Large Scale Central

Sierra sound card and batteries

I have just fitted a used Sierra sound card to my LGB Mogul, the original battery was flat but won’t charge up, I can only get a couple of volts into it. I found I had to have the battery in there for the card to work so I hooked up 4 rechargeable NiMh AA’s, the sound card worked and programmed up nicely but with extended running to get the chuff right I noticed the card in the area of the program buttons was almost too hot to touch. I had read that running anything other than the standard GelCel was a no no because of charging rates thru the sound card won’t suit NiMh’s, so in case this is the issue I have put a diode into the battery lead so the card gets the volts but theoricately the card won’t/can’t try to charge the NiMh, everything appears to be working ok like this and the card isn’t getting hot.
My big question is that as I am running battery power anyway can I run the supply voltage for the card from the main drive battery thru a 5V voltage regulator and do away with a seperate card supply battery?
The Sierra works well but I will definately put some magnets and a switch for the chuff synchronisation, that will be match better than using the automatic chuff, having a chuff that works well on the flat but chuffs madly before it moves if I start on a grade isn’t very prototyical.

Wayne.
You can remove the battery and use terminals 2 & 4 to power the Sierra.
5 volts is marginal. The Sierra can tolerate up to 12 volts, so a 12 volt regulator will be OK. Put a small (.01 mfd mono) cap on the output of the regulator.

Thanks Tony, that will help immensly

Just remember that if you are powering the Sierra by the traction batteries and connecting the output of an ESC that is PWM AND triggering the sound with ESC triggers, you will need an opto set up so the Sierra can go back to idle when the loco has stopped.
If you don’t, the dynamo will be on permanently and there will be no fireman Fred.

Pardon my ignorance Tony, but what do you mean by an ‘opto set up’, ultimately the Mogul will be controlled with Aristo Revo R/C, the only function I intend to use is the whistle with some of the Sierra functions programmed.
At present the Mogul it is controlled by a Greg Hunter design R/C and NiMh battery mounted in a trail car, everything works well, the Revo and LiPo battery will be fitted in the tender eventually, all these projects take time.

With the Revolution, in addition to the opto-isolator circuit Tony describes (I’ll leave it to him to explain what it does), you’ll need a few extra components (resistors and diodes) to get the Revolution/Sierra connection to behave properly. At issue is the fact that the Revolution doesn’t drop completely to zero volts when stopped, so the Sierra never knows the locomotive has come to a complete stop. The trick is to drop the voltage to zero on the motor voltage inputs to the Sierra so that it “gets it.” Here’s a diagram of what I did on mine…

(http://1stclass.mylargescale.com/eastbroadtop/projects/SierraCircuit.jpg)

If you’re using Tony’s opto-isolator circuit, then one diode should prove sufficient. If you’re using Aristo’s opto-isolator board (about four times as large), then you’ll need a few more diodes in series. Also, you may have to change the value of the resistors. Shown are 100-ohm resistors, but I had to use 1000-ohm resistors on some installations. I haven’t the foggiest as to why. Later, K

My Mogul is all wired for sound, I have:-
Fitted the Revo RX.
Fitted a voltage regulator to supply Sierra power from the main battery (18v) as per Tony’s suggestion.
Fitted magnets/reed switch for the chuff.
Wired the whistle to the Revo RX (button 2).
And:-
Fireman Fred works without any other electrics.
The Hiss works whenever I change direction but not when I stop.
No other functions are or will be connected.
But:-Since I have fitted the chuff magnets (or about the same time) the sound keeps cutting out after a couple of minutes, if I turn power off then on or flick the remote volume switch either way or stop the train and hit reverse then forward the sound starts up again immediately, for another couple of minutes.
I had the Sierra card exposed last night when I went back to the start and reset everything and I noticed that the 2 LED’s flashed madly for a time when the battery was turned on, they both went out shortly, the sound started up immediately though.
Anybody got any ideas? The only coincidence I note is that if I was using auto chuff (which is turned off) the circuit will stay active for 2 minutes while you play with the chuff rate, which is about how long my sound lasts before it shuts down???

Wayne

Are you feeding motor voltage to terminals 7 and 8 on the Sierra? If not, that’s your issue. The Sierra will time out after 2 minutes if it doesn’t detect voltage going to the motor. With nothing connected to pins 7 and 8, it thinks there’s no voltage going to the motor (the loco is idle) and will shut down. If you don’t have the Sierra interface board (either from Tony or from Aristo), you can just wire the output of the Revolution to those pins but you won’t get Fireman Fred or any idle sounds, nor will you get directional whistles if you have that option set up. If you want the directional whistles, idle sounds, and the board to stay powered up for more than 2 minutes, you’ve got to use one of the interface boards and the wiring diagram posted above to drop the “zero” voltage (which really isn’t zero) from the Revolution to a “zero” that the Sierra recognizes as being zero.

Later,

K

Yes I am feeding motor voltage to pins 7 & 8, I have been on the Aristocraft forums and have wired mine exactly the same as the wiring diagram posted by Stan Cedarleaf apart from a 12v voltage regulator for sound board supply instead of the battery.
I just went out and checked and as a matter of curiosity reversed the 2 wires to 7 and 8 in case it may have mattered (although I couldn’t see that it would but I am getting desperate), it didn’t, it still cut out after a couple of minutes, I must add that I haven’t timed that but that is about how long it takes.
My next option may be to go back to battery supply and use a 6 volt battery and see what happens - sorry Tony, but I am desperate.

If you have a regulator powering the Sierra at terminals 4 & 2 instead of the Sierra battery plugged in, and if you feed raw PWM to pins 7 & 8, you will not get the “at idle” effects. You must use an opto coupler to isolate the Sierra from the common ground the PWM input provides.

The system is timing out. I am nowhere near a set of Sierra instructions, but, from memory, there is a setting that lets you switch off the auto shut down.

Tony’s right, except that the option to shut off the auto shutdown is only found on the diesel systems … there’s no way to get rid of the auto shutdown on a steam Sierra card.

Matthew (OV)

Since you’re hearing Fireman Fred, that tells me the unit is at idle, as Fred–for whatever reason–only shovels when the loco is stopped. (Personally, I think he needs to get off his duff a bit more often if he’s ever going to make “Engineer Eddy.”) That seems strange to me if you’re wiring the output of the Revolution directly to pins 7 and 8. You shouldn’t be hearing Fred or any sounds triggered by going into or out of idle. That tells me to look at what the Sierra sees as the start voltage. My bet would be that it’s interpreting the full voltage that’s being applied to pins 7 and 8 as the start voltage, thus never leaving idle and canceling out the auto-shutoff counter.

To check this, press the “-” button until you hear 3 whistle blasts. That’s programming step 3. Look at the red LED and compare its state to what’s in the manual. My bet would be it would either be off (below the start-up voltage) or steady (at the start-up voltage), but not flashing (above the start-up voltage.) What I would do, since you’re not running the output of the Revolution through an opto-isolator, would be to disconnect the wires going to 7 and 8, go to program step 3, and set the start voltage by pressing the “+” key. That will tell it that zero (since there’s no input at all) is the start voltage, and anything above that is considered not being at idle. When you plug the Revolution output back into pins 7 and 8, it will see a voltage there, and no longer be in idle mode, and not shut down. You’ll lose Fred, but there are worse things. The guy’s a slacker anyway.

Later,

K

In the book “Set Up Running” John Orr recalls his father (PRR engineer) Oscar’s encounter with a fireman that did a fantastic job shoveling, building and maintaining a beautiful fire…at low speeds. When they got up to speed, he couldn’t continue…too scared to straddle the engine and tender platforms rocking back and forth with nothing to stop him from falling out the side…He was relegated to yard duty.

“There’s a prototype for everything”…

Tried what you suggested Kevin but still no go, I can see where you are coming from with the zero voltage idea and I reckon you are right. I went to step 23 and reset everything to default but it still cuts out after 2 minutes, I tried the step 3 start voltage change, you were right about the LED’s but nothing was happening when I pressed the + button so I think the problem might be associated with this function, maybe something is wrong on the board?
Even after going to default, when I turn battery power on the dynamo and whistle blows and Fred starts stoking the boiler and 2 minutes later all is silent, out of curiosity and desperation I will revert the Sierra to voltage chuff and see if I can reset start voltage and see what happens then.
Tony if you are reading this, I am going to Peter’s on Sunday so if I don’t have any joy I might take it down there and maybe you could have quick look to make sure I have wired it all up correctly? Tony, if you are not reading this I will still take it to Peter’s, LOL

Hello Wayne.

I am planning on being at Peter’s place over the weekend.
I will bring the correct SSI-12v5 and show you how it should be wired up.

Wayne Hoskin said:
...when I turn battery power on the dynamo and whistle blows and Fred starts stoking the boiler and 2 minutes later all is silent...
How many whistles? One, two, or three? I've never gotten a whistle toot on start-up except on one diesel board from eons ago, but I don't see why that couldn't be the case on your board. Given what you describe in terms of shut-down and Fred, I'd expect that it's one toot, which is what it sounds when the voltage going to pins 7 and 8 is zero. (They dynamo spins up regardless of the voltage; it shuts off after a few minutes if the train's not moving, but spins back up once it gets some throttle.)

On the other hand, if it’s two or three toots, I’d expect that from the board if it’s seeing a voltage across pins 7 and 8 that’s greater than the “start voltage.” It would be two or three, depending on the direction of the locomotive. If you’re getting two or three toots, still getting Fred, and the board is still going into shutdown, then something sounds weird with the board. Those should be mutually exclusive.

Beyond that, I’m mystified. It’s just not behaving the way I’ve had these boards behave in the same installations.

Hopefully Tony’s interface board will correct things. (Tony, bring some diodes and a few 100 and 1000 ohm resistors with you to drop the voltage going to the Sierra board down to zero when the throttle is all the way down. I did one last week that needed two diodes in series on each input, and 100 ohms between each of the inputs and ground.)

Later,

K

Thanks for the advice Kevin.
I still don’t understand why AristoCraft did not , and apparently cannot, design the their ESC’s properly in the first place.
If the SSI-12v5 does not work out of the box I will not be able to help.

They got it “right” on the trackside Revo receiver. You still need the interface board, but no additional electronics. It’ll be interesting to see if the new “sound” Revolution boards drop full down to zero. (Of course, with the sound on the board, there’s not a whole lot of reason to drive a Sierra off of it…

At the very least, the SSI will give us a benchmark as to what the voltage coming from the Revolution is doing, as it’s at least predictable. It may not drop to zero without the additional diodes and resistors, but it shouldn’t go into auto-shutdown if it’s sending a proper voltage to pins 7 and 8. You may, in fact, be able to set the “start voltage” on the Sierra to the output of the SSI. Worth a shot, at least.

Later,

K

Understood Kevin.

Unless the REVO FET’s are leaking badly my guess is that the residual voltage problem could be eliminated in software.

BTW. I guess Mr Polk knows best, but not having a linear output option on the new REVO track side seems to be a bad oversight to me. I know of no reliable way PWM can be converted to linear, and carry appropriate amps without extreme overheating, after the output of the controller.