River Rock 1xAA LED Flashlight, retail $~6.84 (www.target.com*)
Manufactured by (Unknown) for River Rock Designs (www.RiverRockDesigns.com)
Last updated 11-08-09

This is the River Rock 1 AA cell LED flashlight. It uses a Nichia 5mm white LED near the focus of a positive (magnifying) lens.

It comes in a mostly aluminum body, feeds its LED from one AA cell, and has a click on/mode change/off switch on the barrel.

Because it uses just one cell, there is a DC-DC inverter somewhere inside to boost the voltage from the ~+1.5 volts produced by the battery to the +3.6 to +4.0 volts needed by that white LED. I attempted to use an oscilloscope to "see" the inverter, but its batteries were deader than doorknobs, so I was not able to perform this particular test...and right now, I just don't have the money to replace them.

* Not found on the Target website; this URL simply leads to their front door.


Press the black button on the barrel firmly until it clicks and then release it to turn the LED on.

Press and release the button the same way again to cause the LED to blink with a flash rate of ~2.50Hz (5 flashes every two seconds).

Press and release the button the same way again to turn the LED back off.

There is no momentary or signalling mode available in this flashlight, so please do not look for or expect to find such a critter.

The flashlight comes with a wrist lanyard, which comes already affixed to the flashlight via a small hole in the side of the tailcap.

To change the battery, unscrew and remove the tailcap, gently place it on the ground, and kick it into the garden so the hungry, hungry praying mantids will think it's something yummy for their insect tummies and subsequently strike at it...O WAIT!!! YOU'LL NEED THAT!!! So just set it aside instead.

Tip the used-up old AA cell out of the barrel and into your hand, and dispose of or recycle it as you see fit.

Slide a new AA cell in the flashlight barrel, orienting it so its button-end (+) positive goes in first.
Finally, screw the tailcap firmly back on.
Aren't you glad you didn't kick that tailcap into the garden with all those hungry, hungry praying mantids now?

Here is what a praying mantis looks like.
I found this guy on the morning of 09-08-06 clinging to the basket of my scooter.

Current usage measures 97.10mA on my DMM's 400mA scale.

This is a loaner. So I won't throw it against the wall, stomp on it, try to drown it in the toilet bowl or the cistern, run over it, swing it against the concrete floor of a patio, bash it open to check it for candiosity, fire it from the cannoņata (I guess I've been watching the TV program "Viva Piņata" too much again - candiosity is usually checked with a laser-type device on a platform with a large display or with a handheld wand), send it to the Daystrom Institute for additional analysis, or inflict upon it punishments that flashlights not loaned to me may have inflicted upon them.
So this section of the flashlight's web page will seem a bit more bare than this section of the web page on a page about a flashlight that is not a loaner sample.

I performed that dreadful suction test (a totally nondestructive test!) on it, and both the barrel and tailcap held a good partial vacuum.
So weatherproof?
And even submersible to shallow depths as well.

This flashlight can be stood on its tailcap on a hard level surface to act as an electronic "candle" if the wrist lanyard is removed. You may be able to balance it that way with the lanyard in place, but I cannot guarantee that this will be the case with yours - and the balance will be quite finicky in any case. Take the lanyard off if you need to use the flashlight this way.

Beam photograph on the test target at 12".
Measures 268,000mcd on a Meterman LM631 light meter.

Photograph of the beam on a wall at ~10'.

Those colored graphics toward the left are my "Viva Piņata" posters, that clock on the right that looks like a gigantic wristwatch is my Infinity Optics Clock, and that sign that's so colorful and gay
* to the right of that clock is my LED ''SIGNS'' Sign. You should also be able to rather easily see two of my SpongeBob SquarePants plush (Squidward Tentacles & Patrick Star) and a Digimon plush (Greymon)

Spectrographic plot
Spectrographic analysis of the LED in this flashlight.
USB2000 spectrometer graciously donated by P.L.

ProMetric analysis
Beam cross-sectional analysis.
Image made using the ProMetric System by Radiant Imaging.

Test unit was sent by a website fan on 08-17-09 and was received at 4:37pm PST on 11-04-09.

Product was made in China.
A product's country of origin really does matter to some people, which is why I published it on this web page.

Sample is a loaner; therefore, the dreadful "" icon will be appended next to its listings on this website when it is returned; denoting the fact that I no longer have the sample for comparisons or additional analyses.

* Gay = bright & lively, ***NOT*** homosexual.

UPDATE: 11-08-09
Using batteries cannibalised out of a few other flashlights, I got my oscilloscope functional -- and did indeed see a train of very fast pulses from the DC-DC inverter in this flashlight. The pulse train was not very high in amplitude; but that is probably due to the relatively slow decay rate of the LED phosphor and fast pulse time of the pulses in the inverter -- but I *DID* see the pulse train on the oscilloscope's screen.

Bright for a single 5mm LED
Durable construction
Water-resistant - even submersible to shallow depths
Uses a battery that's quite common and relatively inexpen$ive
Has both steady-on and flash modes easily accessible with a single pushbutton
Stands on its tailcap if the lanyard is removed

Some users may dislike the "Moon-shaped" beam - this is what nocked that last ― star off

    MANUFACTURER: Unknown for River Rock Designs
    PRODUCT TYPE: Small handheld flashlight
    LAMP TYPE: White 5mm LED
    No. OF LAMPS: 1
    BEAM TYPE: Medium spot w/sharp perimeter ("Moon-shaped")
    SWITCH TYPE: Pushbutton on/mode change/off on barrel
    CASE MATERIAL: Aluminum
    BEZEL: Metal; LED protected by plastic lens
    BATTERY: 1xAA cell
    SUBMERSIBLE: Yes, to shallow depths at minimum
    ACCESSORIES: 1x Duracell AA cell, wrist lanyard
    SIZE: 4.40" L, 1.020" D
    WEIGHT: 4.50 oz (with battery)
    WARRANTY: Unknown/not stated


    Star RatingStar Rating

River Rock 1xAA LED Flashlight *

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