Dimmers - I don't get it

John Locke · July 21st, 2003, 03:32 AM

Rob,

Can't stand to see someone get completely ignored. Yes, Lowel does sell one. You can find it here.

Steven Digges · July 21st, 2003, 11:22 AM

Andrew,

I also did the Home Depot search and went to many other lighting specialty stores searching for dimmers that would be a reasonable solution for my needs. Short of adapting a dimmer designed for a wall mount I could not find what I wanted. I caved in and ordered from Cool-Lux. The Cool-Lux catalog made a lighting dimmer sound very proprietary and perfect for my kit. I ordered 2 of them at $50.00 each. When they arrived I was immediately disappointed to see that they were so cheap they did not even have a ground pin receptacle and my lights have a ground pin (all lighting should be grounded in my opinion). Ten minutes later I was in Target to buy the ground lift adapters needed to plug my lights into the new dimmers. Right there in the electrical department were the exact same dimmers I paid $50.00 for from Cool-Lux for $15.00 at Target. I bought 2 more and vowed to quit buying Cool-Lux products (for other reasons also).

The dimmers Cool-Lux sells for $50.00 are actually made by GE. They can handle up to 600 watts. They work just fine with my Halogen kit. A Cool-Lux sticker is optional and requires an additional $35.00 plus shipping fees.

Also, there with the ground lifts and dimmers was a really cool IR remote control to turn power on and off, I got that too. Go figure, Target?

PS I know absolutely nothing about the frequencies, pulse rates, square gammas, wavelengths, round pulse factors and sub pulse factors of these cheap dimmers. They reduce voltage, for best results, white balance.

Steve

Alex Knappenberger · July 21st, 2003, 11:47 AM

What about buzzing caused by dimmers? Do only the extra extra cheap ones cause the lights to buzz/make noise? Do they all?

Richard Veil · August 6th, 2003, 02:19 AM

White balance on DV cameras is a blessing from god.. with film you would have a problem. but with white balance you can find a medium and hold all the dimmed lights together and not have it look to bad. Chimera makes scrims for their boxes and lanterns... or other peoples boxes if they are consistant in size.. which many Korean boxes are NOT>.
You can also use ND gels. Making dimmers is not hard but you have to watch out for sound interference.
I hope this helps
Strength and honor
r

Andre De Clercq · August 6th, 2003, 04:03 AM

Alex,
All dimmer structures, apart from rheostat or variac based ones, use choppered voltage concepts. The cheap ones, and also the build in dimmers for home appliances, just chop the 60 hz AC voltages, generating a lot of 60hz and higher harmonic currents. These currents (and voltages) can generate acoustic (and RF!) noise in the dimmer circuits (in the snubber circuits, chokes..) and/or in the lamp holder(vibrating wires/mechanical parts...). The more expensive ones are also based on switching on and off the source but this is done by first rectifying the mains voltage (for mains applications) or us the DC battery voltage right away, and chop these sources at high frequencies, far above the audible spectrum. High freq. Switched Mode Power Supply (SMPS) is being used these days in battery chargers, electronic ballasts, TV power supplies...off course with non adjustable duty cycles(fixed output voltages)

July 21st, 2003, 03:32 AM	#16
John Locke Retired DV Info Net Almunus Join Date: Sep 2001 Location: Austin, TX USA Posts: 2,882	Rob, Can't stand to see someone get completely ignored. Yes, Lowel does sell one. You can find it here. __________________ John Locke SursumFilms.com

July 21st, 2003, 11:22 AM	#17
Steven Digges Trustee Join Date: Oct 2002 Location: Phoenix, AZ Posts: 1,828	Cheap Dimmers Andrew, I also did the Home Depot search and went to many other lighting specialty stores searching for dimmers that would be a reasonable solution for my needs. Short of adapting a dimmer designed for a wall mount I could not find what I wanted. I caved in and ordered from Cool-Lux. The Cool-Lux catalog made a lighting dimmer sound very proprietary and perfect for my kit. I ordered 2 of them at $50.00 each. When they arrived I was immediately disappointed to see that they were so cheap they did not even have a ground pin receptacle and my lights have a ground pin (all lighting should be grounded in my opinion). Ten minutes later I was in Target to buy the ground lift adapters needed to plug my lights into the new dimmers. Right there in the electrical department were the exact same dimmers I paid $50.00 for from Cool-Lux for $15.00 at Target. I bought 2 more and vowed to quit buying Cool-Lux products (for other reasons also). The dimmers Cool-Lux sells for $50.00 are actually made by GE. They can handle up to 600 watts. They work just fine with my Halogen kit. A Cool-Lux sticker is optional and requires an additional $35.00 plus shipping fees. Also, there with the ground lifts and dimmers was a really cool IR remote control to turn power on and off, I got that too. Go figure, Target? PS I know absolutely nothing about the frequencies, pulse rates, square gammas, wavelengths, round pulse factors and sub pulse factors of these cheap dimmers. They reduce voltage, for best results, white balance. Steve __________________ www.CorporateShow.com Been at this so long I'm rounding my years of experience down...not up!

August 6th, 2003, 02:19 AM	#19
Richard Veil Chimera Lighting Join Date: Aug 2003 Location: Santa Cruz CA Posts: 293	What I think is this.. White balance on DV cameras is a blessing from god.. with film you would have a problem. but with white balance you can find a medium and hold all the dimmed lights together and not have it look to bad. Chimera makes scrims for their boxes and lanterns... or other peoples boxes if they are consistant in size.. which many Korean boxes are NOT>. You can also use ND gels. Making dimmers is not hard but you have to watch out for sound interference. I hope this helps Strength and honor r __________________ Strength and Honor RLV

July 21st, 2003, 11:47 AM	#18
Alex Knappenberger High School Student Join Date: Apr 2003 Location: Canton, Ohio, USA Posts: 609	What about buzzing caused by dimmers? Do only the extra extra cheap ones cause the lights to buzz/make noise? Do they all?

August 6th, 2003, 04:03 AM	#20
Andre De Clercq Major Player Join Date: Sep 2002 Location: Belgium Posts: 804	Alex, All dimmer structures, apart from rheostat or variac based ones, use choppered voltage concepts. The cheap ones, and also the build in dimmers for home appliances, just chop the 60 hz AC voltages, generating a lot of 60hz and higher harmonic currents. These currents (and voltages) can generate acoustic (and RF!) noise in the dimmer circuits (in the snubber circuits, chokes..) and/or in the lamp holder(vibrating wires/mechanical parts...). The more expensive ones are also based on switching on and off the source but this is done by first rectifying the mains voltage (for mains applications) or us the DC battery voltage right away, and chop these sources at high frequencies, far above the audible spectrum. High freq. Switched Mode Power Supply (SMPS) is being used these days in battery chargers, electronic ballasts, TV power supplies...off course with non adjustable duty cycles(fixed output voltages)