Led flicker

[legacy]

Have four Chauvet quads. These fixtures are suppose to be flicker free
And have never wittnessed them flicker on video. This past year we
Upgraded our video projection and cameras all are HD. I am now seeing
Flicker but only on one of the four which seems strange to me. HD has 1-30
FPS so there is not allot of leway to change feequency. Any ideas here?
Could the fixture in question have a Problem sense they do have some age
On them

 

[FMEng]

Sure, an electrolytic filter capacitor may be drying out from heat and age. A loss of DC filtering could certainly cause flicker to show up on video.

 

[church]

Sure, an electrolytic filter capacitor may be drying out from heat and age. A loss of DC filtering could certainly cause flicker to show up on video.

FM Eng is flagging an important design nuance of LED fixtures. the LEDs are driven from a constant voltage source and usually have a current regulator in each LED string. The switch mode power supply provides the constant voltage to all the LED strings. Switch mode power supplies use a high speed switching frequency to allow the conversion to the required low voltage. It is essential that the electrolytic capacitors used in the switch mode power supply are able to handle large ripple currents and high temperature - this is not an application for cheap electrolytic capacitors. If one or more of the capacitors is breaking down the output voltage will rise an fall with the switching frequency. This appears as the LEDs flickering on an off.

I have seen this numerous times this is not a difficult repair to diagnose or perform.

 

[JD]

Have four Chauvet quads. These fixtures are suppose to be flicker free
And have never wittnessed them flicker on video. This past year we
Upgraded our video projection and cameras all are HD. I am now seeing
Flicker but only on one of the four which seems strange to me. HD has 1-30
FPS so there is not allot of leway to change feequency. Any ideas here?
Could the fixture in question have a Problem sense they do have some age
On them

Flicker free fixtures use a much higher frequency to drive the LEDs and therefore are not usually a problem. HOWEVER, that does not preclude a power supply filter cap from going bad and injecting some good old 60Hz. If it is only the one fixture, it may have a bad supply cap. Sounds like the new equipment uncovered it.

EDIT: You now have 3 votes for "bad supply cap."

 

[dgourley]

CHeck you shutter speed. This is different that the framerate. More than likely it is set higher than 1/120.