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?

Stan, could you possibly post how you hooked up the leds? I'm interested as I have 10 of the Wehonest signals myself, and I'd like to build the circuit----

I think if I were building it, I'd add a lot more delay to the yellow light, but other than that, it looks great!

For common anodes, I went with low-side switching. The original circuit used the 555’s ability to source and sink current on pin (3) allowing it to drive both YLW and GRN.  Can’t do this with common anode, so I added Q1 – virtually any general purpose NPN switching transistor will do. As before, red LED is independent.  In any event, the parts cost is still about $1.

To John's point, with a 10uF cap, I get ~12 sec YLW-to-GRN delay.  To keep the video short, I used a 2.2 uF cap short which is why it's ~3 sec.

If you don’t have a 12V DC accessory bus, the 7812 or 78L12 regulator as used in the MTH circuit makes for a low-cost local 12V DC supply. 

Perhaps obvious but since power is completely removed from the 555 when RED is on, you can’t use the 556 (dual version of 555) to control 2 separate signal heads.  OTOH, if several signal heads are physically near each other, a single 7812 can supply the 12V DC power to multiple circuits if you don’t already have a 12V DC accessory bus running around your layout.

That's great Stan, I've captured it.

I think I'd probably consider just sticking a 78L12 regulator on the board and having independent power supplies.  The regulator and another cap and diode runs the cost up to... $1.50 extra?

Stan, thanks very much!!  I probably would have gotten to the same circuit, you just did it faster. I'll probably add a78L12 to it so I can put the signals anywhere.

John, I see from another thread you have Fastrack. On my to-do list is to design an ITAD-like occupancy detector that completely fits under my RealTrax and does not need isolated-outer-rails.  I have about 7mm height and essentially unlimited area. Does Fastrack have such a cavity and if so how much vertical clearance is there?

Fastrack does have a large cavity under it, a quick measurement comes up with 5/16th of an inch in depth.  Looks to be just a touch deeper than the piece of RealTrax I have is.

Sorry to dig this up from the dead but I may be buying a few of these and I noticed that there is now a control board for these signals from wehonest. This seems like the simplest thing do do, and for the price you get two kits.

http://www.ebay.com/itm/Logic-...;hash=item3a706beaad

Actually, that's a good "dig"!   That's a pretty good price for two IR track sensors.

Just saved the control board  in my Ebay watch list. this company has lots of model rr stuff for all the popular scales---

FYI, I have purchased from Wehonest_USA before. I got the 18v bulbs in a large lot.

Got lost in the mail, but they sent a second set. Using them in my Control Board, still in progress, but so far so good, one or two out of 100 bad.

The Painted People are not what you would expect people to look like, painted or otherwise and they are pretty much 5 versions repeated 50 times. I'd advise staying away from the people.

The boards look like the 153 copy...seems good price.

Ralph

I think the painted people all come from one source.  There have been at least a dozen different Chinese vendors selling them, and they're all the same.

I ordered a pair of the control boards, that's a great price if they work as described.

Please do let me know how long it takes to get them and also how well they work.

Well, I'm sure it'll take several weeks at least to get them, but I'll post how they work when the come in.  I have some of the signals, so I figured I'd get the matching boards and see how well they work.

I just received  a set of these signals 3 over two (see slink below) i am trying to wire them so that they display Green Over Red but for some reason I am not able to have the green led on top be on at the same time the bottom red led is on. I am able to have it be green over green and yellow over red? I can't figure this one out..??? 

http://www.ebay.com/itm/2-pcs-...;hash=item2321db0212

I know im late on the band wagon here..But does any one have a circuit diagram on using the 555 chip to build an LED signal?

Exactly what LED signal, and what functionality are you looking for?  Two lamp, three lamp, what?

3 light LED, R/Y/G. when the train runs over the sensor, it goes from green to red, then after 3 seconds to yellow, then after 3 seconds to green.

What are you using the secondary indicator for?  The reason I avoided those when I got the plain 3-lamp ones was I couldn't figure why I'd want the second group of lights.

Are you talking about the the IR sensor? Its so the LED can go through the Red yellow green phase