Digital Vs Analog Controller

[dw5555]

Those who know me know that I know just enough about electronics to make it not work it I go to messing with it. While reading in another section about upgrading the stock analog controllers, ohms are referenced as a term of sensitivity. Does anyone know what the factory ohms ratings are of the analog and digital controllers. Can I assume that's why the analog controllers are a Pos compared to the digital ones or is it something different?
Dave

[32lbking]

I'm not sure about the ohms, but the springs on the old stock Carrera ANALOG controllers wear out and the throttle gets real slow on the return stroke [which gets the POS designation from me]. The black ones seem to be the worst. The red electronic ones are a little better.
Maybe they need to be taken apart and cleaned?
I don't think I have noticed this on any of my stock Carrera DIGITAL controllers, wired or wireless.
Randy

[Eric P]

I can't answer your question directly, but I have opinions about controllers.
Carrera controllers will break, they typically cost $30-$60 . Why not update to DRS or Tru Speed slowly? My Tru Speed has variable sensitivity that covers the OHM response thing.

[Slotspeed]

Without going out to the garage and getting multimeter out, I am pretty sure they are 70 ohms. I read an instructional how-to modify the stock black controller for 35 ohms by putting the two elements in paralell. (they are wired in series, each with a wiper in stock configuration)

I actually like them. Why? Because they are more robust than the Scaley ones that I was used to as a kid. And they have a brake function. Which my Scaley ones did not have back in the day. One of my Carrera analog controllers got a bit scratchy on the wirewound resistor itstelf but a tiny bit of Inox made it work like new again. This may sound funny but I actually prefer the analog controller to the digital one. Even though I can't make sensitivity adjustments! One thing I do like about the digital one however is that they don't get hot.

Steve.

[indybob008]

The biggest upgrade is to ditch any Carrera controller for anything. Pistol grip controllers like PARMA are excellent as many others. 35ohm is best I think. Digital controllers are nice to but I always prefer just a good old 35ohm resistor controller.

[dw5555]

This wasn't meant to be a which controller is better posting. I was just curious what the ratings were because of the huge difference in feel between the analog/digital controllers.

[Slotspeed]

Hi Dave,

I went back to re-read the original question.

Believe the analog is the value I posted above.

Digital is 10k linear pot with a series 10k ohm fixed value resistor.

The idea of the extra 10k ohm resistor is a slight mystery. Without checking I am presuming its a 5v reference voltage so the extra fixed value resistor is just going to offset the physical position of the plunger in relation to the closed and fully open throttle positions. (edit: I would have thought it would have completely messed with the positioning of the ADC scale that is being digitised but maybe this is accounted for in the firmware programming)

I've actually modified the throttle response curve as mentioned on social media, With good results (better control and feel) with the standard Carrera decoder but unfortunately not so great with the self built decoders that I have (occasional run away issue) So I went back to standard linear curve.

Modifying the throttle response curve is very interesting to me and I am trying to figure out how to modify and re-compile the code for the self built decoders that I have built based on Frank Redlich's design. Having issues recompiling the code unfortunately. Probably a version control issue of the compiler and toolchain. Ultimate goal is to improve on the standard 4 bit throttle resolution. Have had a little bit of success but actually burned up a decoder earlier today with a mod that I had tried. But will press on.

Sorry to digress from the original question, its a habit of mine!

Steve.

[dw5555]

Thanks Steve, no wonder there is a huge difference in feel between the two.
Dave

[BRS Hobbies]

A Carrera digital controller can't really be compared to the ohm rating of the analog controller. All the Carrera Digital controller is designed to do is transmit the the throttle position to the control unit. The way it reads the throttle position is based on the resistance value. Each throttle step has a resistance range that determines what speed to be transferred to the car by the control unit.

With an analog controller, the track power is actually going thru the controller. The ohm rating of the controller is how much voltage is being restricted when you start pressing the controller. If you barely press the trigger and the car goes really fast, then you need a higher ohm controller. Likewise, if you have to press the trigger quite a bit to get the car to move, then you need a lower ohm controller. Basically, not one ohm controller works for all different cars. It's a compromise and if going that route, it's good to have a few different ohm controllers on hand or get an electronic controller that has adjustable sensitivity.

[Slotspeed]

Agree BRS Hobbies, but Dave's comparison made me think of something and I added an edit in my earlier comment above : (edit: I would have thought it would have completely messed with the positioning of the ADC scale that is being digitised but maybe this is accounted for in the firmware programming)

Obviously the scale is offset somehow because of the extra fixed value resistor in the controller. I would have to double check that it is a 5 volt reference scale on the ADC before I could say that for certain, will look at the schematics later. That fixed value resistor is going to have an effect in the feel of the digital controller.

But as you say, you can't really compare as they work on different principles.