Pat wrote:
On Mon, 6 Nov 2017 10:01:55 -0800, "David Farber"
wrote:
Jeff Liebermann wrote:
On Sun, 5 Nov 2017 22:36:43 -0800, "David Farber"
wrote:
I have one of those polarity/line/ground checker plugs. It has
three lamps that illuminate according to the condition of the
120VAC outlet. The neon light that illuminates indicating a good
ground is not lighting up anymore. Will this replacement neon
light work properly for this application?
https://www.digikey.com/product-deta...C2A-ND/3150384
There is a 68k resistor in series with the lamp. What does the
breakdown voltage indicate?
http://www.vcclite.com/_pdf/Neon%20I...amps_7_&_8.pdf
A picture of a similar tester is here.
http://www.acehardware.com/product/i...ductId=3099752
The common NE-2 neon lamp will work just fine. I've never bothered
to tear one apart so I don't know what's inside. Looks like there
are different design schemes:
http://www.giangrandi.ch/electronics/neon/simple.html
http://www.electro-tech-online.com/threads/information-about-electric-tester-circuit.132363/#post-1104807
http://www.marcspages.co.uk/pq/4511.htm
http://www.electro-tech-online.com/attachments/sch-1a-png.87460/
I doubt that the NE-2 lamp is the problem. My guess(tm) is
something fell apart or came loose inside. Probably a bad crimp.
Hi Jeff,
I opened it up and the crimps and resistors are good. Do you have
any idea what the lamp's breakdown voltage specification indicates?
According to the datasheet, the NE-2 has a breakdown voltage of
65VAC. The high brightness bulbs have a higher breakdown voltage of
95VAC.
Thanks for your reply.
You do know that only 2 of the three bulbs should be lit for a good
outlet, right? The ones going from hot to ground and hot to neutral
should be on. The one going from neutral to ground is always off
unless hot and neutral have been swapped due to a wiring mistake.
Hi Pat,
I am aware that only two of the three bulbs are supposed to light under
normal circumstances. The hot to ground light is not working which is giving
the false indication that the ground is open when in fact the ground is in
good condition.
Thanks for your reply.
--
David Farber
Los Osos, CA