Wanted: information on charger for Rio S50 mp3 player

[Beloved Leader]

Hi. The RioS50 mp3 player was on the market some ten years ago. The owner's manual and reviews are easily found online. I got one at a yard sale for not much money a few years back. It lacked the charger and the cable that allows one to download songs from a computer. "That's why it's so cheap," the seller said.

Almost incredibly, I found the cable at a thrift store. iTunes recognizes the device, and it works with Rio's software as well. Storage is limited, but it has an FM radio. It still works, and I still use it.

It was designed to run off a 1600 mAh NiMH cell. It can run off an alkaline cell or a NiCd cell too. Because I do not have the charger, I have to remove any rechargeable cell for recharging. Although the owner's manual and reviews are online, I have not found the details for the recharger. What was its output voltage? How much current did it supply? What was the size of the barrel connector? What was the polarity of the tip and the ring?

If anyone can come up with that information, I would be grateful. The charger probably worked with other Rio players that ran off a single 1.25 volt or 1.50 volt cell.

Thank you.

 

Beloved Leader <Kim_Jong_Il@volcanomail.com> wrote:
> What was its output voltage?

Probably more than 1.2 V. More below.

> How much current did it supply?

The owner's manual says to charge the battery for at least 5 hours the
first time. The supplied battery is (1.6 * 1.2) or 1.9 watt-hours
nominal. If the five hours was a full charge, this implies that the
charger supplies at least 0.38 watt.

> What was the size of the barrel connector?

Go to Radio Shack and try their selection of Adaptaplugs until you find
the one that fits. If you don't mind spending what they charge for
adapters, buy a multi-output adapter and the Adaptaplug; otherwise tell
them you already have the adapter and buy just the Adaptaplug (which is
still a ripoff at $7). If you can solder, and the Adaptaplug happens to
be one of the sizes they carry in a "regular" plug (in the drawers full
of small parts), buy the "regular" plug instead; it's cheaper. If you
can solder and it's a weird size, just solder to the Adaptaplug pins
later. If you can't solder and it's a weird size, buy their 273-350
cable for $5, to turn the Adaptaplug ends into wires.

> What was the polarity of the tip and the ring?

Go home and plug the plug into the MP3 player. Use a multimeter to
measure the resistance between the negative battery contact and each pin
of the DC plug in turn. One pin will probably show a low, constant
resistance (less than 1 ohm.) This is the "negative" pin.

Now you need a somewhat discharged NiMH cell, some fresh alkaline cells
(AA size is fine, C or D will also work), tape (clear office type is
fine, but anything will work), and wire. Put the NiMH cell in the MP3
player. Tape a wire to the - side of one alkaline cell, and connect
that wire to the "negative" pin of the DC power plug. Connect another
wire to the "positive" pin of the DC power plug, and then touch it to
the + side of the alkaline cell. If the "charge" indicator on the MP3
player comes on and stays on, then you need a 1.5 V adapter.

If the "charge" indicator doesn't stay on, then use more tape and wire
to put a second alkaline cell in series with the first one, - to + .
Touch the wire from the DC power plug to the + side of the second
alkaline cell; if the "charge" indicator comes on and stays on, then
you need a 3 V adapter.

If you can't get any response by the time you get to 6 V (4 alkaline
cells in series), don't go up any further.

If you find a voltage that works, use the multimeter to measure the
current the MP3 player is drawing when charging the battery, and select
an adapter with a little more (not a lot more) current than that. Or,
divide 0.38 by the voltage you found to get an estimate - if you found
that 3 V worked, 0.38 W / 0.38 V = 0.13 A. Select an adapter with at
least the measured or estimated current, up to maybe twice the measured
or estimated current. A thrift store can be a good place to find an
adapter, if you don't mind shopping around a little.

Cut off the existing plug on the adapter (unless it happens to match)
and use the multimeter to figure out its polarity. Wire the adapter
to your new plug and enjoy.

Standard disclaimers apply: I don't get money or other consideration
from any companies mentioned.

Also, please be sure to wear appropriate personal protective equipment
while doing all this. You probably don't need arc flash protection at
this power level, but you do need gloves, safety goggles, hand rails,
and if your workspace is near the stairs, a properly-tethered fall
harness. Someone with first aid training needs to be nearby, and it
helps if there is an AED available.

Matt Roberds

 

[Beloved Leader]

On Saturday, November 16, 2013 2:05:48 AM UTC-5, mrob...@att.net wrote: > Beloved Leader <Kim_Jong_Il@volcanomail.com> wrote: > What was its output voltage?

>>>>>
Probably more than 1.2 V. More below.
[snip a whole bunch of good advice}
If the "charge" indicator on the MP3 player comes on and stays on, then you need a 1.5 V adapter.
[more snippage]
A thrift store can be a good place to find an adapter, if you don't mind shopping around a little.
[snip even more]
You probably don't need arc flash protection at this power level,...
[snip again]
Matt Roberds
>>>>>>

I've seen some arc flash videos, and they are quite dramatic. I think I can avoid that fate by being careful.

http://www.youtube.com/results?search_query=arc+flash&sm=12

I have several shoe boxes full of wall warts. It was a thrift store that came up with the computer cable with the odd Rio plug on one end. There are two thrift stores nearby with bins full of cheap, as in $1 or $2, wall warts.. At yard sales, they usually fetch less than that. Finding one with the right current and the right voltage and the right polarity and the right size connector is the trick.

I've been thinking that 3 volts was about right.

Thanks for the help.

 

[dave]

On 11/16/2013 01:28 PM, Beloved Leader wrote:

On Saturday, November 16, 2013 2:05:48 AM UTC-5, mrob...@att.net


I have several shoe boxes full of wall warts. It was a thrift store
that came up with the computer cable with the odd Rio plug on one
end. There are two thrift stores nearby with bins full of cheap, as
in $1 or $2, wall warts. At yard sales, they usually fetch less than
that. Finding one with the right current and the right voltage and
the right polarity and the right size connector is the trick.

I've been thinking that 3 volts was about right.

Thanks for the help.

I'd charge it with a current limiter the first time, to be safe.

 

[Beloved Leader]

On Friday, November 15, 2013 12:30:52 PM UTC-5, Beloved Leader wrote:

Hi. The RioS50 mp3 player was on the market some ten years ago. The owner's manual and reviews are easily found online.
.....

Although the owner's manual and reviews are online, I have not found the details for the recharger.

I just wasn't looking hard enough. The correct voltage is revealed here:

http://transistor-man.com/Altoid%20MP3.html

"The power source was 1 AA / AA NIMH battery, which was dc-dc converted to 3.3V for the devices operation."

So that's the trick. I don't think it's a new page, but I've never seen it come up before in a search.