Lionel New LED Packs - Pics - Polarity

There should be a diode for maximum life of the LED.  I suspect they're counting on the low reverse current not to damage the LED until the warranty runs out.

The polarity is correct for half of the AC cycle, then it's not.  LOL! 

Seems a 1N4001 diode would be up to the task.  Placed any where in the circuit, and as it’s rated at 1A would probably supply all four lights if need be.

Any of the 1N400x diodes will do.  I personally have a lifetime supply of the 1N4003 diodes, I like a slightly higher reverse voltage rating to minimize the possibility of a failure due to a voltage spike.

Thank You for the replies.

With just a resistor in play,  should it not matter which wire goes to positive and which to negative?

The last note on the back of the package,  (below pic)  Lionel wants red to + and black to -    ??

@Soo Line posted:

With just a resistor in play,  should it not matter which wire goes to positive and which to negative?

Of course it matters!  The resistor just limits the current to the LED, the LED is still sensitive to polarity!  If you connect them backwards to DC, you don't get light.

Thanks John...I have come to understand LED required polarity, resistor to limit current and the diode to keep current flowing one way. 

As you mentioned,  on DC,   polarity is necessary to light,  the reverse as you said produces no light.

The Lionel lights have instructions to wire red to positive and black to negative.

I was only wondering if this was truly necessary using AC and trying to understand my results.  Trying to educate myself here 

In the pics below, I am using an AC transformer set at 16 volts AC and I can power the Lionel lights in either direction.    Red to black, black to red ect.  In any configuration I get light on AC.

The additional pic shows only a resistor in the light base cavity. 

Thanks Dave

Correct, if you're running them on AC, they will work with either connection, AC doesn't have "polarity" like DC.

Thanks John

Dave

Think I'll buy a box, every manufacturer needs at least one product with a 1,000% markup.  j

@JohnActon posted:

Think I'll buy a box, every manufacturer needs at least one product with a 1,000% markup.  j

You don't think a one cent resistor and a five cent LED with a little wire and plastic is worth $2.50?

Agreed on the price statements here.

I was curious to see what Lionel put in the little plastic base....they could have fit a diode in there along with the resistor but they did not do it.

Some folks are not comfortable rolling their own and this probably will sell well for Lionel....just my guess.

Dave

Until the LEDs fail for lack of reverse bias protection.

There is no diode in the Fastrack lighted bumpers, either. I put one in when I direct wired all mine.

I am pretty sure Lionel included the polarity in case you powered your model lighting with DC instead of AC, but they probably should have spelled that out on the package.

John