Lionel 180-watt Circuit Breakers [CB's]

The short is just not drawing enough current to trip the breaker.

Are these bricks in phase? Lionel had some that were not. You may need to reverse the leads of one of them.

I'm confused, what's the extra LED?  We have multiple bricks on the modular layout powering different power districts, every time a train passes two bricks are paralleled.  At times, it could actually be three, or even four, as another train or trains could be transitioning the other power district boundaries.  I've never seen it be an issue of any kind.

cjack & GRJ:   Yes; in phase.  The 'extra' LED tells me that its brick is supplying power.  It's not, I believe, a 'short'; the flicker/blips seem to say that there's some sort of a current/voltage  'transient' that ALMOST pops the CB in the brick....until, FINALLY, it does turn off.

John; I too have the same, 'multi-brick' operations as you described.

I've never seen that configuration be an issue, and we've run countless hours in that configuration.  FWIW, we also have an LED on the control panel that indicates when each power district is powered, they have never failed to light if there's power.

Well, John, can/will you consider my specific problem, and possibly suggest a cause? My hypothesis may be a bit of a stretch....

Well...if the bricks are in phase, and it's not a short...that brings us to the idea that somehow the circuit breaker is as you say "building up" and tripping. I think those are pretty fast circuit breakers, not heaters, that probably would just trip if you did in fact have a brief short. As far as them "building up", someone would have to disassemble one to see what the circuit looked like...what chip, etc. is in them and if they have a capacitance to absorb small transients instead of faulting for no good reason. I take you have swapped the bricks around to see if one brick is unique to this.

Anybody ever bust open the circuit breaker?

BTW, I just changed out the switch on the second brick that the LED quit on. They apply 120vac to the LED without an external diode. Assuming maybe the LED is just an LED and not some special LED with a built in diode, I put a diode in series with it. And I reduced the 15K in series with the LED to 8.2K which looks good for illumination and is about 7ma.

We'll see.

Thx, John; that's a start.  I DID swap bricks, to no avail....Same behavior.   The brick is 'normal', I believe.

  I think Dale M has/knows the circuit.  I'm waiting for his input....

I see nothing in the PH180 schematic that would lead me to believe that it accumulates overloads before tripping, and I've never witnessed that kind of behavior.

There's some filtering in the circuit, but with an significant overload they'll trip instantly, and with a gradual one they'll go in a few seconds.  Most of the circuit is a latch to hold the relay until you press the reset button, SW1.  L1 senses the current and provides the over-current sensing.

That was me, Chuck...our posts passed each other in the ether...

This was bricks, right? Not powerhouses...

The only 180 watt Lionel "brick" I know of is the PH180.

I have these.

http://www.lionel.com/Products/Finder/ProductDetail.cfm?ProductNumber=6-22983&expandBranch=0&Keywords=&CategoryID=40&RailLineID=&CatalogId=

I thought that's what Phil was asking about.

They only have a switch, circuit breaker and cords. Essentially a simple transformer.

Chuck, that is the PH180 brick!

They have a lot more inside, open one up.  The circuit I posted is inside each PH180.

 Now that I think about it, I don't know what is in the little plastic circuit breaker box.

I've had them open and they didn't seem to have that much in them.

The pilot light ckt on the input is totally different.

Maybe it is that sophisticated...I wouldn't have guessed they were the same...but they are. Except for the led and the resistor on the input...and maybe more inside the little box. Wonder if it's SMD in the little box.

Interesting enough, Lionel has a suggested configuration of two PH180's in parallel for use with the TPC-400 track controller.

Chuck, I'm confused about your statement about the pilot light.  AFAIK, it's wired just like the schematic, if you trip the breaker (which actually activates the relay), the pilot light stays illuminated on the brick.

Well that's interesting. All the parts in the schematic look to be old stock items. I figured the circuit breaker was something fast, but I had seen that schematic in the past and it looked like something that might have been updated circuit wise. Maybe a commercial sealed item.

Don't these get hooked in parallel when connected to a TPC with the two into one connector? If they are in phase, it should be ok.

Yes it stays illuminated if the brick trips. In the ones I have, the light is an LED inside the switch and is wired with an external 15K in series from the 120vac line output from the switched ac contact and ac common. I found the exact switches a couple years ago and replaced the first one that went out. I put a diode inside to protect the led. Just today, I noticed another LED was out on one and replaced the switch, added a diode and this time I put an 8.2K resistor instead of the 15K which looked a tiny bit not as bright as I wanted.

I think the diode is a good idea for maximum LED life.  I used to lose a couple LED markers and headlights before I put the diodes in, none since I started that practice.

Hold the phone!  Now it seems that my [unique?  Probably.] problem ONLY occurs with one passenger train:  6 K-line Red Cross heavyweights.  An 8-car train of K-line CAL-TRANS cars does NOT cause it! [Even tho' these are high-amperage cars....].  So, let's hold off on 'solving' my problem until I have it better-defined!  Please, tho', keep the related discussion alive; it is very interesting & useful.  BTW, I'm open to suggestions on what else to try.....I'm also going to put an ammeter in the ckt, to see if any new info surfaces.

In the schematic, both U1b and U1c are amplifying the current sense signal.  U1c, the "overload" detector, has a gain of 148, but it is slowed down by the resistor and capacitor on its output.  The time constant (RxC) is 2.6 seconds.  Multiple short hits to this RC combination would charge it up until it trips the relay latch.

U1b has a gain of 37, which means it requires 4 times as much current, but it acts instantaneously for "dead short" situations.

I would expect the lamp in the power switch to be a neon bulb, not an LED.  A neon bulb is typically operated from the AC mains with a series resistor to limit "ON" current when the neon "ignites" and starts to draw lots of current (negative resistance device!)  They also die prematurely if the currents are too high.  Chuck, can you break a removed switch open to see what is inside?

OK. I took one of these apart a year or so ago and considered replacing the LED, but I don't think I did because of it's shape. I went looking for an led and I found the switches.

With a new led, the switch is easily repairable. The rocker just pops in with the two little pivot nibs into the sides of the housing. Maybe I'll look for some of these LEDs again. They should be easy to find.

I think you can see the "cat's whisker" inside the LED...at least that's what I was trying to focus with the iPhone. Thanks for your thoughts on the circuit.

In response to Dale's time constant info:  After the train has left the turnout, the flicker seem to have a cycle time [period] of ~ 1/2 to one second.  This repeats several times [ON/OFF of my LED], then stays OFF.  Brick power is then also off.

Here's an update, ending with a surprise:

1.  I forgot to say that the flickers were not always consistent/simultaneous with the passing of each roller.....just sometimes.  [BTW, that word summarizes the entire situation & my experiences:  SOMETIMES!  Nothing is consistently repeatable.]   Other times the flickers began when half the train had passed the turnout, and then the period was different  [longer] and would continue for about 3 - 5 cycles after the train was gone....always ending in the dark/off mode.

2.  Current measurements showed nothing unusual or suspect:  1 - 4 amperes.

3.  Yesterday, the entire problem was absent!   Same trains, same running conditions.  I can't think of what might have been different........Room temperature?  Humidity?  Time of day?  Day of week?  I'm now more stumped than ever!

Phase of the moon.