Yet More Flickering Fires

[Mushypeas]

We have a mains voltage stove with the Floro Starters in it to make the red yellow and orange bulbs flicker. Traditionally we plug it into the rig and cue it from the board.

 

But the set designer is using two castered trucks to rotate and give the four scenes necessary. He is also quite adamant that the stove is on the truck, with no chance of having one of the cast slide it on during a scene change, so, can Floro Starters work at low voltages 9-12V say? Two 6 volt Lantern batteries with some car bulbs was my first thought, but where would I get the right lamp holders?

 

Or does anyone have any way of cunningly disguising some flex dropping down from the LX bar above?

[LX-Dave]

Not sure whether this is feasible or sensible, but is it not possible to have the stove on the truck, but have an in-line connection (for example) which an actor/stage hand plugs together and unplugs when required to move the truck? rather than moving the whole stove?

 

Dave

[Jivemaster]

Have you space on the truck to hide a battery and inverter? What is the total load and the total on time? Maybe you can predict what size battery and inverter simply and maybe even get a jump start battery from Maplin with inbuilt inverter.

 

IIRC they are 200w max and 17A/h but they are about £100.

 

As a totally alternative project, try some fluttering silk flames with lots of flame coloured LEDs (Red amber and some blues) either in some slow but random 555 timers - you could run this off a battery on the truck too.

 

Remote control probably by some two channel firework controllers - they tend to only pass a short pulse so you'd need a flip flop or latching "relay".

[Mushypeas]

I think my next door neighbour has one of those Jump start with inverters. I'll check.

 

I like silk flames but I have a feeling the set designer won't.

 

I also can't believe I didn't think of an in line connector. Christ. Call myself a lampie.

 

Thanks both of you.

[Jivemaster]

Terralec (and others) have combined DMX and mains cable that you could use for a feed to some LED lanterns programmed on a chase from the desk if you are going to power the truck.

[adam2]

I would use low powered mains voltage incandescent lamps in series with flourescent lamp starters.

Obtain 240 volt power from a battery and inverter, small units should suffice.

Presume 6 lamps each of 15 watts, and not on all the time, an average load of 60 watts might be reasonable.

A 100 watt inverter from Maplin or others is very cheap, and the input current would be about 9 amps maximum and about 6 amps average. A 17 amp hour battery should supply that for at least 30 minutes.

Connect a fuse in one of the battery leads as close as possible to the battery.

 

Another approach would be to use low voltage flashing bulbs, as used to be used in motorists lanterns.

These are less widely available, but can still be obtained, and will work directly from a suitable battery, without any inverter.

They come only in white, but may be coloured with gel or otherwise as required.

[ianknight]

I'd advise some caution with the inverter idea i.e. try it before you get to production.

 

Most budget inverters whilst outputting a waveform that most AC devices will work with, may not have sufficient protection for any noise on the outputs and starters in this mode of use do induce some noise on the mains they're connected to.

 

If you can load the output with a static load as well as the starters then you may get away with it - this could be a couple of orange lamps that stay on to give a background glow to the fire.

 

If I use starters for a fire flicker on a dimmer (and yes - that's the effect that impresses directors most, not the expensive glass gobo you had made <_< ), I always use a dummy load to prevent some of the cack on the mains induced by the starter upsetting the dimmer.

[J Pearce]

Keep it simple and just run a cable out to the truck and use your existing effect (you know it works and you already have it!). If you plan the rotates carefully you might even find it can stay plugged in.

If not put a panel IEC on the truck and have a cable end IEC to plug into the truck. This hides better than most mains connectors.

[Mushypeas]

Sorry to drag this out again, but this can nearly have some closure. I've bought a kettle plug to go on the flex of the stove, but it has removable pins. Because of this the terminal to the pin is merely a screw that tightens through a threaded hole at one end. The screw is rounded and not particularly large in head diameter, 3 mil maybe? I was just wondering the best practice of terminating the wire to the pin, if any at all?

[adam2]

It is far from easy to make a neat and reliable connection to IEC appliance connectors, commonly refered to as kettle plugs.

This no doubt explains why pre-wired moulded ones are popular.

I would try to use a prewired one if possible, they are available in longer lengths.

 

If use of the rewireable style with screw terminals cant be avoided, then I would solder the connections. A pedant might argue that this is contary to regulations, but IMHO it is the most secure and reliable way. The minute screw terminals work loose if not very firmly tightnened, and normally strip the thread if firmly tightened.

 

All this presumes that you have the connectors the right way around ! and are not connecting the part that goes on the kettle or other appliance to the mains.

This may sound obvious, but I have seen it done !

[Mushypeas]

OK.

Ta.