Intermitent lamp issue.

[Awesomealgae]

Hi all,
throwing this out to your collective über knowledge and experiance.

Periodically I have lamp issues with my Polyvar. It's an intermittent fault that presents as flicker visible in the camera only, at usually functional FPS, exposure and shutter settings.

https://flic.kr/p/2n32Sca

Occurrence of the fault is inconsistent but I've checked tested the following

- 12v transformer/controller is plugged directly Into the mains.
- Power supply at the lamp with multimeter gives a 20 second readout of 12v
- I've swapped the 100W lamp for a new one; duration of use is not a factor.

Despite the consistent power reading I'm left thinking it's the Transformer/conroller and that the multimeter is failing to accurately detect an oscillation in supply that's causing improper cycling of the lamp?

I'm pretty handy but inexperienced with electronics, I figured building a new power-supply/controller wired into the existing lamp assembly is worth investigating?

Question is, have I missed something really obvious?

If I go for a rebuild what components are required? Is this practical for an electronics novice (I've got to learn sometime).

Thanks Dan.

[ker2x]

Can you change. your video framerate instead ?
This flickering is very well known since decades.

Or you could use a DC power supply. if it's an halogen lamp, they work in both AC & DC. (I run mine in DC)

[Awesomealgae]

Can you change. your video framerate instead ?
This flickering is very well known since decades.

Or you could use a DC power supply. if it's an halogen lamp, they work in both AC & DC. (I run mine in DC)

Hey ker2x,

Thanks for reply. Unfortunately the flicker occurs periodically and at settings that otherwise function perfectly. When the problem occurs it's visible at all combinations of FPS, Exp, ISO and at lamp brightness levels.

Moving to a DC power source might be the solution I'm looking for.

THANKS

[hans]

Unfortunately the flicker occurs periodically and at settings that otherwise function perfectly. When the problem occurs it's visible at all combinations of FPS, Exp, ISO and at lamp brightness levels.

This seems like pretty good evidence against the flicker coming from the illumination. Maybe electrical interference from some other source is affecting the camera directly? You could try taking video with the camera isolated (running on battery with no other cables connected to it) when the problem occurs or go around the house turning other stuff on/off. (Including lights, especially fluorescent fixtures.)

[Awesomealgae]

This seems like pretty good evidence against the flicker coming from the illumination. Maybe electrical interference from some other source is affecting the camera directly? You could try taking video with the camera isolated (running on battery with no other cables connected to it) when the problem occurs or go around the house turning other stuff on/off. (Including lights, especially fluorescent fixtures.)

Thanks hans that's a great suggestion, I'll get on that tonight and report back! lots of other equipment switched on or off and cables In close proximity. It could definitely explain the intermittent nature of the interference.

Thanks Dan

[hans]

Oh, one other consideration: are the microscope, camera power supply, computer, monitor, and anything else connected to them via cables all plugged into the same power strip? Worth trying that too if they are not already.

Beautiful microscope and video quality, by the way, even with the flicker.