Ok, sow in fact the best thing what i can do perhaps is to just drop this chip and place a 9Amps in his position. And use an external bootstrap configuration???

Should i use 10R for all the gates or per gate???

If you think that with the 9amps driver i will get better results tell me, i have atleast two 9 amp driver (TI model)

problem i see is that in the datasheet they don't mention bootstrap configs??
could i blow out a pin??

Tks

 

Ok,

i'm gonna test the setup..

I have placed 6 resistor 1/4watts in parrallel of each 126ohms it gives us thus 21ohms...

to sink the maximum chip current 420ma i need 30ohms sow we are well unther it...

Hopes it will work..

Tks

 

The best thing to do is to finish building the circuit, then decide what you need to improve, and go on from there. There are literally a couple dozen different parts with different tradeoffs that you could use in this circuit. There may also be mosfets which are better suited for this application. The number of combinations is infinite...

I'd suggest that you build any circuit, test it (possibly to failure) and figure out what you need to improve, if anything at all. It's all about experience - build the circuit, learn something and go on further. You can spend an endless amount of time twiddling with the details, but the only thing that counts is whether the car moves or ends up in a big puff of blue smoke, and there's only one way of telling...

In any case, you should have one gate resistor per mosfet (total of 6 in your circuit). When the mosfet transitions between on-off, source of the mosfet is going to see a very rapid transition. This ends up capacitivly coupling into the gate (along with some other effects) and might cause some oscillations. The gate resistors keep these from interacting with the other mosfets. Personally I just like having a resistor between the gate and the driver chip so that it's easier to diagnose a blown mosfet.

All the 9amp TI mosfet drivers I see are low side drivers. Bootstrap stuff is only used on high-side drivers. Those chips won't work in this app.

James

 

The resistor value is fine - chip internally limits it's current and won't be damaged.

James

 

Ok, James, i now hat ite in parrallel if it isn't dangerous i let it be sow and test the setup...

first with a bulb just looking if it reaches full brightness then i will connect a motor up and start with low pwm and look what it does...

i only have 6ohms and 14ohms..

Tks

p.d. atleast i now have 6x 1/4 watts of resistor power sow in fact an 1,5Watt 21ohm resistor

 

Ok, i have hooked up everything cables where prepared terminals where put on. Have brought some 4mm dia cable..

Ok, first i connected it all up to the battery a small spark occured the 10.000uF cap charged.

Then i prepared the gearbox program to work with the reverse controller.
I made a small test program wich puts some pins high and wich outputs a PWM signal to the board.

First thing i noticed was that the relais didn't switch sow i guessed that the transistor was wrong, changed the transistor and it worked.

Sow at least when i select reverse the universal relais is activated, the fan will start blowing, the reverse light on the car will light up, the starter solenoid will be meshed up with the gear ring.

Anyway that point i reached... then i tested the mosfets...

i hooked up a bulb as load and applied with my multimeter in amp mode i made the connection between VDD (12volts) and the gate the bulb lighted up, the see the difference i touched also directly the bulb and offcourse it lit up a fairly bit more my amp meter showed 1,75amps... (21watts bulb)..

when i touched the gate it shows 0,08amps.. when i touch the gate before the resistors it shows 0,04 but the bulb lights up the same amount.

Sow i started to investigate where wy the chip didn't responded i touched the HIN pin with the 12volts but it did nothing to the bulb..

i checked the pwm signal with a led (keeped iluminating, while the multimeter said 0,01volts) sow i guessed it wasn't that.. comeing home i remembered a Enable pin, watching the datasheet this morning is saw a input SD pin.. INPUT shutdown pin.

If you read the description you would think if high then it shutsdown.. but when i look at the symbols i see it going to AND symbols and to SET symbols sow i guess i just have to wire a 2K Resistor to VDD to that pin not????

Tks

- Didn't tried yet this solution..

 

Ok, its not the SD pin because of the timing sheme explaning it all...

Think i have got the VCC pin connected to 0volts/ground.. and i think it needs to be to VDD Huge fault because i have no clue on how the cap should charge sow a bit of NEWBIE error, hope i didn't broke the chip..

We shall see..

Fase 2 is untherway

Tks

 

Well Fase 2 Succesfully ended!! BUT one small side is that the chip needs 8,5 / 9 volts minimum input voltage!! on the HIN pin!!! thought it was TLL compatible but it isn't sow! there is a solution needed to convert 5volts in 10 volts..

The good news is that when i manualy tick the HIN pin to VDD (12volts) the bulb iluminates!! on full brightness altough i have to say that it automaticly shutsdown but when i tick fast its clearly to see that it iluminates more then when only applying 12volts to the gates sow almost don would i say and then we can try the motor!!!

can i convert this with a NPN transistor?? or do i need a PNP one?? or just an opamp (more hassle??)

Tks

 

Well wich of the 2 cant choose wont make a huge different i guess

Don't want to use a opamp because i have limited room...

I made the 2nd one because i think i don't have a PNP in my toolbox sow basicly i just made 2 invert setups but feeded the resistors with 12volts..

TKs

Attached Images

TransistorSolution.JPG (17.5 KB, 23 views)

 

It *does* support different threshold voltages. Connect Vdd to the logic power supply(5V) and leave Vcc connected to 12V

 

Well to late , i already builded the 2nd sheme and it works... in fact i tested the unit today!!! this is the outcome:

Sow today i hooked up the 2 NPN to pull up the voltage and it worked!

First i connected a bulb(12v 21W) and i could make it glow in such way you you only see the filament being yellow it was working on 1,79Volts

Then offcourse i applied full PWM signal (255) wich means no dips (almost) anymore the light lit up as brightness as it could (checked it with an extra cable from positive to bulb but you coudn't notice it..

Then it was engine time, first i wanted to try with a small engine sow i grabbed my bike starter, i dismanteled it but then it looked like it wasn't a series wounded one sow i didn't like the idea of using it, i closed it up and grabbed the Car Starter..

connected it all up and putted the controller on... when i reached a PWM pulse of 40/50 it started turning but realy realy slow then i gave it some more and soon we where on full power then i turned down again the throttle and it slowed down again... it played abit with the throttle but it looked like the controller etc. worked fine...

BUT!!

When first tried the motor maked a high noise tone like many vorkHeftruck do (the bulky electric cars wich is used to move pallets arround) sow i turned the controller off, to upper a bit the freq i doubled it to 12000Hz we did another run
and again it maked noise but albeit allot higher and nicer... i checked the fets but they gave nothing couldn't notice any heat in them!!!

but then i wanted to do another run a slow run, sow i made a program wich runs from 50PWM to 255 and then shutsdown think it took 30secs..

but then nearly done there came a puff of smoke out the engine! i have dismanteld the motor but coudn't reach the brushes.

anyway thats it!

Facts:
- Controller survived the abuse of a starter motor without load
- controller survived the abuse of shortcircuit in the windings...??
- Motor coudn't survive the testing


The smoke is what me makes think that the windings overheated and are shorted on the other side i coudn't notice nothing on the case of the motor only the part where the brushes where was hot albeit not sow hot that i burned myself (it was the reason i keeped going).

What i did notice was that when on low PWM signal and the first test was at 6kHz that it looked like the brushes sparked, it was better on 12khz

the last longer run the motor was vibrating allot becauseof the fact that my test bence wasn't sow modern sow the motor was laying on the table...

The motor was brandly new (recon unit)

the case never was cant touch it that hot...

The fets never gave everything didn't try the controller after it with a bulb again (to see if was fault or whats sow ever)

Conclusion i guess that the best thing is to buy a normal BIG DC motor also series wounded and connect that shaft to the front piece of the donor shaft sow we can still use the solenoid and the bendix clutch!

my odd feeling says it are the brushes wich just burned or because of the sparking they don't touch enough the rotor anymore...

what also can be a possibility is just that some piece of isulating melted (the positive feed of the motor)...

Anyone ideas????

strange thing is that my motor has a bolt in the axle from his back, sow i have no clue on how to undo it because you barly can hold the shaft to undo the bolt.

Anyway the controller works!!!

i cant feed the chip with 5volts VDD because i don't use it on that board (anyway i could put 2 100R in series and feed that into it, maybe then it also accepts 5volts as high dunno..)

Tks

 

The controller died!

dunno what it could be yet

but have sawn a HO to Gate schema wich looks like the pic.

can someone explain wy it is this way?

L is the motor terminal.

D16 & C14 are the bootstrap.
Also i know the current limiting resistor 22R but wy that diode?
wy D11? Wy D1? wy C36?

its from a servo controller.

Tks

Attached Images

GateDriver.JPG (26.7 KB, 26 views)

 

Hello, I just found this great site. You guys are very good. I have knowledge
of electronics but not much into circuit building. I need some help to build a mosfet driver. Similar to TKA's circuit and actually his might work for me. I want to drive 10 mosfets at the same time for on/off function to replace a single pole switch. Looking for a single driver to drive them all together for simplicity. The mosfets will be kiiling the power to the balancing leads of a lithium battery pack. installed inside an enclosure. Having live wires hanging out is to dangerous.
Wanted to use the irfr2407 n channel rated at 75volt and 42amps.
http://pdf1.alldatasheet.com/datasheet- ... R2407.html

http://pdf1.alldatasheet.com/datashe...M/MAX1614.html

The question is how can this driver be wired to control 10 mosfets?

 

First, this is a very old thread. I suggest you start your own thread, as it may generate more interest.

Second, you need to provide a little more information about the motor you are trying to control. Is it series, shunt, or PM? What is its power or current rating. What voltage? Do you need soft-start, braking, etc.

Good luck. John

 

Thanks John, I will do that.