What is the best, and most handy way to add a fast short current protection to SparkFun Toshiba TB6612FNG?

Thread Starter

ideainnova

Joined Apr 19, 2013
5
Toshiba is almost %100 efficient, no cooler at 2–2.5A, way ahead than any other thing for such currents. So cheap and as a kit perfect to use daily everywhere by youth. One handy short current topology makes it killer because it is stackable as paralel. You can easily do 100A box without a fan or cooler. It will drive not only step motors etc but everything by totempole, high-low current signalisation, a tiny led, wify BT driver, anything in a safe children’s control box. It will be 17to24 channels lpt breakout with fast optos + for arduino io + for general purpose multy channel voltage current controllable io box, supply box, fed from xl4015s, giving %50 duty at 80khz, fast enough high quality switching for my son and for childrenand for controllers.

Constructing this by arduino is too slow by high side sense kits for 12 output channels. Fast fuses are never close to such speed and is not suitable for wide current band. I examined all of pdfs, not practicle. l293 with short protection mentioned at application notes is good only under 300mA total current, otherwise around %40 efficiency in reality is out of sense, a too old ic. Lm138 current limiting per toshiba kit just for a channel is not practicle and again, can create efficiency and heat problem for more than 500mA in closed box.

There could be short protection ic, having [(high side sense for hbridge)+(fast multiplexer)+(adc)+ (its own fast clock)+signal out for each channel and or'ed common signal out]. So what can i use for high side fast short protection or is there any Toshiba specific way, what can I do? Thank You.
 

Delta Prime

Joined Nov 15, 2019
1,054
Hello there!:)
It will drive not only step motors etc but everything by totempole, high-low current signalisation, a tiny led, wify BT driver, anything in a safe children’s control box. It will be 17to24 channels lpt breakout with fast optos + for arduino io + for general purpose multy channel voltage current controllable io box, supply box, fed from xl4015s, giving %50 duty at 80khz, fast enough high quality switching for my son and for childrenand for controllers
Great Caesar's ghost!
I have no idea what you are talking about.
 

Thread Starter

ideainnova

Joined Apr 19, 2013
5
Hello there!:)

Great Caesar's ghost!
I have no idea what you are talking about.
My son didnot know reading&writing but was programming in dos pc booted to borland C example file. Constracting some meccano, lego, stickle bricks and using any sensor input to any output device. He loved parts since 1,5 years old. Soldering and basics were yet too complicated. He knows max current for load, adjust current limiter, and connects. Thus he uses parts like lego, and code in simple environment, using some premade functions and flow commands. For safety and isolating unnecessary knowledge, he needs a box, a safety layer for his jobs. A box:
5 x (5V->sensors->fast optos)-> lpt or later arduino -> 12 x (volt&current limiting)->any load
*sw pushb: source -sw> load -sw> gnd, when on or off as source or sink method
*relay: source -r> load -r> gnd, when on or off as source or sink method
*relay:as perfect buffer
*relay on: source -r> load -> gnd AND relay off: gnd -> load -> gnd, not button sw tr but double way device
*tr: ugly relay as source method loosing vcc abit
*tr :ugly relay as sink method loosing perfect gnd connection
*tr :ugly relay as buffer loosing vcc abit
*totempole tr's : ugly double way relay loosing a bit vcc loosing from perfect gnd connection.
*variable vcc totempole tr's : handy way of the one above

If a port has output style of variable vcc (totempole)/(source and sink)/ (double way) on off working method, we call it silent fast optimum relay. This can source as low as 1V or as high as 30 or more, according to design. And sink source current unlike arduino 40mA or lpt 25mA or some stages 5mA, is easily more than 1A, say 50A arduino port giving a voltage from 1v to 30V but having a current limiter, and short circuit protection. By it, nondesctructable control unit and V I controllable control output to any load. These totempole ports can be used as hbridge, say you can connect a motor to lpt1 and lpt6 and use these as hbridge. 11brake-10up-01dn-00brake. You can signal up to ~500khz probably more in advance, with toshiba you get perfectly square shape %50 on off states at 80khz at 1-2-3...A, it can be used as paralel. Because totempoles are just like amplfier push pull outputs, can be used in paralel by 1 control input. A child can connect anything availabe to it. adjusting current even just a led without resistor. Key word is current.

12 channel power supply : each channel is 1.2A, each has (arduino adc multiplexer lcd) memorised current limited, each short protected, each can be increased to 3A, groups(4 channels) voltage adjusted seperatedly by xl4015 's. Total more than 12 A and no cooler at all. Fed from pc power supply 12v output. Chocolate pack size 12 channel cpu controlable, opto isolated power supply box + opto isolated 5 input or more. Childrenfriendly safe C automation. led, 3V flament lamp, laser, 3-4.5-6-9-12v motors either 1 way or hbrisgde between anyoutput, steppers, preschool IT education box. Manual or cpu connected, also 27-40-49khz rf at channels. No cable crowd, no heat, no burns, simple interface, step by step learning. mach3 compatibility, as it is named, for a children my simple io. graphs of load, RT current and io monitor. simple child graphs on borland putpixel, simple text chars.

I need those silly 12 x short protections. High side sensing, fast, channelwise and wholesystem disabling output. Not 12 discrete kits inside another box(already i have 2 layers of oem in box ,pics from previous designs), just an 2021 ic, multy line in-out-signalout-vcc-gnd-clk etc. Still no answer from anyone anywhere. My son learned reading writing waiting for the short protection.
 

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Sensacell

Joined Jun 19, 2012
2,851
Your writing style is extremely difficult to follow.
Perhaps try re-posting with simplified language and no abbreviations?

I get only the vaguest idea of what you are asking after reading your post.
 

LowQCab

Joined Nov 6, 2012
743
It sounds like you want to cram all this stuff into a Wristwatch-Case
with zero additional parts or Heat-Dissipation.

What do you intend to Power all this with, a single Coin-Cell maybe ???
.
.
.
 

Irving

Joined Jan 30, 2016
1,845
All right.Thank you, for clearing that up .
There is a way to protect your 12 channels. Take a look at this link
You can employ the ESD protection scheme the principal would be the same for your application, using TVS
Diodes, This is only a suggestion.
I hope it helps :)
https://toshiba.semicon-storage.com...wledge/e-learning/discrete/chap2/chap2-7.html
Not sure how TVS/ESD protection is going to help with short-circuit current?

The TB6612 is a cheap device suitable for low-end consumer products like toys, automation, etc. where overcurrent protection is not required as current draw is limited by design, e.g. battery driven or current-limited power sources.

There are better motor controllers available that have built-in over-current protection and proper current sensing for starting torque control.

The only way to do fast protection is to monitor the drive current with a series sense resistor and turn the supply off if it exceeds a set limit...
 

Irving

Joined Jan 30, 2016
1,845
Hello there! :) I'm a big fan of yours.
Thanks :oops: :)


I use TVS diodes in cheap electronic devices because there are plenty in my drawer fast and effective for short circuit protection in no way do I incorporate this method in my own designs.TVS diode will fail in one of three modes
These are shorts,opens, and degraded devices. In most applications,the preferred method
of failure is a short.
A short is defined when the TVS device has
a resistance value of less than 1Ω at a DC voltage of 0.1 V
(ref. ANSI/IEEE C62.35).
a short before the TVS with respect to the source voltage will start to conduct a significant amount of operating current to ground.
Sorry about the format stupid phone I'm using is messed up
But you still haven't explained how a TVS which is a voltage spike suppression device used in parallel with a circuit can protect against an increased flow of current in the event of a fault in the circuit being supplied. A TVS goes short circuit temporarily when the voltage across it exceeds it's breakdown voltage and thus prevents damage from excessive voltages. Maybe I'm missing something here but I've never seen a TVS used for short-circuit suppression.
 

Irving

Joined Jan 30, 2016
1,845
That still only deals with an over-voltage situation from the power source, it has no effect on anything that occurs within the load. Specifically, the load can still develop an over-current problem and the TVS will be completely unaware.

Additionally, with a resistor there this circuit is typically used to protect ESD sensitive inputs. Power circuits can't have a series resistor of any significance else too much energy is wasted in the resistor.
 

Irving

Joined Jan 30, 2016
1,845
I suspect your TVS is solving a different but nevertheless real issue. These cheap CN-manufactured toys are built down to a price which means nasty noisy motors that generate a lot of spiky back-emf, and cheap under-rated reverse protection diodes that eventually die, or none at all! Your TVS is probably dealing with some of that so prolonging the life of the toy...
 

Thread Starter

ideainnova

Joined Apr 19, 2013
5
I think I could not explain my trouble, and in fact it is a terminology issue that i am lost inside. I added block diagram of myIO box. No matter about what it does. In the last section, i have 12 output from any hbridge drivers. I have 12 x high side current sense kit. I will measure sense voltage by arduino through analog mux. I will compare this value with prememorised value if there is overcurrent state for that output, to disable system and give error mesage about that output. Highside is necessary due to hbridge connection. I will also continuously show voltage and current values on display. By this software polling, i can re-measure the same output 3 ms later, after all 12 finish. 3ms is not bad for motors, flament lamps or some devices. But solid states can blow in less than 100ns. Say it is a power amplifier with defective(short) transistor or the worst, shorted terminal, vfet rise time was 30ns at 1974. No fuse was valid ever for this. At home, commonly fuse blows after everything burns due to latency. I have nearly 1 fuse per outlet at home. So overcurrent protection is strategie against small deviations that are tolerable for wihstand time of devices that is under control within tolerable speed. This condition is almost static in a product. But connecting a tip120, 5mA 1.5V led and then 500mA motor to 12V, speed parameter gets out of control. And a current that is normal for motor is way more than short circuit for the led. Ok we already adjust overcurent but slow cpu is problem, simple dusty pot is another problem also is not informative about what is going on. I think i must use simple pot adjusted protection X 12 kits + opamp + latch, but also measure the output for educational aim with similar idea. Another huge layer in box just for protection.
1624586240349.png

Therefore I have asked if there is any ic. I dont understand where tech,ic tech is. Even ad712 itself has 3.5usec rise time to catch state, these are all toy comparing to old school 70s amplifiers. I found another device and some latching or current limiting examples.
https://cxem.net/arduino/files/arduino86_AN39.pdf

Rather than crazy toshiba, i must restart searching for an hbridge driver with adjustable reference and disable output also having its own sense. So it will need a pcb design to solder 12 of smd parts. Yet i will fall in to efficiency hell with hıge coolers again. If this lasts 6 months more, it will not be necessary because my son will already be doing things on his own. And this is why 300mA, 3ms latent, 100hz ultra slow silly relay replacer only siemens plc with just short protection still sells tons more. Marketing strategies, or i could not be siemens yet, or it has not been let possible. Should i buy one? dos pc is 420 khz x 12 lines through lpt, i am in less than 2ms by fast optos yet in 80khz. I need just a customisable short protection even to kill siemens more. Or maybe i should buy one siemens first..But they work only through its own cpu modules. What will happen in the end? He will work at siemens at germany and pay for city bla bla, selling his life for his hunger. I prefer moving to US for no dig till weed food forest garden, olive,milk, bread for hunger, free time to live and construct diy plc for garden jobs. The dos pc with C was plc cpu unit to load firmware directly from keyboard.

Do you think you used life happily and efficiently for yourself or earth used you efficiently Irving?
 

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Irving

Joined Jan 30, 2016
1,845
I'm sorry, I tried, but I'm struggling to follow this confusing mixture of random technical commentary and philosophical conjecture plus something related to your son growing up. And I've no idea what your last comment was about.

The TB6612FNG chip is quite good, though reading the data-sheet and looking at the Sparkfun board layout its maybe not as good as you think. I don't understand your fixation on short-circuit protection, which seems to be an artefact of your choice of H-bridge especially as the data-sheet makes it clear that this device doesn't have any integral protection and is intended for situations where that isn't necessary. And you bemoan that current monitoring ICs + MCU are too slow for S/C protection; well that's because that's not their purpose and trying that route is not an appropriate solution.

Maybe if you started at the beginning with a few short sentences giving a simple, purely technical, explanation of what you are trying to achieve and why you need 12 channels in a box it might be possible to advise more appropriately.
 
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