I have a set of Buschs crossing signals but I dont want to run them off of the box that came with them. I have purchased an IR detector by Berkshire Junction just to activate these bad boys. But I cant figure out what is the negative and what is the positive to the crossing signal LEDS. What there is is four copper wires for each led and two copper wires but painted black. Am I safe to assume the black colored copper wire is negative and the other copper wires are positive sides? Has anyone ever done this? If need be I could scan the diagram that came with the signals. Thanks in advance.
If the signals came with a schematic diagram, it should indicate which wires are positive and which are negative.
I would not make the assumption that the black colored wire is the negative – I have ran across items of European and Chinese origin that the color code was just the opposite.
The safest way to determine what the color code means is to wire a 1k resistor into one of the unmarked leads and connect a variable power supply with reversible polarity, such as an MRC power pack, to the black wire and the resistor.
Slowly turn the throttle up about 1/4 of its range. If the LED doesn’t light, turn the throttle down and reverse the polarity (direction) switch. When the LED lights, determine which wire is positive and go from there.
If you have a Multimeter with a Diode check function, you can use that also. Otherwise I agree with the 1K + 12Vdc solution
Does the IR detector you purchased from Berkshire Junction also include a flasher circuit to animate your crossbucks or is it just a detector?
Thanks everyone for the information I wish I would have been back before I went to radio shack. Maybe I can get my dad to get some he works near one so maybe I can get these going.
To the other question the Berkshire Junction set up has the flashing circuit on it so I cant just hook up the Busch circuit to the sensor.
I checked the wiring schematic for these signals and it appears that you are correct. The black wire is the common wire for the LEDs and the copper wires are connected to either side of the flaser circuit. I hope this helps.
Tractionman
If the wire with the black mark is the common, that probably means it is the positive input side of all the LEDs. If that’s the case, you’re going to need individual resistors on each of the other 4 wires that connect to the flasher circuit, and the value of the resistors is going to depend on the input voltage applied to the flasher module according to the following rule:
For an Input Voltage of the Resistor value will be
9V DC 390 Ohm, 1/4 Watt
12V DC 470 Ohm, 1/4 Watt
16V DC 680 Ohm, 1/2 Watt
On most of these signals, one wire is connected to all of the LEDs on their positive leads, and the flasher module turns the ground, or negative, side of the LEDs on and off. Individual resistors are necessary on each LED to protect the flasher module if one of the LEDs should burn out.
NOTE: The resistor values above were provided with the Grade Crossing Pro flasher module that I use on my layout, and yours may be different. Read through its instructions for a chart of resistor values.