Lighting functions output of decoders—A/C or D/C?

[richg1998]

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

[rrinker]

 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

 

[cacole]

The lighting outputs of a DCC decoder are DC current at around 12 Volts.

[jjdamnit]

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.