153IR Controller

Popped open the unit to look for anything obvious and the only thing found was a difference in the IR detector sensors.  Were these changed/upgraded at some point?  Can they be repaired/replaced?  All solder points, other components and wiring looked good. 

Thanks.

As first-hand knowledge does not appear forthcoming...

Can you trigger it by sunshine or an incandescent (not LED) lamp aimed at the detector?

When you say difference in the sensors, do you mean you're comparing this to another 153IR you have?  If you're saying the two devices within a single 153IR look different, that is to be expected as one is an LED emitter (sending out the IR beam) while the other is an phototransistor receiver (detecting the reflected IR beam). 

If you have some photos I can probably give additional troubleshooting suggestions such as voltages to measure.

Stan,

Thank you for the reply, what I meant by difference was between two different units, not the "eyes."

The reason I mentioned the difference, is, I had suspicions that someone has been into this unit before.

I can try the different light scenarios, and also post photos when I get home tonight, (that's if the MI "state bird, aka mosquito, doesn't carry me off).

Pursuing this for own edification, not end of the world if the darn thing can't be fixed. 

Since you have a 2nd unit (presumably working) it's going to be so much easier to edify.

For example, if it's convenient to hook up both at once you could shoot one unit's beam toward the other unit's sensor.  And you're probably familiar with the trick of looking at an IR emitter with a digital camera to see the blue-ish/purple-ish glow if it's actually emitting IR energy.

I think you'll be able to repair it and learn something along the way.  I tried searching for "153IR schematic" without luck, but if you have a clear photo of the board I think that might suffice.  The sensors are about 25 cents in small quantity and I believe you don't need a specific part.

Ok Stan, great info   Did not get photos or even down to the layout last night, but...  I have a four day weekend coming up so will be able to do the things you've suggested as well as post some photos.  Really appreciate your help! 

Hey Stan,

I played around with these a little tonight, and discovered that when power is applied to the one that is working it clicks.  The one that is not working does not click, but does pass power to the accessory.  So maybe there is a relay that is bad?

Tried to upload some photos, but our ISP will not allow them to go through.  May be I can get up to the Mickey D's tomorrow and upload them.

Thanks again for the support and help.

If not already familiar with them, I'd fiddle with the sensitivity and time-delay adjustment controls on the working unit to insure they indeed work.  Here's a photo from the 153IR user manual.

You should be able to trip the working unit (click) and then when you remove the source of IR energy reflection from the unit's emitter (or from external "stray" sunshine/lamp) the adjustable time-delay runs out and relay clicks off.

When the relay turns on, power is passed to the accessory thru the NO (normally open) contact.  If the non-working unit is passing power thru the NO contact when the relay is off (you never heard a click) then you either have a wiring problem...or I suppose the relay could have failed "stuck" on.  With a meter, measure the AC voltage between ACC PWR and ACC GND to first determine the voltage being switched.  Then measure the voltage between the NO and NC contacts and ACC GND.  When relay is on, you should get the voltage on the NO contact but not on NC.  When relay is off, you get the voltage on the NC contact but not on NO.

If you do get a chance to upload photos, the more the merrier.  I've never seen close-ups of the 153IR interior.

Stan... regards sensitivity control and working 153, yes I am aware, and yes it is working correctly, had it controlling a block signal last night.  I had forgotten about the relay clicking it had been so long since I had hooked one up.

Ok... now for pictures...

First is the working eye...

Here is the eye of the non working unit...

Ok, now for pictures of the boards, in the following the left board is the working one...

So to be clear, the non-working unit applies power to the accessory via the NO contact...and it does so without hearing the click?  So the relay frozen/stuck in the on state?

I retract my suggestion about just shining light on the non-working unit.  In both designs the IR sensor/detector requires modulated (pulsed) infrared energy.  This pulsing is at around 40 kHz (or so) so steady IR energy from sunshine or a lamp will not trip the sensor.

The non-working unit has a shield on it - this is particularly useful for this sensor in TV's and VCR's where there is a lot of other electronic noise but should work fine without it (as demonstrated by the working unit).  Typically you can buy the sensor with or without the shield (a few pennies difference) though these run closer to $1 than the non-modulated sensor I initially though they used.

It's funny that the unit on the left looks like it has more re-work done on it!  And that's the working one.

So if the relay is frozen "on", then obviously it needs replacement.  I see the Massuse ME-1A-5B relay on the web from Asian suppliers but doesn't seem to be in US distribution (Digi-Key etc.) though I admit I didn't look that hard.

If the relay is no frozen "on" and it really does click on/off though perhaps with a mind of its own (not tied to the sensor), then we can proceed.  For example, this is where you'd shoot the beam from the good unit to the bad unit to see if it trips.  I was going to suggest swapping boards, but what appears to be the newer (non-working) board based on board version number has a different connector 5 vs. 6 pins so I don't think you can do so.  The non-working board appears to use a crystal which is probably to generate the pulsed IR - an crystals as vibrating elements can fail.  I assume you don't have an oscilloscope (?) so if we get there I'll have to about how you can test this.

Regards the revision, I was thinking the same.  Don't have another to compare to.

My BF has an oscilli... however you spell it.  What do we need to do?

First answer question about relay.  Is it really stuck 'on'?  So power is applied to accessory via NO contact and the relay never clicks.

Yes, it is stuck on.  Yes, power is applied to accessory via NO contact and no clicking.

OK.  Let's confirm the relay is stuck on.  From what appears to be the Massuse relay datasheet I found online, I copied the relevant connection info into your picture. 

So the relay's "com" terminal which carries ACC PWR is somehow making a direct connection to the relay's "NO" terminal even with the relay off (relay coil not powered).  To confirm this, I'd disconnect all wires and use meter's resistance mode to see the zero (or near zero) Ohm reading between the ACC PWR (com) terminal and the NO terminal.  I can't see any solder splashes or whatever but inspect the board closely to make sure there are no tiny strands of wire or whatever that might be bridging the gaps between these two terminals or the printed-wiring on the board.

So if there is a short between these two terminals with no power applied, then I'd say the relay needs to go.

When checking between the COM and NO spots you pointed out, there is 0 on the meter.  My BF says that's bad, so I assume to fix this puppy I gotta find a new relay.  So now comes the big search, eh? 

Would it be safe to say that further trouble shooting is on hold until the relay is replaced?  What would cause the relay to get stuck, a short, or too much power or what?  I'm thinking "what made the relay fail in the first place, eh?"

I'd hold off on further troubleshooting until you replace the relay.  Yes, I suppose you could mess around taking measurements to see if relay-coil voltage is being applied when the unit is triggered but I think there's a good chance you replace the relay and bingo.

I recognize some of the Asian suppliers that come up in a web search with the part # but I don't have any experience with them.  I don't have much Lionel stuff but I wonder if one of their service centers can get this part?  If it's nowhere to be found I suppose you might try a replacement - it may require some soldering-handiwork or the like but it appears to be a 5V SPDT relay with 2 Amp contacts which should be easy to find for a $1-2 I'd think. 

Good question on what made it fail.  I'm sure everyone has a relay story, but what I'd do (remember, we're talking edification!) is carefully cut it open and see.  Obviously these are very simple devices with just a few moving parts.  You may destroy the evidence in doing so but what else are you going to do with the relay?!

OOOh, I almost said...  "sounds like a plan... ",  sorry.  But, yes, I agree.  If it's toast what else is it good for.  I've got a couple electronics stores here I can check with and go from there.

Thanks again for all your help and patience, I'm learning   I'll update if I find a relay and get 'er workin'. 

FWIW, found an online source and ordered 5, will see...

Since board appears to have solder pads on one side only, it should be fairly simple to remove the relay.  Suggest a quick meter check after removal right on the relay pins to confirm COM and NO are indeed shorted with no power applied.  If you do end up opening the relay and can take some photos, I'd be interested if there's something to see.

Well....

Got the new relays today.  In the process of removing the old one part of the trace on the board came up   I used a piece of wire to jumper the trace.  Hooked 'er up, and... 

No joy .  How would I activate one of these little dudes off the board?  I'm thinking there is another component here that is not passing power to the relay.

We are still on the verrrrrry slow internet highway here, in fact, our ISP is folding their tent and calling it quits the end of Sept., so posting pix are a no go until tomorrow from work.

Perplexed!!

But does the unit pass power to the accessory all the time like it did before?  I assume at least that problem went away.

If you momentarily apply DC voltage to the 2 coil pins of the relay you should hear it click on and off.  See diagram from earlier post showing the 2 coil pins.

Next would be to go step by step thru the signal path.  First confirm unit is putting out a pulsing (modulated) IR beam from the transmitter. Then confirm receiver/sensor is detecting that pulsing beam which can be done by measuring the voltages on the 3-pin black sensor chip.  Then it gets a little tricky since it looks like the right hand unit uses a custom circuit to perform some kind of timing before it applies voltage to the relay coil.

Call me illiterate, but...  coils?  Do you mean the NC/NO pins?  When I put DC voltage on the relay, I couldn't hear/get any response.  I have an HO DC transformer and I measured output to keep at/below 5V.

There is a regulator/rectifier that power passed thru before reaching the relay and I am wondering if that is bad.

As to power, there is no change in the behavior regarding that.  I was also testing with out the optical module in the circuit.  I can retry testing with that hooked up, but I should think the relay would respond either way.

BTW, looked for email in your profile, none there, was going to catch you up that way when I can't get onto the WWW.  FWIW.  Appreciate your interest and insight.

HO DC transformer set to 5V (or so) is perfect for testing the relay.  Apply 5V DC (4V to 6V will work fine for this relay) to the relay coil as shown.  + or - orientation does not matter.

The coil is so named because it's essentially an electro-magnet created by winding a coil of wire around some ferrous object....like around a nail in the iconic high-school science project.  The electro-magnet when activated pulls a small arm so the COM contact moves over to the NO contact.

If power is still getting to the accessory with the optical board disconnected that's a problem.  If I didn't suggest it earlier, the idea here is to use a meter to see if there's some kind of wiring short between the COM and NO contacts on the board with the relay out of the circuit.  Likewise when you pulled the allegedly bad relay from the board, I'd measure the resistance between the COM and NO pins on the loose relay to see if it's indeed stuck "on".  Obviously you can compare readings to one of the new relays to confirm that there is infinite resistance between COM and NO when no power is applied to the relay coil.

Jumping ahead a bit, are you familiar with the "trick" of using your digital camera to look at an active IR transmitter to see that it is indeed transmitting IR?  It should appear as a purplish-blue-ish glow in the viewfinder while obviously invisible to the naked eye.  This is not fool-proof when testing modulated IR transmitters as used here but it's a start.

Stan is talking about powering up the relay coil with a voltage source, not talking about the contacts on the relay at all ok!

He is trying top verify that your relay coil is now

 working when powered up ok

Alan

About the digital camera, yes, somewhere it was mentioned, but I could not see any thing on either my working or non working unit through my camera.  Does the camera need to be set some way for this to work?  I have a Canon Rebel.

See...  I knew I was doing it wrong! LOL will pursue this tomorrow as it's nearly bedtime for me and report back then.  I was trying to use the COM and NO/NC pins to power the thing .  I can follow wiring diagrams and solder, but the terms are a little sketchy for me .  I'm learning.

Will also double check the original relay for short now that it's off the board.  I also check the working unit to see if it passes power with the op mod disconnected to confirm whether that is truly good/bad.  Thanks for checking in, appreciate all your teaching

OK, decided to do a quick test before bed.  I pulled the op mod out of the unit and hooked it up, applied power, and no change.

I tested, via the coil, both the newly installed and the old relays and they both click, so the old was ok.  Wish I had figured out how to do that before I took it off the board.  Sigh...  live and learn, eh,

I also, for giggles, applied DC power to the coil of the relay installed and it would click and change the lights from green to red.  So I still am thinking it isn't getting power.  That dohickey with the hole on top is in line with common/ground going to the relay.  It has "L7805CV MKO700235 China ST" on it.  It's kinda brown and toasty looking and it's center pin is the one inline with the relay.  FWIW. 

The 7805 device is what generates regulated 5V DC used throughout the 153IR.  It has 3 pins.  You should be able to measure 5V DC between the center pin (Ground) and the top pin of the picture as labeled.  As you observed the Ground is connected to one side of the relay coil.  And as you observed you can apply 5V to the relay coil and hear it click.  So what's going on is quite simply.  The 5V DC from the 7805 goes via the Yellow wire to the optical module.  When the optical module detects the passing train it sends back the 5V DC to the relay coil via the Brown wire.

What's puzzling is you're saying there's no change in behavior with the optical module disconnected.  In other words the accessory is still getting power even with the relay in the "off" state...and in fact even with the relay taken out of the circuit board!  That tells me you have some kind of short-circuit (from a solder blob, errant wire strand, whatever) shorting between the relay's COM contact and the relay's NO contact.  So with the optical module disconnected, are you really reading a short (0 ohms) between the relay's COM contact and the relay's NO contact? 

Ok, your pix helped alot. I thought at first it was a matter of just looking through the camera, (ya gotta take the shot, lol)  So I did, and yes, I got the purple glow from the eye, so it's getting power.  So what about the crystal and the oscillascope thing.  Think that's a possibility?  Think maybe a bad trace?  Waiting for my instruction, teacher

Since this is about learning, if you have a scope convenient I'd hook it up as it will be more instructional than a meter.

To review, the idea is the IR LED sends out a modulated stream of pulses...probably about 40,000 times per second or every 25 microseconds or so.  The IR sensor detects the reflection of this beam off a passing train.  The sensor has internal electronics that is tuned to detect this pulsing IR beam; the tuning rejects ambient or stray IR energy from lamps, sunlights, etc.  The detected signal triggers the relay and there's a timing circuit that keeps the relay closed for some period (settable by control knob).

So as you correctly stated, the purple glow simple means the IR LED is getting power.  But it could indeed be that it is not pulsing at the magic frequency, or it could be stuck "on" putting out continuous IR energy like sunlight, or whatever.  Since you have the scope out minds as well see what the IR drive signal to the LED looks like.  Connect the ground clip of the scope probe to the 7805 metal tab (with the hole).  The metal tab is the circuit "ground" and will serve as the reference voltage to the scope for all the measurements. 

Here's an annotated front/back pic of the broken board.  It should have enough resolution to click on it and get additional detail.

1. First confirm that you have 5V DC coming into the optical module at the 6-pin connector.  So that's a "solid" line on the scope.

2a. Now confirm that the LED is pulsing.  Typically one of the two legs of the LED will be at a fixed voltage and the other leg will be wiggling up/down 40,000 times per second.  So attach probe to one solder blob and note what it is doing, then attach probe to other blob.  In all likelihood you'll see a pulse-stream or square-wave with each new pulse occurring every 25 microseconds or so.  The amplitude or height of the pulses should be about 1 Volt.

2b. Whether or not you see the pulse stream, rotate the sensitivity (NOT the delay) knob over the full range and make sure the pulse stream does not vanish.  I'm guessing you'll see a slight change in amplitude of the signal but the timing should not change.  Assuming it's pulsing, leave the control at the mid-point.

3a. Now to the sensor.  First confirm the sensor is receiving power.  That's the top pin in the photo labeled "power".  It should be about 5V DC.  The center pin should be at ground or 0V DC.  The bottom pin is the magic signal that should change from 0 to 5V when the reflected IR signal is detected.  I'm pretty sure it should go to 0V when a reflection is detected and 5V otherwise.  So put your hand or whatever in front of the LED-sensor pair and see if you can make this signal alternate high/5V and low/0V.

Note: if you are tempted to try this on the working unit, it appears the sensor on that optical module is mounted upside down relative to the non-working unit.  In other words the sensor output signal is on "top".  In any event the 3 legs of the sensor should show +5V on the power pin, 0V on the ground pin, and a high/5V or low/0V signal on the output indicating whether or not reflected IR has been detected.

4a. Finally, look at the signal which drives the relay coil.  Yes, there is all kinds of circuitry between the sensor output and the signal which drives the relay coil but without a schematic it's tedious.  So jumping ahead to the processed signal (with time delay).  I believe or it looks like a brown wire which drives the relay coil.  This comes from the 6-pin connector as shown.  There's a transistor (black component with 3 legs) that drives the coil with 5V DC when the relay is triggered.  The key signal is the top solder connection with the pink line.  If you probe that signal it should go low when the sensor detects the reflection and high when no reflection.  It will have the delay on it so when the reflection disappears it will stay low for seconds (depending on what you set on the time-delay knob).

4b. If the transistor is getting its control signal on the top pin, it boosts the current to drive the relay coil.  So on the connector, the signal should go to 5V when triggered and 0V when off.

There.  Now that's quite an assignment.  So get out your #2 pencil and let the games begin !

KD

This might not get done right away, lol. I use mechanical pencils!  (w/#2 lead)   As soon as there is something to report, report I will   Thanks again for your help!

Ok, haven't had a chance to put this thing on the scope yet, to many things to do!!!  Anyway, I did take the top off the old relay, and here it is...

I didn't go any further as it's sill working and I figured I could always tape a new cover on it and still use it, lol.

FWIW