Some guidance on Pilot lights please...

[1blueheron]

I have seen pilot lights run off 110V power, and I have seen them also run off the filament current circuit.  In my current project, it was originally running off the filament circuit.  I thought it might be better and more convenient to power it off the 110V mains circuit.  Is this misguided?  Is there any virtue in having it one way or the other?

Will I get more or less noise if I change it?

As far as I can tell, the only benefit of having it on the filament circuit is to indicate that your filaments are getting power when you power on?

[shooter]

as long as you know a 6v neon will not last long in a 110 circuit then there isn't any reason "where" other than convenience

[jjasilli]

This is a good question.  Other alternative is to convert the filament powered bulb to LED.  I think Doug has a "kit" or info on his bulb page.  Sluckey recently posted LED pilot bubs that fit in the standard incandescent bulb socket, available on eBay.

[sluckey]

I have switched over to lighted power switches for my last six projects. The 120VAC neon pilot lamp is built into the switch housing. Three wires gets you power and indicator. Very simple/clean wiring. Take a look...

     http://sluckeyamps.com/dual_lite/dual_lite.pdf

[PRR]

There are no "6V neons". They don't begin to glow until >100V.

Neons last forever in theory, not many years in practice. Therefore they are usually "permanent" and a hassle to replace when they go bad.

Incandescent lamps are made from 1V to 240V. But few low-power lamps in the higher voltage. You only need like 1 Watt (even less) for a pilot. But the smallest 120V or 240V lamps are often 3 Watt (1950s christmas bulbs). That's why all radios used the 6V lamps, even when they did not have 6V power (the special rectifiers had a tap for pilot lamp).

Today LEDs are the bees-knees. They are naturally 2V, and must have a series resistor to control current. Taking them from a low-Volt supply (like heater) makes much sense.

If you have "noise" from your pilot light, your layout is bad.

[glass54]

I thought this might be of interest to some:

https://www.intl-lighttech.com/specialty-light-sources/neon-lamps

[st]

One more thing: 6v bulb may draw as much current as a preamp tube heater, so if you're low on filament current, go led  or mains neon.

[1blueheron]

Thanks for all the useful information.  As always it has got my gears of thought innovation turning.  In this build, I have the small, original plastic "jewel" that came with the organ amp and was backlit with 6V.  It was originally turned on and off on the vibrato speed control.  Weird.

In my new layout, it is located right next to the AC toggle switch on the panel.  Rather than use up valuable filament voltage that could be used for something else, I thought it might be simpler to find an incandescent miniature bayonet bulb that ran at 120V and tap off the AC switch as power indicator.  However as PRR mentioned those bulbs are not as common as I thought they might be.  I'm not finding anything in my junk pile.  Lots of 6V, 6.3V and 28V.  No 120V.   It looks like I Would need to buy a #967 bulb for 120V operation in either incandescent or LED.   It looks like this would be a drop in LED replacement...


LED Equivalent Specifications:

Lamp Shape: T3.25 (10mm)
Base Style: Miniature Bayonet (BA9S)
Length MOL: 1.10"
Diameter MOD: 0.40"
Electrical Data: 36-130V AC/DC (Bi-Polar), 20ma
$5.95
or its incandescent version at $2.99

[1blueheron]

But reading these posts makes me wonder if it wouldn't be more fun to use some of the free miniature neon bulbs I salvaged from an oscillator circuit on an organ.  It looks like it should be pretty simple to solder a neon bulb and resistor to the side of the switch and illuminate the jewel beside it.

I will take a picture of the neon lamps I have and post them up, they look very similar to this


Would this Neon bulb/resistor also act as a surge suppressor on the AC line?

[labb]

I have had good luck with this from Mouser...607-6010M1         120 volt, neon.

[1blueheron]

Thank you for all the suggestions.  I am going to try this adaptation of sluckey's switch using my salvaged neon bulbs tonite.  If that doesn't work, I will pull off filaments or buy LED

[PRR]

> Would this Neon bulb/resistor also act as a surge suppressor on the AC line?

About the same as sticking a stake in a levee on the Mississippi.

[Willabe]

> Would this Neon bulb/resistor also act as a surge suppressor on the AC line?

About the same as sticking a stake in a levee on the Mississippi.

       

[1blueheron]

> Would this Neon bulb/resistor also act as a surge suppressor on the AC line?

About the same as sticking a stake in a levee on the Mississippi.

I'll take that as a no... However, I am conjuring images of what Holland would look like had it not been for one little finger....?

[Willabe]

> Would this Neon bulb/resistor also act as a surge suppressor on the AC line?

About the same as sticking a stake in a levee on the Mississippi.

I'll take that as a no... However, I am conjuring images of what Holland would look like had it not been for one little finger....?

     

[shooter]

whenever I read threads like this I keep hearing ....when the lights went out in.....

[1blueheron]

Installed the neon lamp last night using a 150K resistor.  It works, but I am not happy with its brightness.  It is very dim.  Going to go to a 100K resistor and see if its any better.  If not, I'll go to something else.

[sluckey]

Post a pic of the lamp holder you're using. May inspire additional guidance.

[1blueheron]

Here is the lamp holder that came with it and I was planning to re-utilize. 

[sluckey]

Hmmm, looks like one of the electrical connections is physically part of the mounting flange. If so, that means one side of the filament winding would need to be connected to chassis. If this is the case I would not use it.

[1blueheron]

I will have to take a better picture.  Now that you have commented, I see how misleading that angle might be.  There are two wire connections.  They are both isolated from the mounting bracket. 

As another note, the holder was not originally mounted to the chassis.  It was remotely mounted on an isolated plastic panel.  I intended to mount it to the wood cabinet so as to maintain the isolation and connect it to the 110v switch.

[sluckey]

OK, but don't put a 120V lamp in that socket! Think safety!  Stay with 6.3 just as the mfgr intended.

[1blueheron]

I have the amp together and working with a neon lamp wired to the AC power switch as shown in diagram but using a 100k resistor.  It isn't in a holder of any type at this point. it is heat shrinked to prevent shock hazard and its proximity allows it to illuminate the jewel adequately.  This was purely for experimentation purposes and learning.  Was a fun little experiment.

I am planning to go back and use a proper lamp holder with the 6.3V bulb off the filament supply.

[sluckey]

OK, but don't put a 120V lamp in that socket! Think safety!  Stay with 6.3 just as the mfgr intended.

Don't know what I was thinking.     That lampholder will only be accessible from under the chassis. No need to ever change a bulb with the amp hot. There is a cheap NE-51 with a bayonet base that will simply plug into that socket. Still need the resistor though. Bet if you look you can find them with the resistor built into the base.

[acheld]

I've been using LEDs from the heater circuit for my lest few builds.  They work great, are inexpensive (look for 6V LED with resistor on eBay), are small, and have not failed me yet.  I just epoxy them into the jewel for mounting using a small plastic bushing.  They draw very little current.

The lighted switches I've seen would be simpler (Doug has a lighted switch that looks great) -- but I haven't found one suitable that is not square. It is very easy to drill a hole in a chasis;  small rectangular holes, not so much.  If someone knows a way to create small rectangular holes in a chasis cleanly, let me know.   

[sluckey]

Radio Shack has one that mounts in a round hole. Surely other suppliers have them too. I have one on my toaster. Look here...

     http://sluckeyamps.com/smoky/smoky.htm

[acheld]

Hah!  I thought Radio Shack was out of business, but they do have several illuminated switches, all of which mount in round holes.   I will use these -- it saves panel space, reduces the AC wiring in the amp.   Only drawback is that I really trust those Carling DPST switches.