thanks for the tip hminky..photos of caboose pick up trucks

[cwclark]

hminky..thank you for the tip about using the kadee coupler springs as pick up trucks...got home at 3pm and got done with the project by 7pm...I cut the springs and bent them and hooked them up to an atlas metal truck ..even put in an LED light in the caboose..at first it flickered like all get out but then i put in a big hogg'in capacitor and it took the flicker away...here's the pics and the ABS system really works like it should...it drove me crazy when the lights went from red to green before the train passed...now it doesn't until the caboose passes...chuck

[hminky]

Thank you for visiting my website and glad I could be a help

Harold

[Anonymous]

What do you expect when you ask for help from the best? Harold is awesome.

[MudHen_462]

For DCC operation, do you need to add a resistor between the LED and the the pickup ? (i.e.: 1/4 Watt 750 Ohm resistor )

Thanks,

Bob

[Anonymous]

I was thinking about doing this too. I have the same question as Bob. What if any resister would I need for an LED?

Kevin

[cwclark]

anytime you use a LED it MUST have a resistor in the circuit..it doesn't matter which wire, the cathode or the anode just as long as there is one...if you connect it to a power supply directly it can explode or burn up in your hands.....I use a resistor between 300 and 600 ohms will work...I don't know what it will do with DCC..that's kind'a why i'm afraid to put in DCC because of all the electronic stuff i like to mess with that is everywhere on the layout.......chuck

[NeO6874]

i don't think it'd work on DCC without adding a decoder for the light... although my understanding is rather limited of DCC, so you might be able to get away with a directional lighting circuit, a capacitor, and a resistor.

I figure you'd need this because DCC uses AC (yes, I know there are differences between Wall-AC and DCC-AC).  The directional circuit would keep the poser going the "right way" through the LED, the capacitor would keep it from flickering, and the resistor would keep it from blowing out right away...

[cwclark]

i don't think it'd work on DCC without adding a decoder for the light... although my understanding is rather limited of DCC, so you might be able to get away with a directional lighting circuit, a capacitor, and a resistor.

I figure you'd need this because DCC uses AC (yes, I know there are differences between Wall-AC and DCC-AC).  The directional circuit would keep the poser going the "right way" through the LED, the capacitor would keep it from flickering, and the resistor would keep it from blowing out right away...

This post is a blast from the past!...and yes, it works great for a DC system. I'm about to make a big investment into a digitrax super chief system and the first thing that's got to go is the way these cabooses are wired and lighted, also,  my dallee signalling system will also have to go...what I've read so far, capacitors across the rails are a big no-no with DCC systems....chuck

[DigitalGriffin]

anytime you use a LED it MUST have a resistor in the circuit..it doesn't matter which wire, the cathode or the anode just as long as there is one...if you connect it to a power supply directly it can explode or burn up in your hands.....I use a resistor between 300 and 600 ohms will work...I don't know what it will do with DCC..that's kind'a why i'm afraid to put in DCC because of all the electronic stuff i like to mess with that is everywhere on the layout.......chuck

Add two diodes (DC), or a full bridge rectifier (DCC). Problem solved.

track rail 1->diode->300 Ohm resistor->Capacitor in parrallel with LED->diode->track rail 2 (DC)

Technically this should work for DCC also, but I haven't tried it yet.

You could leave the capacitor and diode out, but you would definitely get flicker.  With a very small capacitor the above circuit also good for directional lighting on DC with no flicker. 

Orientation of the diode is important here. 

DCC version

With a rectifier you shouldn't really need a cap like the diode setup, as direction of the current doesn't matter.  HOWEVER the cap does help reduce flicker on sections with poor pickup.