Large Scale Central

Using Supercaps with a Sierra soundcard?

Electronics
#1

I have a NW2 with a Sierra sound board in it. I have been using a rechargeable 9volt battery to power it on my track powered RR but it does not always work. I thought about putting in a bank of super capacitors to give it constant power with no drops over sketchy track. I have a GP with a Phoenix that I bought used and it performs nicely. I don’t know what type of battery is in it but it recharges from the track.
I bought a super cap setup for the Sierra that is used by the Revolution system. Did I make a mistake here? The caps are rated for 25v 3300uF. The plug is the same on the super cap setup and fits the Sierra battery input plug but I think they are too powerful?

The bigger question is if not super caps then what type of battery for the Sierra board?
My understanding of electronics is amateur. I can install things but I can’t build boards and circuits etc…

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Any ideas? Thanks.

2022: The Year in Review
#2

Shouldn’t be a problem as long as you run at ~12 volt minimum. At lesser voltages, the board doesn’t put out enough to charge the caps.

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#3

Will these be ok at 25 volt or do I need to get smaller ones? I will give it a try.

#4

They are fed power from the Sierra board and it puts out ~7.5 volts.

#5

The NW2 is still torn apart. The supercaps are not working. The Sierra board comes to life over 12v and I have connected the caps to the battery terminal on the board. My meter tells me that 7.5 v is present at that terminal. I have run the engine on my test rollers for several minutes but once I drop the throttle below 12v the sound cuts out.
What am I doing wrong here?

#6

Does the meter say that you have 7.5 volts at the supercap terminals when the track voltage >12 volts?

#7

Thanks for getting back Todd.
I saw your post and went back to check. At 12v the unit is sputtering. At 13+ it is working. With the engine humming along at 14 volts I checked at the terminals that go into the caps and it was sketchy but each cap read 6.8v ?
This is weird. I also noticed that one of the little squares on the Sierra board is melted. That can’t be good.

#8

Nope, not good.

I’ve found that the caps work so long as the voltage stays above about 13+. When it starts dropping below (down around 12), the cap probably goes into a continual discharge/recharge and the board gets very hot and can and will burn out parts.

I’ve got one dieing such as yours is and I can see the parts smoke when I power up. I believe these are either the regulator chip, or onboard capacitors.

One of the guys, maybe on MyLargeScale, put together a circuit that I designed that let the Sierra run down to less than ~5 volts and has not smoked anything. It uses a boost circuit too raise the voltage, then a buck circuit to reduce it to the proper level.

#9

UGH… So this board is on its way to becoming junk?

I thought the supercaps were an alternative to the older style batteries but it seems not.
I was hoping that by using them I would be able to keep the sound going over spotty track and at lower speeds and while switching cars.

Where can I get a battery that will allow this?

#10

Good question.

My circuit, but he used separate buck and boost modules.

#11

When I looked at your board, I noticed that there appeard to be an additional part. Looking at it, I figured that they had added an in-rush suppressor/current limiter to take care of this potential problem. I guess not.