| Author |
Message |
Craig colliass (Craig_colliass)
Member
Username: Craig_colliass
Post Number: 32
Registered: 3-2007
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| Posted on Tuesday, December 22, 2009 - 9:09 am: |
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Many thanks for all your help.
Craig |
georgeuk
Unregistered guest
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| Posted on Monday, January 11, 2010 - 6:37 pm: |
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Re the Sabertooth dual 5A motor controller.
In the PDF manual it states that you can feed the 5v back into the controller analogue input via a potentiometer to provide speed control to an attached motor.
Can you tell me a good value potentiometer (lin/log?) to provide a good range of speed control from very slow to ful speed please??
Thanks
george |
Admin (Admin)
Board Administrator
Username: Admin
Post Number: 1185
Registered: 10-2004
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| Posted on Saturday, January 16, 2010 - 10:45 am: |
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Dear George,
The most common value pot to use is 5k or 10k linear for the variable speed input to speed controllers.
Kind regards
Paul |
Ian Hopper (Ianhopper)
Member
Username: Ianhopper
Post Number: 7
Registered: 3-2007
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| Posted on Friday, January 29, 2010 - 12:56 pm: |
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Hi Paul,
I've just got around to working with a Sabertooth 2x50 controller I bought a couple of weeks ago.
I had hoped to use the 5v output to power my control equipment however with 20V applied to the battery connections (no motors connected yet) there is no voltage on the 5V output. The fan runs for about 0.5sec when the battery is connected then stops. I do get a single green status LED.
I can't see any reference in the manual to any enable/disable function for the 5V output. Should the 5V be there always? Is the fan operation continuous or temperature controlled for example?
The controller is straight out the box and had no motors or input equipment hooked up.
Ian |
Ian Hopper (Ianhopper)
Member
Username: Ianhopper
Post Number: 8
Registered: 3-2007
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| Posted on Friday, January 29, 2010 - 1:53 pm: |
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.....update to my last message.
Fixed - poor connection on the 0V screw terminal beside the 5V terminal, sorted after screwing down the connector a couple of times. I'm now reading 5V as expected!
Pardon the false alarm.
Ian |
Admin (Admin)
Board Administrator
Username: Admin
Post Number: 1190
Registered: 10-2004
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| Posted on Saturday, January 30, 2010 - 9:59 am: |
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Hi Ian, good to hear from you even though it was a false alarm. As this is a new controller to the market, it would be interesting to hear your feedback when you use it with your motors.
Regards
Paul |
Herman v/d Meijs (Herman02)
Member
Username: Herman02
Post Number: 10
Registered: 12-2008
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| Posted on Sunday, April 25, 2010 - 1:31 pm: |
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Hi Paul,
I've had some strange experiences with the Syren25 controller(s). I've three of them, all have the same behaviour. If I change the output fast to accelerate ( from 127 to 187 in 20ms) and drive more than appr. 50% (> 185 decimal) sometimes the controller output remains on, even if I set the input to zero (127dec). The only way to stop it is removing the power. I monitored the motor current when it happens, the initial current is appr. 18A peak. The motor I use is a MY1016 24V/250W.
I control the Syren in simplified serial mode, baud rate = 19200. The S1 input is connected to an optocoupler (to prevent ground currents flowing into the control unit). S1 is connected to the collector of the phototransistor in the optocoupler, 0V is connected to the emittor. Between the 5V and S1 there is a 2200 ohm pull-up resistor. When I drive the optocoupler the input S1 is almost 0V, if I don't drive the opto-led S1 = 5 Volt. On a scope, the input signal looks good.
I did some test with a small capacitor (1nF) between S1 and 0V but it did not solve the problem. It looks that it is a little bit better but it still happens.
I had a quick look at the layout of the Syren, I didn't find any filter components between the input and Atmel micro-controller.
Is the serial signal digitally filtered in the Atmel micro controller ?
Hope you have any ideas how to solve this problem ?
Regards,
Herman |
Herman v/d Meijs (Herman02)
Member
Username: Herman02
Post Number: 11
Registered: 12-2008
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| Posted on Tuesday, April 27, 2010 - 11:50 pm: |
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Additional I did some experiments:
If I set the drive instantly to more than 40% drive (both forward as reverse) the SyRen hold the output drive even if I set the control to zero drive !!!
It also hapens if the output is >40% driven and set instantly the SyRen to zero drive. The motor stops but the SyRen hangs, it don't respond to any command. Only removing power will reset the SyRen.
There is no problem if I set the output gradually. I checked the 5V and serial control signal: looking good, see no problem.
Please help
Regards, Herman |
Admin (Admin)
Board Administrator
Username: Admin
Post Number: 1242
Registered: 10-2004
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| Posted on Wednesday, April 28, 2010 - 9:40 pm: |
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Herman,
Sorry for the delay in replying, for this one I really need to talk to the designer and get back to you.
Regards
Paul |
Herman v/d Meijs (Herman02)
Member
Username: Herman02
Post Number: 12
Registered: 12-2008
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| Posted on Wednesday, April 28, 2010 - 11:35 pm: |
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Hi Paul,
I made some progress in analysing the problem:
With a good probe (100A,10MHz) I measured the inrush current in the motor leads at startup. When it is more than 35A peak (peak duration is miliseconds), the SyRen locks or hangs. Because the MY1016 motor has a low DC resistance (0.3-0.4 ohm), I added two 0.1 ohm resistors in series with the motor. It improves the situation, now I can instantly drive upto 65% (was 40%). So I think it has to do with the current I believe.
Remark: Today I also send a copy of the information to Dimension Engineering support because next weekend I will demo my application and hope that the problem is solved before that event. Normally you are replying instantly so I was afraid that you were not in the office this week.
Regards, Herman |
Admin (Admin)
Board Administrator
Username: Admin
Post Number: 1243
Registered: 10-2004
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| Posted on Friday, April 30, 2010 - 9:22 am: |
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Hi Herman,
I have sent all of your info which is very helpful by the way, to the design team at Dimension. We have other customers using the Syren25 with MY1016 motors with no reported problems. However, your rate of change is so quick that the controller is seeing stall currents. During these periods, what is the battery voltage doing? It may be that the battery voltage is dipping due to their internal resistance.
Regards
Paul |
Herman v/d Meijs (Herman02)
Member
Username: Herman02
Post Number: 13
Registered: 12-2008
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| Posted on Monday, May 3, 2010 - 11:24 pm: |
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Hi Paul
I've measured the motor-current (M1 terminal) together with the 24V and 5V. It's measured just beyond the level (35A) the SyRen locks or hangs as described. The 24V and 5V are measured on the terminals, probe zero/gnd is the B- terminal. See attached document.
As you can see is the current 34A peak, drops the 24V from 26V to 22V and is the 5V stable.
Hope this will help you.
Regards
Herman
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Admin (Admin)
Board Administrator
Username: Admin
Post Number: 1247
Registered: 10-2004
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| Posted on Wednesday, May 12, 2010 - 8:55 pm: |
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Hi Herman,
Just to keep you informed, I have had a confirmation back from Dimension that they are looking at the problem.
Regards, Paul |
Admin (Admin)
Board Administrator
Username: Admin
Post Number: 1260
Registered: 10-2004
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| Posted on Friday, September 3, 2010 - 3:39 pm: |
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Hello Paul,
Good news, Dimension Engineering send me a new version of the controller and this one runs ok upto 50A peak. I did not tested above 50A because I don't want to expose the controller beyond the maximum peak current.
I'm very happy that the problem is solved.
Regards,
Herman v/d Meijs |
SyRen25_report