best choice of motor driver?

Beitrag von Karl » 29 Mär 2021, 23:21

Hallo,
L293 NE - 1A - Peak 2 A

L 293 DNE - 600 mA - Peak 1,2 A

L293 DNE has internal "Clamp-Diodes", L 293 NE not.

Quelle - Texas Instruments
https://www.ti.com/lit/ds/symlink/l293.pdf

The DRV8833 can also control two DC - motors,
Inputs A and B - Outputs A and B each a coil array of a stepper motor..
https://www.ti.com/lit/ds/symlink/drv88 ... 52FDRV8833

Take a look at page 8.
Grüße von
Karl

Es gibt immer viel mehr Lösungen als Probleme.

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