Can you test driver chips outside of electronics?

Think i may have a problem with either some of my driver chips or maybe the electronics.

5V voltage regulator is getting very very hot and soemtimes various stepper drivers are getting hot.

is there a test to test them outside of the electronics?

You can put on the drivers some fan cooler, this should help for this hot driver/s.

Best Regards,
Rafal

Edited 1 time(s). Last edit at 08/27/2012 08:05AM by RAF.

---

www.gadgets3d.com - parts for your 3D printer
GADGETS3D on eBay - parts for your 3D printer

yeah they not getting hot in use each driver has a different problem. I think it may be a problem with the electronics this is why i wanted to know if i can test the drivers outside of the electronics to rule them out.

1 driver does nothing 1 driver just gets hot within seconds along with the 5VR and then another just attempts to move but does nothing.

altering the pots does nothing.

while im here whats the default KOhm reading for the pots? and ill set them all at default

If you're using those little pololu carrier board based drivers, yes, they can be moved to a breadboard for testing, as long as you have appropriate support materials (jumpers, caps, a few resistors, 3.3V-5.5V and 8-35V power supplies for the electronic and motor drivers respectively), a bit of know-how, and instruments (multimeter, and possibly oscope)

refer to http://www.pololu.com/catalog/product/1201 or the associated documentation for the newer 4988 for info on hookup and operation.

It looks like you could just wire them for static operation in a fixed direction, with fixed stepping to run a motor, using only jumpers, a few resistors, and the power supplies. Then you'll need to step the input. Unfortunately, I don't have a working pololu board or I'd hook it up to sketch out a basic test. No clue as to the default trimmer-pot setting either. Perhaps direct correspondence with Pololu might be in order there.

good luck

Edited 1 time(s). Last edit at 08/27/2012 12:29PM by xiando.

looks like 3 of my drivers have died

attached are Arudino sketch and wiring diagram PDF (testing diagram is last page)

you can hook it up and test the driver with a motor to see if it works.

note i didnt use the capacitors to test

Are you sure you're generating the step pulse? If you have problems upstream (at the output of the arduino) your drivers would appear unhealthy even if they were fine, since they'd never see step pulses and so the motors wouldn't move

Make sure by using a scope or even simpler, by driving an LED (w appropriate limit resistor) with the line used to pulse the motor, in order to verify the presence of a step.

If you already knew that, forgive me for saying so...and for this... Also, in the future, try to make sure to use the decoupling caps if you can.

Bummer if they're blown. Which chip are you using? the 4983 or the 4988? I suppose the silver lining, if there is one, is that if you were using the 93, then at least the replacement is a bit more robust, since it has over-current protection, which afaik the original does not. Easy for me to say, since I don't have to cough up the $36 (US) to replace them...

Edited 1 time(s). Last edit at 08/27/2012 02:22PM by xiando.

which board are you using?

using the Pololu - A4983 chips

my fault i was messin with a pot earlier while half asleep as i was having stuttering problems on Z also had extruder problems with skipping etc so was going to check the pots out. then all of a sudden nothing

using the setup from the pololu site and the arduino sketch on an arduino 1 chip spins the motor all other 2 are just dead to the world nothing at all and the other just heats up a lot in seconds .

ill test them again before i bin them might make up a test arduino sheild so its easier to test them in the future

i mean as in what are they plugged into ? a sanguinololu type board or a bread board,

i've had problems with these drivers to, i gave up and put in some industrial ones, haven't had a problem since

@Jolly, wit all due respect, reliable industrial stepper controllers don't usually cost $10-12 each.

The replacements Enlightx will being getting (I hope) have onboard over-current protection, unlike the original 4983s, which assumed a certain degree of recognition and secondary design efforts by engineers that many less stringent users might discount or simply not realize they need.

@Enlightx, sorry to hear that. fortunately they're not terribly expensive, but still. Do make sure to avoid getting direct replacements and use the upgraded part instead. the 4988 instructions also outline setting the overcurrent protection, so make sure to read the docs.

iya guys

yes i had them in a breadboard connected up to a normal arduino running the code form that sketch file.

also have got the latest model with the protection circuits in (old ones are now not made anymore).

thanks guys

Linear VReg's get hot for 2 Reasons:

1. Too much current
2. Too much voltage drop.

What voltage are you operating the steppers at?

Also hot is a relative term, electronics can quite happily run at temperatures that are uncomfortable for a person to touch.

Quote

1. Too much current

True. As the ATmega and the Pololu chips require some 50 mA together, only, it looks like there's something different going on. Like the 5V from the voltage regulator competing with the 5V from USB or the 5V coming from an ATX power supply.

But we still have to know which electronics Enlightx is trying to run to give useful hints.

---

Generation 7 Electronics	Teacup Firmware	RepRap DIY

remember im testing these chips on a breadboard using an arduino uno and just switching off and changing the chip over to the next to test.

to me that says its the chips if 1 spins the motor and 2 are dead and 1 gets super hot?