# Battery substitute for the AirWire Drop-ins



## dawinter (Jan 2, 2008)

Hard to know which forum to post this. Traditional DC or Radio Control. Whatever works I guess.

So....I'm investing in a "bunch" of Drop-Ins and I can save big $$$ by using a good DC voltage on the track rather than installing a 14.8 volt battery in every engine + having a charging system. I want to know how low the i/p voltage can drop before the AirWire boards shut down.. Would they work with a regulated 12 volt PS? Would they be damaged with a 15 volt i/p? 

I sent off an email to AirWire/CVP but got no response.

Any help?

Dave


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## K27_463 (Jan 2, 2008)

15volts is no problem, as is any higher voltage up to 28 or so. On the low end, the radio circuitry will stop functioning around 7.5- 8 volts, so an 8 volt overhead for proper radio ops is a safe assumption. 
I have done a large number of installs with 11 or 12 volt batteries with no issue whatsoever. There are diagrams available for running airwire off track voltage . 
jonathan/EMW


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## dawinter (Jan 2, 2008)

*Just to be fair. This is the reply fron CVP....,*

Good morning

1. Your suggested battery voltage is 14.8 volts DC. Could you please let me know the +/- operating voltage range of the drop-in boards. IE: How much lower, or higher, can the i/p voltage be and still have the board function correctly? 

Min volt is 11v. The board will tolerate up to 24v after the battery charge however higher voltages will impact the range. The best is to use a 14.8 v battery! 

2. Are the T5000 throttle and the SD40-2 Drop-ins available now. 

T5000 throttle will be available this fall.
Right now it appears the SD40 will be next winter. 

3. How much farther down the road are the NW2 Drop-In's? 

Not sure on a date yet for the NW2 

Thank you.

Dave Winter

*Good> I have a well regulated, controllable PS that will put out plenty of power, Sad part is that I wanted the SD40-2 now. Could be years at this rate. Oh well, It's not a life/death issue is it?* 
*Anyway. Track power it is. And much thanks for your support through my floundering about this.*


*Dave*


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## Michael Glavin (Jan 2, 2009)

Dave,

Some consideration should be given to track polarity! If by some fluke you’re able to reverse the polarity with a switch or put the engine on the track backwards as phased initially the smoke will be let....... IMO a bridge rectifier is a must on each engine!
You could get the Airwire G2 and wire the SD40’s now, albeit you have to do some wiring yourself.
Michael


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## Bill Swindell (Jan 2, 2008)

I have converted 10 engines to run on track power with both drop-in boards and G-2 boards. In each case, I have also installed a Phoenix P-8 sound system. 

The bridge rectifier is a MUST. Otherwise, if you turn the engine around without changing the track polarity, you will get to buy a new AirWire board. The track voltage should be about 15V or do. That is because the bridge rectifier will drop about 3 volts.


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## dawinter (Jan 2, 2008)

Thanks for the advice regarding the bridge. I've picked up a few at the local electronics supply place already. Question though: Are there not various track power in puts to the original USAT boards? Wheels and sliders for example? Would all of these have to be tied together at the bridge input somehow BEFORE connecting the +/- output to the new board? Perhaps a simple drawing would help me here. Of course, once the SD70 is up and running I will know more about the whole system. Waiting for the new T5000 anyway.


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## dawinter (Jan 2, 2008)

Posted By Bill Swindell on 03 Aug 2011 09:03 PM 
I have converted 10 engines to run on track power with both drop-in boards and G-2 boards. In each case, I have also installed a Phoenix P-8 sound system. 

The bridge rectifier is a MUST. Otherwise, if you turn the engine around without changing the track polarity, you will get to buy a new AirWire board. The track voltage should be about 15V or do. That is because the bridge rectifier will drop about 3 volts. 

That's exactly what I intend to do. Right down to the number of engines and the sound system. All USAT. I guess my SD40-2 will get a G2 and so will both my NW2's (SW1200rs) I have ordered a good commercial, regulated 15 volt DC power supply that will replace the old Control Master 20 that's been the work horse for 12 years. It's definitely a project for the winter so I'm going to have to pick your brain when the convertible is put away. Thanks for the advice.


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