Author Topic: Bowling foul detector  (Read 3860 times)

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Offline RyanG

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Bowling foul detector
« on: May 17, 2018, 03:20:08 am »
I got this board from someone that got it from someone else. They want me to see if I can fix it. I think I know what the problem is, but I figured I would see what everyone here thinks. They said that it blows the main fuse(F1) every time it is plugged in. The fuse is in the black fuse holder below the transformer in the picture. Someone else originally worked on this board because the transformer broke off. They reconnected it by using all the wires jumped off of it, and epoxied the transformer to the board.

I checked everything on the secondary side, although I was fairly sure that wasn't the problem because the secondary fuses (F2 + F3) were alright. There were no shorts on the 2 separate secondary rails. I checked for shorts on the secondary side of the transformer, which has 2 outputs of 12v and 24v. One of them read around 160 \$\Omega\$, while the other read open circuit where I would have expected either half or double the resistance depending on which winding is which. I then checked the primary side, which read 0.3 \$\Omega\$ between any 2 taps on the transformer. So, I am assuming that the transformer is shot because it should be able to accept 110v or 220v. Could it be anything else?
 

Offline Bratster

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Re: Bowling foul detector
« Reply #1 on: May 17, 2018, 03:30:40 am »
You should get a lower resistance on the secondary side and a higher resistance on the primary side.
My guess is when that Transformer broke off whoever put it back on, put it on backwards putting Mains power on the low voltage secondary, which keeps blowing fuses.

And whatever Force caused it to break off may have fractured the connection between the Transformer pin and the winding itself, and that could be the cause of 1 winding open circuit.

I would disconnect all the wires off that Transformer and then take ohm readings off of it and see what you get.

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« Last Edit: May 17, 2018, 03:34:51 am by Bratster »
 

Offline RyanG

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Re: Bowling foul detector
« Reply #2 on: May 17, 2018, 04:43:11 am »
I pulled the transformer off the board and desoldered the wires from it. On what was wired as the primary there was one winding with around 10 \$\Omega\$ and the other with 0.3 \$\Omega\$. The other side read open and 160 \$\Omega\$. I pulled the tape off the transformer and the one pin had no wire connected to it. So, it looks like you were right about them putting it back on backwards and one of them being broken. I am having trouble finding a datasheet for the transformer. If anyone knows where to find one or what the part number might mean for a ST-5-2370 that would be a big help.
 

Offline floobydust

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Re: Bowling foul detector
« Reply #3 on: May 17, 2018, 11:32:32 am »
Check Signal Transformer ST series pdf , but -2370 sounds like a custom part that is more than 6-pin, like a triple secondary part.
I wonder why it's installed upside down?
You could ask the bowling board manufacturer what the correct part is, or you would have to sketch a schematic of the board to estimate the voltages.
 

Offline RyanG

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Re: Bowling foul detector
« Reply #4 on: May 17, 2018, 10:52:47 pm »
It is an 8 pin transformer. It is labeled as 120/240v input with two outputs of 12v@0.5A and 24v@0.15A. I contacted Signal Transformer to ask them for info, but it looks like they won't be much help because they are asking for my business information instead of answering my questions.
 

Online james_s

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Re: Bowling foul detector
« Reply #5 on: May 17, 2018, 11:51:38 pm »
Well you have all the information you need there to find a suitable replacement, anything with similar voltage ratings and equal or greater current capacity will work. Try the parametric search on Digikey or Mouser and see what comes up. You will likely have two separate 120V primary windings that can be connected in either series or parallel to set the voltage, then two separate secondaries.
 

Offline Cyberdragon

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Re: Bowling foul detector
« Reply #6 on: May 18, 2018, 12:31:39 am »
If some daft dingus reverses the transformer and kept plugging it in, the transformer being fried is the least of the problems. Unless it has overvoltage protection on the secondary, it would have boosted the mains to insane levels and toasted it. I'm suprised the cap didn't become a bomb. :scared:
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Offline RyanG

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Re: Bowling foul detector
« Reply #7 on: May 18, 2018, 12:40:52 am »
I powered the 12v part of the circuit from another transformer I had around and everything seemed to work. I don't have a 24v transformer to try to hook the entire thing up. I might have two 12v around here somewhere though.

This transformer that I found on Mouser should work https://www.mouser.com/ProductDetail/Bel-Signal-Transformer/DST-5-24?qs=sGAEpiMZZMuKmRn7rpQYPW79jdBrHTAV%252bTfgpFz71P89OLHFadBeOQ%3d%3d. It is the same size according to the part number 5-2370 vs 5-24 since the 5 is the size according to the datasheet. The power rating is good. One question is about the secondary side. It says 24VCT/12V. Would that mean the windings are separate as the dual winding states or is it just 24V center tapped for 12V? Sorry, never had to pick a transformer out for anything.
 

Offline floobydust

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Re: Bowling foul detector
« Reply #8 on: May 18, 2018, 12:47:12 am »
8-pin dual primary are the DST series, which have two isolated secondary windings.
Off-the-shelf transformers always have these two windings with the same rating. So a 12V and a 24V winding would be a real oddball. It should be dual 12V windings in parallel.

Can you check if the secondary windings are in series (pin 6,7 connected) or parallel (pin 5+7 and 6+8 connected) on the PC board.

When I look at your PC board, I see only one bridge rectifier, a buck SMPS and one extra diode.
Making the 12VDC relay coil voltage seems to be the most needed. U7 may be a 78L05 5V regulator IC.

There is fuse F1 so that is probably why no smoke happened.
 

Offline RyanG

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Re: Bowling foul detector
« Reply #9 on: May 18, 2018, 01:06:50 am »
Here is a picture of the top and bottom together with the bottom mirrored. No traces on the top connecting any pins on the transformer.
 

Offline RyanG

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Re: Bowling foul detector
« Reply #10 on: May 18, 2018, 02:43:58 am »
Could it be that it is just 2 12v windings and the rating on the transformer is for the series and parallel usage? The trace that runs up to the black wires goes to a buzzer labeled as 12VAC. So, that seems likely.
« Last Edit: May 18, 2018, 02:46:35 am by RyanG »
 

Offline Gregg

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Re: Bowling foul detector
« Reply #11 on: May 18, 2018, 02:49:04 am »
It almost looks like the transformer has been replaced and isn't the same footprint of the original.  It looks like the original may have had pin terminals through the board, but the replacement wouldn't work without wires, which were inverted when installed.
 

Offline RyanG

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Re: Bowling foul detector
« Reply #12 on: May 18, 2018, 02:55:02 am »
The transformer broke off the board. This is a foul detector for bowling, and they get hit by balls and people step on them often. When it broke off the pins broke so they flipped it over to solder it back on, but soldered it backwards. That is how I received it.

Attached picture of the label on the transformer.
 

Offline KE5FX

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Re: Bowling foul detector
« Reply #13 on: May 18, 2018, 03:02:53 am »
Whoever replaced that transformer has entered a world of pain.  Was his name "Smokey?"
 
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Offline floobydust

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Re: Bowling foul detector
« Reply #14 on: May 18, 2018, 03:48:46 am »
Ah one winding powers the board, and the other winding goes to the relays to the buzzer?

It could be a label typo, it should read 24V 0.25A (series) if it's a "normal" part and bowling system uses 12VAC for lights buzzers etc.

I'd measure the transformer pins and confirm size, and get the DST-5-24 or Hammond 162G24 or Tamura 3FD-24 etc. as 12VA parts are a common size and footprint.

Hardest part is desoldering that mess
 

Online james_s

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Re: Bowling foul detector
« Reply #15 on: May 18, 2018, 03:52:29 am »
It's probably a custom transformer, I certainly have some in my junkbox that produce multiple different voltages, I think it was more common in older equipment. If you get desperate you could replace it with two separate transformers to get the voltages you need, or get a transformer with two 24V center tapped secondaries and use only half of one of them to get the 12V.
 

Offline RyanG

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Re: Bowling foul detector
« Reply #16 on: May 18, 2018, 04:06:35 am »
I found the manual for this thing. Found the important info.
 

Offline RyanG

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Re: Bowling foul detector
« Reply #17 on: May 18, 2018, 07:07:09 am »
I do think there is something else wrong with this though. I hooked up a 12vdc power supply to the board, and I can't get the IR detectors to work. The emitters are working. I used an IR receiver on a breadboard to check for that. I can't get the LEDs to blink, which is what the manual says is supposed to happen when the receivers detect the emitters being reflected back.
 

Offline Cyberdragon

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Re: Bowling foul detector
« Reply #18 on: May 18, 2018, 09:07:11 pm »
I do think there is something else wrong with this though. I hooked up a 12vdc power supply to the board, and I can't get the IR detectors to work. The emitters are working. I used an IR receiver on a breadboard to check for that. I can't get the LEDs to blink, which is what the manual says is supposed to happen when the receivers detect the emitters being reflected back.

As I said, it got blasted by HV due to the backwards transformer (the fuse only stopped a fire, not all damage). You might just have to replace the chips controlling the receivers (the diodes themselves should be fine).
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Offline floobydust

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Re: Bowling foul detector
« Reply #19 on: May 18, 2018, 09:21:34 pm »
If the 5V and 12V rail is OK, I see two trimpots and two test points for setup.  R5/TP1 maybe for the LED driver, and R6/TP2 for the receiver.
We have no idea where the ribbon cables go.
Otherwise you'd have to troubleshoot measuring IC voltages.
 

Offline RyanG

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Re: Bowling foul detector
« Reply #20 on: May 18, 2018, 10:56:37 pm »
U1 is a TLC274 Quad Opamp. U4 is a PIC16C71-04. U5 is a ULN2003. The MCU has 2 outputs doing 50% duty cycle at 1.96Khz and 2 outputs doing 16.5% duty cycle at the same frequency. The 50% duty cycle goes out to the ribbon cables. That then seems to go to the IR emitter. The voltages for each IC are correct, but I don't know what voltage the onboard SMPS is supposed to put out. The 2 test points have nothing on them with or without the IR being reflected. I don't know what to do with it.
« Last Edit: May 19, 2018, 12:24:29 am by RyanG »
 

Online james_s

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Re: Bowling foul detector
« Reply #21 on: May 19, 2018, 12:51:09 am »
You'll probably have to reverse engineer a bit to figure out what conditions the IR signals. The fact that the PIC is doing something is a good sign, if that's dead then it's game over unless you want to re-write the firmware from scratch.
 

Offline RyanG

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Re: Bowling foul detector
« Reply #22 on: May 19, 2018, 04:47:36 am »
The first thing I have tried to reverse engineer is the connection to each IR module. There are 4 wires in the ribbon cable. They are V+, GND, 1.96Khz connection to the ULN2003 to flash the emitter, and the last I assume is the wire for the signal of when the beam of light is broken. I have not been able to get that signal to change on either IR module when I reflect the light into the receiver. I even made a flasher with an IR LED hooked up to an Arduino at the correct frequency with no success. I even took each of the modules off and pointed them straight into each other. That didn't do anything either.
« Last Edit: May 19, 2018, 05:02:57 am by RyanG »
 

Offline floobydust

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Re: Bowling foul detector
« Reply #23 on: May 19, 2018, 06:55:07 am »
Each IR module looks identical, it must be a reflective-type sensor covering a bowling lane on either side, with a mirror on the opposite end? I can see red alignment screws but no idea about focal length or how directional these are. It must have an analog output and LED pulsed out-of-phase to prevent crosstalk with the other lane perhaps.
Otherwise I can 't see why you need the quad op-amp. Can you give a pic of the IR module, I wonder if it's made by Sharp.




 

Offline RyanG

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Re: Bowling foul detector
« Reply #24 on: May 19, 2018, 08:18:59 am »
They do have a reflector opposite them when installed on a lane. I just checked the outputs from the MCU and they are 180 degrees out of phase. Picture isn't the greatest for some reason. It isn't a Sharp module by the looks of it. It just has a TLC272 opamp, a diode, a bunch of passives, and obviously the emitter/receiver are on the other side. I've tried reflecting the light back at many distances and tried angling the mirror/reflector slowly to hit it in the receiver, but it never works. I fed the 5v into the inverting inputs on the quad opamp and I can get the LEDs on the board to blink, so I think everything is still working alright on that part. I really don't think that I need to stand the width of a bowling lane away from it to reflect the light back correctly, but I could try.
 

Online james_s

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Re: Bowling foul detector
« Reply #25 on: May 19, 2018, 06:03:55 pm »
Are the IR emitters working? Some digital cameras can see IR to varying degrees, you can test that with a TV remote. I've seen IR LEDs fail on a number of occasions.
 

Offline RyanG

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Re: Bowling foul detector
« Reply #26 on: May 19, 2018, 07:07:16 pm »
I used a 2 pin IR receiver to light a LED on a breadboard. That worked, so I assume it is working. I also looked straight into the emitter, which has a lens on it that magnifies the diode. I could see some glowing in there, which would stop when I unplugged it. Between those two things I am fairly sure they are working.
 

Online james_s

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Re: Bowling foul detector
« Reply #27 on: May 19, 2018, 10:54:24 pm »
Yeah it certainly sounds that way. Careful staring directly into those things, I don't know if there's any risk of eye damage but some of them are very bright despite the fact that it's far enough into IR that you perceive only a very dim glow.
 

Offline RyanG

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Re: Bowling foul detector
« Reply #28 on: May 19, 2018, 11:39:39 pm »
Yeah, I thought about how it might be bad for my eyes. I did it anyway. I tried powering an IR LED from the circuit through the ULN2003 in case the flashing has to be precisely in time with the MCU signal and nothing changed.
 

Offline floobydust

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Re: Bowling foul detector
« Reply #29 on: May 20, 2018, 02:58:22 am »
I would measure the voltages at the 4-pin flex cable going to the sensors.  Power, GND, IR TX LED, IR RX and see what the RX voltage is doing.
It looks like a vanilla photo-diode amp, so I would expect an analog output voltage, but pulsed at the 1.6kHz unless you use a flashlight. A DMM should still average it.

I think the trimpots are for setting a sensor comparator signal to the MCU. You can note their position and try turn them either way.
But both sensors drifting might be another problem elsewhere in the circuit.

If this unit was hit by a meteorite (bowling ball), it might have knocked out something in the optics.
 

Offline RyanG

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Re: Bowling foul detector
« Reply #30 on: May 20, 2018, 03:23:36 am »
On the 4 pin connector I have the following.
Pin 1 - Low side of emitter going to ULN2003 50% duty cycle voltage ~6v and ~5v, this goes to a resistor then the ULN2003 so the voltage difference would just be the voltage drop of the LED
Pin 2 - VCC at ~6.7v
Pin 3 - GND
Pin 4 - constant ~450mv from one module and under 50mv on the other
 

Offline floobydust

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Re: Bowling foul detector
« Reply #31 on: May 20, 2018, 05:36:48 am »
From the pics I can trace a bit of the circuit. Hard to see the traces.
Quad op-amp U1 is has a gain stage with trimpot, so it amplifies the sensor's output, and then a transistor switch and output to the test point, and another op-amp stage and transistor switch to the MCU. Measuring the voltages on U1 will tell what's going on I think.

On the sensor PCB, their output is AC-coupled through capacitor C2. So, little DC expected. You could try measure ACV at the sensors' output for signs of life.
I'd expect <50mV DC on their pin 4 so the ~450mV measurement seems suspect.

Where is the 6.7V rail from, I thought 12V for the relays. U3 might be a 8V voltage regulator for U1, and U7 a 5V reg for the MCU. What are the part numbers on U7, U3?

The trimpots set the sensitivity (gain), so I'd give them a whirl.
 

Offline RyanG

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Re: Bowling foul detector
« Reply #32 on: May 20, 2018, 08:02:12 am »
Those measurements I gave were taken with a scope, so it was a flat DC value on the scope.

The 6.7v is from the LM3578. U7 is a 78L05 and U3 is a MC34064 undervoltage IC. I'm starting to think that random 6.7v rail is the problem. The relay coils are connected to the output of the LM3578. That might be enough to pull them, but I highly doubt that is the correct voltage. I put 12v straight onto the cathode of the schottky diode coming off of the LM3578 and I do get some output signal from the sensors then and at the test points. There isn't much of a voltage difference between high and low, but there is an approximately 2Khz square wave signal coming out. The voltage isn't the same between the 2 sensors but the frequency and phase of the signals are the same. I did figure out which pins on the quad opamp are for the inputs from the sensors when they detect a reflected beam. The test points go to ~3.5v when the correct pin is pulled high. When I stop pulling it high the 2khz wave comes back, which also triggers one of the relays. Even with that signal, reflecting the light back in or hooking up a separate LED to do the flashing doesn't work.
 

Online james_s

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Re: Bowling foul detector
« Reply #33 on: May 20, 2018, 05:54:24 pm »
Yeah that doesn't sound right, can you tell where that 6.7V rail is coming from? Often relays have their coil voltage printed right on them. It's possible that the 6.7V is supposed to be 12V, it may be coming from a regulator that is expecting to be powered by the 24V secondary.
 

Offline RyanG

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Re: Bowling foul detector
« Reply #34 on: May 20, 2018, 06:40:43 pm »
The 6.7v comes from the LM3578 that is connected to the big electrolytic cap, which is fed from the bridge rectifier. It would make more sense that the caps to are 50v rated if it is expecting a 24v winding on the transformer. 24v makes the LM3578 get extremely hot, but it puts out 12v.
 

Offline floobydust

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Re: Bowling foul detector
« Reply #35 on: May 20, 2018, 07:37:34 pm »
I'd say it should be regulating at 12V as the main rail for the relays, opto sensors and 78L05 input.
LM3578 is not a stellar part for efficiency.
But there's very little load, it should not get hot with say 18VDC input ((12VAC*120%)-2V)*1.414

I would check for other hot parts like those tantalum slug capacitor C18 to see if there is something drawing excess current. Otherwise the SMPS may be unstable if C20 is open, or maybe the IC is damaged from the backwards transformer overvoltage.

Another method is to reverse-engineer the LM3578 feedback resistors (R17 and nearby) to see what the design voltage is.

Getting close to fixing it ;)
 

Offline RyanG

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Re: Bowling foul detector
« Reply #36 on: May 20, 2018, 08:06:41 pm »
Hard to see most stuff around the LM3578 on top of the board because they spilled the epoxy all over that stuff when they used it to stick the transformer down. I checked to see if it is conductive, and it is not.
 

Offline RyanG

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Re: Bowling foul detector
« Reply #37 on: May 20, 2018, 09:16:36 pm »
Found this picture on the TI website. The red values are the values I found in the circuit, and from what I can see the circuit on the board is the same as the one in the picture.

The formula in the data sheet for R1 is:

R1 = (Vout -1) * R2

That makes Vout = 12v

With power applied I don't see any oscillation on pin 3, it is at the input voltage, and pin 1 reads as the input voltage
« Last Edit: May 21, 2018, 01:26:09 am by RyanG »
 

Offline floobydust

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Re: Bowling foul detector
« Reply #38 on: May 21, 2018, 11:44:28 pm »
The oscillator at pin 3 is 0.55Vpp not a huge signal. If the IC is dead or transistor switch shorted it would not step-down (buck) at all, just pass-through. Does it step down at all?

I wondered if the toroid inductor core is cracked, I would look closely. If the unit was bashed hard. It would give low inductance and might explain the regulator's behaviour.
 

Offline RyanG

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Re: Bowling foul detector
« Reply #39 on: May 21, 2018, 11:56:37 pm »
When I was testing the it with a higher input voltage(18v-20v) the LM3578 was really hot and then the LEDs started blinking. After that the TLC274 let out the smoke. I ordered a new of both and had to break the other ones to get them off the board because of the spilled epoxy. I burned the rest of the epoxy that I could easily get to with my soldering iron and scraped it off. So, now I'll wait until I get the new ones and I'll see what happens. Hopefully nothing else is wrong after the smoke.
« Last Edit: May 22, 2018, 12:44:21 am by RyanG »
 

Offline RyanG

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Re: Bowling foul detector
« Reply #40 on: May 29, 2018, 03:15:26 am »
I finally got the stuff in to try to fix this things. I soldered in the new transformer, opamp, and LM3578. I replaced the blown fuse. The voltage is regulated at 12v out of the LM3578. It turns on, but I still have no detection of the reflected IR.
 

Offline NiHaoMike

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Re: Bowling foul detector
« Reply #41 on: May 30, 2018, 05:51:30 am »
I always assumed those worked with strain gauges or weight switches under the floor. Wouldn't an IR beam be easy to step over for someone wanting to cheat?
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Offline RyanG

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Re: Bowling foul detector
« Reply #42 on: May 30, 2018, 03:04:17 pm »
If you mean step over without breaking the beam, then I would like to see someone do it. About 4 inches on the far side of the beam is where the oil starts on a typical bowling lane. If you step on that while approaching to throw a ball you will fall.

Back to the thing that is broken. I am going to get an actual reflector made for this thing from work next time I go in.
 

Offline floobydust

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Re: Bowling foul detector
« Reply #43 on: May 30, 2018, 07:47:56 pm »
I think you have the power supply fixed now, decent 12V? The TLC274 smoked, its max. is 16V I guess 18V killed it.

I would go back to the voltages/waveforms at the sensor 4-pin connector and see if they survived. You could even inject IR remote 38kHz light and see if you get a response.

For an IR mirror, a CD works. You can use a flashlight or laser pointer first to actually see where it aims.
The sensor's lens, I keep thinking it has a focal point, not a straight (collimated) beam. But it shouldn't be so finicky unless bowlers are to the mm.

In the old days, I'd use an IR detection card which has phosphor that glows when IR hits it. There are cheap ones out there.
 

Online james_s

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Re: Bowling foul detector
« Reply #44 on: May 30, 2018, 08:20:45 pm »
I always assumed those worked with strain gauges or weight switches under the floor. Wouldn't an IR beam be easy to step over for someone wanting to cheat?

What is gained by cheating at bowling? Kinda takes the fun out of the game, and certainly won't win you any friends. For any type of official tournament surely there would be someone keeping an eye on things in case anyone gets any ideas.
 

Offline RyanG

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Re: Bowling foul detector
« Reply #45 on: May 31, 2018, 02:56:26 am »
I tried bouncing the IR back with an actual reflector and it didn't do anything.
The 4 pin connectors are:
1- low side of IR emitter
2- 12v power
3- ground
4- 0v on one of them and a constant ~2v on the other

The main difference between the two is that the voltage across the IR receiver is about 8v on one side and less than 1v on the other. Neither side works though. Could it be the opamps on each of the IR modules are blown?
 

Online james_s

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Re: Bowling foul detector
« Reply #46 on: May 31, 2018, 04:13:32 am »
Possibly, doesn't seem like there are a lot of other things you haven't checked. Have you traced out the IR sensor circuit? Often there's a pullup resistor.
 

Offline floobydust

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Re: Bowling foul detector
« Reply #47 on: May 31, 2018, 05:44:06 pm »
The sensor looks like a vanilla (single-supply) photo-diode amplifier. It should have 1/2Vcc (6V) 1.1V across C4 from R5, R6.
I think the amplifier is AC-coupled between the two op-amp sections and at the output with C1 and C2 perhaps. C3 is for 12V power filtering.
You don't want the sensor output to include (DC) from room lighting and shadows etc. Only the HF carrier pulses. Unless D1 is not a clamp but a demodulator.

If you can measure some voltages and compare the two sensors- although both seem to be not working despite different voltages. That could also be due to the main board input affecting the sensors' output.
I tried to sketch a schematic but the pic is a bit blurry.
« Last Edit: June 01, 2018, 03:26:45 am by floobydust »
 

Offline RyanG

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Re: Bowling foul detector
« Reply #48 on: June 01, 2018, 01:51:26 am »
Here is a terribly laid out but accurate(I think) reverse engineering schematic of the IR module. I put the parts on the schematic as they were on the board for easier following of the layout while going through the process of following everything. I forgot to connect the V+ pins on the opamp symbols, but they are just connected to pin 2 of the P1 connector. Also, C2 value is unknown not 1uf. I will go back and make the schematic better later.
« Last Edit: June 01, 2018, 01:58:06 am by RyanG »
 

Offline floobydust

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Re: Bowling foul detector
« Reply #49 on: June 01, 2018, 04:34:28 am »
That looks good. The first op-amp is a photo-diode transimpedance (I to V) stage with the second op-amp I think as DC-restoration to keep the amplifier from saturating due to ambient light. It is a voltage-follower that integrates over a long time constant R4/C1 (~3.2 seconds) and very slowly keeps the (output) first op-amp biased at about 1.1V
R5/R6 at C4 sets 1.1V as the bias point with 12V power.
I would look for 1.1V at IC pin 5 and 6; pin 3 and 2 should be the same voltage and a bit higher at about 1.5V but I could be wrong here.

There's really the op-amp and photo-diode to have gone bad, unless cracked resistors from a bowling ball hit.

SMD marking code 5D probably a MMBD914 diode.
 

Offline RyanG

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Re: Bowling foul detector
« Reply #50 on: June 01, 2018, 06:41:00 am »
On one of the modules I get 1.1v at pins 5 and 6 and pin 2 is 750mV and pin 3 is ~500mV. On the other module 5 and 6 are at 8.75v, pin 2 is 9.5v, and pin 3 is 9.1v. The photodiode on the one with the high voltages is pretty warm, but not hot. It tests good with a multimeter with a voltage drop of about 0.46v which matches the other one. I checked the resistance of each resistor with a meter and they read what you would expect on both sides and they matched close enough to be within tolerance of the resistors. I wish I had a good one to compare to.
 

Online james_s

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Re: Bowling foul detector
« Reply #51 on: June 01, 2018, 06:50:09 am »
I wouldn't expect a photodiode to get warm, does the voltage across it change depending on the amount of light exposure? Do you have another photodiode you can try? It doesn't have to be an exact replacement, pretty much any photodiode ought to work for testing.
 

Offline RyanG

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Re: Bowling foul detector
« Reply #52 on: June 01, 2018, 06:12:30 pm »
The voltage doesn't seem to change between darkness and direct sunlight. I do have some other 2 pin IR photodiodes but I don't get how there is 9v at D2(the photodiode) anyways. One side is connected to the voltage divider to get the 1.1v and the other side is connected to an opamp input. I would think it has to be something wrong with the opamp. Maybe V+ is shorted to the inputs since everything reads around 9v on that opamp? Even if that is the case it doesn't really explain why the other one doesn't work when the voltages on that one are what they should be.
 

Offline floobydust

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Re: Bowling foul detector
« Reply #53 on: June 01, 2018, 08:43:24 pm »
I say the op-amp is shorted for the sensor with the high voltage readings at pin 5,6. The photo-diode is surrounded by high value resistors and normally there is not enough current available to warm it. The op-amp's inputs are probably shorted to power.

For the second sensor board, what is the output voltage (pin 7)? The voltage seems a little bit low on pins 1,2,3.
 

Offline RyanG

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Re: Bowling foul detector
« Reply #54 on: June 01, 2018, 10:55:03 pm »
The 2nd board has voltage of 750mV on pin 1 and 2. Pin 3 is around 500mV. Pin 7 is 47mV. Pin 5 is 1.1v. Pin 6 is 800mV.
 

Offline floobydust

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Re: Bowling foul detector
« Reply #55 on: June 02, 2018, 12:39:36 am »
For the second sensor, I think the dual op-amp IC has also failed.
The op-amp output at pin 7 is not coming up. I think it should, as (+) input 1.1V and (-) input 0.8V, so I think the IC is bad or there is a short on the output line, if it's connected to the main board. Also the second section (+) input pin 3 0.5V and (-) input pin 2 0.75V, and output 0.75V so not working as a voltage follower. Pin 3 and 2 should be very close to the same voltage if that op-amp is working.

I'd cut all the IC's pins to get it out and then use a soldering iron to wipe off the remaining leads and clean up the pads.
 

Offline RyanG

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Re: Bowling foul detector
« Reply #56 on: June 02, 2018, 01:48:51 am »
I guess it would make sense for both of those to be no good since the quad opamp went bad with the higher voltage before. If the V+ went up to the 18v when I hooked it up then they are probably bad, which it probably did because they run from the 12v supply that was having problems.
 

Offline RyanG

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Re: Bowling foul detector
« Reply #57 on: June 07, 2018, 05:42:05 pm »
I got the opamps in for each of the IR modules. I replaced them and everything works great. Thanks for all the help.
 
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Offline floobydust

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Re: Bowling foul detector
« Reply #58 on: June 07, 2018, 06:10:40 pm »
Hey that's great news. It was a lot of work.
Any other hassles and the trimpots may need adjusting.

For the search engines, QubicaAMF AMF Radaray Plus Foul Detector
Scantek Inc. 400-0038-000, 400-0038-001, 400-0035-001
 


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