Holisitic Understanding of Home-made Dimming Switch Circuitry

Discussion in 'General Electronics Chat' started by DutchlandDiesel, Dec 17, 2014.

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  1. DutchlandDiesel

    Thread Starter New Member

    Dec 17, 2014
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    Hi all -- this is my first post on here.

    The short version is that I started an industrial/rustic furniture & lighting design company, and the edison bulbs I use for my displays only really look good dimmed.

    I have tried to integrate panel dimming switches into the design of my lamps by either hiding them inside, coring a 4x4 with a band saw and shoving them in there --
    anything to avoid a visible gang box (My opinion only: I hate the way it looks and I think it's cheating).

    I want to make my own dimming switches, and I have never done circuitry before. I have read a textbook on it and have familiarized myself with Ohms law, and the schematics,
    and the symbology. However, the practical application of circuitry -- sitting with a circuit board and trying to understand why and where things get soldered, why the
    capacitor is needed in this situation rather than a transformer, and why a neon lamp can be used instead of a DIAC...these are the issues I have. I am unable to undertsand
    them in relation to one another.

    Does anyone know where I can find a video or step by step tutorial where someone is making a dimming switch from start to finish? I have already looked in the resources
    page. For example, 'STEP 1: we are soldering the potentiometer to this side of the circuit board because .....', and 'we are using 2 0.068 250V Capacitors because...'

    I know it seems strange, but I haven't set been able to understand circuitry holistically.

    The bulbs are 60W, and the potentiometer is 10k.

    I have been attempting this schematic.
    http://www.aaroncake.net/circuits/dimmer.asp?showcomments=all

    Thanks in advance, and for taking the time to read.
     
  2. blocco a spirale

    AAC Fanatic!

    Jun 18, 2008
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    A mains powered dimmer switch is an odd choice for a first project and not one that anyone would recommend. It is best to start with low voltage DC circuits involving op-amps, transistors, timers and counters etc. if you want to safely get experience of electronic circuits and components.
     
  3. DutchlandDiesel

    Thread Starter New Member

    Dec 17, 2014
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    Do you think this is a better choice? This is what I want to make: link

    That way, I can learn WHILE creating something useful!
     
  4. blocco a spirale

    AAC Fanatic!

    Jun 18, 2008
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    No. Isn't this also a mains powered dimmer?

    You should also be aware that circuits which connect directly to the mains, such as this, cannot be discussed on this forum as they are considered to be too dangerous.

    Apart from the real risk of electrocution, exploding components aren't funny.
     
  5. MikeML

    AAC Fanatic!

    Oct 2, 2009
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    Dutch is also totally naive about why AC dimmers are required by IEC Code to be mounted inside an approved enclosure, such as a 2x4 gang box. The first house he burns down having mounted his dimmer inside a wooden 2x4 will end his furniture business...
     
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  6. DutchlandDiesel

    Thread Starter New Member

    Dec 17, 2014
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    I think it's implied that anyone doing this for under a year is naive. Admittedly. Which is kinda exactly why I'm on a message board asking advice...see how that works? Just like a circuit.
     
  7. DutchlandDiesel

    Thread Starter New Member

    Dec 17, 2014
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    Question -- This rotary switch has a 3/8" threaded stem. If I install this by screwing it directly into a 3/8" x 3/4" reducer that sits flush in a block of wood, and is wired through the block and out the back into the AC power source, is that acceptable?
     
  8. MikeML

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    IEC, UL and CSA are all concerned about a failure in the dimmer starting a fire by being in intimate contact with flammable material like wood. It either has to be in a metallic enclosure, or in an approved box with an approved cover plate.
     
  9. ronv

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    Nov 12, 2008
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  10. ErnieM

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    Apr 24, 2011
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    May I step back and ask a question? Do you really need an adjustable dimmer or just want the bulb to glow softly, not as bright but with that warm yellow glow?

    How about just using a 60 W bulb for 220V service. It will glow nice and soft by itself, no electronics needed.
     
  11. MikeML

    AAC Fanatic!

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    Or just use a 60W 120Vac bulb with a 1000piv rectifier diode in series with it.
     
  12. DutchlandDiesel

    Thread Starter New Member

    Dec 17, 2014
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    Hi -- thanks for the feedback and suggestions.

    MikeML -- I don't know what a 1000piv rectifier diode does, and when I looked it up, it's for micro-circuitry, and I'd have to solder somewhere and to something (neither of which I understand). If you had a sec, would you let me know?

    Ernie -- I think the dimmed Edison bulb gives it a kind of ambiance that can't be replicated despite wattage. Plus -- if I'm being candid -- it does class it up a bunch.

    ronv -- Thanks for suggestion. I use vintage cloth-covered cables, and this cord is $16, which isn't good for margins. At that point, Id' buy a dimming socket for $20, which I was hoping to avoid. I

    I'm attaching some lamps I've made, and any suggestions for placement of dimming switches in properly housed receptacles (or any other feedback) would be greatly appreciated by me.

    Thanks!

    Table Lamp (example3).jpg 2b_TableLampMasonJar.jpg
     
  13. ian field

    Distinguished Member

    Oct 27, 2012
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    Not to mention the RFI with no choke/filter etc.
     
  14. DutchlandDiesel

    Thread Starter New Member

    Dec 17, 2014
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    Wait -- so is what I did a good or bad idea, I can't tell by your post. WE GET IT.
     
  15. Kermit2

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    Feb 5, 2010
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    i second the vote to use a diode. super simple and should give you the dimmer glow you desire.
    i recommend you attach a diode and see if it dims to a level you like. no polarity worries either. Its AC ya know.
     
  16. tcmtech

    Well-Known Member

    Nov 4, 2013
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    The correct value of non polar capacitor in series with tour bulb would work well too.

    Two wire and no brains to hook up once the correct impedance is found. Cheap, easy to hide and dead reliable too.
     
  17. ian field

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    I got reminded of the terms of service last time I mentioned a wattless dropper.

    Simplicity and reliability could be served by a transformer with the secondary bucking the voltage applied to the primary. An assortment of taps would facilitate finding the optimum reduction.
     
  18. DutchlandDiesel

    Thread Starter New Member

    Dec 17, 2014
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    I had no idea I could open up a light bulb and add a non-polarized capacitor in it. I'm going to try this. Thanks!
     
  19. cmartinez

    AAC Fanatic!

    Jan 17, 2007
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    :eek: Open up a light bulb??? Have you any idea of what would happen if you (successfully) opened it and then switched it back on?
    Light bulbs have a gas mixture (like argon, krypton, nitrogen, etc...) at a calibrated pressure in them... if you were to be able to open it without destroying it, then the filament would instantly react with the oxygen in the atmosphere when you tried to switch it back on and get blown to smithereens, probably destroying the glass as well and potentially injuring someone...
    In short, you CAN'T just open up a light bulb... I strongly advice you against it...
     
  20. DutchlandDiesel

    Thread Starter New Member

    Dec 17, 2014
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    Oh. Ok -- I don't know how I would attach a non-polarized capacitor to a circuit. There's no circuit. There's the AC to switch to bulb socket. That's it. Where would I attach anything there, unless I made a small receptacle containing a capacitor that I put in a gang box.
     
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