(Topic ID: 29684)

FS: LED OCD - Eliminate LED flicker/strobe/ghost - Control brightness

By herg

7 years ago

Topic Stats

  • 763 posts
  • 159 Pinsiders participating
  • Latest reply 1 year ago by MustangPaul
  • Topic is favorited by 123 Pinsiders


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    LED OCD Ramp Example (No-Ghost).png
    LED OCD Ramp Example (Standard).png

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    #72 6 years ago

    I agree that CoinTaker's warm white frosted LEDs aren't as warm as I would prefer, they are more of a pure white. The look more authentic under plastics and behind ramps.

    #76 6 years ago

    Use frosted LEDs for GI, they are also rectified. You really have to look close to notice the flicker on these vs the unrectified LEDs which give you a headache.

    1 month later
    #94 6 years ago

    Once this really gets out there I think Robin should add functionality to the site where you can upload your own LED OCD configuration files so everyone has access to optimal per-game settings. This will allow people to enjoy the device without spending a tremendous amount of time fine-tuning the settings to make it look right. There can be versions for CoinTaker, Pinball Life, Ablaze, etc. Add it as a tab to the game info page.

    #101 6 years ago

    Put some frosted CoinTakers in there, they are rectified and flicker will be virtually unnoticeable.

    1 week later
    #115 6 years ago

    Backbox lighting is GI. To be honest if Herg made a small tie-in board to smoothen out the GI circuit (or even add fade effects via a capacitor) I would be all over that. When using LEDs for the GI on Addams Family, for example, the flickering during the start of multiball is a bit disorienting compared to the smooth fade of incandescents. I can't see it being difficult to make and it would only make sense given his taste in fading circuits. It would also allow people to save money on non-rectified and premium no-flicker/fading LEDs. Please do this Herg!

    3 months later
    #153 6 years ago

    Is there a limit to how many incandescents you can use with the board since they draw much more power?

    #162 6 years ago

    You know working in the shop on these games got me thinking. Once miniature incandescents are phased out I strongly believe this board will be pivotal in furthering the use of LEDs. What else are we going to do? Spend a premium on "non ghosting" "no flicker" LEDs that only work so-so? Continue to get headaches? This is hands-down the best aftermarket board since LED displays.

    1 month later
    #216 6 years ago
    Quoted from altan:

    Thanks for the details. Just to be clear, I'm not saying it needs to be 100% pass thru. What I'd like to be able to do is a mostly accurate A/B comparison from what the factory state looks like vs. the optimization with the OCD. If you could "emulate" the factory state fairly close, that would be good enough.
    But then allow quick and easy swapping between the factory and original...

    Just focus on an insert that's part of a group, like the bingo awards on Ripley's. Install an incandescent right next to it and set the incandescent insert to instant on/off (no fade time) as a control test. What brightness setting sets the duty cycle of the lamp to 60Hz, replicating the brightness and fade time of a normal matrix output? Ideally if you are wanting to match the brightness and fade time to an incandescent then you want to set the fade time to zero and brightness to whatever setting that would produce a 60/250Hz duty cycle (which should be 24% assuming 100% is the full 250Hz scan rate).

    #219 6 years ago
    Quoted from toibs:

    alongside the menu showing it as all the bulbs having blown...

    Even if Harold were to make a Pin2k version (doubtful), the board wouldn't draw enough current for that.

    #223 6 years ago
    Quoted from herg:

    There is none. The OCD always outputs at 250 Hz, and it changes the brightness by reducing the amount of time a lamp is on during its 500 ns timeslot. Doing it this way prevents lower brightness values from flickering due to lower refresh rates.

    So you're saying the LEDs still scan at 250Hz but the actual on time of each cycle is lowered? What an awesome solution!

    #225 6 years ago

    He said he was looking at GI but that was most likely not going to work out because of the amount of current involved, even with LEDs. At most you would have 18 lamps per string (4.5A) and with LEDs it would be around 0.75A just for a single string. Still, I would love to see this done simply for the sake of Data East/Sega games that like to flash the GI a lot and WPC games that use fading effects. Both are quite disorienting with the instant on/off effects of straight LEDs, especially in a darker room.

    #234 6 years ago
    Quoted from viperrwk:

    Tech question for Herg (and others who might have a thought about this):
    Given the frequency you're driving the lamp matrix, would it be better to have LEDs with longer (recombination) lifetimes to minimize strobing effects? I'm assuming given typical rise/fall times and a high input step current that this would be the determining factor to the LED's response from the board's input.
    OTOH, shorter lifetimes would mean better responsiveness to the board's inputs (?)
    Of course, getting this info from the vendors is another question entirely...

    LEDs that exhibit light persistence? Where did you hear about these? Also the bias current should be fairly low or ghosting wouldn't be a problem.

    #238 6 years ago
    Quoted from Jam_Burglar:

    If somebody has commented on this already I appologize, but can somebody chime in on the difference between using this board with standard LEDs and using premium non-ghosting LEDs without the board? In other words, if I already have a bunch of non-ghosting LEDs in my inserts, would I see any difference if I installed this and went back to standard LEDs. I know that LED OCD allows much more precise control of lights, but I'm more referring to the fading effects.

    Non ghosting LEDs have no fading effects, no brightness control, and they still strobe. Spend your money on the OCD board with Pinball Life's $0.39 Ablaze LEDs.

    #249 6 years ago

    Correct, lamps in the lamp matrix are controller by TRIACS on the driver board. Wonder if someone makes a fading TRIAC, or if it's easy or practical to put capacitors in parallel with each string to make games that like to flash GI much less disorienting?

    #256 6 years ago
    Quoted from Kneissl:

    Holy smokes the optiflux must have some expensive capacitors

    Tooling required to produce these en masse. PinballBulbs is looking into making a fading LED that matches the characteristics of incandescents. We really need to move incandescent LED replacements forward.

    #258 6 years ago
    Quoted from Aurich:

    That would be nice. Once you go LED it's hard to go back, but it sucks to give up some of the more subtle advantages of incandescents.

    For me not so much from a subtlety standpoint but more from an operator practicality standpoint. A lot of these games like to dim and flash the GI (White Water, Frankenstein, Addams Family during multiball start, etc). And it looks quite disorienting to me, just imagine what that would do to people who are epiletics for example (including turning them off from playing your games). It wouldn't be so bad if you don't have a game in a dark location with all LEDs in the GI to address burning connectors and short lamp life (where replacing GI lamps would require a full playfield teardown on many games). With Herg able to pull off something so amazing and complex as the OCD board I'm thinking surely someone somewhere will be able to come up with a simple solution to this issue, whether it be in the form of fading warm white LEDs or a similar feed-through smoothing board for the GI circuit. I would absolutely love to see this problem addressed.

    #261 6 years ago

    You have my support Herg! If you can pull it off we are likely to buy some.

    1 week later
    #267 6 years ago

    Since you have a high speed camera ever thought about doing some gameplay?

    2 months later
    #287 5 years ago

    Guys at shows/showrooms need to put these in their games with a sign that says "LEDs with LED OCD" and have a machine next to it that says "Straight LEDs" and let people compare in person.

    #298 5 years ago

    Works with WPC I believe.

    #301 5 years ago

    Lol, a thumbs down honestly? Next time remind me not to give advice.

    #304 5 years ago

    This thread discusses LED OCD in general. The thing started with WPC. We are off topic.

    Back on topic, I'm pretty sure I'll be in for one of these once I find the money. One could easily spend the same $200 on premium LEDs , non-ghosting, etc. but you get much better effects using this board with cheap LEDs.

    8 months later
    #573 5 years ago

    What is LED mode vs incandescent mode?

    1 week later
    #588 5 years ago

    Best to stick with plain old basic LEDs for this application. Even polarized ones will work since the lamp matrix is driven with DC. Herg, riddle me this. Do the diodes in rectified LEDs impact the response time of the LED with regards to the 250Hz refresh rate of the OCD matrix? Or do they not impede the function at all? I know certain types of diodes have a frequency response ceiling but I think that limit would be much higher than what we're working with.

    1 month later
    #640 5 years ago
    Quoted from TheDrewster:

    This may just be my imagination, but after using the LEDOCD boards, I cannot see any difference between an $.89 "ghost-busting" LED bulb and a cheapo $.39 LED bulb. I have all the cheap $.39 LEDs in the inserts for my Funhouse and it looks exactly like my STTNG with the more expensive LEDs. This is great!

    Thank goodness too, this keeps conversions under $200 for route operators leaving the price still a bit steep, but it's definitely worth doing to know you'll never be heating up the 25 year old wood and plastic that's constantly bashed by a steel ball, plus the fact that you'll rarely have issues with inserts not lighting again (blown bulbs). But obviously the real benefits are true incandescent emulation and reduced power consumption.

    2 weeks later
    #651 5 years ago
    Quoted from Fifty:

    I always thought insane fast was faster than crazy fast.
    I'm with herg, but I don't know if I feel sorry for people being able to see 120Hz strobbing or if you're lucky for having such a super power.

    I can see it, but only if I move my head or watch the ball in darker areas of the playfield. It's really not that bad, and I forget about it quickly.

    #654 5 years ago
    Quoted from herg:

    Wouldn't that make it difficult to play the game?

    D'ope! You got me. Strobing doesn't exist, your board is a hoax, etc.

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