LED signal with Lionel 153ir

You need a diode and a resistor if you're running them on AC.  No need for a bridge, a single diode in the ground lead with the resistor will do it.  What voltage are you running on, and what value is the resistor?

Who made the signal?
Was there an instruction sheet?
Do you even know what the intended voltage is? and weather it's meant for DC or AC operation
Diode or not just hooking it to 14 volts shouldn't have burnt them out if they were rated for 14 volts

David

Not sure who made it - got it from a friend that had bought several from China.  No instructions.

As I said when I just had the red/black wires hooked to my 14v acc bus it worked fine.  Only when I added the 153ir to the mix.  Not sure I didn't hook it up wrong.

The rated reverse voltage for most LED's in in the 5-7 volt range.  A 14 volt AC signal will present a reverse voltage of over 19 volts.  No, it typically won't cook them immediately if you have a large enough resistor, but if it doesn't, it'll drastically shorten their life.

Stan I think your right.
I wondered why the black would be hot?I mean not that it couldn't happen but I think he fed it backwards and poof.
Prob. if he'd fed it like the ones in the pic it'd still be working.
Not much you can do to fix it dude other than replacing the LED's which I'm sure will be a chore
sorry

David

Is this the control? O Scale 3 Aspects Railroad LEDs Signals G/Y/R

I'd put a diode in with the resistor.

Yes that's the control -  the O version of the one Stan posted.

Not to be too dense, but do you have an example part number for the diode?  So it would go black wire -> resistor -> diode -> Acc Pwr(153ir)?

I don't want to repair it, I have another one.  Just trying to make sure I get it right so I don't destroy another one!

While a quick yellow flash might be nice, I think I'll try and stay simple.

A 1N4005 is what I typically use, you can use most any of the 1N400x family if you can't find the 1N4005.  The only difference is the voltage rating, I like to have lots of spike protection.   Of course, you have to have the diode in the correct direction or the LED's won't light at all.  If you try it one way and it doesn't light, just turn it around.

Those have no resistors or protection diodes internally, they're just bare LED's.  I got some of them as well, and I'm working on how I'll get all the lights to sequence in a logical manner.

You could probably do something tricky with a medium sized capacitor to get a brief yellow light, I'd have to think about it.

Virtually any diode you can dig up will work.  If you are willing to wait, I see the 1N4005 on ebay 25 for $1 w/free shipping.  Or for $2.99 I see Radio Shack has a value-pack of 25 diodes that includes the 1N4005 (actually, any in the assortment will work for what you're doing).

Virtually all diodes have a silver band on one side.  That side goes to the resistor in your sequence of parts.

One comment.  I'm speculating the ebay supplier assumes you're using a DC supply of 12-16V and sized the supplied resistor accordingly. If you're using a 14V AC accessory supply, the LEDs (being diodes themselves) use only half of the alternating voltage - if that makes sense. But they may be bright enough in which case you're done.  Otherwise post back and there are several low-cost options to bump up the brightness.

So John, are you looking to insert yellow-to-green delay timing?  I'm always impressed by how much the major suppliers charge for that feature!  I'm thinking a few transistors, resistors, capacitors could do it for, say, $1.  Or a bit more if one is "lazy" and goes 555.

Yep, I was thinking something like a simple cap delay and a gate, a 555 would probably be a useful tool here too.

The hard part is defining it so it's somewhat universally acceptable.  Actually, wouldn't it go from yellow to green normally as the train gets farther away?  Typically, a signal would go red when a train went by, then yellow for a spell, finally green. 

I don't have one but there have been a few recent threads discussing the MTH signal and how to hook it to NO and NC of an ITAD.  As I understand it, NC powers the yellow-green LEDs. NO powers the red LED.  The train trips the sensor and RED turns on via NO - the red circuit is probably just a diode and resistor.  The train passes and NC powers the yellow-green circuit which has more to it.  Yellow turns on for a while, then Yellow turns off and Green turns on until the next train.  I figure this is why they say in the instructions that when first powered up, don't be concerned that Yellow comes on because it will shortly turn to Green and all is well.

Does someone already sell such an assembled circuit? With eBay supplier "WeHonest" (!) and their bare LED signals, I'd think there's a need for such a circuit.  If not, I figure we ought to be able to come up with a DIY circuit for $1 or so.  I figure it should work with an ITAD and/or optionally direct to isolated rail without the cost/bulk of a relay.

The MTH 3 aspect signals do use a 555 chip, but it's not the conventional circuit that is mostly used. I had at one time traced out the circuit and laid out the schematic on paper. As I recall, it was a time delay circuit. I'll have to dig thru my train stuff to find it. Stan has it right-- the red led is separate from the yellow/green--

EDIT: I found the diagram that I drew up. I'll have to redraw it to make it neat & tidy. once I do, i'll post it here.

I think it would be sufficient if the red came on when a train entered the block, when it departs, the yellow comes on for a predetermined time, then the green comes on until another train comes along.  That's pretty easy to do.

You can do it that way Dale, but for a couple bucks worth of parts I can wire up a 555 to do a similar function.

If you have one, the cheap solution may be the way to go.  However, I have 10 of these that I hope to use at least a majority of them, so I'd like something cheaper to make them go.

I only go to Radio Shack if I need a part like NOW.

Who gets most of my buying is Allelectronics, Jameco, Mouser, or Ebay. depends who has best prices & shipping.

Digikey gets a lot of my business, they're shipping is dirt cheap, and they have competitive prices.  I also buy stuff at Mouser and AllElectronics.

here's the MTH 3 led signal schematic. to use it with the Wehonest 3 led signal will require that the signal be modified.

Or perhaps this circuit could be modified to match the signal?