Discussion:
OT Electronics question followup
(too old to reply)
r***@optonline.net
2013-01-19 00:20:33 UTC
Permalink
A while back I posted the follwing question:

------------------------------------------------------------------------------------------------------------------
Has nothing to do with HDTV but I figure there's electonics experience here.

I bought a rather inexpensive small string of colored LED light, 20 lights in
all, to use in a little village I set up for Christmas. The string takes 3 AA
batteries and has a simpl on/off switch.

It eats batteries. I was replacing them every couple of days. I have two
identical strings and they both do the same thing. I wrote to the dealer I got
them from and they said to check their ad, and it clearly states that batteries
last an average of 15 hours. I missed that, but I have a string of white LED
lights, also about 20 in the string that has been lit on the same batteries for
weeks.

My question is this. I like the lights and want to be able to use them again
next year. Can I somehow splice them into an A/C adapter and plug them in next
season? I'd have to put a switch in line, unless I wired into the little battery
box that already has the switch. Are LED's AC or DC? And do I just look for an
adapter for 4.5 volts? Thanks.

---------------------------------------------------------------------------------------------------------------------

I got many useful replies. I went ahead and found a 100-240v converter adapter
with a 4.5v output rated at 350mA. I bought it and have connected it to the
string of lights, and it works like a charm. I have a couple of other strings
that I'd like to convert from battery to the ac adapter. I just found one with
the same specs but rated at 1000mA, or 1 amp. Will this one work as well given
it's three times the output amperage wise? I don't know about these numbers
except that if I'm buying batteries, the more mA the longer the batteries last.
I'd appreciate someone clearing this up for me. Thanks again.
Stephen H. Fischer
2013-01-19 00:45:58 UTC
Permalink
...
Post by r***@optonline.net
---------------------------------------------------------------------------------------------------------------------
I got many useful replies. I went ahead and found a 100-240v converter adapter
with a 4.5v output rated at 350mA. I bought it and have connected it to the
string of lights, and it works like a charm. I have a couple of other strings
that I'd like to convert from battery to the ac adapter. I just found one with
the same specs but rated at 1000mA, or 1 amp. Will this one work as well given
it's three times the output amperage wise? I don't know about these numbers
except that if I'm buying batteries, the more mA the longer the batteries last.
I'd appreciate someone clearing this up for me. Thanks again.
More current means that you can connect several identical strings in
parallel.

Even the 350mA one is quite likely overkill.

You need a meter to measure the DC current of each string to see how many
you can connect in parallel.

http://www.mcmelectronics.com/product/72-7940

It is rated only 200mA DC, well able to handle a LED string.

But I have never had any LED strings like yours.

I did create a series string of single LEDs to use in my VAN.

This one is rated to 10A.

http://www.mcmelectronics.com/product/72-9440

There are so many choices at very low prices today.

My first one was $60.

I now have this one in my toolbox:
http://www.mcmelectronics.com/product/72-7725


SHF

Loading...