Panel lamps anyone?

Discussion in 'General Electronics Chat' started by ErnieM, Sep 19, 2013.

  1. ErnieM

    Thread Starter AAC Fanatic!

    Apr 24, 2011
    7,386
    1,605
    I've been searching for a simple incandescent panel lamp to run off 120 VAC. All I seem to find are neon types, but my voltage is dimable so incandescent is a hard requirement.

    I even checked Radio Shack... Nothin!

    Anyone know where I could get me one of these?
     
  2. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,509
    2,369
    120v panel lamps are pretty much a thing of the past, most machine panel lamps are now 24vdc.
    What is the application, is it a new one?
    If existing, what is the base type?
    Max.
     
  3. #12

    Expert

    Nov 30, 2010
    16,257
    6,757
  4. ErnieM

    Thread Starter AAC Fanatic!

    Apr 24, 2011
    7,386
    1,605
    Thanks. Good find too, I was on Mouser for an hour.

    Just why did you search for a lamp under "optoelectronics" ??? :confused:
     
  5. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    5,435
    1,305
    Standard LED panel lamps that include a series resistor to run from 120v AC should also be "dimmable", and will give you more suppliers and types (and more reliability).
     
  6. shortbus

    AAC Fanatic!

    Sep 30, 2009
    4,004
    1,523
    For stuff like that, miniature bulbs or any bulbs for that matter, Grainger's catalog is always my first stop. Then after getting an industry part number, you can go from there for price. They seem to have the best selection available. And the catalog price is usually just a "suggested" price, wwhen you go in person to buy it the price is usually lower.

    http://www.grainger.com/Grainger/ww...g/N-kigZ1z09b6s?Ndr=basedimid10071&sst=subset
     
  7. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,509
    2,369
    There are some panel lamp manuf, that make them with a small transformer attached.
    But for long life, I go with 24vdc LED.
    Max.
     
  8. #12

    Expert

    Nov 30, 2010
    16,257
    6,757
    I didn't. I wrote, "lamp" in the search box, then chose incandescent, 120V. Taa daa!

    Mouser always had a PIB search engine. I guess I'm getting better at it.
     
  9. strantor

    AAC Fanatic!

    Oct 3, 2010
    4,302
    1,988
    If it's not on 1000bulbs.com, it probably doesn't exist. Their site is like my desk; hard to navigate if you don't already know where to look, but they've had everything I've ever needed. Here's their 120V mini bulbs section; it only shows 6 bulbs, but they have way more. I just can't find them all right now. Here's the full list of mini panel bulbs; you can dig there.
     
  10. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,509
    2,369
    Last edited: Sep 20, 2013
  11. ErnieM

    Thread Starter AAC Fanatic!

    Apr 24, 2011
    7,386
    1,605
    Thanks for the help. Best I can find thru preferred vendors is a 14VAC buld that fits in a panel mount holder, and that gets run off a step down transformer. 2 of 3 are on the shelve at Radio Shack, but I have to expense that. Or I can track them down at a DigiKey or Mouser so purchasing can chase them down for me.

    Why 115VAC? Cause that is the given input to this.

    Why not a LED? LEDs don't dim the same way incandescent do. The voltage is gonna dim and should generally match other nearby items.

    Why not a series resistor? Well, that would work, but as the power in the resistor is some twenty watts my poor box will glow brighter inside then the light does outside.

    It's possible to make an incandescent-like dimmable LED you add some very special circuitry. I've done that, made a product once to do make a LED mimic the intensity of an incandescent for voltage control. I don't have any left (that still work anyway), and I'm not going to build all that for this anyway.
     
  12. shortbus

    AAC Fanatic!

    Sep 30, 2009
    4,004
    1,523
    No Graingers in your area? Just the first page of the link (out of 29) has more than 5 120V panel bulbs. Both screw type and bayonet.
     
  13. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    5,435
    1,305
    A 120v AC panel LED has an inbuilt resistor dropping 118v and the LED dropping 2v, so it behaves on a phase angle dimmer exactly like a resistive load (ie it dims perfectly, giving half the light when receiving half the phase angle).

    I don't know why you think you need to add "special" circuitry to the 120v panel LED to make it dimmable, they are already dimmable and will match the dimming behaviour of the tiny 120v filament bulbs pretty well.

    The reason 120v tiny filament bulbs are hard to find is that they are obsolete, the LED versions work (and dim) just as well but are hundreds of times more reliable. You're not the first person that needed to dim panel lamps!
     
  14. ErnieM

    Thread Starter AAC Fanatic!

    Apr 24, 2011
    7,386
    1,605
    That is not what I said. Read it again, it says "the same way incandescent do." That means they have same brightness vs voltage characteristic. And to achieve that you need "special circuitry."

    Until you are ready to put a photometer on an incandescent bulb and an LED you don't have the information to have an opinion.
     
Loading...