# Basic TE & Sierra Sound System Installation



## BillBrakeman (Jan 3, 2008)

I have purchased a pre-owned Sierra C-16 Sound Board and would like to install it in a battery powered engine that I control with an Aristo Craft Basic TE. 

If I power the sound board with an auxiliary battery do I have to use a Gel Cell battery as specified in the directions or can I use either NiCad or Nimh batteries?

If I power the board with the main 14.4v drive battery do I have to put some type of device between the battery and the board to make the electronics work correctly?


Bill


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## Greg Elmassian (Jan 3, 2008)

Any chemistry batter will work, it's the voltage that is important. Meet the manufacturer's specs. 

You do not need the aux battery. 

14.4 volts is fine for the sierra. 

Regards, Greg


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## TonyWalsham (Jan 2, 2008)

Greg.
That does depend on how the 14.4 volts is connected.
My advice from Sierra was that whilst you can delete the normal 6 volt Gel Cell and power the Sierra with terminal Pins 4 (+) and 2 (-), the maximum voltage you can feed into pins 4 & 2 is 12 volts.
I make a small interface pcb # SSI-12v5 that has an opto coupler so that it converts the pwm signal to regular DC and supplies a regulated 12 volts to the Sierra sound pcb.

For the life of me I cannot figure out how to insert a pic that is stored at my own website.


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## Greg Elmassian (Jan 3, 2008)

Tony, max voltage on pin 4 is 12? 

Ahh, I checked some schematics, the Sierra uses the track inputs on 7 & 8 to determine "speed"... so you cannot power it from there.. I got it now... you HAVE to power it from the "backup battery" pins 4 & 2. 

I see the optocoupler schematic here.... cute.... the 2 couplers are used to read positive motor and negative motor voltages, and then feed them to the right and left track inputs... I did not see how the PWM got converted unless it's the "smoothing" from the motor load. 

Regards, Greg


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## TonyWalsham (Jan 2, 2008)

Hi Greg. 

Because of the common ground, if you don't use the Opto coupler the Sierra sees the PWM signal as full speed. 
That means, for steam engines you lose the forward and reverse toots when starting and the "at idle" effects such as the Fireman Fred and the stop toot. 
Dismals ramp up to full speed. Period. 

The opto allows the Sierra to "see" the PWM as DC at pins # 7 & # 8. 

You need 12 volts at Pin # 4 because if you don't you cannot get the diesel sound to fully ramp up to notch 8. 

This is the image I was trying to insert before.


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## BillBrakeman (Jan 3, 2008)

Greg & Tony, 

Thanks for your input. 

Bill


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## Dan Pierce (Jan 2, 2008)

For the battery, consider the Supercaps that have been used for both LGB and Phoenix sound systems. 
These to me are better long term solutions as batteries do deterioate over time and need constant refresh charging. 

On the other hand, supercaps can be discharged for a year and still work perfectly the next time they are used.


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## TonyWalsham (Jan 2, 2008)

Dan. 
If Bill uses the regulator and opto coupler he will not need any batteries at all.


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