rec.arts.theatre.stagecraft

On Sat, 09 Feb 2008 22:49:03 -0000, David McCall
wrote:

>
> "Duncan Wood" wrote in message
> news:@lucy...
>> On Fri, 08 Feb 2008 15:43:30 -0000, David McCall
>>
>> wrote:
>>
>>> You would probably get away with it because the voltage at zero is
>>> pretty
>>> small.
>>
>> WEll with most dimmers over 10 years old it's 240V.
>>
> If you are talking about the potential when there is no load you may
> well be
> right on?
> Good point. If you had a dummy load on the dimmer you could alter that,
> right?
>
>>

Assuming nobody unplugs it etc. Not exactly ideal for life safety. (Not
that I'm bitter about falling off a truss this week after touching a bare
wire)

>>> However, it would certainly be considered bad practice by anyone here.
>>> As long as the circuit is connected, there is a always the possibility
>>> that
>>> the
>>> circuit could become live and hurt someone. I would have the lamps
>>> connected
>>> to a dimmer, but have an easily accessable conection off stage that
>>> could be
>>> unpluged before anyone had to touch it. Being Am-dram, I might have the
>>> person that could be in danger pull the plug personally before he
>>> enters
>>> if he is off stage at the time.
>>>
>>> Did you really mean to say 50 volts? I'm from the other side of the
>>> pond
>>> and have never heard of mains power at 50 volts. 250 is more likely.
>>>
>>> David
>>>
>>
>> 50V secondarys are quite common
>>
> Very interesting.
> Under what conditions would you find 50v?
>

It was fairly common voltage for central backup battery units

>>
>>> "Bob Nixon" <@> wrote in message
>>> news:$@...
>>>> Hi all
>>>> Like to pick your experienced brains
>>>> I am an Am-dram SM and we are in the UK doing "Absurd Person Singular
>>>> Alan
>>>> Ayckbourn " There is a point in the play when the female character is
>>>> constantly trying to sincerely commit suicide by various means other
>>>> characters mis-read her actions as her struggling to do something
>>>> One action is to climb on the table with a rope (washing line) to
>>>> attach
>>>> the rope to the light flex in order to hang herself, to accomplish
>>>> this
>>>> she removes the lampshade and bulb having already turned off the power
>>>> at
>>>> the wall switch [There has to be two fittings so that one remains
>>>> "on"]
>>>> She then ties the rope at the top of the flex and pulls twice and it
>>>> holds
>>>> However on the third pull it slides down the flex and pulls off the
>>>> bulb
>>>> holder exposing the bare wires, Someone misunderstanding her action
>>>> thinks
>>>> she is trying simply to change the bulb and offers to do this
>>>> realising
>>>> the bare wires he tries to refit a bulb holder but he is very poor at
>>>> doing this and someone comes in and not thinking turns the power back
>>>> "on"
>>>> so giving the man an electric shock
>>>>
>>>> My question
>>>> 1) The light fitting needs to originally be operational (How can I
>>>> secure
>>>> the bulb holder so that it will be sufficiently attatched to safely
>>>> operate correctly and light the bulb BUT loose enough to be pulled of
>>>> easily when she pulls the rope first time after the third pull (ie
>>>> pull
>>>> 1
>>>> + 2 hold, then pull three pulls off bulb holder at one pull)
>>>>
>>>> 2)WHAT VOLTAGE WILL THERE BE AT THE bulb when the LX operator pulls
>>>> the
>>>> fader to zero ( Our LX guys very experience amateur operators /
>>>> designers
>>>> feel the will be virtually no voltage not enough to give a shock (we
>>>> are
>>>> on DMX system)
>>>> I feel it is unsafe, but don't want to cause unrest and loss of
>>>> friendship
>>>> and trust not knowing the correct situation first However If my theory
>>>> is
>>>> correct I will make the safety first decision and over ride their
>>>> ideas
>>>>
>>>> We have a 50v system with 50v bulbs could this be attached to the DMX
>>>> channel as a switch rather than dimmer circuit.
>>>>
>>>> Sorry for long winded question
>>>
>>>
>>
>> Use a 12V bulb (you can get them in mormal gls sizes) & an isolating
>> transformer or lose the bulb holder to the grid & use a dummy flex.
>
>