On Wed, 24 Apr 2013 03:16:38 +0000 (UTC), gregz
wrote:
The Daring Dufas wrote:
On 4/23/2013 7:55 PM, Percival P. Cassidy wrote:
On 04/23/13 07:48 pm, John Grabowski wrote:
Our doorbell is the standard one with the small rectangular
"illuminated" button,
that is screwed to the door frame.
Every so often, usually just prior to Halloween 
I go out and replace the button - as the tiny bulb has burned out.
Wonder if there are any LED style replacements ?
I had seen some comments on an electronics forum
about how you might contruct one -
but was curious if any retail versions existed ?
*They are available, but I would avoid them. I have received at least
two phone calls about problems with them and someone posted on here
months ago with a similar issue. Evidently some door bells require that
a diode be added to the circuit. The button instructions even mention
the diode, but none are offered as an accessory to buy. Stick with neon.
AFAIR, the lowest voltage on which neon lamps will work is 70 or
thereabouts. Door bells typically operate on a far lower voltage.
Perce
The standard NE-2 neon lamp takes at least 90 volts to fire and most
doorbells operate on 16 volts AC. The standard lighted doorbell button
has a simple low voltage incandescent lamp parallel to the switch
contacts and it lights due to the small current flowing through it and
the solenoid coil of the doorbell as long as the button is not pressed.
When the button is pushed, the full current goes to the doorbell making
it ring. ^_^
TDD
90 volts dc. 63 vac will fire the lamp. Temperature and external light
probably affect voltages. Trouble with most indicators, including led, they
try to get too much brightness, shortening life.
Um, 63VAC has ~90V peaks. He was right, NE-2s "take at least 90 volts
to fire". Yes, you are also right, in that it is temperature and
(interestingly) external light dependant. The problem is that to save
a fraction of a cent, they're built like crap. I've never had a bulb
fail before the switch, though. I just had one go after less than a
year (plastic button broke, exposing the bulb).