# Current Rating of LGB 5 volt smoke generator?



## LGB333$$$$ (Oct 11, 2017)

Hi All - Does anyone know the current draw for the LGB 65853 5 volt smoke unit? I'm planning to install it into a Soundtraxx Tsunami2 4400 Sound Decoder which doesn't have a direct connection for a smoke unit. But it does have four additional lighting connections, FX3 - FX6. Here's my question and the response I received from Soundtraxx:

My question: "I want to attach an LGB# 65853 5 smoke generator 5 volt to the decoder's FX3 connection. It appears that the lighting connection and the FX connections are all 12 volts. The only guidance I see in the documentation is that to reduce the lighting voltage use a resistor. What value resistor do I need to use to power the 5 volt smoke unit?"
Response: You can, but.. you will need to drop the voltage with resistors. The other factor is each output is good for 300mA. Just be sure your smoke unit draws less than 300 mA at 5v (with resistors) so you’ll be below the current limits of the FX3." 

The "Function Common" Volts (+) is rated at track voltage minus 1.5 volts. See attached.


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## Dan Pierce (Jan 2, 2008)

First of all, that is a seuthe 4-7 volt smoke unit. LGB runs these between 6.2 and 6.8 volts. Current changes (lessens) as the element heats up. So to protect a decoder one must measure the 'cold element current' which can be figured out by i=e/r or planned voltage divided by resistance of element. Problem is if using a resistor in series to V+ then as the current changes (heater element heats up), so does the voltage. 

Not the simple answer you were looking for is it.


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