Ok, now this is becoming a bit confusing. Some sources are saying go with ground on pin 10 some say go with positive on pin 10. Newzed, people are saying that the darlington will sink the current from the device (motor) and will be enabled to sink when the corresponding BS2 pin is set to HIGH.
I have included an updated version of my schematics, I have tried this exactly setup with the power source wires reversed, still nothing, although, the motor will lock, not move but is being held in a position when the positive is connect to pin 10, absolutely nothing when the ground is connected to pin 10.
kb2hap, I don't understand your diagram very well. Why do you have the source power going to the BS2 as well?
I have wired up dozens and dozens of Darlingtons.· I will repeat this one more time.
Pin 9 of the Darlington goes to system ground.· This includes the Stamp ground AND the Darlington power supply ground.· Pin 10 of the 2803 goes to the positive side of whatever power supply the 2803 is controlling.· If I'm running 12 volts relays Pin 10 goes to 12 VDC.· If I'm using 5 volt relays Pin 10 goes to 5 VDC.
That's all.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔ Sid Weaver
Do you have a Stamp Tester?
So I have adjusted my schematics to comply with your advice. Assuming the stepper is connected in the correct pattern, is the rest of the wiring correct?
Also... Darlingtons 2803's·are good for 500mA, this stepper in paticular is slightly over that, however, my power source is rated at 340mA, which after some manual testing, is enough to power the motor. Is there any possibility that the power source went over 500mA and ruined my darlingtons and thats why I can't get this to work?
Thanks
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Johnny
Post Edited (Jonathan Allison) : 3/1/2005 4:53:28 PM GMT
The 2803 is ratedat 500ma max for single channel.· I take this to mean that if you are using more than one channel the total current thru the 2803 can not esceed 500ma.
I am not an authority on steppers but it appears that the rest of your schematic is OK, assuming you are only driving one winding at a time.
If you are concerned about whether the 2803 is good, replace your motor windings with a 12volt LED and see if the LEDs light up on command.· Remember - 12 volts to positive side of LED, negative side of LED to pin of 2803.· If you do not have 12 volt ·LEDs, temporarily switch to a 5 volt supply and 5 volt LEDs.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔ Sid Weaver
Do you have a Stamp Tester?
the common terminal on the 2803 (pin 10) is just for elimating counter emf in coils and preventing other negative supplies from damaging the ouput driver. i think the ckt will work with pin 10 disconnected all-together.
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League Bowling.... it's not a sport, it's a way of life
Take good look at the schematic of the 2803 in the data sheet.· The voltage on pin 10 provides reverse bias on the clamp diodes.· If disconnect it, you have no diode kickback protection.
I give up on getting the darlington array to work. I've tried everything, no go [noparse]:([/noparse] I'm sure if someone could physically look at it and see what I'm doing they could point out the problem but thats not the case.
I'd like to go with using a series of TIP120s, they are rated for a higher current anyway.
What other parts, resistors / capacitors / diodes will I need to connect those to my stepper?
Also, look at this schematic below, there is a .01uf cap between Pin9 and Pin10 of the darlington. Not sure whats up with that, I definitly didn't have that in place, could that be my prob?
In most cases I dont think you need the cap. It may be for power/noise filtration?
I have never used a cap when I used the 2803. I'm not sure why you had so much trouble with it Its probobly very simple but due to frustration it got the best of you.
Anyways on to what you really need to use the TIPs
I would put a 470ohm resistor on the base to keep the current on stamp pin resonable
then just wire power into the motor. your 4 leads off the motor...just hook each one up
to the collector of a TIP(4 TIPs total). the emitter of the TIP goes to ground.
Should work just fine.
Hi Jonathan,
I was having the exact same problem that you were having. No matter what I would do I couldn't get the darlington to work. I finally figured out what was going on. I think that your problem may be similar. Just for clarification pin 10 should be hooked to the positive of the power supply you are using to run your motor. Pin 9 was the problem for me. I tried grounding to the stamp power supply first. That didn't work. Then I tried grounding to just the motor power supply. Didn't work again. Finally after about 4 hours of utter disillution. I hooked pin 9 to both the stamp power supply and the motor power supply. Viola! It's working like a champ now. Newzed pointed this out in one of his posts but I didn't understand what "system ground" meant.
Comments
I have included an updated version of my schematics, I have tried this exactly setup with the power source wires reversed, still nothing, although, the motor will lock, not move but is being held in a position when the positive is connect to pin 10, absolutely nothing when the ground is connected to pin 10.
kb2hap, I don't understand your diagram very well. Why do you have the source power going to the BS2 as well?
Help!! [noparse]:)[/noparse]
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Johnny
Pin 9 of the Darlington goes to system ground.· This includes the Stamp ground AND the Darlington power supply ground.· Pin 10 of the 2803 goes to the positive side of whatever power supply the 2803 is controlling.· If I'm running 12 volts relays Pin 10 goes to 12 VDC.· If I'm using 5 volt relays Pin 10 goes to 5 VDC.
That's all.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Sid Weaver
Do you have a Stamp Tester?
http://hometown.aol.com/newzed/index.html
·
So I have adjusted my schematics to comply with your advice. Assuming the stepper is connected in the correct pattern, is the rest of the wiring correct?
Also... Darlingtons 2803's·are good for 500mA, this stepper in paticular is slightly over that, however, my power source is rated at 340mA, which after some manual testing, is enough to power the motor. Is there any possibility that the power source went over 500mA and ruined my darlingtons and thats why I can't get this to work?
Thanks
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Johnny
Post Edited (Jonathan Allison) : 3/1/2005 4:53:28 PM GMT
I am not an authority on steppers but it appears that the rest of your schematic is OK, assuming you are only driving one winding at a time.
If you are concerned about whether the 2803 is good, replace your motor windings with a 12volt LED and see if the LEDs light up on command.· Remember - 12 volts to positive side of LED, negative side of LED to pin of 2803.· If you do not have 12 volt ·LEDs, temporarily switch to a 5 volt supply and 5 volt LEDs.
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Sid Weaver
Do you have a Stamp Tester?
http://hometown.aol.com/newzed/index.html
·
pins 8 & 9 here are 9 & 10 on yours
the com pin on the 2803 goes to your voltage +12
(its a parallax pic not mine)
Newzed has you on the right track
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DTQ
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League Bowling.... it's not a sport, it's a way of life
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Sid Weaver
NEW! 4 MB EEPROM
http://hometown.aol.com/newzed/page4.html
·
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League Bowling.... it's not a sport, it's a way of life
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Sid Weaver
NEW! 4 MB EEPROM
http://hometown.aol.com/newzed/page4.html
·
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League Bowling.... it's not a sport, it's a way of life
I give up on getting the darlington array to work. I've tried everything, no go [noparse]:([/noparse] I'm sure if someone could physically look at it and see what I'm doing they could point out the problem but thats not the case.
I'd like to go with using a series of TIP120s, they are rated for a higher current anyway.
What other parts, resistors / capacitors / diodes will I need to connect those to my stepper?
Also, look at this schematic below, there is a .01uf cap between Pin9 and Pin10 of the darlington. Not sure whats up with that, I definitly didn't have that in place, could that be my prob?
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Johnny
I have never used a cap when I used the 2803. I'm not sure why you had so much trouble with it Its probobly very simple but due to frustration it got the best of you.
Anyways on to what you really need to use the TIPs
I would put a 470ohm resistor on the base to keep the current on stamp pin resonable
then just wire power into the motor. your 4 leads off the motor...just hook each one up
to the collector of a TIP(4 TIPs total). the emitter of the TIP goes to ground.
Should work just fine.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
DTQ
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League Bowling.... it's not a sport, it's a way of life
I was having the exact same problem that you were having. No matter what I would do I couldn't get the darlington to work. I finally figured out what was going on. I think that your problem may be similar. Just for clarification pin 10 should be hooked to the positive of the power supply you are using to run your motor. Pin 9 was the problem for me. I tried grounding to the stamp power supply first. That didn't work. Then I tried grounding to just the motor power supply. Didn't work again. Finally after about 4 hours of utter disillution. I hooked pin 9 to both the stamp power supply and the motor power supply. Viola! It's working like a champ now. Newzed pointed this out in one of his posts but I didn't understand what "system ground" meant.