Hello All,
Does anyone know whether the output of a decoders lighting functions are Alternating Current or Direct Current?
I’ve converted an analog Athearn Blue Box F7B unit to digital using a Bachmann #44914 decoder. It’s a simple 2-function decoder.
Because there is no headlight—per se—in the B-unit, I’m using the bulb as an interior prototypical “work light.”
As currently wired through the decoder it the bulb is directional; when the unit reverses the interior “work light” goes out.
I’m considering using both output functions of the decoder to provide a continuous “work light” to the single bulb.
I suspect that the light output functions are D/C which would require the use of diodes between the output functions of the decoder and the single bulb, to eliminate “back-flow” of direct current to the decoder.
I’m running a E-Z Command DCC controller which does not allow for higher CV functions of “All On.” That’s why I’m considering this solution.
Again, thank you for all your thoughts.
"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"
The lighting outputs of a DCC decoder are DC current at around 12 Volts.
Function outputs of decoders are DC. There is a bridge rectifier on a decoder which rectifies the DCC to power the processor and the function outputs.
Function outputs are also current sinking - the blue common wire is +, the white and yellow front and read light wires are the -. As such, you cna connect 2 or more functions ot the same bulb or LED and all of them will operate the light. It doesn;t matter if one, both, or all are on at the same time - think of it as havinbg a switch connecting the circuit to ground. One switch, 2 switches, it does not matter.
If using an LED< put the resistor on the blue side, only 1 resistor is needed. Connect the other side to both the white and yelloow wires and you will have an always on light regardless of direction, without programming the decoder.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
A diode is not needed. The lighting outputs are “power sinks”. Explained below.
http://www.wiringfordcc.com/locos.htm
More lighting info below.
Store all links.
http://www.members.optusnet.com.au/nswmn/function1.htm
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.