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I dont think there is a straw there? The ferrite & capacitior on the motor are to prevent unwanted motor generated noise getting to the in car electronics. So as we are talking analog cars, without an in car chip I do not think it will offer any help.

Slightly perversely however the only way I can get this pulsing problem is with an NSR with a digital chip fitted running in analog mode.
I cannot get the problem with any of my pure analog NSR cars.

I think the clue to this problem is that it can be fixed by putting a second car on the track, even as I remeber another car which itself pulses? This indicates that there is some sort of resonance condition being setup, and putting the other car on the track then removes / damps that resonance. The resonance is presumably a function of motor speed & PWM frequency?

Further random thoughts:-

I do not think we have this problem with PB-Pro in analog mode?

I do not know off the top of my head what the PWM frequency for PB-Pro & C7042 are?

Does the problem exist whatever the track length /all the way round the track. Can it be seen with a car wheels in the air on just a Powerbase?

Is it possible to damp this condition with some components fitted either in the car or on the rails?

Rich
 

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If you take the bottom off the Powerbase there should already be a capacitor (103) across each of the tracks? Are they there?

Worth just trying a couple of experiments first.


Does to 104 cap (10 x the size of a 103) work anywhere on the track?

Can you try putting it across the braids of the car & see if that works?

Does a 103 cap work or does it need the 104?

There is a limit to the size of cap you use. It supresses interference, however at some point it degrades the digital signal.

You mention low rev pulsing, have you got pulsing at other revs?

In terms of where you put it, I would solder it across the rails of any convenient track piece in case it needs to come off again.


Rich
 

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Hi Chris

The Powerbase caps I am refering to are on the track piece, not in the Powerbase itself.

So we still have a top end pulsing problem?

Rich
 

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If the caps are there and soldered in they will be fine, cannot be checked with a multimeter. They are usually 103, so I guess it just needs a bit more cap to get rid of the low end pulsing?

Rich
 

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Most any cap will be fine for this purpose, dont go less than 25 Volts, the ebay one looks fine. M will be the tolerance, (20%) again not critical here. Only thing not to do in digital is to end up with too many of them in parallel as they add up and will eventually degrade the signal.

Rich
 
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