Small inductive loads on dimmer channels

[Johnno]

I've to supply lightning for our school's next production. We have two small strobes (Soundlab Mini Strobes). In my store room I got a reasonable lightning effect from them if run for a second or so at a high flash rate. Since these are designed to run off the mains they will have a small transformer in their power supply. Would they be likely to cause problems if fed from a dimmer channel operated full-on (Zero 88 Chili)?

[dwh]

Yes. Don't do it. They do *not* get on. At all.

 

Personally I can't explain all the theory behind it (I'm sure someone will be along to do that in a moment), but the general rule of thumb (and what trying it once or twice very quickly has shown me) is that they do not like it. At all.

[tokm]

Hi,

 

The general rule with things like strobes/effects requiring hard power, is that you shouldn't use them on anything with a triac (a dimmer basically), even if its set to switch, only time you should run hard power from a dimmer rack is if its one of the module style racks such as the ETC Sensor or Strand SLD ones where you can get a relay/contactor module for a channel.

 

But, past experience has taught me this is not always true.. Big strobes like the 500w/750w or higher power strobes really do screw with the triac, but small/very low power strobes like the ones said by the O/P should be OK, if your just giving them a short 'blast'.

 

I'm sure some will disagree, as it goes against good/common practise, but in this instance I really don't think 2 small strobes are going to hurt a Chilli Rack..

 

Here's a tip.. Just to make sure the strobes do get as close to 100% power that the dimmer will put out & so that they can't accidentally be set to something less than 100%, go into the menu on your Chilli Rack, and set the dimming curve/law on channel your plugging the strobes into, to Switch. The manual for the Chilli dimmer tells you how to do this >> http://support.zero88.com/main/en/product/23 Its page 3-10.

 

HTH.

 

Tom

[Brian]

I've got some of the same strobes which I've used on Betapack mk2s just fine. It isn't good practice but it works. IIRC I had a bit of a problem with there being enough leakage current that they didn't go cleanly off when the dimmer was set to zero, they would fire a few more times. A 'ballast' load sorted that out.

[paulears]

This seems to be one of those things that we all don't recommend as it is bad practice, and perhaps 10 years ago was good advice. As Brian says, the usual thing with any non-fillament device plugged into a dimmer is use a dummy/ballast load plugged into the dimmer channel to at least mimic to the dimmer that a convenional load is present. My venue has pretty ancient dimmer (STrand STMs) and despite being incapable of driving 'odd' loads a few years ago, they seem quite happy to run modern fittings like fluorescent tubes, small strobes (as in this post), mirror ball motors and UV cannons without the load? Now maybe this is to do with the better design of modern devices? It can't be the dimmers, as these are original 1970s issue. I always work on the idea that it's a good idea to have an old 500W lantern or two lying about for load duty, but a rare thing now to need them.

[GaryP]

Yes. Don't do it. They do *not* get on. At all.

 

Personally I can't explain all the theory behind it (I'm sure someone will be along to do that in a moment), but the general rule of thumb (and what trying it once or twice very quickly has shown me) is that they do not like it. At all.

 

Here is an explanation....

 

PTFD