@@Trafficlightdoctor What would happen if you pulled the load cell before putting the intersection into flash mode? Will the controller sense the fault and go into flash mode? Just curious.
@@paulburns4721 The lights will probably just turn off. That load cell determines what has power. So I'd assume that the lights would just turn off. The flash override probably has a secondary power connector for just the flashers.
if properly set up, programmed, and functioning, it should never happen. IOW if it happens something is broken. In this case it looks like a bad capacitor. Rare, but can happen.
It's interesting to see the load cell uses a Cinch Jones connecter that was first manufactured in the early 1930's for juke boxes & pinball machines among other devices. The connectors saw heavy use during WWII & are still relevant nearly a century later.
The missing visors on some of the heads and the wiring makes me think this was repaired quickly after a hurricane to a working condition then put on hold. Since you said its one of the rougher area of the city, finishing repairs is probably very low on the priority list unless there's a component failure as shown. Band-aids get you back on quick, but they can easily cause worse issues and more expensive repairs down the road.
I'm proud of the statement you made about where you came up from. Same thing is where I'm from. I grew up I did great but this town is still got his problems. So I'm proud that you have applied yourself and you will teach your kids do that. You do a great job
The Failed component is probably a Triac if it is AC, Transistor if DC, Shorted is the most likely failure mode. The conflict monitor does not know if the Red light is on, it only knows if the red light is commanded to turn on or off.
@pctek961 You are partly correct. The load switch would have a shorted triac. The monitor DOES "know" the red light is on (It monitors the output of the load switch) it doesn't trip since this condition is NOT a conflict. It is safe for a vehicle to proceed on a green light regardless if the indicates a red at the same time. If the green light triac was shorted it would be a different story. However, the monitor can be programmed to detect "dual indication" and it would trip anytime more than one indication is displayed.
for anyone wondering whats what in the video: The triac are the 3 pin devices bent 90 degrees from the board with the grey heat paste on the back and a hole in the tab. Those orange things are resistors, probably used to monitor current and detect shorts or opens. The white squares with 6 pins are opto-isolators, basically a solid-state switch that uses an internal LED to trigger an optical switch. They allow a circuit with one voltage to control a circuit with another voltage, where you don't want any chance of arcing from a relay or from power surges. in this case they power the indicator LEDs.
There are 360° cameras you can mount on your dash, and edit in-post to show all the angles you may want to show off; Your face, the road, stuff on the side, and others
I remember a frozen signal with both yellow & red stuck on. Temps had crashed overnight, was probably below 10F in winter. Philly had a lot of mechanical control boxes and the rainstorm probably had forced water into the cabinet before the front came through and froze
I remember seeing traffic lights do that as a kid in Mobile. There was one on Government Street near the old MCPSS building (Barton Academy) that did it on the regular. Always confused drivers on what to do next!
The circuitry of that load cell looks similar to something I used to build a long time ago for a lighting program called Discolitez. The three white ICs if I’m not mistaken, are Opto isolated. They basically work almost like a relay. Since they can’t hold a load, the high voltage side of those ICs then go to a transistor which can handle a load. The issue of one of those circuits being latched on would either lie in the white Opto isolated IC, or on the transistor that it is connected to.
Judging by the other components & age of the technology, the opto-isolators are most likely driving triacs for controlling line voltage to the signals rather than transistors.
The 'transistors' are probably triacs. Very common circuit for switching AC mains with an isolated DC signal. Most likely the transistor failed short. The optocoupler getting stuck on is a possibility too, but they tend to fail open (no signal) which would keep the fault channel off.
Optocouplers are typically pretty robust, and don't handle a lot of current, so they don't usually fail (if the circuit is designed properly). Much more likely it's the switching transistor/TRIAC (which is handling a lot more load, and is also directly connected to the external wires, making it a lot more exposed to things like voltage transients from nearby lightning strikes, etc).
More than likely. It’s been so long since I played with DC switching mains circuits (13-14 years). Built those TRIAC circuits to control traffic lights at my first event with a DJ friend of mine… After all of that, I found DMX lighting and kinda took off!
There are quite a few lights on one load cell, is it possible that the current/power draw is a bit too much for a single load cell to control 2 phases.
Back in the day, there were one or two sets of lights in the city of Fall River, Ma on South Main St that intersected with one way streets. These lights were 4 light heads, and when you had a permissive signal, it would light with a red ball, Green Arrow Straight, and Green Arrow for the one way street. Those were like that for well over 20 years. Looking at the earliest street views from 2008, they had taken out the red/green indication. But that confused the hell out of people who weren't from the area.
First time ive seen the inside of a output module/load cell. (in my world, i associate load cell with weight sensor). Ive designed circuitry exactly such as the above, and it looks just like a triac SSR board meant for AC only. With those designs, what happens is the triac will short. Replace the triac and its generally good to go. The wildcard is if it damaged the opto-isolator driver IC for the triac. Ive not seen a triac short without an external factor such as a surge or perhaps an intermittent short causing a current spike on the transistor, and thus failing. I dont see any current limiter or sense lines on that module so it likely just blew out because of that.
I drive school buses right now..... I was told by our trip coordinator that renting a full size school bus costs $90/hour and includes a driver and all fuel...... I don't understand how they make money on that so i get how companies are trying to provide more of a service than fully driven by profit.
Is Hattiesburg considered south Mississippi? That's where my mom and her folks are from. I enjoy every one of your videos and I think you're a terrific guy.
Probably would replace the optoisolator ( small 6 pin IC ) and any surface mount diodes on that one phase for the red as well as the solid state device (transistor or mosfet) that is heatsinked to the housing. Sometimes those optoisolators are the first to short out from a surge.
The 1206 SMD resistor is visibly popped, so you're looking at that resistor, the opto, and the triac at a minimum. At $30 to replace the whole module, it's not worth the time.
Are there any tricks for when a motorcycle isn't detected? Where I live you basically need to chose which law you're going to break to get out of that situation as there are no legal ways out. I've had it happen at both induction and camera based intersections (often at induction sensors, only once on a camera based one and I kept moving around trying to be seen).
I saw a flashing yellow signal with the greens on including a green left turn arrow late one night. Called police and they sent a signal tech out and right before he got there the signal corrected itself. I went over and told all this and he said that the contacts were froze. He said he would be back out during the daytime to fix it. That was in the 90's. Also did anybody notice the green out on the side street in the opposite direction? I would have thought he would have fixed that before leaving.
When I pause the video at 6:37, I can see discoloration on that top-right resistor, the one just below the right LED indicator. Maybe it is that resistor that has short circuited, maybe from a surge, causing it to always stay on.
Over 40 years ago in Columbus, Ohio, one of my mom's neighbor was at killed in a auto accident at a busy intersection when all sides of the intersection had the green light on at the same time! Have you ever encountered anything like this when responding to a traffic signal malfunction at a busy intersection?
Systems from the last 20+ years include what's called a conflict monitor and it will put the entire intersection into flash if it detects something like that.
When you put the light in flashing mode, the problem lights flashed red in stead of orange. And the traffic light does not have traffic detection loops? It makes the red waiting time much shorter when there is no other traffic.
I recognize the circuits as 3 AC type Solid State Relays (SSR) using TRIAC's. The white squares are optocouplers or optoisolators. The black things with 3 legs and the white grease are the current carrying TRIAC's. The most likely failure is one of the TRIAC's has shorted out (never turns off). At $30 it's not even worth a technician opening one of these up to repair it.
Traffic light doctor , can you make a video on or explain to me how those weird pedestrian crossing lights that don’t have any call buttons work? I pass by one everyday on my way to work in a school zone and there’s no buttons to push but anytime a pedestrian on foot gets close to the designated waiting area the yellow lights start flashing.
Passive Pedestrian Detection: It's typically infrared sensors scanning a pre-set box in the viewfinder of the infrared camera. Anytime something (or someone) moves into the box giving off heat energy, the infrared radiation is picked up by the sensor and a call is placed for the appropriate phase, just like radar or pavement loop detection. If I'm not mistaken, these are used at the HAWK signal on North Ave between I-85 and Tech Parkway (although the pushbuttons also still place calls). Why aren't these used more? That's a question for you to badger your local government about, but it probably has to do with trying to accurately assess WHICH direction a pedestrian intends to cross when at a four-way intersection. At mid-block crosswalks, it's pretty obvious a standing pedestrian is going to cross in one and only one direction.
@@jovetj He's referring to HAWK signals, also called Pedestrian Hybrid Beacons. These are "DON'T WALK" for pedestrians and dark for motorists until a pedestrian calls it. At that moment, the vehicle indications go from dark to flash-yellow, then steady-yellow, then red. Once those are red, the pedestrian signals go to "WALK."
Very cool! In theory, could the conflict monitor prevent this from happening to the signals themself? For example, if the CM senses the output of the load cells and it sees something is stuck, kill the output and switch to flashing yellow?
It depends on the jurisdiction, and the environmental loads. Span-wire traffic signals mounted on an aluminum clad steel messenger wire are the cheap design. Some jurisdictions require mast arms, and only allow span-wire signal mounting when the signal is grandfathered.
I forget where I heard it, but one of the videos i saw (may have been from another channel) explained that older cabinets won't catch this because they were usually designed to only monitor for conflicting greens. Newer ones do go into flash when this happens (dual indication fault).
Ok we had a light here a few days ago that had the 2 lane lights would be red but the sidewalk light was green and yellow. When the light would go green the yellow on the side light would go out but when it would cycle the green would go to yellow and then the green would come back on and the yellow stays on when it should be red. Would this be the same kind of issue?
Doesn't the conflict monitor monitor for these things? I mean a Red+Green indication on a light is probably up there in failed indications. It's good they monitor the controller because those things are complicated, but I thought they also checked the output of the lights themselves in case something shorts out and you get conflicting phase greens because of a shorted output wire. I suppose in this case it wasn't a dangerous failure, but isn't that what conflict monitors are for?
"We should charge more" *meanwhile, charging 2 hours for a job that took 1 minute with a 40 minute round-trip drive* You're charging for work you didn't do. If anything, you should be charging for the work you're doing and making sure THAT cost is worth the work.
@@Dyanosis everyone has a minimum rate and we should charge more. Nothing out here is free and just because we know where to tap the hammer to fix a problem doesn’t mean it’s going to be “cheaper”.
In the early days of the M105/M205 detectors (emergency infrared strobe and receiver) we had a problem with all lights turning green. Imposible? Not so.
Is a load cell timed GYR and the controller times time between both load cells or is that component just suppling the 3 130 volt voltages and the controller tells the load cells what to do?
The controller uses 24V DC logic to tell the load switch what to do. There is no timing in the load switch other than to trigger the triac at zero voltage crossing.
Older cabinets and conflict monitors don't check for dual indication, only green conflicts. He mentioned in the video that it's pretty common for older cabinets...this is why.
It wasn’t a computer glitch, and there was nothing to report it was failing to do its job. A monitoring circuit would be a smart redesign for that part though.
why is there even a traffic light here instead of a simple yield sign (or stop sign)? does this area get intermittent traffic on event days or something? I would say that it would be for pedestrian safety, but looking at the narrow width of the road and the low traffic I can't see pedestrians getting hurt
4:35 When you switch the intersection into flash, why does the faulty red start flashing instead of staying continuous if it's held on? 5:14 I'm also surprised that taking it out of flash puts the flashing amber straight to green instead going to red first.
Flash is provided by a separate flasher circuit and it disconnects the load cells. This is why the lights did not go out when he removed the module. The lack of delay surprised me too.
The lower power, low voltage control circuitry uses the "load cell" to control the high voltage light circuits. It's what a traditional mechanical relay does, except this has no moving parts.
The real problem is when those style lights are on a street in an area that is really built up so you can't make a left turn because they are in sync for a time when the area had no traffic. Add the fact that the timing hasn't been adjusted for the traffic and oof.
Why do they make us stop and waste so much energy before the vehicle is even detected? We have tech that can see cars coming a mile away. tldr: why are traffic systems so dumb?
USA traffic systems are dumb. From what I've seen, most of the Netherlands' intersections are way smarter than any intersection we have here, to the point of doing green before traffic has left the intersection. For instance, on a left turn going to red, the oncoming straight traffic will turn green before the turning traffic has left the intersection because by the time the straight traffic gets there, the turning traffic will have left. This is obviously not at every intersection, but I've seen it at some. Check out "NotJustBikes" for more on this.
Luckily with this issue the approach with the fault has the right away and the other approaches will be red! So this usually causes a lot of complaints but not as many accidents during one of these malfunctions.
Proceeding through an intersection on a green light is safe regardless if the light is red at the same time - not a conflict. Different story of the green is stuck on and displayed during a red indication.
@@MikeM-cz5ln-- Red and green would have me checking all the heads so I know what everyone else might be doing. Then pulling over afterwards and calling it in.
Please stop screwing around with your camera while driving. It's not worth getting hurt/killed or hurting/killing someone else to make videos for TH-cam while operating a multi-ton vehicle.
Hey man. You do great work educating people about traffic lights. But I cannot support somebody driving their vehicle, Much less a heavy service truck, While distracted messing with an electronic device for a youtube video. Do better man.
This is my 6th Traffic Light Doctor I've binged and EVERY single video there's someone blatantly running a red light. Come on people
Imagine working on them for a living you’ll see so many!!
@@Trafficlightdoctor What would happen if you pulled the load cell before putting the intersection into flash mode? Will the controller sense the fault and go into flash mode? Just curious.
@@paulburns4721 The lights will probably just turn off. That load cell determines what has power. So I'd assume that the lights would just turn off. The flash override probably has a secondary power connector for just the flashers.
I was once told by a snotty know-it-all that a signal simultaneously showing red and green is "impossible" - I've now saved this video.
if properly set up, programmed, and functioning, it should never happen.
IOW if it happens something is broken.
In this case it looks like a bad capacitor. Rare, but can happen.
Well, who are you going to believe? Him, or your lyin' eyes? LOL
@@jeauxbleaux618 Every time someone questions the news media haha
@jwenting. Not a bad capacitor.
Why save it they know it all
It's interesting to see the load cell uses a Cinch Jones connecter that was first manufactured in the early 1930's for juke boxes & pinball machines among other devices. The connectors saw heavy use during WWII & are still relevant nearly a century later.
They definitely need some new visors on those signals.
The missing visors on some of the heads and the wiring makes me think this was repaired quickly after a hurricane to a working condition then put on hold. Since you said its one of the rougher area of the city, finishing repairs is probably very low on the priority list unless there's a component failure as shown.
Band-aids get you back on quick, but they can easily cause worse issues and more expensive repairs down the road.
I'm proud of the statement you made about where you came up from. Same thing is where I'm from. I grew up I did great but this town is still got his problems. So I'm proud that you have applied yourself and you will teach your kids do that. You do a great job
The Failed component is probably a Triac if it is AC, Transistor if DC, Shorted is the most likely failure mode.
The conflict monitor does not know if the Red light is on, it only knows if the red light is commanded to turn on or off.
@pctek961 You are partly correct. The load switch would have a shorted triac. The monitor DOES "know" the red light is on (It monitors the output of the load switch) it doesn't trip since this condition is NOT a conflict. It is safe for a vehicle to proceed on a green light regardless if the indicates a red at the same time. If the green light triac was shorted it would be a different story. However, the monitor can be programmed to detect "dual indication" and it would trip anytime more than one indication is displayed.
for anyone wondering whats what in the video:
The triac are the 3 pin devices bent 90 degrees from the board with the grey heat paste on the back and a hole in the tab. Those orange things are resistors, probably used to monitor current and detect shorts or opens.
The white squares with 6 pins are opto-isolators, basically a solid-state switch that uses an internal LED to trigger an optical switch. They allow a circuit with one voltage to control a circuit with another voltage, where you don't want any chance of arcing from a relay or from power surges. in this case they power the indicator LEDs.
@@voyager1713 Those "orange things" are snubbers.
@@MikeM-cz5ln It's a conflict in my book. Not a phase conflict, but a clarity conflict. Drivers are stupid.
@@MikeM-cz5ln Actually the "Orange things" are capacitors.
Transistors fail to a shorted on state. 50 cent part. Voltage spike in the high or low (short/overloaded) conditions usually cause it.
When I saw him open up something called a "load cell" and it just had a bunch of 50 cent parts.. I wonder what it had in the 80s
@@jeffdafoe Mechanical rotary contact relays!
1206 SMT resistor is popped, right near the LED and optocoupler.
Enjoyed the video. You do a good job of explaining everything!!!
FETs don't like surges or shocks, and when they fail they tend to short on.
Fixed many a melted coil in a pinball machine from shorted FETs.
Please don't hold your phone and film yourself while driving. Get a dash mount for your camera. Be safe out there!
There are 360° cameras you can mount on your dash, and edit in-post to show all the angles you may want to show off; Your face, the road, stuff on the side, and others
@@NeverJhonsenhe's holding it with his hand though. He should not be doing that.
I remember a frozen signal with both yellow & red stuck on. Temps had crashed overnight, was probably below 10F in winter. Philly had a lot of mechanical control boxes and the rainstorm probably had forced water into the cabinet before the front came through and froze
I remember seeing traffic lights do that as a kid in Mobile. There was one on Government Street near the old MCPSS building (Barton Academy) that did it on the regular. Always confused drivers on what to do next!
The circuitry of that load cell looks similar to something I used to build a long time ago for a lighting program called Discolitez. The three white ICs if I’m not mistaken, are Opto isolated. They basically work almost like a relay. Since they can’t hold a load, the high voltage side of those ICs then go to a transistor which can handle a load. The issue of one of those circuits being latched on would either lie in the white Opto isolated IC, or on the transistor that it is connected to.
Judging by the other components & age of the technology, the opto-isolators are most likely driving triacs for controlling line voltage to the signals rather than transistors.
The 'transistors' are probably triacs. Very common circuit for switching AC mains with an isolated DC signal. Most likely the transistor failed short. The optocoupler getting stuck on is a possibility too, but they tend to fail open (no signal) which would keep the fault channel off.
Optocouplers are typically pretty robust, and don't handle a lot of current, so they don't usually fail (if the circuit is designed properly). Much more likely it's the switching transistor/TRIAC (which is handling a lot more load, and is also directly connected to the external wires, making it a lot more exposed to things like voltage transients from nearby lightning strikes, etc).
@@foogod4237I agree! Shorted triac - not a bad opto-isolator.
More than likely. It’s been so long since I played with DC switching mains circuits (13-14 years). Built those TRIAC circuits to control traffic lights at my first event with a DJ friend of mine… After all of that, I found DMX lighting and kinda took off!
Thanx for showing the inside of the load switch. No electrical-mechanical relays. Interesting.
There are quite a few lights on one load cell, is it possible that the current/power draw is a bit too much for a single load cell to control 2 phases.
Back in the day, there were one or two sets of lights in the city of Fall River, Ma on South Main St that intersected with one way streets. These lights were 4 light heads, and when you had a permissive signal, it would light with a red ball, Green Arrow Straight, and Green Arrow for the one way street. Those were like that for well over 20 years. Looking at the earliest street views from 2008, they had taken out the red/green indication. But that confused the hell out of people who weren't from the area.
First time ive seen the inside of a output module/load cell. (in my world, i associate load cell with weight sensor). Ive designed circuitry exactly such as the above, and it looks just like a triac SSR board meant for AC only. With those designs, what happens is the triac will short. Replace the triac and its generally good to go. The wildcard is if it damaged the opto-isolator driver IC for the triac. Ive not seen a triac short without an external factor such as a surge or perhaps an intermittent short causing a current spike on the transistor, and thus failing. I dont see any current limiter or sense lines on that module so it likely just blew out because of that.
The 1206 SMD resistor is also visibly popped.
I would check the goose necks for phase 4 for bare wires when the wind moves the signal around..
The 1206 resistor near the LED is popped! That resistor is what drives the optocoupler and she is popped.
I drive school buses right now..... I was told by our trip coordinator that renting a full size school bus costs $90/hour and includes a driver and all fuel...... I don't understand how they make money on that so i get how companies are trying to provide more of a service than fully driven by profit.
Wish u was up by Columbus way. We got a couple lights that will make the side street wait 20min sometimes.
I'm guessing those are three triacs, and that one of them is shorted.
I'd love to get my hands on one of them to check it.
I've seen that type of malfunction in Memphis. Except the red was flashing in the green wasn't. And also the pedestrian signals are still on.
Peds should be deactivated while in flash a bad main bus relay would cause this fault typically where the intersection is in flash but still running.
@@Trafficlightdoctor yeah I was telling myself that pedestrian signals shouldn't be on during the intersection is in flash.
Is Hattiesburg considered south Mississippi? That's where my mom and her folks are from. I enjoy every one of your videos and I think you're a terrific guy.
For the most part it is!
Who the heck is Mrs. Sippi, and where's Mr. Sippi?
Probably would replace the optoisolator ( small 6 pin IC ) and any surface mount diodes on that one phase for the red as well as the solid state device (transistor or mosfet) that is heatsinked to the housing. Sometimes those optoisolators are the first to short out from a surge.
The 1206 SMD resistor is visibly popped, so you're looking at that resistor, the opto, and the triac at a minimum. At $30 to replace the whole module, it's not worth the time.
That intersection could just use a roundabout.
Are there any tricks for when a motorcycle isn't detected? Where I live you basically need to chose which law you're going to break to get out of that situation as there are no legal ways out. I've had it happen at both induction and camera based intersections (often at induction sensors, only once on a camera based one and I kept moving around trying to be seen).
I saw a flashing yellow signal with the greens on including a green left turn arrow late one night. Called police and they sent a signal tech out and right before he got there the signal corrected itself. I went over and told all this and he said that the contacts were froze. He said he would be back out during the daytime to fix it. That was in the 90's.
Also did anybody notice the green out on the side street in the opposite direction? I would have thought he would have fixed that before leaving.
When I pause the video at 6:37, I can see discoloration on that top-right resistor, the one just below the right LED indicator. Maybe it is that resistor that has short circuited, maybe from a surge, causing it to always stay on.
Over 40 years ago in Columbus, Ohio, one of my mom's neighbor was at killed in a auto accident at a busy intersection when all sides of the intersection had the green light on at the same time! Have you ever encountered anything like this when responding to a traffic signal malfunction at a busy intersection?
Systems from the last 20+ years include what's called a conflict monitor and it will put the entire intersection into flash if it detects something like that.
Well said, Brother.
Triac or opto coupler failure.
Aspect: The look of a signal, lights, shapes, arms, etc.
Indication: What the aspect of the signal indicates you should do.
When you put the light in flashing mode, the problem lights flashed red in stead of orange.
And the traffic light does not have traffic detection loops? It makes the red waiting time much shorter when there is no other traffic.
You could probably fix these loadcell modules for some cheaper repair options. Use a flir or multimeter
Schrödinger's traffic light...
I recognize the circuits as 3 AC type Solid State Relays (SSR) using TRIAC's. The white squares are optocouplers or optoisolators. The black things with 3 legs and the white grease are the current carrying TRIAC's. The most likely failure is one of the TRIAC's has shorted out (never turns off). At $30 it's not even worth a technician opening one of these up to repair it.
Traffic light doctor , can you make a video on or explain to me how those weird pedestrian crossing lights that don’t have any call buttons work? I pass by one everyday on my way to work in a school zone and there’s no buttons to push but anytime a pedestrian on foot gets close to the designated waiting area the yellow lights start flashing.
Yellow lights start flashing? Like, flash mode? Or, it cycles to allow the pedestrian to cross?
Passive Pedestrian Detection: It's typically infrared sensors scanning a pre-set box in the viewfinder of the infrared camera. Anytime something (or someone) moves into the box giving off heat energy, the infrared radiation is picked up by the sensor and a call is placed for the appropriate phase, just like radar or pavement loop detection. If I'm not mistaken, these are used at the HAWK signal on North Ave between I-85 and Tech Parkway (although the pushbuttons also still place calls). Why aren't these used more? That's a question for you to badger your local government about, but it probably has to do with trying to accurately assess WHICH direction a pedestrian intends to cross when at a four-way intersection. At mid-block crosswalks, it's pretty obvious a standing pedestrian is going to cross in one and only one direction.
@@jovetj He's referring to HAWK signals, also called Pedestrian Hybrid Beacons. These are "DON'T WALK" for pedestrians and dark for motorists until a pedestrian calls it. At that moment, the vehicle indications go from dark to flash-yellow, then steady-yellow, then red. Once those are red, the pedestrian signals go to "WALK."
Did you update the paper log in the cabinet? Or is it a digital log?
I think I saw the light at 32nd street in Gulfport in flash mode flashing both red and yellow at the same time on the main street.
So, What’s the oldest traffic signal intersection you can show us?
Very cool! In theory, could the conflict monitor prevent this from happening to the signals themself? For example, if the CM senses the output of the load cells and it sees something is stuck, kill the output and switch to flashing yellow?
I wonder if Big Clive would be interested in digging into something like this.
I guess those traffice lights wanted to be a train signal.😂😂😂
As a Australian i dont understand why American traffic light are hang in wires? Cant they add a metal pole?
It depends on the jurisdiction, and the environmental loads. Span-wire traffic signals mounted on an aluminum clad steel messenger wire are the cheap design. Some jurisdictions require mast arms, and only allow span-wire signal mounting when the signal is grandfathered.
That's how woman do to us guys green and red at same time lol
What is actually powering the lights when they are in flash mode?
I always thought it was the load cells but clearly not.
Seperate flasher circuit.
Shouldn't the Conflict Monitor see the Dual Indication and flag a fault? Any idea why it didn't trip and put the intersection into flash?
Shouldn’t a conflict monitor pick that up and put it into flash?
That’s what I was thinking. I don’t think I’ve seen this happen yet.
I forget where I heard it, but one of the videos i saw (may have been from another channel) explained that older cabinets won't catch this because they were usually designed to only monitor for conflicting greens. Newer ones do go into flash when this happens (dual indication fault).
@@wolstechActually, dual indication can be switched off. For instance, a red indication during a left turn green arrow could be normal.
I wondered the same. Red and green on---MMU should have went to "all red flash" mode.
I use to work a Ingalls back when it was Northrup Grumman ship systems.
On the railroad that’s a Diverging Clear indication. 😂
That load cell looks like an easy fix to me
Diverging clear!
former signal tech here, why didnt your MMU catch the dual indication and throw it into flash? i also preferred EDI products as well.
Ok we had a light here a few days ago that had the 2 lane lights would be red but the sidewalk light was green and yellow. When the light would go green the yellow on the side light would go out but when it would cycle the green would go to yellow and then the green would come back on and the yellow stays on when it should be red. Would this be the same kind of issue?
Doesn't the conflict monitor monitor for these things? I mean a Red+Green indication on a light is probably up there in failed indications. It's good they monitor the controller because those things are complicated, but I thought they also checked the output of the lights themselves in case something shorts out and you get conflicting phase greens because of a shorted output wire. I suppose in this case it wasn't a dangerous failure, but isn't that what conflict monitors are for?
Older ones did not, newer ones are programmable and can have that feature enabled or disabled.
Based on what we saw in this video, this junction should be a mini roundabout
"We should charge more"
*meanwhile, charging 2 hours for a job that took 1 minute with a 40 minute round-trip drive*
You're charging for work you didn't do. If anything, you should be charging for the work you're doing and making sure THAT cost is worth the work.
@@Dyanosis everyone has a minimum rate and we should charge more. Nothing out here is free and just because we know where to tap the hammer to fix a problem doesn’t mean it’s going to be “cheaper”.
In the early days of the M105/M205 detectors (emergency infrared strobe and receiver) we had a problem with all lights turning green. Imposible? Not so.
Why wouldn't the conflict monitor put the intersection in flash?
Why is the conflict Monitor not putting the intersection in Flash? Is it complety useless in this System?
Is that not something that the conflict monitor checks?
Is a load cell timed GYR and the controller times time between both load cells or is that component just suppling the 3 130 volt voltages and the controller tells the load cells what to do?
The controller uses 24V DC logic to tell the load switch what to do. There is no timing in the load switch other than to trigger the triac at zero voltage crossing.
I haven't heard the term "load cell" in this context before, is it similar to a relay?
I posted that before you showed the internals...I guess more similar to a MOSFET maybe?
Why whenever there is a hurricane in Houston traffic lights and blinking red or off over a month later?
Because nobody cares about fixing them. They have more important things to do like drive around in their new pickup trucks all day. 🤣
In case like that why the intersection does not go to flashing this mean an dual indication fault🤔
Older cabinets and conflict monitors don't check for dual indication, only green conflicts. He mentioned in the video that it's pretty common for older cabinets...this is why.
@@wolstech i understand thanks
How come this didn't cause a fault on the conflict monitor?
It wasn’t a computer glitch, and there was nothing to report it was failing to do its job. A monitoring circuit would be a smart redesign for that part though.
I'd take a guess: because the green light was only illuminating when the other phase was on red, so it wasn't a true conflict.
@@tomsixsixCorrect!
Kids are preconditioned BY THEIR PARENTS!
Tell & help your kids reach their potential!!
why is there even a traffic light here instead of a simple yield sign (or stop sign)? does this area get intermittent traffic on event days or something?
I would say that it would be for pedestrian safety, but looking at the narrow width of the road and the low traffic I can't see pedestrians getting hurt
A classic system design fail if ever there was one.
4:35 When you switch the intersection into flash, why does the faulty red start flashing instead of staying continuous if it's held on?
5:14 I'm also surprised that taking it out of flash puts the flashing amber straight to green instead going to red first.
Flash is provided by a separate flasher circuit and it disconnects the load cells. This is why the lights did not go out when he removed the module.
The lack of delay surprised me too.
@@uzlonewolf Thank you
What is the purpose of a load cell?
The lower power, low voltage control circuitry uses the "load cell" to control the high voltage light circuits. It's what a traditional mechanical relay does, except this has no moving parts.
Would the MMU catch this type of issue?
Bad load switch and/or moisture in the wires.
So, isn't the point of the conflict monitor to react and do something when this situation arises?
The real problem is when those style lights are on a street in an area that is really built up so you can't make a left turn because they are in sync for a time when the area had no traffic. Add the fact that the timing hasn't been adjusted for the traffic and oof.
That Triac is dead and stuck open. a few cents part to swap a new Triac into there.
Shorted not open. (Not shorted to ground)
I think the lights are having a identity crisis
So do I go or stop thus was never in my driving book
I agree. I think it's preposterous that this should be allowed to happen.
Both🤣
If a signal is giving you mixed messages like this, treat it as a stop sign, to give other traffic the benefit of the doubt.
Why do they make us stop and waste so much energy before the vehicle is even detected? We have tech that can see cars coming a mile away.
tldr: why are traffic systems so dumb?
Because the city/county which installed them was cheap and didn't buy the vehicle detectors.
USA traffic systems are dumb. From what I've seen, most of the Netherlands' intersections are way smarter than any intersection we have here, to the point of doing green before traffic has left the intersection. For instance, on a left turn going to red, the oncoming straight traffic will turn green before the turning traffic has left the intersection because by the time the straight traffic gets there, the turning traffic will have left.
This is obviously not at every intersection, but I've seen it at some. Check out "NotJustBikes" for more on this.
You needed a cop to direct traffic.
Thats what putting it into flash is for. You should remember that from when you learned to drive!
I guess I didn't have to ask you the question if a traffic light malfunction ever cause a crash! Red-Green... Ouch.
Luckily with this issue the approach with the fault has the right away and the other approaches will be red! So this usually causes a lot of complaints but not as many accidents during one of these malfunctions.
Proceeding through an intersection on a green light is safe regardless if the light is red at the same time - not a conflict. Different story of the green is stuck on and displayed during a red indication.
@@MikeM-cz5ln-- Red and green would have me checking all the heads so I know what everyone else might be doing. Then pulling over afterwards and calling it in.
@@MikeM-cz5ln But a driver cannot tell the difference. That's the danger!
You should not be using your cellphone or camera while driving.
Skip to 2:30
That’s not good at all, it’s a Christmas Color of Red & Green at a Same Time
Diverging clear
You press the gas and brake at the same time
Why is the traffic signal head placed close to the center of the intersection?
What do you mean?
@@jovetj Why can't you see that the question isn't for you to answer?
@@jbb3design What don't you understand what "community" means?
Please stop screwing around with your camera while driving. It's not worth getting hurt/killed or hurting/killing someone else to make videos for TH-cam while operating a multi-ton vehicle.
I’ve seen Both Green and Red Lights ON simultaneously once or twice in the past. 🤔👎
wha do I go
Hey man. You do great work educating people about traffic lights. But I cannot support somebody driving their vehicle, Much less a heavy service truck, While distracted messing with an electronic device for a youtube video. Do better man.
The light is female...
@@curtisscott9251 100%
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