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Advanced Notification of Interruption to Shipping

We are now expecting to move to our new premises in Rugby during the last week in November. During the move, we will not be shipping any orders out for the period Tuesday 25th November to Tuesday 2nd December. Last shipping day will be Monday 24th November and re-commence Wednesday 3rd December. Orders placed after 12 noon GMT on the 24th will be processed from the 3rd December

Machining Services

Whilst our machine shop is re-located, we are unable to carry out machining modifications on gears, sprockets, pulleys etc. Any order placed which includes machining options is unlikely to be processed until mid December.


Archive through December 22, 2009

Technobots FAQ » Motor Speed Controllers & General Electrical » Speed Controllers » Technical Support for Specific Speed Controllers » Dimension Engineering Controller Support » Archive through December 22, 2009 « Previous Next »

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Admin (Admin)
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Username: Admin

Post Number: 1119
Registered: 10-2004
Posted on Monday, September 14, 2009 - 9:00 pm:    Edit Post    Move Post (Moderator/Admin Only)

Herman,

It is never a good practice to suddenly remove power to a speed controller for the very reason you state. You really need to have a limit switch before a mechanical end stop to allow time before stalling the motor. What operating mode are you using i.e. signal input type?
Herman v/d Meijs (Herman02)
Member
Username: Herman02

Post Number: 5
Registered: 12-2008
Posted on Monday, September 14, 2009 - 10:09 pm:    Edit Post    Move Post (Moderator/Admin Only)

The limit switch acts before the mechanical end- stop, so stalling will not occur. The operating mode is simplified serial. When running at normal conditions the current never exceeds 15A. The 24V power source is a lead acid battery. There is a 25A fuse between the battery and the controller to protect the battery and wiring in case of short circuit.

Regards, Herman
Admin (Admin)
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Username: Admin

Post Number: 1120
Registered: 10-2004
Posted on Tuesday, September 15, 2009 - 7:03 am:    Edit Post    Move Post (Moderator/Admin Only)

Packetized serial mode uses S2 as an emergency stop but thatoption does not appear to be available in simplified serial mode.

How do you generate the serial data? If you are using a programmable controller, could you wire the limit switches to the controller that would then force the value to 127 if they were to operate?

Regards

Paul
Herman v/d Meijs (Herman02)
Member
Username: Herman02

Post Number: 6
Registered: 12-2008
Posted on Tuesday, September 15, 2009 - 10:46 pm:    Edit Post    Move Post (Moderator/Admin Only)

Paul,

I appreciate your ideas but I need an overall emergency stop, also if the controller or the Syren 25 breaks down.

I had the oppertunity to met a specialist today and he offered me a possible solution. He assumed the Syren 25 is H bridge controller with 2 lo-side and 2 hi-side mosfets (with diodes) driven by a microcontroller.

"Wire the relay contacts in series with the power leads to the Syren 25 and add a big capacitor and a diode (K to +, A to -) across the battery terminals of the Syren 25. When the relay contacts open, the capacitor discharge and the (motor) current slowly decreases. No excessive voltage is generated which can harm the controller. There is a little chance the capacitor voltage will reverse, the diode protects for that."

The technician adviced to put a resistor across the relay contacts to charge the big capacitor before the contacts are closed. Without charge closing will damage the relay contacts.

Do you think this will work ?

Regards, Herman
Admin (Admin)
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Username: Admin

Post Number: 1121
Registered: 10-2004
Posted on Wednesday, September 16, 2009 - 8:15 pm:    Edit Post    Move Post (Moderator/Admin Only)

Herman,

Clearly an emergency stop acting via the software is not a true emergency stop but more of a 'soft' stop.

A method I use in remote control electric vehicles with a remote kill / failsafe is to set teh drive to neutral and then 2 seconds later kill the power using a relay contact in the positive supply line. The motor controllers has plenty of internal capacitors across the supply line (essential for dc motor speed controllers) but it is still possible to pop them if the above precautions are not taken.

Yes, there are 2 lo and 2 hi-side MOSFETS as is the case in most full H-Bridge solid state speed controllers. As to whether it will work, firstly it will not do any harm to the speed controller and the idea of a resistor is valid one although I feel you will need an on/off switch between the speed controller and the relay contact. As to whether this solution will work depends on the regen time and the capacitor value.

Regards

Paul
Craig colliass (Craig_colliass)
Member
Username: Craig_colliass

Post Number: 22
Registered: 3-2007
Posted on Saturday, October 10, 2009 - 4:16 pm:    Edit Post    Move Post (Moderator/Admin Only)

I have a sabertooth 25a speed controller i think it is bust! it is fitted in my walker and has worked ok at the Portsmouth show last week, this afternoon i tried it and it won't go i have looked at the LEDs and the fault led flashes when i try to move the walker the motors try to turn but hav no power were do i send it for repair it is less than 12 months old
Admin (Admin)
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Username: Admin

Post Number: 1129
Registered: 10-2004
Posted on Sunday, October 11, 2009 - 8:49 pm:    Edit Post    Move Post (Moderator/Admin Only)

Hello Craig,

Please return it to Technobots with a brief note of your application including motor data as well as the invoice number which can be found on your Email order confirmation or on the paper receipt sent with your order. We will then test the controller to confirm it is faulty. If faulty, we will assess your application to see if this controller is suitable or not.
Herman v/d Meijs (Herman02)
Member
Username: Herman02

Post Number: 7
Registered: 12-2008
Posted on Tuesday, November 3, 2009 - 11:20 pm:    Edit Post    Move Post (Moderator/Admin Only)

Hello Paul,

I have three Syren 25 in use. I mounted them directly to a metal frame such as described in the user manual. I noticed that one of the controllers has a leakage to the metal frame. I removed the controller from the frame and measured with a multimeter the resistance between the terminals and the heatsink. There is almost zero ohm between the B- terminal and the heatsink. The other two controllers have an infinite resistance between any terminal and the heatsink.

If I put a little pressure on the heatsink, the resistance will change. It seems to me that there is a contact between the PCB and heatsink.

Is this normal? Can it cause failures or damage the controller ?

The controller (not mounted on a frame) with a little motor and analog input is running ok.

regards
Herman
Admin (Admin)
Board Administrator
Username: Admin

Post Number: 1140
Registered: 10-2004
Posted on Wednesday, November 4, 2009 - 8:37 am:    Edit Post    Move Post (Moderator/Admin Only)

Hello Herman,

I have passed on your query to Dimension but it certainly does not sound right.

Regards

Paul
Craig colliass (Craig_colliass)
Member
Username: Craig_colliass

Post Number: 25
Registered: 3-2007
Posted on Wednesday, November 11, 2009 - 6:54 pm:    Edit Post    Move Post (Moderator/Admin Only)

Hi

Any joy on my speedo
thanks
Craig
Admin (Admin)
Board Administrator
Username: Admin

Post Number: 1149
Registered: 10-2004
Posted on Wednesday, November 11, 2009 - 9:16 pm:    Edit Post    Move Post (Moderator/Admin Only)

We have returned it to the States, we are hoping they will carry out a repair under warranty even though it has been previously repaired by yourself. We would normally replace a unit ourselves under our own warranty but your repair technically negates that warranty. We will advise as soon as we hear back, I will say that Dimension Engineering have an exellent track record for customer service so I am hopeful of a positive response from them.
Craig colliass (Craig_colliass)
Member
Username: Craig_colliass

Post Number: 27
Registered: 3-2007
Posted on Thursday, November 12, 2009 - 8:50 pm:    Edit Post    Move Post (Moderator/Admin Only)

many thanks

Craig
Admin (Admin)
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Username: Admin

Post Number: 1157
Registered: 10-2004
Posted on Saturday, November 21, 2009 - 1:04 pm:    Edit Post    Move Post (Moderator/Admin Only)

Craig,

Just awaiting a report from Dimension, will be in touch soon. There is also a new 2x50A controller coming out soon from Dimension Engineering, we have a unit on the way for evaluation but looking at the specs, it's looks very promising for the larger motors.
Herman v/d Meijs (Herman02)
Member
Username: Herman02

Post Number: 8
Registered: 12-2008
Posted on Saturday, November 28, 2009 - 8:22 pm:    Edit Post    Move Post (Moderator/Admin Only)

Paul, any news from Dimension about the leakage problem ?

Herman
Admin (Admin)
Board Administrator
Username: Admin

Post Number: 1169
Registered: 10-2004
Posted on Sunday, November 29, 2009 - 11:23 am:    Edit Post    Move Post (Moderator/Admin Only)

Hi Herman,

My apologies we did but I failed to post here.

The reply we reived was:

"Well, if the driver's running fine aside from that...

If he's got a metal frame he'll want to electrically isolate the heatsink from the frame. Something like Kapton - thermally conductive but electrically insulating - would be ideal. With that in place, it shouldn't cause any problems for the driver at all."

It is a manufacturing fault so with that in mind, if you wish to return the controller to us, we will arrange for it to be put right.

Kind regards, Paul
Herman v/d Meijs (Herman02)
Member
Username: Herman02

Post Number: 9
Registered: 12-2008
Posted on Sunday, November 29, 2009 - 11:09 pm:    Edit Post    Move Post (Moderator/Admin Only)

Hello Paul,

I isolated the additional heatsink from the metal frame, so there could be no leakage to other drivers, supply or motor. I did some initial tests and all seems to be working fine. In the comming month's the system will operate at full load conditions, if everything is normal I don't replace that driver.

If there is strange behaviour, I will contact you for returning the controller.

Regards,
Herman
Admin (Admin)
Board Administrator
Username: Admin

Post Number: 1170
Registered: 10-2004
Posted on Tuesday, December 1, 2009 - 7:04 pm:    Edit Post    Move Post (Moderator/Admin Only)

Herman,

As long as you have over some the problem, then that's fine but do not hestitate to contact us in the future.

Regards, Paul
Admin (Admin)
Board Administrator
Username: Admin

Post Number: 1177
Registered: 10-2004
Posted on Thursday, December 10, 2009 - 8:53 pm:    Edit Post    Move Post (Moderator/Admin Only)

Craig, we have not received a report of the cause of failure but a replacement is being sent out anyway with our next shipment so we will be supplying you with a replacement.
Craig colliass (Craig_colliass)
Member
Username: Craig_colliass

Post Number: 30
Registered: 3-2007
Posted on Saturday, December 12, 2009 - 8:43 am:    Edit Post    Move Post (Moderator/Admin Only)

That,s great many thanks

Craig
Admin (Admin)
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Username: Admin

Post Number: 1179
Registered: 10-2004
Posted on Tuesday, December 22, 2009 - 7:34 am:    Edit Post    Move Post (Moderator/Admin Only)

Criag, after a delay in customs, your replacement has been sent.

 

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