# GP30 Lights problem with REVO



## billsharron (Jan 3, 2008)

I know this topic has been discussed, but can't find it. I want to know if a fix was ever found which allows the Revo receiver to be installed in a USAT GP30 in those situations where the original electronics board in the loco is retained. I have in the past gutted these and installed Leds, but now want to do it without gutting the electronics.

please point me to the thread about this.

Bill


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## Treeman (Jan 6, 2008)

You may be looking for a board that converts the pulse DC, to linear.


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## Greg Elmassian (Jan 3, 2008)

The quick and dirty method is to feed the original track inputs from the Revo motor output. That will let you not rewire the lights, but it will not give you constant lighting.

With the PWM output of the Revo, the lights will come on sooner than running on straight DC.

I have a page on my site for this method if interested. 

Greg


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## TonyWalsham (Jan 2, 2008)

........Or you could run the motors direct from the Revo and use a small relay to switch the polarity of the full battery voltage which would be connected to the old isolated track pick ups. Use a lighting output to control the relay coil and switch from Forwards to Reverse.
Switched full battery voltage gives constant brightness directional lights and and full voltage for the smoke unit.


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## billsharron (Jan 3, 2008)

Thanks Mike, Greg, Tony for the quick responses. 

Greg, can you point me to the page on your site, I have searched GP30, your TE page, and the USAT loco page. I am missing something

Does anyone know of an available board that converts PWC to linear?? I know Aristo used to make them, but so far I have been unable to find one.

Bill


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## Greg Elmassian (Jan 3, 2008)

http://www.elmassian.com/index.php?option=com_content&view=article&id=465&Itemid=528

Note, no converter is needed in most cases...

LS Trains .... Motive Power .... USAT .... DCC quick and dirty....


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## billsharron (Jan 3, 2008)

OK thanks Greg, but I am not using DCC, but the Crest Revo. Are the results the same using it instead of a DCC decoder??


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## Greg Elmassian (Jan 3, 2008)

Yep


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## billsharron (Jan 3, 2008)

Greg, OK another quick Question. Does using a battery instead of track power change things in any way? Batt + to the input + Batt - to input minus. 

Ok wired it up quick & dirty using battery. Motors run perfect, but no lights. Using my meter I probed the output from the main board to the lights but only get .65 volt. Even when I run up the power to 95, no lights. and still get only .65 volt. Should be at least 3.5 to 5 volts to light the lights. Continuity is good from springs to lights. Lights worked perfect on stock DC.

Bill


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## TonyWalsham (Jan 2, 2008)

Double Post


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## TonyWalsham (Jan 2, 2008)

Navin still has the ART 57091 pcb.
I know, I just bought 10 x from him.


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## billsharron (Jan 3, 2008)

Tony, Since Crest is shutting down, Navin has already disabled the "store" Link. I will try calling him at home next week to see what he can do.

Bill


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## Doug C (Jan 14, 2008)

Loco Bill; 

Ya might find some of what you're lookin' for within one of Mr. Norton's articles on their OVGRS site; 
http://ovgrs.org/the-trains/battery-power-radio-control-and-sound/usa-trains-gp-30/

Does have a 'chapter' on lighting upgrades. 

good luck,
doug c


p.s. i also tend not to find what i'm looking for on the new g.e. website. might be better (timesaver) if i send a email direct to greg asking if, where, pls. and thank you.


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## billsharron (Jan 3, 2008)

Hi Doug,

Thanks for the response, unfortunately the Paul Norton article is about gutting the original electronics rather than using them like I want to.

Bill


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## Greg Elmassian (Jan 3, 2008)

I'm not a fan of gutting unless forced to. 

Even though I might never sell a loco, I prefer to try to work with the existing wiring, sockets, etc.

It seems like more work to understand the existing wiring, but once you understand it, it's a lot less effort than cutting wires out and soldering new ones.

Greg


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## Ted Doskaris (Oct 7, 2008)

*Revo PWC to Linear Implementation*

Bill,

Though I use the Revolution Base Station for track power, I included the controllable use of the ART-57091 PWC to linear board.










You may find it informative to see "Vignette" hosted for me by Greg E. on his Web site.
Title:
"*Implementation of an Aristo Revolution Base Station with Switchable PWC to Linear Output*"

-Ted


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## billsharron (Jan 3, 2008)

Ted,

I read through your solution and it looks great. I found a source for the 57019's and I think I will try it since both you and Mike recommend it. Do the lights on the USAT locos work normally using the PWC to linear board, If not what differences have you noticed?

Bill


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## billsharron (Jan 3, 2008)

I forgot to ask, but anyone know if could I use the lighting outputs on the receiver adding dropping resistors bypassing the stock electronics and connecting the revo light outputs to the lead in the shell of the GP30 to the lights???

Bill


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## Michael Glavin (Jan 2, 2009)

Bill,

You'd have to hack the lighting PCB's at both ends. You can cut the traces of the PCB's at the headlamps and drive them from the Revo RX as you describe. Problem is you need to drive the classification lights and the number boards too. Depending on your classification light and number boards needs various approaches are doable with the six AUX outputs of the RX (there are limitations). I have done this on several locos for others with nary a problem.

Michael


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## Greg Elmassian (Jan 3, 2008)

The classification lights are bipolar leds, 2 leads and reverse the polarity for the other color. A bit tricky to do with a decoder. I think I outlined how to do it with function outputs on my site on the F3 pages.

Just for grins I did one install with the stock lights and dropping resistors to see if I could do it... but the current draw of the incandescent lamps was higher than I liked and required higher wattage resistors.

If you want sophisticated control of the lights, I would pull the lamps out and replace with LEDs.

Greg


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## Treeman (Jan 6, 2008)

We are changing the bi colored LED's to common anode so that they can easily change color with DCC and have full intensity.


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## Greg Elmassian (Jan 3, 2008)

circuit for bocolor leds from a decoder:


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## billsharron (Jan 3, 2008)

Thanks for all the responses, there are many options. I have decided to try the PWC to linear board, and If I don't like the results, I will gut it and put in the led's like I have in the past.

Bill


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## TonyWalsham (Jan 2, 2008)

Bill, before you gut it why not try a simple relay solution. Everything works as it did originally because you get full voltage either way that follows direction change. 
Obviously there is no control over individual lights.


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## billsharron (Jan 3, 2008)

Tony, I considered that but sent away for some of the PWC to linear boards just to try it out. 

I was fooling around today with the idea of going ahead and using the lighting outputs on the revo receiver and bypassing the the USAT main board. The output from the Revo receiver was 15.85 volts at the lighting outputs. So I'm thinking that I need to drop that to 5 volts if I connect to the upper wiring harness leading to the lights. 
So I added a 1000ohm resister to the + output terminal on the revo and put the meter on it, I was surprised to see no voltage drop at all. I used a 1 watt resistor. I double checked the output with the same result. I know little about electronics, and wonder if you can burn out a resistor??? Or does there have to be a load on it to see the drop?

I will try the PWC to linear board first and go from there. 

In the past when I gutted the units and replaced the bulbs with the led's, I always got rid of the bicolor class led's, because to me they just didn't fit prototypically at least to my liking.

Bill


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## Cataptrra (Mar 16, 2015)

billsharron said:


> Tony, I considered that but sent away for some of the PWC to linear boards just to try it out.
> 
> I was fooling around today with the idea of going ahead and using the lighting outputs on the revo receiver and bypassing the the USAT main board. The output from the Revo receiver was 15.85 volts at the lighting outputs. So I'm thinking that I need to drop that to 5 volts if I connect to the upper wiring harness leading to the lights.
> So I added a 1000ohm resister to the + output terminal on the revo and put the meter on it, I was surprised to see no voltage drop at all. I used a 1 watt resistor. I double checked the output with the same result. I know little about electronics, and wonder if you can burn out a resistor??? Or does there have to be a load on it to see the drop?
> ...


Get an old L.E.D. and put a load on the resistor, if I recall correctly from my days in the electronics field, there has to be a load to get a voltage reading and the resistor has to be "out of the circuit" completely to get the resistance reading. 

A 1,000ohm{1K} resistor is good, but a better alternative would be an LM7805 Voltage Regulator, as long as the + output is DC and always +, then the LM7805 will give a constant 5VDC output. 

You'd wire the LM7805 {+}input pin to the + side of the + output of the controlling device, the center pin goes to ground or the - side, the 3rd pin is the output pin {+ 5VDC} and that would go to the + leg of the L.E.D.'s it would be powering. 

One thing to note, the LM7805 can get quite hot, so a heatsink would be recommended for it. Also the tab of the LM7805 has a hole for a screw, but be careful as this metal tab is linked internally to the middle pin {-} or ground of the LM7805.

And to answer your question if the resistor is NOT of a high enough wattage to handle the current, yes, you can burn it out. Believe it or not the heating elements in some smoke units, the ones that can be replaced in, for example, fan driven smoke units, are actually resistors and these burn out, they just an inside out resistor to put it simpley, but the correct name for them is actually "thermistor" because the voltage is what causes them to heat, the higher the voltage the hotter they get, too hot and they burn out. Same with a standard resistor.

Most G loco's usually need at a bare minimum, depending is 1/4 watt, you really shouldn't need over a 1/2 watt resistor for most lighting applications. Minimum resistance I've used is 470 ohm, but most often I up that to 1k {1,000 ohm}, it does diminish the L.E.D. brightness, but not enough to really notice, especially if you use "super bright" L.E.D. types.

Good Luck!


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## Greg Elmassian (Jan 3, 2008)

OK...

First you cannot measure the voltage dropped by a resistor unless you have current flowing through the system, and a voltmeter is not the same as the actual load.

The voltage "dropped" is equal to the resistance times the current. The meter takes microamps to measure voltage. Try multiplying 1000 times 10 to the minus 6.

That shows the voltage dropped by the resistor is almost zero. So you should read basically the full supply voltage. Basic ohms law... so you need to know what the current draw of that lamp is IN CIRCUIT, and then you can calculate the resistance needed, but this is a poor way to do it, since minor differences in voltage can burn out an incandescent light bulb.

Turns out that most of the incandescent lights are fed from a somewhat regulated supply, so you need to measure that voltage, but be aware, you need to measure those voltages against a range of inputs.

Next there are several voltages in play in most USAT locos, again read my pages on the F3 and you will see the voltages I measured... it's crazy, and a lot of work.

Remember also that the current handling of the Revo is limited in the lighting outputs, so be sure to verify you are not going to draw too much current.

The "quick and dirty" method is sounding like a better choice for you the more I read here. 

Greg


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## billsharron (Jan 3, 2008)

Orville, Greg,

Thanks for the education on measuring the voltage drop of the resistor, very helpful!
Orville, Using the voltage regulator is something I would like to try time permitting. Greg, I will reread the F3 pages for the voltages before proceeding with any experimentation.

Greg, unfortunately the quick and dirty method did not work as far as the lighting goes and I got no lights at all, which is why I want to at least try the PWC to Linear board suggested by Mike.
If I am not happy with that, I will go on from there. Right now I am awaiting the arrival of the last two PWC to linear boards Robby at RLD Hobbies had in stock.

Bill


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## Greg Elmassian (Jan 3, 2008)

Very weird Bill, if you are feeding the motor outputs of the decoder to the main board, you should have lights.

Remember, leave the motors connected to the original main board. Normally the linear regulators will "put up with" the PWM input to the main board.

Are you sure you are feeding the decoder to the main board, and not to the motors?

Greg


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## billsharron (Jan 3, 2008)

Yes Greg, I am absolutely certain, and all I get is motor function working perfectly but no lights. Batteries to input on the revo, motor output to the USAT board! When I put the meter on the light output leads I only get about .85 volts no matter what power level I use on the transmitter. The lights on my GP30 are all working fine in factory configuration.

Can anyone help with this new problem??
My PWC to Linear boards arrived today. When I opened one up I found it is different than in the photos. The photos show 2 PWC "in" terminals, and 2 linear "Out" terminals, but on the ones I got there are three PWC "in" terminals. There are no instructions, so how do I wire it from the REVo receiver to the PWC input terminals??????

Bill


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## Treeman (Jan 6, 2008)

Greg Elmassian said:


> Very weird Bill, if you are feeding the motor outputs of the decoder to the main board, you should have lights.
> 
> Remember, leave the motors connected to the original main board. Normally the linear regulators will "put up with" the PWM input to the main board.
> 
> ...


I can't explain it either, but some of the USA boards acted this way. That is why Navin came out with the linear output board.


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## Greg Elmassian (Jan 3, 2008)

Yeah, they are linear regulator ic's for the lights, and normally they do come on at part throttle.

Greg


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## billsharron (Jan 3, 2008)

Mike,

Any Idea how to hook the CRE 57091 to the revo receiver?? I don't want to make bad smoke!

Bill


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## billsharron (Jan 3, 2008)

Cancel the above question, I just learned that the center input terminal on the CRE57091 is NOT used. I will try to install one later today.


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## billsharron (Jan 3, 2008)

OK All,

I installed the PWC to linear board between the "motor" outputs on the Revo and the input terminals on the USAT main board. I clicked up on the power button on the /Revo transmitter in increments of three and although the locomotive started smoothly by step 9, there were initially no lights. I kept upping the power and the lights finally came on very dimly at speed step 37. As power increased the lights got brighter and more visible. All the lights functioned as advertised by USAT. class lights showed the correct colors based on the headlight display. UNfortunately the numberboard lights remained quite dim. Unless someone has a simple way to at least start the lights when the power is first increased, I would have to say don't waste money doing the PWC to linear method to get lights.

To me it is so unacceptable I will next look into using the voltage regulator or dropping resistors using the lighting output on the Revo receiver. Failing that I will gut the original boards convert everything to LED and get it over with.

Frustrated and disgusted!!!!

Bill


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## Greg Elmassian (Jan 3, 2008)

Well, if I remember correctly, the Revo "outputs" are good for somewhere between 10ma and 100ma, and there is also a total for the board which is not equal to all outputs at max, it's lower.

With the variety of voltages used inside, I'd go all LED now, getting the voltages just right for incandescent bulbs makes the resistors tricky, and also higher wattage like 1 or 2 watts.

Greg


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