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Old 14-10-2017, 11:43 PM   #1
Pjlons83
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Default Voltage range

Hello,

Thereís lots of opinions on the net about what voltage N gaugee should be run at with 12v max being a common answer. Has anybody measured what voltage they have when the speed controller is at minimum? Does it go down to zero or enough to run very slowly. After doing some testing today, I couldnít get the engine moving below around 4 volts so Iím wondering if the voltage range should be more like 4-12 volts?

Keen to know the output range of ďoff the shelfĒ controllers.

Thanks
Paul
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Old 14-10-2017, 11:49 PM   #2
brian1951
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What make of controller are you using Paul, also remember the locos you have are tight yet until they have done some running.
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Old 15-10-2017, 08:47 AM   #3
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Hi Brian. Iím using my own controller powered using an Arduino UNO board. Itís only delivering 5v for now. The next step is to modify the power circuit to up it to 12v. The diesel ran well for a good while, albeit quite slowly as per your advice on running in.

As Iím programming the controller myself I can choose the range that the pot delivers.

Paul
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Old 15-10-2017, 12:46 PM   #4
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Thats all well beyond me, us old ones use 12 v controllers, using a 5v max is not going to do the locos justice IMHO.
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Old 16-10-2017, 01:30 PM   #5
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Quote:
Originally Posted by Pjlons83 View Post
Hi Brian. Iím using my own controller powered using an Arduino UNO board.
What kind of output stage are you using - Analogue DC via a DAC, or PWM?
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Old 16-10-2017, 01:35 PM   #6
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Brian when did model railways get so complicated?
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Old 16-10-2017, 02:10 PM   #7
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WTD, it is only as complicate as the wobbly heads wish to make it. However some members obviously enjoy the challenge of building electronic systems and they no doubt contribute to the hobby.
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Old 16-10-2017, 02:45 PM   #8
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Quote:
Originally Posted by Gordon H View Post
What kind of output stage are you using - Analogue DC via a DAC, or PWM?
Hi Gordon,

The track is connected to a transistor, which is switched via an output pin.
I have a pot across +/- varying the output voltage from 0-12v.
The potentiometer provides an analogue input to the UNO.

Pretty much as per the image attached. I believe this is a form of PWM? Not sure on the correct terminology.

Thanks
Paul
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Old 16-10-2017, 03:36 PM   #9
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I used to build ampifiers and other electronic gadgets Jim.
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Old 16-10-2017, 03:37 PM   #10
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It will be fairly easy to step the output up to 12V max, either another drive chip or MOSFET should do it, depending on what the end result you are going for it would be worth doing a stall test on the loco motor at full voltage to see what the maximum current draw is going to be, to build the circuit capable of that as a rough maximum.

PWM, is pulse width modulation, basically the output is always at the maximum voltage but it switches on and off, with the duty cycle changing (time spent on/off) to achieve speed control. it is a better and more effective way of changing the speed than simply applying a varied voltage

what option are you using for reversing the loco?
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