
Can higher voltage increase output?
#1
Posted 01 February 2009 - 12:18 AM
#2
Posted 02 February 2009 - 12:40 PM
This does not apply to HMI's or Kinos. The ballast regulates that voltage that reaches the lamp, so you might damage the ballast with enough voltage, but you won't get anymore light out.
#3
Posted 02 February 2009 - 02:51 PM
To increase the power of practicals it is much better to just insert higher wattage globes.
Not too long ago we increased the voltage for some practicals in a house in a remote area on a weekend and they blew out very quickly with around a 25% voltage increase.
Since it was night there were no shops open and we just about made it with our spares.
Beware!
#4
Posted 02 February 2009 - 11:28 PM
Some people start turning up voltage when experiencing voltage drops. When you put a load on, and the voltage drops as you add lights, some crank up the voltage, but as you turn off lights the reverse happens, and the voltage could pop and blow bulbs or other equipment.
It is just safer to run your genny at proper voltages and with proper cable runs.
Best
Tim
#5
Posted 02 February 2009 - 11:46 PM
#6
Posted 03 February 2009 - 02:28 AM
#7
Posted 03 February 2009 - 02:46 AM
#8
Posted 03 February 2009 - 03:08 AM
Second: this is a terrible idea. DO NOT TRY IT.
Bulbs are rated a certain watt, at a certain volt (120) for a reason. There really isn't a safety factor built into them, letting you get away with X amount of %. Granted peaks in voltage coming from the power station are normal, but they hardly exceed 121/122. That's for a reason.
You can decrease voltage by the use of a dimmer, but you can not increase the voltage past the rating for a product. A lot of people all ready posted some serious concerns for other peoples gear as well... Good points.
#9
Posted 03 February 2009 - 03:52 AM
When we put the lamps on house power they did throw about a 1/4 stop more light, however on that job we were going through an average of a par globes, two tweenie globes and a pup globe every two days. Of those lamps we only had 8 pars, 4 pups and 2 tweenies out of the truck! Went through a lot of prac globes as well.
Off that experience one can definitely assume doing this on purpose does not work out cheaper or more time efficient, especially for a gain of about a 1/4 stop!
#10
Posted 03 February 2009 - 04:04 AM
Recently did a shoot in an older building that was getting mains power that we were metering at 257-261v besides our generator power of a perfect 240v. Because of budgetary constraints, we had to run of house power even at those voltages.
When we put the lamps on house power they did throw about a 1/4 stop more light, however on that job we were going through an average of a par globes, two tweenie globes and a pup globe every two days. Of those lamps we only had 8 pars, 4 pups and 2 tweenies out of the truck! Went through a lot of prac globes as well.
Off that experience one can definitely assume doing this on purpose does not work out cheaper or more time efficient, especially for a gain of about a 1/4 stop!
HERE HERE! Don't do it!
#11
Posted 03 February 2009 - 02:38 PM
Along the ceiling were crisscrossed strings of vintage clear 60-watt bulbs. "I barely got a T1.4 or even a T1 out of the whole tent being lit up," recalls Miranda. "We had to crank the voltage up to a 140 to get some sot of exposure out of them. The bulbs got very, very warm."
So, of course it is done, and even people with I'm sure unlimited resources turn to doing it. Just an example when it worked.
#12
Posted 03 February 2009 - 03:39 PM
#13
Posted 03 February 2009 - 07:42 PM
Bear in mind that while overvoltage is bad news for light bulbs, undervoltage is bad news for motors. Motors make up for low voltage by pulling more amps, and running hot. That's why motors are often rated 115/230 instead of 120/240.
-- J.S.
#14
Posted 03 February 2009 - 07:51 PM
I am in Australia where we are purely based on a 415/240v three phase system. Was an old building in an old area.
Cheers,
Matt.
#15
Posted 04 February 2009 - 02:20 PM
Wow, do you guys have three phase in your homes? Here the DWP will only sell single phase 120/240 to residential customers, even if there's three phase on the pole. Three phase motors are much more cost effective than single phase -- no capacitors or starting crap.John,
I am in Australia where we are purely based on a 415/240v three phase system. Was an old building in an old area.
Cheers,
Matt.
As for the overvoltage, if the building was big enough, it might have its own multi-tap transformer that was set up correctly for a full occupancy load, but ran high if you were the only users in the place.
-- J.S.
#16
Posted 05 February 2009 - 08:00 AM
We were in a hall in the middle of an older industrial area. We never did work out what the problem was, so your theory might very well be right.
#17
Posted 05 February 2009 - 08:22 AM
Wow, do you guys have three phase in your homes? Here the DWP will only sell single phase 120/240 to residential customers, even if there's three phase on the pole. Three phase motors are much more cost effective than single phase -- no capacitors or starting crap.
Hi John,
three phase power (380V) is pretty common here. We had it in my parents house from the start. Numerous other people who have hobby workshops would also have it. And out in the country is pretty much everywhere as nearly every one who does farming or gardening on a larger scale has a couple of appliances for three phase power.
Cheers, Dave
#18
Posted 09 February 2009 - 04:08 PM
-- J.S.
#19
Posted 10 February 2009 - 03:25 AM
Thanks, guys -- I'll have to keep Austria and Australia in mind as good places for a machinist to retire.... ;-)
Another advantage is quality of tools made here in Austria and of course Germany.

Cheers, Dave
#20
Posted 11 February 2009 - 03:19 AM
Three phase motors are much more cost effective than single phase -- no capacitors or starting crap.
Hi John, a small refresher
