What is this part called?

[tubedude]

And where to find it...
Its like the power light on a Seventh Circle chassis, or on tons of other pieces. They kind of look like rubies or saphires, etc, kind of diamond cut looking. I want to mount one on a blank woodgrain rack space panel and run it off a 9 volt battery with an on/off toggle next to it. Yeah its stupid but I have that Funk Logic bug and I want this to look cool. The other side will have my talkback momentary switch (On/off/mom) that I'm still not sure how to wire, either. More info on THAT appreciated also.

Will I need a resistor between the 9 volt battery and the light?

If you know what stuff I should use or where to find it, please post the links.

Thanks.

[travtele615]

http://www.tubesandmore.com/scripts/..._TREE03=JEWELS

Sorry for the long link
They're called Jewels at this place

Don't know about the circuit design but maybe someone else can chime in.

Travis Tackett

[Chris Nighman]

Do you mean the LED? Or maybe the acrylic light pipe that reflects it? Mouser stocks them if that's what you mean.

[Chris Nighman]

That's probably it Travis.

[paully]

http://www.fliptops.net/catalog/index.php?cPath=25_63

RadioShack has a good selection of mini-bulbs: all bases and voltages.

Paul

[jonmatifa]

Pilot lamp? Is that what you're talking about?

[Geoff_T]

Originally Posted by tubedude

And where to find it...
Its like the power light on a Seventh Circle chassis, or on tons of other pieces. They kind of look like rubies or saphires, etc, kind of diamond cut looking. I want to mount one on a blank woodgrain rack space panel and run it off a 9 volt battery with an on/off toggle next to it. Yeah its stupid but I have that Funk Logic bug and I want this to look cool. The other side will have my talkback momentary switch (On/off/mom) that I'm still not sure how to wire, either. More info on THAT appreciated also.

Will I need a resistor between the 9 volt battery and the light?

If you know what stuff I should use or where to find it, please post the links.

Thanks.

Hi

Neons and incandescent bulbs are out if you run it on a 9 volt battery and even with a led and a dropper resistor the battery life won't be that long.

If you must battery operate it, you'd be better off with a pack of 6 AA batteries. You can buy battery clips for these guys and they have a lot more life (mA/hours) than a 9v cell.

As for the device, there are loads and loads of LED's that fit panels and have fancy designed tops. You can even get them pretty large size too. A google search should find them.

EG http://www.ledtronics.com/markets/panel_index.htm

PS The current limit resistor in series with the led depends on the type of led... some have internal resistors and are designed to work at, say, 12 volts. A "basic" led resistor is calculated by (voltage input - led voltage)/led current. So, if your led runs on 2 volts and uses 10mA current, that's ((9-2)/0.01) = 700 ohms.

If you used 680 ohms it would work. Then the power of the resistor is voltage dropped squared/resistor value = 7 x 7 = 49/680 = 0.07W = a standard quarter watt would do fine.

[paully]

Originally Posted by Geoff_T

Neons and incandescent bulbs are out if you run it on a 9 volt battery and even with a led and a dropper resistor the battery life won't be that long...

>>>>>>>>>>>>>>>>>
Totally agree, but I know what this guy's after. There's nothing like being a beer or two over the line, and finding yourself staring at that gorgeous, brite, jeweled pilot lamp on the front of your amp. Totally mesmerizing. LEDs jus' 'taint the same thing. Hmmm.. think I'll grab a brew and go practice .

Paul

[ulysses]

You can put an LED behind that jewel, and it'll look like it should. The battery life will also be WAY longer than with an incandescent. Like Geoff said, neon is out since it needs a high AC voltage. The trick to getting good battery life off of an LED is to set it up so you're not wasting too much power. If you have more than one LED for extra brightness, put them in series. But you'll probably be fine with one bright one behind the jewel. A T 1 3/4 white LED from mouser or digikey should be around $2. It will have a voltage drop in the neighborhood of 3 or 4 volts. So a battery pack that's significantly higher than that will only force you to waste power by dumping more voltage across the current-limiting resistor. Three AA batteries in series will give you about 4.5V, which is reasonable. If you want to use Geoff's suggestion of six AAs, you use a series-parallel combination (two stacks of three). I think you're better off replacing the 3 batteries more often. Once you know the exact battery voltage you're using and the exact voltage drop across the diode (which is almost constant regardless of other conditions), then you can figure out the resistor value using Ohm's Law:
Vs-Vl=Vr (Supply voltage minus LED voltage equals voltage dropped across the resistor).
Vr/I=R (Voltage dropped accross the resistor divided by desired LED current equals resistor value).
For example, say you have a 4.5V battery pack and you find the LED drops 3.6V. That leaves you with 0.9V to drop across the resistor. If you decide that 17mA gives you the brightness you want without burning out the LED, then you would need a 53-ohm resistor (0.9/.017=52.9). The nearest standard value will be 51 or 56.
The power consumed by the LED will be 61mW, and the power wasted in the resistor will be 15mW. The total power consumed from the batteries would be 77mW (4.5V*0.017A). You can use a 1/4W resistor, no problem.
If you want to use rechargeable batteries, that's great. But NiCads put out 1.25V, so you have to re-do the math. You could also put a potentiometer on the fron panel to control the brightness, if you really want to be excessive. A 47-ohm resistor and a 50-ohm pot in series would give you some range. Be careful that the brightest setting doesn't destroy the LED. If you don't overdo the current through it, the LED should last longer than you do.
If you're really concerned about battery life, you can use some specialty battery types like computer PRAM batteries or camera batteries that put out 3.6V or so. The only problem is that small changes in battery voltage, resistor value, or even temperature can have a significant effect on LED current. And of course the resistor value will have to be much smaller.
Oh, one other thing. You can usually find a brighter LED for less money if you choose a color instead of white. Blues are expensive too, and typically not as bright as reds and yellows. If your jewel is red, try a red LED and it'll still be red. Or if you want to be a wise-ass, put a green LED behind the red jewel (or vice versa) and see what you get. Could be cool. But if your goal is to make it really bright, look for the biggest red, yellow, amber, or green LED you can find, with the highest millicandella rating, and choose a jewel that's the same color. If you want to be able to change the jewel color later, stick with a white LED.