Mini review of MINI :D

Hard to find but I finally did on eBay so I have ordered some in 40 cm or 16” length. Add greatly to USB light versatility.

These just hit the wire at FT

http://www.fasttech.com/products/1/10009843/1864901-usb-powerd-flexible-neck-1-75w-120lm-6000-6500k

If the listed color temperature is correct that is a very warm LED as it claims a 3000K-3500K color range. That is incandescent range IIRC.

Just a small update on a subject of this mini usb. My idea was to use battery pack with this light for camping so I would have a small stationary light that does not need charging for weeks. For this purpose I bought Xiaomi battery pack but, unfortunately, it turned out that this battery pack is not suitable for intended use because when I dim the light, current draw is so small that battery pack just turns itself off and you have to unplug the usb light and then plug it again to work.
You could leave it on max but that is way too much light for small 2-persons tent.
Also, if you leave it on max it will get quite warm, opposite to when it is powered from computer USB port. My usb doctor show that it is sucking 0,17A from computer but 0,20A from battery pack on max.

I have the same problem - also with xiaomi powerbank. It looks like the limit is 0.05A - if the current is lower than that, power bank will cut the power in less than a minute.

My ENB triple power pack has the same issue. I'll only use the ENB triple pack when I need max light for longer times. I have a cheaper/smaller single-cell power bank I use when less light is needed.

http://www.ebay.com/itm/USB-2-0-A-female-to-Micro-USB-5-pin-male-plug-flexible-metal-stand-cable-Promot-/252006300504?hash=item3aacbefb58 …………………To microUSB on many smartphones.

…but I am not sure that phone will give you power on output without any data transfer, phone needs to check what device is plugged in to be able to provide power. I think powering this mini light is not possible from the phone.

USB, in general, is totally fine providing power with no data. However, it doesn’t work the other way around unless you have special hardware designed for it.

I only know this because I spent far too much time trying to make a data-only USB cable work in order to keep a wired connection to a phone while running power usage tests on it. Instead of doing it that way, I had to set everything up, unplug USB, let the phone do its own thing for a while, then reconnect later and pull the logs. But at least plugging/unplugging USB is easy to automate with a net-controlled relay connected to the VCC wire.

Next I get to figure out how to automate pressing the phone’s physical buttons, and how to automate swapping between two different phones with only one DMM and one power supply. So I can test more than one phone. That should be fun… but it’s totally off-topic.

Have ordered the MINI but not tried it with a mobile phone.
However I have used the setup in the photo. Samsung phone,OTG cable and a fake Xiaomi light. Test just for you : My old Xiaomi and Sony phones also worked but not the ZTE.

Since this is a budget forum; new lower price;

http://www.ebay.com/itm/321806257557

(if they change it, China dollar 0.99 = ~US 0.80)

Seeing this thread it took me more than a year to buy one
and wow, this is going to be expensive.
Will find endless needs for them and Fasttech show 23 styles
of USB-lights up to 120 lumens.
Thanks SIRIUS9, for posting this.

You are welcome :beer:
I bought like 25-30 pcs, most of them I gave away, left with only 3 pcs.
Btw, nice ebay find, shows $0.74/piece, must order some :bigsmile:


Warm White!

Have to order one with a photosensor for long runtime on a backup battery.
Then I can place it wherever I want without intallation
and I also have to buy more for gifts.

Sweet idea, but you have to be sure that your powerbank doesn’t shut down by itself…I have this problem when the current draw is too low

Sorry, I didn’t see that it was a walwart…not a powerbank.
However, here is the setup I made today to carry in my everyday backpack :

Two neodymium magnets are glued on the base of my ENB powerbank to be used on metallic surfaces.
I also cut the shell to embed the mini.

Just out of curiosity, I decided to test a few USB adapters with my USB light to see how efficient they are. While USB lights are handy for plugging into computers and other devices that equip their USB ports for peripherals, they become rather inefficient while plugged into a dedicated wall adapter. My guess would be becasue the wall adapter is inefficient in converting lower current outputs from AC to DC. They are typically designed to provide 1-2A max, while the minuscule current draw from the USB light is lucky to draw 0.2A (mine draws 0.12A). This is of no surprise, since expensive commercial duty high quality AC LED drivers must run at 75-80% capacity (or greater) to convert power at maximum efficiency.

I just took a few measurements using one of HKJ’s recommended AC USB adapters and recorded the following results:

Watts drawn from AC mans while powering the USB light: 1.2W
Watts drawn from a 3 SMD USB light: .62W
Power factor was electronically measured at a miserable .49
HKJ recorded idle power: 0.13W

While none of this is that significant (considering a device that consumes less than 2W while in use), my expensive $1k+ commercial LED arrays show a .99 - 1.0 power factor.

All in all, the USB light really illuminates a room quite well, especially considering the power consumption is just over 1W total. But the power factor is quite poor. On the upside, while comparing a 3W incandescent night light, the USB light appeared to be 4-5 times brighter while drawing only half the power.

I decided to try a few more cheap chinese adapters and discovered more pitfalls. One of them put out 5.49V and made my USB light noticeably brighter and it ran hotter. So this will probably reduce the emitter life significantly. Another adapter idled at .21W. Whilst powering the USB light, it drew 1.5W. But when the USB light was turned off, the adapter idled at .48W and would not idle back down to its original .21W resting state until it was unplugged and plugged back in again. Im not a fan of crappy vampire devices, and this particular adapter would be the last one Id use for a constant duty device (always plugged into AC mains). Sure, its a nit-pick thing… but when I have a box full of cheap chinese junky adapters, etc, I can afford to be choosy… even if its only to save 1/4 of a watt! :smiley: Besides, I have other things that waste power like Al Gore’s home… OK, not really. :wink:

As an aside, I was surprised to test several wallwarts and various other AC adapters in my home that idled up to 4 watts! What a waste!

I also have a pack of cheap plugin LED nightlights from Walmart (with built in photocell for dusk to dawn operation). They draw only 0.2W from AC mains while powered on. I think they came in a 5 pack for about $8. While not nearly as bright as the USB light, they are aesthetically far more appealing and still provide sufficient light through a crappy 5mm emitter. Ive thought about converting them to a nichia GS but havent gathered the motivation.

I wonder if these would be good for cabinet lighting run on a battery bank of 18650s.

That’s a waste of energy at every step IMO…
4,2v to 5v in the powerbank then 5v to ~3V to the LEDs
But yeah it works, and the 6 emitters touch controlled ones draw about 180mA under 5V so you can have a huge autonomy depending on your powerbank

Shows $5.99 now…so $.59 a piece