A New Quirk for the 153IR Accessory Controller

When it randomly triggers (once per minute or whatever), does it stay on for interval as set by the Delay control?

Does the sensitivity control have the intended effect?  If you operate it in darkness (or drape a black tent over the unit) is the false triggering still once per minute or whatever?

@stan2004 posted:

When it randomly triggers (once per minute or whatever), does it stay on for interval as set by the Delay control?

Does the sensitivity control have the intended effect?  If you operate it in darkness (or drape a black tent over the unit) is the false triggering still once per minute or whatever?

Stan, the sensitivity control seems to work normally. And it seems to stay on for the usual delay time sometimes; other times much shorter. I have not tried it in a darkened room, but I will give that a shot and report back.

Rod

I don't like the "other times much shorter" delay time.  There have been different versions of the 153IR over the years, but the one I dis-assembled for study had a proprietary microcontroller chip that controlled the delay time.  Obviously with such a timing mechanism you should expect a consistent delay time every time it is triggered...even if a spurious trigger.  If the microcontroller has gone flakey then game over since there's no replacement chip available.

If the sensitivity control behave "normally" adjusting the range as expected, then it too suggests possibly the microcontroller chip has gone south randomly and incorrectly deciding there was an occupancy trigger from the IR sensor when not.  Again game over.

Another explanation could be a flakey power supply that converts the AC Accessory voltage to 5V DC used by the microcontroller chip.  But if such were the case I'd expect more frequent spurious events rather than "only" once per minute.

Given the price of the 153IR I would be pleasantly surprised if anyone was determined enough to open it up and attempt a DIY repair.  And of course it would be cheaper to buy another unit than send it in for professional repair if any tech would even accept it!  I'd of course take a look at it on principle but as you know we aren't even in the same country!

Rod,
I experienced a problem with my landline phone a while back that was intermittent over a period of months. The tech back at the phone company ran a check on the line from there but could not find a problem. So, I disconnected the line at the outside box and all equipment inside. I got a somewhat high resistance continuity reading between two lines. When I opened the phone cord outlet box, near the floor in the finished basement, I found a couple of dead Earwig bugs across the terminals. Evidently, as the humidity changed in the room, the resistance across the bug carcasses changed. After I vacuumed out the debris, the continuity disappeared, and the problem never came back.
If you haven't done so, open the unit and look for unwanted guests.

Dave

So I tried the 153IR today with the trainroom essentially dark, except for a small amount of building and accessory lighting. It behaved more or less the same way. The delay time was pretty stable, and the repeat time was maybe every 30 seconds, with the flashing lasting about 15 seconds. But sometimes the repeat time was more like a minute between cycles. Pretty flakey.

And every once in a while between major cycles it would "blip" for a fraction of a second, with no delay at all. I guess its pretty safe to say the 153IR is shot. But OTOH, the spurious crossing light cycles are not hurting anything really, so maybe its not a big deal. Time will tell. And Dave, I will likely pull it off the layout and open it up for a cursory inspection anyway, and who knows what might "jump" out of that?

Rod

If you pull it from the layout and look under the hood, would be a good time to squirt some contact-cleaner spray at the "open-frame" control pots.  I don't think this is your problem...but it has fixed flakey 153IR performance before.

Well, made some progress. Attached are a few pics of the inside of the suspect. Oh, and there were no varmints of any sort inside this thing, in fact its pretty clean.

Man these are crude and archaic looking boards by today's standards. We have come a long way with pcb's. I had written on the bottom "2002" which is likely the year I bought them. The upper left main board pic has a 7805 vreg in the top center, under the wire harness. Checked and the voltage coming out is 5vdc, as it should be. I tested the IR led for output with my phone camera, no joy. Nothing at all.

The upper right pic shows a view of what appears to be some sort of IC buried under a black blob mounted on a small board, which is soldered into the main IR board below it. The lower pic is the underside of the IR board and shows an NE555 timer chip at the top, and the joints where the IC board is soldered in. A couple of the solder joints look a bit suspect so I might touch them up, but I don't know if this board has anything to do with control of the IR leds. But I am not expecting any miracles here. I think maybe the patient is best put out to pasture.

One thing I always liked about these controllers is the cool spring loaded wire connectors. You can just see a corner of the output connector block in the lower left of the bottom pic. They sure make wiring and unwiring easy. Anyone know who makes them? I would love to find a source for these guys if they are still made.

Rod

Another observation is the relay in this old girl is rated at only 1 amp. I think newer versions have a 3 amp relay if I'm not mistaken?

Rod

OK I touched up the suspicious solder joints, but no change. Still no IR activity. I guess its "game over" as you say Stan. Ho-hum.

Rod

Well another update. I re-assembled this thing and just for laughs I hooked it up to power and a test light on the bench, with absolutely zero expectation of a happy ending. Well miracle of miracles, it works just fine again!! I gave it a full bench function check at various sensitivities and delays; all good. So I plopped it back on the layout and so far so good. Have to give it a good long run later this evening after company leaves.

I don't know what changed; maybe the solder touchups were more important than I suspected. Weird that there was no indication of IR light from the led? Hmmmmm....

Rod

Well, if you're not seeing the purple in your digital camera, then the IR LED is not producing.  It could be the circuit driving the LED...but I've had the 5mm IR LED for my TV remotes go out on me and changing the 5-cent IR LED solved the problem.  And while I am looking at a bag of 5mm IR LEDs, it does you no good since I'm a couple thousand miles away from you.

I also don't think this is your problem since if there is no IR LED energy, there should be no reflections that trigger the occupancy detector!   And yet you're getting triggers.

I suppose you could satisfy your curiosity, if you really have nothing better to do, by measuring the DC voltage across the 2-pins of the IR LED.  If you get 0V, then I suppose the 555 timer circuit which is pulsing the IR LED at about 40 kHz might be dead.  But if you get a reading of a few Volts, then it likely the IR LED is done.  If operating properly you should measure around 1/2 to 1 Volt DC across the 2 IR LED pins.

@Rod Stewart posted:

Another observation is the relay in this old girl is rated at only 1 amp. I think newer versions have a 3 amp relay if I'm not mistaken?

From an earlier 153IR thread, you appear to have an older design.  The one on the right below has the 3A relay.

Stan2004; I don't know what to say about the lack of iphone-visible IR from the led. There was no sign on my phone, but she's back on the layout working just fine again. I ran it a good long while today and tweaked the adjustments to get just the right amount of sensitivity and delay, about where it was previously. I like about 20 wig-wags after the train has departed the controller; this seems to have enough duration that most trains can make it from one 153IR to the other before it cancels, yet its not too long after the train has left the area. Others may like more or less of course.

If I still had it on the bench I would do the voltmeter tests that you suggest, but I am reluctant to tear it apart again of course. I have these two that were purchased in 2002, so they are older for sure. I also have another pair that were 2000 or 2001 maybe. They were the first issue and they have the annoying inconvenience of cancelling out after the delay period, even when a train is parked in front of them. I don't use them for that reason.

Sounds like it would be a good idea to order up some IR leds just to have spares around. Gotta do that. Anyway all is well that ends well and I thank you for all your help!

Forgot to mention that I also used some nail polish remover (couldn't get my hands on the contact cleaner, that I know is somewhere!) brushed on the two pots, and twisted them back and forth a few times. Who knows but what this might have solved the dilema as well?

Rod