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Finding the correct power adapter for a no-name brand music stand light.
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David Farber
Jan 12, 2017, 4:23:44 PM1/12/17
to
The stand light looks like this:
https://images.duckduckgo.com/iu/?u=http%3A%2F%2Fwww.long-mcquade.com%2Ffiles%2F19166%2Flg_light-2.jpg&f=1
but the light I have has only 9 LED's.
The only information on the battery is 3.7 volts and it looks like this:
https://images.duckduckgo.com/iu/?u=https%3A%2F%2Fwww.pi-supply.com%2Fwp-content%2Fuploads%2F2014%2F12%2F2011-03.jpg&f=1
however my battery does not have any amp-hr rating written on it.
My question is, how can I figure out what voltage and current rating the
power adapter needs to be in order to power the light and charge the battery
efficiently? If I put 4.0V on the input jack without the battery installed,
the lamps seem to light up fine. If you look closely inside the battery
wrapper, you can see an attached pc board. The wiring from the DC jack goes
to a series diode, then a transistor, then to the red wire extending out of
the neck of the lamp where the LED's are attached. There is also a blob of
round black stuff on the main pc board that looks like it could be covering
a uP.
Thanks for your replies.
--
David Farber
Los Osos, CA
https://images.duckduckgo.com/iu/?u=http%3A%2F%2Fwww.long-mcquade.com%2Ffiles%2F19166%2Flg_light-2.jpg&f=1
but the light I have has only 9 LED's.
The only information on the battery is 3.7 volts and it looks like this:
https://images.duckduckgo.com/iu/?u=https%3A%2F%2Fwww.pi-supply.com%2Fwp-content%2Fuploads%2F2014%2F12%2F2011-03.jpg&f=1
however my battery does not have any amp-hr rating written on it.
My question is, how can I figure out what voltage and current rating the
power adapter needs to be in order to power the light and charge the battery
efficiently? If I put 4.0V on the input jack without the battery installed,
the lamps seem to light up fine. If you look closely inside the battery
wrapper, you can see an attached pc board. The wiring from the DC jack goes
to a series diode, then a transistor, then to the red wire extending out of
the neck of the lamp where the LED's are attached. There is also a blob of
round black stuff on the main pc board that looks like it could be covering
a uP.
Thanks for your replies.
--
David Farber
Los Osos, CA
whit3rd
Jan 12, 2017, 6:16:10 PM1/12/17
to
On Thursday, January 12, 2017 at 1:23:44 PM UTC-8, David Farber wrote:
> The stand light looks like...
> The only information on the battery is 3.7 volts and it looks like...
OK, that's a Li-ion rechargeable cell.
presumably there's voltage and current charging limitations (I'd guess
0.1 to 1 ampere of charging current), plus whatever your LEDs
require (could be up to one half ampere). The
voltage must not get more than 4.3V, typically, on such a battery (but
that could be regulated in the power adapter, OR inside the lamp circuitry).
The circuitry and envelope around the battery are intended to prevent fire.
The prudent course is to find another identical unit, and get an exact match
to its wall tumor charger. Otherwise, you need to reverse-engineer the
charging scheme of a poorly documented battery that has the potential
to burst into flame if mistreated.
This kind of problem is why cellphone chargers are USB micro-B with 5V output:
no one could get the right charger when they needed it, and nations passed laws...
> The stand light looks like...
> The only information on the battery is 3.7 volts and it looks like...
OK, that's a Li-ion rechargeable cell.
>
> My question is, how can I figure out what voltage and current rating the
> power adapter needs to be in order to power the light and charge the battery
> efficiently?
It's not so much 'efficiency', but safety that you should be concerned with;
> My question is, how can I figure out what voltage and current rating the
> power adapter needs to be in order to power the light and charge the battery
> efficiently?
presumably there's voltage and current charging limitations (I'd guess
0.1 to 1 ampere of charging current), plus whatever your LEDs
require (could be up to one half ampere). The
voltage must not get more than 4.3V, typically, on such a battery (but
that could be regulated in the power adapter, OR inside the lamp circuitry).
The circuitry and envelope around the battery are intended to prevent fire.
The prudent course is to find another identical unit, and get an exact match
to its wall tumor charger. Otherwise, you need to reverse-engineer the
charging scheme of a poorly documented battery that has the potential
to burst into flame if mistreated.
This kind of problem is why cellphone chargers are USB micro-B with 5V output:
no one could get the right charger when they needed it, and nations passed laws...
David Farber
Jan 13, 2017, 1:17:11 AM1/13/17
to
about the chargers that come with similar stand lights containing Li-ion
batteries.
Peter Gierschner
Jan 13, 2017, 6:21:53 AM1/13/17
to
peter
Look165
Jan 13, 2017, 9:27:15 AM1/13/17
to
The battery cell is a rechargeable one.
This explains the diode and transistor.
So a standard 5V 3A power supply is enough.
But according to what you say, the battery is empty ; needs a 24-hour
recharge.
David Farber a écrit :
This explains the diode and transistor.
So a standard 5V 3A power supply is enough.
But according to what you say, the battery is empty ; needs a 24-hour
recharge.
David Farber a écrit :
David Farber
Jan 13, 2017, 1:33:20 PM1/13/17
to
http://webpages.charter.net/mrfixiter/images/Electronics/Music_light/DC-plug.jpg
I have a 5V 1.5A power supply from an old Epson Zip drive but the connector
is too big. The connector on the lamp seems to be on the smaller end of the
spectrum.
Here is the pc board:
http://webpages.charter.net/mrfixiter/images/Electronics/Music_light/PC-board-lamp.jpg
Thanks for your reply.
Fred McKenzie
Jan 14, 2017, 11:54:27 AM1/14/17
to
In article <o58s1u$q6b$1...@dont-email.me>,
David-
I recently purchased a similar stand light, so your article caught my
eye. Mine is more like the 10 LED version with replaceable batteries.
Searching Amazon, I found at least four 9-LED lights that are close to
what you have. I think they all can be powered (or charged) from either
an AC adapter or a from a USB outlet.
The four are:
Kootek
Sipik
Ohuhu
Lumiens L9B.
It is possible that two or more of these are actually the same light
imported by different companies. Is there anything about yours that
might suggest one of these names?
Fred
I recently purchased a similar stand light, so your article caught my
eye. Mine is more like the 10 LED version with replaceable batteries.
Searching Amazon, I found at least four 9-LED lights that are close to
what you have. I think they all can be powered (or charged) from either
an AC adapter or a from a USB outlet.
The four are:
Kootek
Sipik
Ohuhu
Lumiens L9B.
It is possible that two or more of these are actually the same light
imported by different companies. Is there anything about yours that
might suggest one of these names?
Fred
David Farber
Jan 15, 2017, 2:32:52 AM1/15/17
to
I personally have the 9 LED Mighty Bright that I purchased a couple of years
ago which uses 3 AA batteries. It also can be powered with an AC adapter
which is 4V 400ma.
There isn't any kind of identifying writing anywhere on this other light. I
haven't opened up the lamp compartment but I may do that just because I've
looked everywhere else.
Thanks for your reply.
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