Film-Tech Forum ARCHIVE: Orcon 1000b lamphouse causing buzzing

This is topic Orcon 1000b lamphouse causing buzzing in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Matthew Taylor (Member # 2310) on 10-15-2006, 01:52 PM:

My Orc 1000 seems to have started some significant buzzing sound in the sound system. The buzzing is only apparent whilst the lamp is on. My CP50 setup even picks up the buzz when I disconnect the sound lead totally, suggesting to me that maybe there's a noise suppression capacitor that has stopped working in the lamphouse. Would I be on the right lines with this theory?

Posted by Gordon McLeod (Member # 33) on 10-15-2006, 03:00 PM:

Your ORC 1000 uses what is in effect a triac lamp dimmer circuit for the current control to the lamp as such it generates switching noise
It can be induced or powerline born
It is important that the lamphouse has a good ground connection as does the soundsystem
Also put the lamp on a different phase of the panel as the soundsystem

Posted by Matthew Taylor (Member # 2310) on 10-15-2006, 04:58 PM:

We only have single phase electricity.

Also, this problem has only started happening recently. Surely if it was the usual switching noise I would have had the problem before?

Posted by Gordon McLeod (Member # 33) on 10-15-2006, 05:00 PM:

Check your grounding
possibly a loose or corroded connection

Posted by Matthew Taylor (Member # 2310) on 10-16-2006, 11:04 AM:

Do you mean grounding inside the lamphouse?