Will a dimmer work from the neutral side of a bulb??

[@jerryk3562]

Thank you for being honest telling us what you can and can not do and what you understand what you do not understand. As for me, it's helpful to think that I'm not so stupid after all.

[@bobr9605]

Hands down, Bar none, this is the most practically informative electrical KZbin channel to have existed.

[@Stevenj120volts]

@@bobr9605 thanks so much

[@Roboli-nr1mv]

Yo I've been thru hundreds of hours of electrician school and you my friend blow every instructor I've had out if the water in terms of teaching and simplifying complex concepts

[@Sparky-ww5re]

For those that don't know,, there are some versions of dimmers that actually vary the amplitude of the sine wave rather than chopping off a portion, although there are very rarely if ever used in this day and age. . 1st is a salt water dimmer aka liquid rheostat, consists of a glass jar or cylinder with a fixed electrode at the bottom, and an electrode connected to a lever that is moved up and down to vary the distance between them in a salt water solution to vary the resistance, which had to be regularly replenished as it would literally boil away from the heat caused by the large currents passing through, and the electrodes would corrode and require regular replacement. The liquid rheostat also posed a high risk of electric shock and electrocution to the operators. They were also load dependent, meaning if one lamp burned out during use, the voltage to the remaining lamps would increase and vice versa, so typically all the lamps on the dimmer were of matching wattage. This crude setup was used around the early 20th century for dimming theater and stage lighting. Next we had the resistance dimmer, or variable resistor. Although safer and more user friendly than the liquid rheostat, the resistance dimmer suffered similar drawbacks. Load dependent, and dissipated substantial heat and thus the device's were very bulky. To overcome these limitations before the 1960s when triac dimmers became available, the variable autotransformer , or variac was developed. While still farily bulky like the resistance dimmer, it proved to be superior as it was far more efficient, and wasn't load dependent and thus could be made smaller than the resistance dimmer for a given maximum wattage rating.

[@mydude3254]

This is why I like going to the comments. Thanks for the info, very interesting

[@breakthroughschool1456]

I like how real you keep it. We are all always learning. This is an electronic dimmer your using. Magnetic works differently.

[@SouthernGuardian]

Wow. Good info.

[@devmeistersuperprecision4155]

Triac…. Now there is a term I have not heard in a while. But then I am an old fart living in a small mountain town working as an apprentice while enjoying elk traffic jams. You can have the rat race. But in another day, there were SCRs and TRIACs. Used in power applications. It’s really cool to watch either fire on a scope. My old metal lathe runs a 5 HP DC motor. The speed control is a two stage vacuum tube like arrangement. I say like as the main tubes are thyratrons. These are argon filled and not vacuum. It also has a mercury vapor rectifier and a couple other tubes. I had to rebuild the diode module. In this we’re hunk in large diodes, zener diodes and a couple of SCRs. It operates on two distinct modes controlling both the stator DC voltage and or the rotor voltage/current. It took me a while to figure this out!!!! Now we see the new stuff showing up all over the place.

[@gnic76]

The older triac dimmers work well for incandescent but need a threshold load to work. If you have a multi bulb light and put LED's in it they may have a slight glow even when off. If you keep one incandescent bulb in, it adds more resistance and keeps the light off. (Or something like that. Lol) I thought triacs clipped the sinewave into a partial square wave lowering the frequency which dimmed the bulb. 🤷‍♂️

[@SpecialAccess77]

For those wondering, Voltage(rms) = Voltage(peak-peak) × ✓2 / 2 Assuming AC is a sine wave.

[@jbsimmons54]

Kindly hook up an oscilloscope to show the waveform dynamically as you dim/brighten the bulb.

[@jasondavis7913]

I just looked up how dimmers work about a year ago. Never found good info on exactly how the triac functions so that would be a good video when you’re able to explain it. Can you clear up something for me, is forward phase, leading edge, MLV all synonyms and like wise for reverse, trailing and ELV? For instance driver calls for ELV dimmer then any dimmer listed as reverse or trailing edge would theoretically work?

[@fredhoyt6900]

That's me. A dim bulb 😊

[@RichardWhiffen]

It's also why not all LED bulbs work with dimmers and can flicker instead of getting dim. Those "breaks" turn the bulb off.

[@randalamschel7589]

Is this how variable speed pumps operate?

[@jacobmurray3621]

A question I’ve had. Why do appliances and other electrical devices on ac have a plug that use polarity?

[@Stevenj120volts]

@jacobmurray3621 most everything I can think of will work either way. But some of our stuff like a screw in light bulb the shell is exposed. So it less of a shock hazard to make that be the neutral. And then I think some appliances want to do their internal switching on the hot, so s stuff illl have no voltage present above ground. So they build them expecting the hot to come in on a certain wire. But you do see it does not matter with things that are 240

[@onradioactivewaves]

The only 2 prong device i can think of offhand is the old analog clocks where the second hand moved constantly, which would actually run backwards if plugged in backwards. They used a nifty circuit called a phase locked loop ( PLL) to achieve this. Other than that, reversing inputs doesn't matter so much aside from the safety aspect of it - it will still look an AC input, unless you have a reference to a ground plane or utilize the PLL or other circuit that can detect phase. Some dimmers only have a hot and ground input with a load output- these devices are low power on the controls, as they are allowed to leak up to 50 micro amps to ground ( they may also leak a bit through the load).

[@SpecialAccess77]

​@@onradioactivewaves This cannot be true. There must be a reference that breaks the symmetry between each terminal. A sine wave is time translational symmetric. t = 0, hot = 170 V, neutral = 0 V, hot on left of plug t = 1, hot = 0 V, neutral = 170 V, hot on right of plug In both cases, the hot prong sees 170 V relative to the neutral prong. With only two prongs, the clock cannot know which state it is in. There must be a break in the symmetry of the waveform or a third reference point that breaks the symmetry between these two cases. These clocks had a fault where the clock may run backwards regardless of which way you plug them in.

[@onradioactivewaves]

@@SpecialAccess77 yes I guess you are correct, there would need to be another reference for that to work 😬

[@okaro6595]

@@onradioactivewaves That makes no sense. You are confusing with three phase motors where switching any two phases switches the rotation. Three points on a circle define the direction of rotation. Two do not. I have had such a clock and it always ran in the right direction. Plugs here are not polarized. If the clock is not grounded it has absolutely no way of knowing which is neutral and which phase.

[@ianclifford31]

Hey I’m in CT where are you? Sounds like Maine ?

[@Stevenj120volts]

@@ianclifford31 grew up mass moved yo maine when o was 21