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Markerlights for Marx a caboose
Things you'll need:
1 5mm flashing LED
1 5mm Red LED
1 9 volt battery holder
Some Heat shrink/Tape
Dark paint
PCB strip board
The circuit for this design is very basic and the batterys should last for a few months if they're left on. I designed my marker lights off 2 AAA batterys but as they say the best way to make god laugh is to tell him your plans and I had to revise the circuit.
You can use either of the two circuits but I haven't tested it with AAA's yet.
Assembly
Step 1
I've used 5mm LED's but you could use another size if you want. The circuit is designed to run off a battery so you may want to fit a switch. First cut a piece of PCB the right size I pays to work out what tracks will do what first. See how I cut the PCB in the diagram below. Cut a track at the 3rd hole in on one of the edge tracks.
Step 2
Mount the resistor across the gap you cut in the PCB track leave the bottom hole empty then in the next hole up mount the flashing LED across the circuit to the two outside tracks Eg.the one above the resistor to the opposite side missing the two middle tracks. Attach the battery clip and see if the LED flashes.
Mount the two other LED's these are the marker lights in series across the circuit in series on quite long legs. Insulate the legs of the LED's with the tape or heat shrink. Again test the circuit. The normal LED's should go bright when the flashing LED is off.
Step 3
Mount the circuit in the caboose I mounted mine on the under side of the roof and taped it in place. I also put the battery in the caboose and left the shell holding tabs undone so to change the battery all I have to do is pull the shell off. The LED's should be held in place by the tape. Finally I taped over the flashing LED and painted it brown so you can't see it in the caboose windows.
Running it off track power
If you want to run the circuit off AC power(eg. track power) use the below circuit but remember the voltage to the LED's can't be too high so you'll need a larger resistor.
How it works
The flashing LED has a micro chip that controls the flashing rate when the flashing LED is on all the electrons travel through it as its the easiest route when its off the normal LED's get the full power and go bright.
I ended up having the flashing LED in series with a normal LED and I'm running the circuit on 4.5 volts.
I'll add photos soon
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