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Digital conversion problem - niklasw - 14th-Jan-24

Hi
I bought a RevoSlot Alfa Romeo GTA. Trying to convert it to digital using a Scalextric c7005 module for single seaters.

Is using this module a mistake? The car runs and changing lanes fine, but only if I use minimal (5%?) throttle. As soon as I go beyond that in throttle the car stops and behaves as if it is dead. When I take it out of the slot and put it back it resets, but works the same again. 

Anyone who think they can help me with this?

Thanks in advance

[attachment=33451]

RE: Digital conversion problem - Drifter2 - 14th-Jan-24

Have you tried the c7005 in a different car to compare?

RE: Digital conversion problem - niklasw - 14th-Jan-24

I’ll do that to see if this one is faulty. I have used another c7005 successfully in a non-single seater previously.

RE: Digital conversion problem - ScorpiusWireless - 15th-Jan-24

Obvious question have you tried another controller? 
If so it’s probably a faulty chip but I’ve never seen this issue.

niklasw - niklasw - 15th-Jan-24

Thank you for the suggestions! I have tried both another engine and different controller. 

Both controller and chip works fine with another “smaller” SSD F1 engine. 

Which points to what another esteemed member of the forum hinted at, which is that the c7005 probably is not “rated” to run with an engine this powerful and therefore “shuts down” when being exposed to too much power.

RE: niklasw - ScorpiusWireless - 15th-Jan-24

(15th-Jan-24, 06:50 PM)niklasw Wrote:  Thank you for the suggestions! I have tried both another engine and different controller. 

Both controller and chip works fine with another “smaller” SSD F1 engine. 

Which points to what another esteemed member of the forum hinted at, which is that the c7005 probably is not “rated” to run with an engine this powerful and therefore “shuts down” when being exposed to too much power.
RevH is the latest and the one to choose. But 7005 should still turn the wheels but eventually it will blow anyway. 
The F1 motors actually do 22k and draws over 3A on start up hence the issue as the 7005 is 3A max from memory.
Glad you solved it

RE: Digital conversion problem - Drifter2 - 16th-Jan-24

@niklasw 
It seems like when the car is lifted from the track and put back on it is actually reseting the microcontroller in the c7005. It's possible the motor has a fault and is crashing the microcontroller with electrical noise. If this is the case then this motor will damage car decoders. 

A good test is to run just the motor on a bench power supply and measure how many amps it draws compared to another known good motor of it's type. Another test would be to run the motor in an analog car and see if it gets excessively hot with moderate speed. Also check the commutator for excessive wear if the motor has had a lot of use. 

If the motor checks out 'ok' ,  fitting a "ferrite man" to the motor may improve things.

RE: Digital conversion problem - niklasw - 16th-Jan-24

Thanks @drifter2!

The motor is completely new out of the box from RevoSLot so it hasn't seen a lot of use. But faulty parts from factory is not unheard of. I did run it as an analog for about 30min before starting to convert it and can't recall it becoming excessively hot. 

I'll make sure to do a bench test as you recommended to make sure. What amperage should I be expecting here? I can't find any data online on the RevoSlot motors but I do have a couple of similar motors I'll compare with.

Also as you can see in the original picture I only have one 'ferrite man' and for the next step I will make sure to add a 2nd one on the motor side.

RE: Digital conversion problem - Drifter2 - 17th-Jan-24

I just tested a couple of motors at 12v, I don't have any like yours but for general comparison here goes..
[attachment=33460] This one 0.350 amps at 12v free running on the bench

[attachment=33461] This one 0.250 amps at 12v free running on the bench

Another motor identical to the Red one in the first photo sparks when connected and pulls 2 amps then settles to 0.95 amps and smells like a something is getting hot. It's also noisy, like it needs oiling or something. This motor is "expired".

Getting back to the Revo, if it stops again I suggest pushing the car (without removing from the track) over a lane change and see if it triggers the lane changer. The lane changer flipper could be manually set to the middle position to see if the flipper moves either way when the car is pushed over the lane change IR sensor. This will indicate if the microcontroller in the c7005 is still working or glitched out.

Did you have the body on the car or off the car before when it stopped?

Furthermore my F1 SSD decoder has the same Mosfet motor transistor as the SSD DPR saloon decoder.

RE: Digital conversion problem - Kevan - 17th-Jan-24

(17th-Jan-24, 05:30 AM)Drifter2 Wrote:  Another motor identical to the Red one in the first photo sparks when connected and pulls 2 amps then settles to 0.95 amps and smells like a something is getting hot. It's also noisy, like it needs oiling or something. This motor is "expired".

Sounds like a burned comm/brushes, you can resurrect by cleaning with contact cleaner spray and carefully poking a wooden toothpick along the 3 slots to clean out the brush deposits but it's usually curtains once a motor has started letting the smoke genie out.