120 VAC indicator lamp??

Any suggestions would be appreciated. What do you use?

I've got 2 projects that require a light which illuminates when the DAC or preamp is on.

The DAC has 120VAC in so it would be easiest to find a small 1/8" red or blue light that will work with 120 VAC. Could I just use a resistor?
I am using a Qualtek power entry module and would like to wire the lamp to the on/off switch:
http://www.alliedelec.com/search/productdetail.aspx?SKU=6894214

The pre-amp can run on 5.5-26 VDC so looking for a small lamp for that too.

I've done a lot of searches at Allied Electronics and Newark but all they have are 3/8" dia lamps for 120 VAC. I don't know the right questions to ask them to get the right answer either.

Bot lamps will be mounted on a 5/16" thick aluminum faceplate...somehow...
 

Hearinspace

Member
Paid Member
2008-06-03 5:18 am
Getting rid of LEDs and neon lamps from commercial audio components was a tweak years ago. Nobody seems to care about it much these days.

Anyway, I think straight AC on indicators are best on the AC mains side of the circuit and will use whatever I like the look of and drop it to the voltage or brightness I want with resistors.

I have some switches that say they use AC LEDs but I don't really know if they're true AC devices or have a rectifier built in. But even if there aren't real AC devices, if you like LEDs it's easy enough to build a little circuit to go with it. Maybe one like this?
 

Hearinspace

Member
Paid Member
2008-06-03 5:18 am
Any suggestions would be appreciated. What do you use?

I've got 2 projects that require a light which illuminates when the DAC or preamp is on.

The DAC has 120VAC in so it would be easiest to find a small 1/8" red or blue light that will work with 120 VAC. Could I just use a resistor?
I am using a Qualtek power entry module and would like to wire the lamp to the on/off switch:
Qualtek Electronics Corp. - 761-18/003 - Power Entry Modules (PEM) - Power Products - Allied Electronics

The pre-amp can run on 5.5-26 VDC so looking for a small lamp for that too.

I've done a lot of searches at Allied Electronics and Newark but all they have are 3/8" dia lamps for 120 VAC. I don't know the right questions to ask them to get the right answer either.

Bot lamps will be mounted on a 5/16" thick aluminum faceplate...somehow...

Thanks for the replies but I do not want to make this into some laborious project. Don't know about P-S rails or designing a circuit for LED's.

Have a 120 VAC wire and would like to hook a small light to it. That's about it.
Is there such a thing?

OK, I'll try once more. Yes you can get lights that are the size you want, and yes you can use lights that are rated for a lower voltage by putting the appropriate resistor(s) in series with them. You apparently already use Allied so search on their website. There are lot's of lamps of various voltage and watt ratings you could use - you just have to think a little creatively. If you can't get a light tiny enough to suit you you could drill a tiny hole in the plate and simply mount a low powered light behind it. Lot's of possibilities actually. If you find some that you like and you don't know how to implement them in your project then post again with specifics and somebody can help you decide part values.
 
Hearinspace, I found this but have no idea on its size:
http://www.alliedelec.com/Images/Products/Datasheets/BM/HIRSCHMANN/391-0029.PDF

and this which looks to be .4" at least:
EIKO - LED-120-MB-G - Lamps - Optoelectronics & Lighting - Allied Electronics

and this which is over 1/2":
SloanLED - 5002-12016 - Indicators, Panel Mount - Optoelectronics & Lighting - Allied Electronics

and these but they appear to be over 1/2" dia:
Search results for "miniature neon panel mount indicator" - Allied Electronics

and this:
Search results for "miniature led 120vac" - Allied Electronics

I don't really know about this stuff. But searching on and off for 2 weeks. That' why I thought I'd post here.
 

Hearinspace

Member
Paid Member
2008-06-03 5:18 am
Well, It's a little hard to know how to answer because you've said you don't want to get into "some laborious project" yet what the guys are advocating above is from the perspective of soldering and mounting only slightly more involved that the little passive pre you've already built - with the one important difference that it involves working with mains voltage and current and getting something wrong there as you know can be dangerous.

I also don't have any idea what tools you've got and what you're comfortable with in terms of drilling holes in the front panel etc. You can make a good looking panel indicator by drilling a 1/16" - 1/8" hole from the front and then using that as a centre guide drill a hole only partially through from the back side of the panel to fit the lamp or LED. But this takes a little care and precision to do well and can look like crap if done badly - especially if the panel is already anodized. If you don't want to get into it then best to take it to a shop or get a DIYer friend in the neighborhood to help.

Also something else that I thought last night. If you would actually like to get into this stuff more and the fact that you don't know much is holding you back I would strongly recommend starting with building kits. Good kits with good instructions can teach you a lot and give you guided experience in things like hookup, soldering and also importantly, layout. Start with small/cheap ones and if you find you enjoy the building process then work up from there. In the absence of local friends and mentors it can be overwhelming in the beginning to try to take on the steep learning curve. Better to take advantage of others' expertise and get a happier start.

I hope something here is useful.
 
Any suggestions would be appreciated. What do you use?

I've got 2 projects that require a light which illuminates when the DAC or preamp is on.

The DAC has 120VAC in so it would be easiest to find a small 1/8" red or blue light that will work with 120 VAC. Could I just use a resistor?
I am using a Qualtek power entry module and would like to wire the lamp to the on/off switch:
Qualtek Electronics Corp. - 761-18/003 - Power Entry Modules (PEM) - Power Products - Allied Electronics

The pre-amp can run on 5.5-26 VDC so looking for a small lamp for that too.

I've done a lot of searches at Allied Electronics and Newark but all they have are 3/8" dia lamps for 120 VAC. I don't know the right questions to ask them to get the right answer either.

Bot lamps will be mounted on a 5/16" thick aluminum faceplate...somehow...[/QUOTE

This is what I build and is realy easy.;) using Two led's
 

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Lanchile, I like your project. Where did you get the LED's? Are they 120VAC.


Hearinspace, I bought the circuit board, TDK motorized pot, and learning remote. Somehow managed to solder it together, programmed the remote and it all works! I used a 9 volt battery but also considering:
* 4 AA batteries. Charge with a solar charger. Use an On-Off-On switch to go between off, charge circuit, and use circuit.
* 12 VDC Wall-wart.
* Umbilical from my Zamp to the pre-amp but Parasound doesn't like the 80mAh to run the motor and I can't read the schematic they sent for the Zamp.


Machining stuff is no problem. Just need the 120VAC LED's :))
 
At 117VAC it is quite a simple job to use a standard LED.

Firstly solder a 200V diode (1N4002) across the led so that the Cathode of the LED is connected to the Anode of the diode and the Anode of the LED is connected to the Cathode of the diode - i.e. Back-to-back.

You might need to play with the resistors to get the brightness you require. However, you are looking for about 20K Ohms and 2W of dissipation.

Two x 10K 1Watt resistors in series with the LED/diode pair will give you a reasonably bright LED.

REMEMBER - Everything will be at MAINS potential so must be insulated and protected against touching anything.