Light Bulb Wattage Question.

[JohnCU]

Originally posted by: NL5

Originally posted by: us3rnotfound

Originally posted by: JohnCU
well shit since when did dimmers come with SCRs? i thought it was just an increasing/decreasing resistance. fuck they don't teach you anything in school

I definitely agree. I'm a junior in EE and I wasn't aware of this either.

Edit: but my friend who's a EET did. I knew I should have just gone for that degree.

Wow. It was like day three of electronics 101.

day 3 of electronics 101 was holes and pn junctions

 

[NL5]

Originally posted by: JohnCU

Originally posted by: NL5

Originally posted by: us3rnotfound

Originally posted by: JohnCU
well shit since when did dimmers come with SCRs? i thought it was just an increasing/decreasing resistance. fuck they don't teach you anything in school

I definitely agree. I'm a junior in EE and I wasn't aware of this either.

Edit: but my friend who's a EET did. I knew I should have just gone for that degree.

Wow. It was like day three of electronics 101.

day 3 of electronics 101 was holes and pn junctions

That was day 5. 🙂

 

[JohnCU]

Originally posted by: NL5

Originally posted by: JohnCU

Originally posted by: NL5

Originally posted by: us3rnotfound

Originally posted by: JohnCU
well shit since when did dimmers come with SCRs? i thought it was just an increasing/decreasing resistance. fuck they don't teach you anything in school

I definitely agree. I'm a junior in EE and I wasn't aware of this either.

Edit: but my friend who's a EET did. I knew I should have just gone for that degree.

Wow. It was like day three of electronics 101.

day 3 of electronics 101 was holes and pn junctions

That was day 5. 🙂

how can you cover components before you cover the basics that make the components work?

 

[NL5]

Originally posted by: JohnCU

Originally posted by: NL5

Originally posted by: JohnCU

Originally posted by: NL5

Originally posted by: us3rnotfound

Originally posted by: JohnCU
well shit since when did dimmers come with SCRs? i thought it was just an increasing/decreasing resistance. fuck they don't teach you anything in school

I definitely agree. I'm a junior in EE and I wasn't aware of this either.

Edit: but my friend who's a EET did. I knew I should have just gone for that degree.

Wow. It was like day three of electronics 101.

day 3 of electronics 101 was holes and pn junctions

That was day 5. 🙂

how can you cover components before you cover the basics that make the components work?

I had one heck of a great professor...LOL. 😉

He didn't believe in teaching things "in order". We actually discussed dimmers during 'intro to AC", so we knew what they did, before we knew the "how".

 

[JohnCU]

Originally posted by: NL5
I had one heck of a great professor...LOL. 😉

He didn't believe in teaching things "in order". We actually discussed dimmers during 'intro to AC", so we knew what they did, before we knew the "how".

hmm interesting, sounds better than my professor :thumbsup:

 

[Jeff7]

Originally posted by: us3rnotfound

Originally posted by: JohnCU
well shit since when did dimmers come with SCRs? i thought it was just an increasing/decreasing resistance. fuck they don't teach you anything in school

I definitely agree. I'm a junior in EE and I wasn't aware of this either.

Edit: but my friend who's a EET did. I knew I should have just gone for that degree.

If a dimmer was dissipating all of that power into the wall box, your house would have burned down the first time you dimmed your lights. 😉

Originally posted by: PlasmaBomb

Early dimmer switches were variable resistors 🙂

Modern ones use a triode alternating current switch (and some other electronics).

If you hook up a really cheap dimmer switch, you can get a buzzing noise, due to vibrations in the bulb filament caused by the triode alternating current switch.

Edit: Actually its caused by the effects of the Triac when it starts conducting and causes a larger than normal change in the voltage, resulting in changes in the magnetic field around the filament.

And I think it's this magnetic field that makes the filament move around rapidly, which is perceived as a buzzing noise.

 

[NL5]

Here is a great site for explaining how they work - scroll to the bottom -

http://www.casemodvideos.com/tech/Variacs-Dimmers.htm

 

[Eli]

No, you don't need new lightbulbs. It's normal.

You're hearing the frequency of the triac switching in the dimmer.

Edit: I hate replying to threads that have so many replies already. lol

 

[IronWing]

On the same topic, sort of....

When using a 26W CFL in a three way 75/100/150W floor lamp the CFL doesn't light at all when the three way switch is set to "low" but does light up in medium and high. Am I right in thinking that I should use the lamp with the three way switch set to high as opposed to medium or should it matter as long as the CFL lights?

 

[Eli]

Originally posted by: ironwing
On the same topic, sort of....

When using a 26W CFL in a three way 75/100/150W floor lamp the CFL doesn't light at all in when the three way switch is set to "low" but does light up in medium and high. Am I right in thinking that I should use the lamp with the three way switch set to high as opposed to medium or should it matter as long as the CFL lights?

Hmm.

I'm not sure. I guess it would depend on how the 3 way switch works.

I killed one of my CFLs playing the dimmer with it. 🙁 lol

 

[BigJ]

Originally posted by: ironwing
On the same topic, sort of....

When using a 26W CFL in a three way 75/100/150W floor lamp the CFL doesn't light at all in when the three way switch is set to "low" but does light up in medium and high. Am I right in thinking that I should use the lamp with the three way switch set to high as opposed to medium or should it matter as long as the CFL lights?

It's recommended to use it on the middle setting. Beats the hell outta me why though. That's just what GE says.

I don't see why either of the settings wouldn't work fine.

 

[Elstupido]

A dimmer , or any other lower wattage converting device will kill a cfl, not rated for it, in a hurry.
As Eli said.

 

[Twista]

Buzzing is coming from the light bulbs. I have (2) 100 watts up.

 

[jagec]

Originally posted by: BigJ

Originally posted by: ironwing
On the same topic, sort of....

When using a 26W CFL in a three way 75/100/150W floor lamp the CFL doesn't light at all in when the three way switch is set to "low" but does light up in medium and high. Am I right in thinking that I should use the lamp with the three way switch set to high as opposed to medium or should it matter as long as the CFL lights?

It's recommended to use it on the middle setting. Beats the hell outta me why though. That's just what GE says.

I don't see why either of the settings wouldn't work fine.

Either works fine. The only reason I can possibly think of to use the "Medium" instead of "High" would be because "High" energizes the third metal tab in the socket (which doesn't contact non-3-way bulbs), and I guess if that tab got bent upwards it could cause a short.

Of course, since you have to flip it through "High" again to turn it off, that seems like a pointless precaution to me. Maybe it you knock it off the table and the tab temporarily shorts against the bulb on impact? Again, seems like a pretty minor concern.

 

[BigJ]

Originally posted by: jagec

Originally posted by: BigJ

Originally posted by: ironwing
On the same topic, sort of....

When using a 26W CFL in a three way 75/100/150W floor lamp the CFL doesn't light at all in when the three way switch is set to "low" but does light up in medium and high. Am I right in thinking that I should use the lamp with the three way switch set to high as opposed to medium or should it matter as long as the CFL lights?

It's recommended to use it on the middle setting. Beats the hell outta me why though. That's just what GE says.

I don't see why either of the settings wouldn't work fine.

Either works fine. The only reason I can possibly think of to use the "Medium" instead of "High" would be because "High" energizes the third metal tab in the socket (which doesn't contact non-3-way bulbs), and I guess if that tab got bent upwards it could cause a short.

Of course, since you have to flip it through "High" again to turn it off, that seems like a pointless precaution to me. Maybe it you knock it off the table and the tab temporarily shorts against the bulb on impact? Again, seems like a pretty minor concern.

Yea that's the only reason I could put together from looking at it quickly. But in that case, it's not just an issue with CFLs, but all bulbs that are not 3 way bulbs.

 

[AlienCraft]

Originally posted by: Twista

When i DIM the lights i can hear a buzzing sound coming from the light bulbs. The sound goes away when i turn the dimmer to full power.


Do i need different type of light bulbs?

-------------------
I was just brought a dimmer light switch (rotary). It says 120v/600 W on the switch.

Does that mean the max wattage light bulb that can used is 60 watts? Or can i buy a 75w or 100 watt bulb and have no problem.


Thanks

Filament "singing" is common in consumer quality dimmers. As you go up into the commercial stuff and theatrical, this has been eliminated with better quality components / circuits.
In the olden days of Rock & Roll Touring, when we used Auto Transformers on wheels, then clunky boxes of SCR dimmer banks weighing slightly less than the afore mentioned Auto Xfmrs, to control banks of lights, when they would be in anything other than full on or off, sometimes the filament noise would be audible onstage.
Since a light bulb is a chamber it has a resonant frequency ( kenneth), and it's really awesome to hear(see) a string section send a sympathetic light into harmonic resonance.
The filament will bounce around to the extent that the "holder" maintains it's integrity.
They have dampeners on "pro" lamps, but household models and really old semi pro theatrical lamps may not.

todays newer lamps have much better characteristics, but it is still possible to see this in small theatre lights, etc.

Changing light bulbs may give you different results, especially if it by different makers.


That el-cheapo dimmer will get warm as the load (wattage) goes up.
Try not to use all 600 watts or stuff it into a wall box that is overcrowded.
You could go 300 watts of incandescent lighting , no problem.

Never put a common CFL on a photo switch or a dimmer.
They have CFL's rated as such and they will not catch on fire like the others will.


< Been a "squint" since 1973. Former Nocturne Lighting bench tech.

 

[AlienCraft]

Originally posted by: BigJ

Originally posted by: jagec

Originally posted by: BigJ

Originally posted by: ironwing
On the same topic, sort of....

When using a 26W CFL in a three way 75/100/150W floor lamp the CFL doesn't light at all in when the three way switch is set to "low" but does light up in medium and high. Am I right in thinking that I should use the lamp with the three way switch set to high as opposed to medium or should it matter as long as the CFL lights?

It's recommended to use it on the middle setting. Beats the hell outta me why though. That's just what GE says.

I don't see why either of the settings wouldn't work fine.

Either works fine. The only reason I can possibly think of to use the "Medium" instead of "High" would be because "High" energizes the third metal tab in the socket (which doesn't contact non-3-way bulbs), and I guess if that tab got bent upwards it could cause a short.

Of course, since you have to flip it through "High" again to turn it off, that seems like a pointless precaution to me. Maybe it you knock it off the table and the tab temporarily shorts against the bulb on impact? Again, seems like a pretty minor concern.

Yea that's the only reason I could put together from looking at it quickly. But in that case, it's not just an issue with CFLs, but all bulbs that are not 3 way bulbs.

All three of you guys do know that changing the lamp socket out to a standard would take like all of 5 minutes? I had to do exactly that same thing when the head decorator commanded it be done.
I mean, come on, on this tech board, to NOT swap out a lamp socket would be downright ironing. :roll: 😀


We really do need a rim shot / snare drum / kick drum smilie......:laugh:

 

[0roo0roo]

they make 3 way cfl's u know. that being said they probably cost more.