Hi:
The following is a message that I posted in the "Canada Good Deals cont'd" thread on cpfmarketplace. Anyways we've been discussing these bulbs on there for a while but they really deserve their own thread which is what this thread is. So I am double posting my message here as well.
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I sent the following email to Dorcy support to see whether these bulbs
are bi-directional in regards to polarity. Anyways, they claimed that
they "SHOULD BE". So I tested one of the 3/4 cell bulbs and it looks
like it is in fact bidirectional. It didn't burn out when I changed the polarity. I guess the reason they produced a 2-cell and a 3/4-cell bulb, rather than a single 2-4 cell bulb, is that they probably couldn't fit all the electronics in the can to make it bi-directional and be able to run off 2-4 cells. I haven't checked the 2-cell version as I don't ever see using it in anything but a flashlight with positive applied to the base.
P.S. I am also posting this message to the other thread that is actually devoted to these bulbs.
++++++++++++++++++++++++++++++++++++++++++
Peter,
They should be bi-directional
Mike Riley
Vice President, Sales & Marketing
Dorcy International
From: Mark Craddock
Sent: Monday, October 04, 2010 10:42 AM
To: Mike Riley
Subject: FW: FW: technical question
Know the answer?
From: Peter P
Sent: Monday, October 04, 2010 2:54 AM
To: Mark Craddock
Subject: Re: FW: technical question
Hi Again:
I sent you this email some time ago and I thank you for your reply.
Anyways I have used these bulbs and they work great. The polarity
profile I have used is to apply positive to the base of the bulb and
negative to the bulb can. However there is an individual who claims
they are using these in a Dorcy lantern which applies negative to the
base of the bulb and positive to the bulb can. So i'm wondering if in
fact these bulbs may be bidirectional in regards to polarity. I would
think that having bulbs that potentially burn out due to the
application of incorrect polarity probably generates alot of returns of
product as defective. It would make more sense to produce a bulb that
can handle any polarity profile. So i'm thinking that this is what has
been corrected in this new design. Of course I could try a reverse
polarity test on one of my own bulbs, however I'm somewhat skittish
since I don't want to inadvertently blow one of my bulbs in case the
other person is wrong. So I was wondering if you could find out for me
and if so, could test it out yourself and let me know, This would apply
to the following bulbs
41-1644 40 Lumen 4.5V - 6V LED Replacement Bulb
http://www.dorcydirect.com/p-354-41-...ment-bulb.aspx
41-1643 30 Lumen 3V Replacement Bulb
http://www.dorcydirect.com/p-353-41-...ment-bulb.aspx
Thanks/Peter