adapting a negative polarity controller for positive polarity track Options

[iti20090]

Whilst the nature of NPN circuits, wired remotely from the trigger stops, permits a transistor polarity change ala Difalco etc (as also with make and brake relays for potentiometer circuits), I am intuitively thrown on how one could achieve this for PWM circuits which incorporate braking adjustment as part of their circuit, without the aforementioned stops.

In a blonde moment I acquired the new Ninco Xlot Hall effect controller, incorrectly assuming in might be polarity switchable like one of their other less suitable for club racing Hall effect offerings.

I have little hope of being able to adapt this negative wired unit for our club positive wired club track but there is a small glimmer of hope, given that the other Ninco Hall effect controller is touted as mode switchable, suggesting some clever trickery within its circuit to achieve this.

Is there any way one could construct a home brew adapter to allow me to use this negative wired controller for our positive club track?

A circuit drawing would be first prize

Thanks and regards
Dave

[300SLR]

It depends on the PWM circuit.
If it was designed to work with either polarity there won't be a problem.
It is much more common to design them to work on one polarity. It could be possible to modify the circuit to work on either polarity, but it would need a good understanding of how that controller circuit works.
Just a few initial thoughts - The main drive transistors are usually MOSFETs, these only work one way round, so to reverse it I suppose n channel devices would need to be replaced by p channel etc. Then the voltage to the gate would need to be the right way round, so another voltage rail would be needed. Maybe the low current control circuitry could be common with a bridge rectifier in its supply so it was always working on the right polarity ...... ahhhh its getting complicated. I think I'd either go for rewiring the track to a common standard or two controllers or try and find one designed to work on both polarities.

[iti20090]

I concur with everything you say, especially the braking aspect - it just intrigues me as to what bit of PWM trickery Ninco used to achieve a dual polarity Analog "Vario 16 Dual" Electronic Hand plus electronic brake controller.

Ninco dual polarity electronic

How I translated above in to the Xlot was the silly bit on my part.....

Cheers
Dave

[Screwneck]

There's a former post on this topic if you do a searchword for it.

In the meantime, think about a controller extension cable with the wires fixed the other way around. I'm not sure if it will work, but it sounds possible and it will save a load of faffing around with squillions of alternatives and dozens of electrical components if you go another route.

Alernatively, the folks at this club you mention would have already done this work with theior own controllers so why not simply ask them to help you out? It would be an odd club if they refused to

[300SLR]

In the meantime, think about a controller extension cable with the wires fixed the other way around. I'm not sure if it will work

Unfortunately that doesn't work in most circumstances.

With some simpler electronic controllers, it will work if only conected to one side of the power supply (so the brakes are disconnected). That leaves no brakes, also the full power relay, fan and power on lights don't work (of course the last 3 aren't fitted to some controllers)

The more complex circuits (including all the PWM types I've seen circuit diagrams for) won't work without a connection to both sides of the power supply (the" brake connection"), so that controller extension idea won't work.

P.S. I've not seen the inner workings of a Ninco dual polarity electronic controller

[Chappy]

Hi Dave not sure this will be helpful at all as I assume you are talking electronic controllers vs resistance controllers.
Fly had produced some pro controllers which last year were selling out for 15 to 20 dollars each, 45 ohm etc.
These controllers had adjustable brakes via some sort of capacitor in the grip, and also a polarity switch at the bottom.
Running it normally the polarity switch in, the brakes worked great. With the polarity switch out there were no brakes.
Normally polarity dosent effect a resistor type controller so I'm not sure why Fly had this in there.
Bottom line is I have stripped one or 2 out of the controllers and if you would like to try and do something with one , I can send you the components.
Bob

[iti20090]

Thanks for kind offer, Bob, discussed on PM.

Cheers
Dave

Hi Dave not sure this will be helpful at all as I assume you are talking electronic controllers vs resistance controllers.
Fly had produced some pro controllers which last year were selling out for 15 to 20 dollars each, 45 ohm etc.
These controllers had adjustable brakes via some sort of capacitor in the grip, and also a polarity switch at the bottom.
Running it normally the polarity switch in, the brakes worked great. With the polarity switch out there were no brakes.
Normally polarity dosent effect a resistor type controller so I'm not sure why Fly had this in there.
Bottom line is I have stripped one or 2 out of the controllers and if you would like to try and do something with one , I can send you the components.
Bob

[RichD]

You can't switch the polarity of an electronic controller by switching the track connections around. The internal wiring of the controller has to be changed. I have a controller with a switch that does that and I also have a Difalco controller that has plugs that can be changed to reverse the polarity.

[Chappy]

Hi Dave I found this on the web and thought you might understand it or that it may be helpful to you.
Bob


[attachment=11098:JayGee_C...matics_2.pdf]

Hope the attachment worked, I'm pretty new at this stuff.

[Phil Kalbfell]

The BSCRA site has diagrams for both track polarities.