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mydonkeykong
54
Sep 25, 2017
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The last brass version I have received was PWM to regular the brightness. It is noticeably flickering at dim mode. I was surprise that it uses PWM for this torch. I am rather sensitive to PWM and does not like it.
Sep 25, 2017
MassivePressure
25
Oct 19, 2017
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mydonkeykongWhat's PWM?
Oct 19, 2017
rdtshaw
47
Oct 30, 2017
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MassivePressurePulse Wave Modulation. The light is turned off and on rapidly at different rates to dim and brighten the light... Many LED's and florescent lights dim using this method. Some people are more sensitive to it and can perceive the flicker... I can see it below 60 Hz myself. In this case the it is more likely the light is defective though, the modulation in the dimmest setting is probably well above 60Hz..
Oct 30, 2017
EDCer123
73
Nov 8, 2017
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rdtshawIt's actually Pulse Width Modulation. The frequency is not supposed to change with each brightness setting. Instead, it's the duty cycle that changes while the pulse frequency stays constant. Thus, if you can see the flicker, then I think you have a defective light. The frequency is supposed to be chosen high enough so that no human can detect the flicker, but a defect in circuit components can cause the flicker to be noticeable.
Nov 8, 2017
EDCer123
73
Nov 8, 2017
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rdtshawI'm curious. Do you see flickering when you watch movies in theaters?
Nov 8, 2017
rdtshaw
47
Nov 8, 2017
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EDCer123I get what you mean , but I don't think it's quite the same thing. The lamp on the projector isn't below 60Hz. The 24-30fps of the movie is fluid motion vs. the stroboscopic effect of an off/on flicker. A better example of what I'm referring to is if you change the refresh rate of your monitor on your computer to less than 60 hz. I can see that flicker; that one drives me crazy. Or a dying fluorescent light (or ballast?)... And thanks for the clarification on the duty cycle vs pulse frequency, reading up on that now. I've been on the user end of that vs. the design perspective. Also, I totally blew it on the acromyn, no excuse having been in the radio control world for so long. Doh!
Thinking about it more... would be yes an older film projector running at 24fps does produce a noticeable flicker with the mechanism they used to use. I remember that from when I was a kid. The newer digital ones change frames in a different manner so not normally something I would notice today. I'm stating this without completely understanding the mechanics of a newer projector so I may be wording it wrong... That make sense?
Nov 8, 2017
EDCer123
73
Nov 9, 2017
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rdtshawYes, I was referring to the film movies shown in theaters, not digital movies. In film projectors, the way each frame is shown is essentially stroboscopic because the projectors use shutters to prevent the moving frames from appearing like blurs. It is not like digital movies. I asked the question because I was curious to see how sensitive your eyes are to flickering and it seems that they are much more sensitive than mine.
Nov 9, 2017
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