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Hi from Hitchin Hackspace, UK

PostPosted: 16 Sep 2021, 22:02
by nifty1a
Hi,
We have a couple of power wheelchair bases that were donated, which we hoped to use in a model Dalek we have.

The controller we have is a Dynamic DK-PMA01 Shark, but it seems the brakes on the chair it was on were 24V operated, but the brakes on the motors we have are 12V.
I believe that the controller can be reprogrammed to use a single 24V brake, and we can wire the 2 x 12V motors in series.
But to do this we need the Wizard software, with an OEM dongle, which is impossible for hobbyists (and Hackspaces) to get hold of.

Has anyone got a solution for reprogramming a Shark to be used on a different chair/platform.

Thanks
Paul

Re: Hi from Hitchin Hackspace, UK

PostPosted: 17 Sep 2021, 01:15
by Burgerman
Wire in series.

Re: Hi from Hitchin Hackspace, UK

PostPosted: 17 Sep 2021, 08:21
by LROBBINS
Don't know the Shark, but on the Dynamic DX when using 12V brakes they are, as Burgerman said, wired in series and then connected as though just one brake (take a look at the Dynamic installation manual to see where that should be connected). The motors themselves are, and remain, 24V. Do recall that these solenoid brakes are just parking, anti hill roll, brakes - the actual braking when moving is dynamic braking by the drive motors.

Re: Hi from Hitchin Hackspace, UK

PostPosted: 17 Sep 2021, 08:41
by Burgerman
On dynamic I dont think there is anyplace to change brake voltage from memory. So series is the only choice.

Re: Hi from Hitchin Hackspace, UK

PostPosted: 17 Sep 2021, 10:57
by LROBBINS
This is definitely the case on the DX - 24V only, so 2 brakes in series if 12V coils.

Re: Hi from Hitchin Hackspace, UK

PostPosted: 17 Sep 2021, 23:33
by nifty1a
We have wired in series, but it is giving a brake warning error for the other side as it is programmed to expect both brake outputs to be connected. From reading the manual there is a settings bit that needs to be changed, but that can only be done with OEM/factory level access in Wizard

Re: Hi from Hitchin Hackspace, UK

PostPosted: 18 Sep 2021, 09:04
by LROBBINS
The other thing you could do is connect a resistor across the unused brake connection. For example, a 200 ohm 5 Watt resistor will draw approx. 0.125 Amp (the real brake draws ca. 1 A), and that's certainly enough to fool the controller. You might also experiment with higher value, lower wattage, resistance, e.g. 600 ohm, 1 Watt - I'll bet it would work too.

Re: Hi from Hitchin Hackspace, UK

PostPosted: 18 Sep 2021, 11:16
by Burgerman
Do you want a programmer? Also easy.

Re: Hi from Hitchin Hackspace, UK

PostPosted: 18 Sep 2021, 19:30
by nifty1a
@Burgerman, Where can we get one from? Or get the details to build one? I'm sure there will be other parameters that won't be matched between the controller and the motors.

Re: Hi from Hitchin Hackspace, UK

PostPosted: 18 Sep 2021, 20:25
by Burgerman
see pm

Re: Hi from Hitchin Hackspace, UK

PostPosted: 07 Oct 2021, 20:32
by nifty1a
Thanks to @Burgerman and @WoodyGB, I have built the adaptor and we can talk to the Shark controller :dance
We have changed the brake setting to SINGLE so we no longer need a dummy brake resistor.

Thanks for all the help.

Paul