source for electric switches (interuptors)

Patryk_Rebisz

Patryk_Rebisz

Veteran
I need to build a switch board to reroute power for various lights for music videos i shoot. Basically the board will have 5 channels. Each channel should support up to 20A (at least 15A) of power. What i need is switches that temporarily turn the power on or off on each channel. A typical switch has a spring that forces the switch to stay in one position so when i tell my gaffer to play with the switch according to the rhythm of the song to create some kind of lighting effect that goes along the switch (as it's not to be used in that manner) quickly dies. So i'm looking for a switch that would take the abuse. Anyone?
 
The most conventional solution is to use regular modern dimmers and some sort of controller. Should be available to rent at most places that rent lights, etc.

Or if you are up to DIY, (but remember that you are playing with mains power that could seriously kill you, your lighting guy and the entire cast and crew!)...

Conventional relays like this one...
http://www.allelectronics.com/make-a-store/item/RLY-482/120-VAC-40-AMP-RELAY/-/1.html
This one is noisy and takes 120v mains voltage to control, but 40A and costs $2.50

Or solid-state relays like this one...
http://www.bgmicro.com/index.asp?PageAction=VIEWPROD&ProdID=12878
This one costs $10 but completely silent and can be controlled with small buttons (like doorbell buttons) and 9V transistor radio battery.
 
i was told what i'm looking for is "momentary switch." question is if you know where to get the "momentary switches" that can hold 15-20A and be industrial strength for continuous on/off operation with quick changes of the switching rhythm?
 
Patryk_Rebisz said:
i was told what i'm looking for is "momentary switch." question is if you know where to get the "momentary switches" that can hold 15-20A and be industrial strength for continuous on/off operation with quick changes of the switching rhythm?
Click to expand...

Any kind of switch that can take rapid, repeated breaking at 20A is going to be big, stiff, clunky and noisy. By design. Because you need a strong "snap" when you break the current or the contacts will arc and quickly fail. Any kind of mechanical switch (even relay contacts) will have a significantly reduced life-expectancy if used as you describe. And it will be difficult to actuate quickly in rhythm.
 
Richard, so why is it that we do it successfully with regular switches and the thing that seems to fail inside are not the contacts but the spring holding it in on/off position as after a repeated use the switch hags loose and doesn't have the "snap"?
 
Patryk_Rebisz said:
Richard, so why is it that we do it successfully with regular switches and the thing that seems to fail inside are not the contacts but the spring holding it in on/off position as after a repeated use the switch hags loose and doesn't have the "snap"?
Click to expand...

If by "it" you mean conventional on/off at the wall switch in your bathroom, the switches have a life expectancy of many years because they are being run at a fraction of their full rating, and are being cycled only a few times a day.

If by "it" you mean rapid switching of a significant load (>10A), then it is a function of the design and manufacture of the particular switch whether the contacts or the mechanism fails first. You proposed use is way beyond the design parameters of most conventional mechanical switches. So the fact that it works at all is rather surprising.

IMHO, your proposed use is really not suited for conventional mechanical switches. A high-budget production would rig up a sound-activated controller and/or sequencer which would command conventional dimmer packs. But if you want to do it on a low budget, you should consider using the solid-state relays ($10 per channel), or at the very minimum, the mechanical relays ($2.50 per channel). Finding a suitable (current rated, mechanically tough, operates fast and quietly, etc) could easily cost even more than the relays.

Trying to do that with conventional mechanical switches is just asking for trouble. Trouble in the form of early switch failure, or even worse, in the form of dangerous exposure of lethal voltages to the light operator. At least that is my opinion from my engineer's perspective as well as a producer and safety advisor.

You won't get a recommendation from me to use mechanical switches of any kind for this application. Perhaps others have low-ball suggestions. :shocked:
 
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