industrial light dimmer supplies?

[miles and jules]

Hi guys
I have been dimming lights using a 400watt light dimmer from bunnings. It is working great only now I need to dim a 2000watt light. Not sure where to look or what to ask for. I dont want anything that has electronics in it . I have used a stage light dimmer but its inbuilt ellectronic components stopped me from getting acurate reading on my voltmeter.

I really just need a light dimmer like the $15 one I got from bunnings only bigger
Thanks for any Suggestions
miles

[watson]

G'day Miles,
I reckon even the small one from Bunnings has electronics in it.....

With those constraints....maybe your only go is a variac.

[miles and jules]

Hi Noel
Yeah I've heard variacs are perfect for my needs only thing is they seem to be old school and hard to come by. Couldnt find any that were 240 volt on ebay and non from oz. I'll keep looking.

If anyone knows where i can get a variac in brisbane that would be great!

[malb]

Variacs are definitely old school, but oh so versatile, and you get a sinewave output, rather than a string of spikes.

What are you trying to dim, there are not a lot of individual lights in the 2K region that don't exhibit some negative characteristics when dimmed (i.e. shortened life etc). Stage, Film,TV halogens cop it but normally have reduced bulb life (generally also compromised by transport/rigging jolts anyway.

Also, why the multimeter requirement, dimming would normally be controlled to meet situational requirements rather than trying to meet a specific output voltage. Different meters wil respond differently anyway, depending on whether they are true RMS or peak responding and calculated RMS (for a true sine wave, not a chopped one), meter bandwidth (determines the harmonics included in the measurement) and other factors.

Best source for variacs is generally electronics disposals type places, but some new units are available but big dollars in the 10A plus range.

[watson]

Miles,
these places may be good to keep a watch on :

www.rockby.com.au
http://secure.oatleyelectronics.com//index.php

Often they have them on sale

[miles and jules]

Thanks Watson I'll theck out those links!
Hi Malb. We have been using the 400 watt dimmer with the multimeter across its ouput for an animation we are shooting. We use the dimmer/multimeter to tell us what voltage the main current is giving us then we adjust as need. What happens is as the mains power fluctuates throughout the day it gets recorded on the camera as a subtle flicker.

So our dimmer lets us compensate for the 1-5 volt drop or spike, that we get every day. It sounds low tech but it works flawlessly. I've heard power conditioners get rid of these problems but they are $1000 and up for 2k watt.

thanks
miles