USB Power Supply/charger Test and tear down

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HKJ
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USB Power Supply/charger Test and tear down
USB Power Supply/charger Test

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I decided to check a couple of cheap USB power supplies and also a few more expensive ones. Recently there have been some tear downs of USB power supplies on the internet, where people has shown how bad quality and safety they where, I decided to also include a tear down to see how safe they look.
In the test I also included a test with a high voltage ohm meter, to see how much voltage they can handle between mains and low voltage.

Note: Many people call these units USB chargers, but they are not battery chargers, if you connect a battery directly to them they will damage the battery. Most of the time I will call them "ps" for power supply.



USB Power Supply #1

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From: ebay:ecitygo/150660255174
Name: EU USB AC Power Adapter Charger For iPod iPhone 3G S 4G

Official specifications:
  • EU AC Plug.
  • Output: 5v - 1A.
  • Input: 100-240v - 50/60Hz 0.15A.
  • Easy to use, plug and play. No installation needed.
  • Featuring a new, ultracompact design, this power adapter offers fast, efficient charging at home, in the office, or on the go.
  • It works with any iPhone and all iPod models with a dock connector.
  • Compatible with: iPod Nano, iPod Video, iPod Touch, iPhone, iPhone 3G, iPhone 3GS?iPhone4G.
  • Color: White.
  • Size: 5cm x 3cm x 2.5cm.




Measurements

A small PS that can deliver 1A, lets test it:

USB%20PS%20%231%20load%20sweep

The PS can supply about 0.6A, but the voltage is slightly low.
How does it handle the load over time, in the curves below I test for one hour.

USB%20PS%20%231%200.5A%20load%20test

At 0.5A it is only slightly below minimum voltage.

USB%20PS%20%231%200.6A%20load%20test

but with 0.6A it is significant below.

How does the output look at 0.5A:

Trace%201a

A lot of spikes, this might be fine for running a simple charger, but not for anything electronic.

High voltage test failed.



Tear down

DSC_1214

The electronic can be pulled out of the box with a bit of force.

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The ps has a single rectificer diode, that charges a 2.2uF capacitor. It has two transistors and a opto coupler for feedback. This opto coupler is the reason for the stable voltage during load sweep.

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There is not much space between the mains and the low voltage side.
The (mostly missing) resistors R6, R7, R8 and R9 is used to make it Apple compatible.

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The distance between the two red lines is what it protecting the user from the mains voltage. This distance is way to low (The ruler has 1 mm between tick marks)!



USB Power Supply #2

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From: ebay:365digital/320986478607
Name: USB AC Power Supply Wall Adapter MP3 Charger EU Plug 35DI

Official specifications:
  • Color : Black
  • Compact and exquisite design, convenient to carry
  • USB interface
  • Fast charging speed and low power consumption
  • Suitable for DVs, cell phones, MP3 players, PDAs and etc.
  • Input Voltage:100-240V 50/60Hz 0.1A
  • Output Voltage: 5V 500mA
  • LED power indicator.
  • Build-in Smart IC chip can recognize a full battery and automatically switch to stand-by mode to protect your cell phone's battery from over charging




Measurements

According to specifications this ps can deliver 0.5A, how does it measure:

USB%20PS%20%232%20load%20sweep

That load test shows a very interestning looking curve, the ps start at 6 volt, drops to 4.5 volt, goes up to 5.5 volt and drops again. This is not good!

USB%20PS%20%232%200.3A%20load%20test

At a 0.3A load the ps will stabilize at an acceptable voltage after 10 minutes.

USB%20PS%20%232%200.4A%20load%20test

At a 0.4A load the voltage is way to low.

How does the output look at 0.3A

Trace%202a

The output is not very stable and has a lot of noise, this can also be used for a charger, but is not very good for anything with electronic in it.



Tear down

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One screw to remove and it is open.

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The ps has a single rectificer diode, that charges a 2.2uF capacitor, this is very easy to see in the output with the 20 ms periode time. It has one transistors (or IC) and not feed back, i.e. very bad stabilization as can be seen on the load sweep curve.

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Notice the twisting trace at the red wire, it is probably supposed to be a fuse.

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This ps has much better distance from mains to low voltage side.



USB Power Supply #3

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From: ebay:at.store/261030303042
Name: EU USB Wall Home AC Charger Adapter For iPhone 3G 3GS 4 4G 4SAC Adapter EU

Official specifications:
  • USB AC Adapter Charge for iPhone 3G 4G 4S
  • Compact and lightweight, easy to use and storage
  • This power adapter offers fast, efficient charging ,great for home use and traveling
  • World traveler (100-240V). The innovative travel charger automatically adjusts to all voltages and frequencies in the Europe
  • Patented circuit board design to protect your valuable gadgets from short circuits
  • Compatible With: iPhone 3G 4G 4S
  • Plug: EU plug
  • Input: 100V-240V 50/60Hz 0.15A
  • Output: 5V 1A
  • Size: 66 x 34 x 14mm (approx)
  • Color: White




Measurements

Again a 1A ps, how does it live up to that:

USB%20PS%20%233%20load%20sweep

It does deliver 0.5A with a good voltage.

USB%20PS%20%233%200.5A%20load%20test

When it gets hot, the voltage drops a bit, but because it starts well above the minimum limit, there is no problem.

How does the output look at 0.5A:

Trace%203a

The output is not very stable, and has a lot of noise, it is not very good for anything with electronic in it.



Tear down

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The glue used to keep this ps together was very easy to break (Oops).

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The ps has a single rectificer diode, that charges a 2.2uF capacitor. It has two transistors and a opto coupler for feedback. This opto coupler is the reason for the stable voltage during load sweep.

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On this ps the two usb data pins are shorted, this signales that it is a dedicated charger.

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The resistor with brown-black-gold might be working as a fuse.

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There is a good distance between mains and low voltage side.



USB Power Supply #4 Ioncell

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From: intl-outdoor.com
Name: Ioncell 4 USB 2A Power adapter

Official specifications:
  • Input: AC 100-240V ~50/60Hz 15W
  • Output: 5V DC 2A (For 1-4USB)
  • 5V-2A using 1 USB
  • 5V-1A using 2 USB
  • 5V-0.66A using 3 USB
  • 5V-0.5A using 4 USB
  • Power LED
  • Can be used with a 2 Prong/Figure-of-8 power cable




Measurements

This is a 2A ps, the total current can be drawn from a single port or from multiple ports. Can it really deliver 2A?

USB%20PS%20%234%20load%20sweep

The answer to that is definitly yes, it has absolutely no problems delivering 2A, it can deliver considerable more.

USB%20PS%20%234%202A%20load%20test

The output is perfectly stable while doing it.

USB%20PS%20%234%203A%20load%20test

The ps does also show a nice output with 3A, at least for the first 30 minutes.

USB%20PS%20%234%203.3A%20load%20test

How much current can it deliver, here I tries 3.3A, sadly that was fatal for the ps. After I removed it from the test bench it could not power up anymore.

How does the output look at 2A:

Trace%204a

Very smooth output, perfect for anything.



Tear down

DSC_1258

I could not open this ps, except with help from a Dremel.

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This ps has a nice construction with input noise filter, bridge rectifier, control IC and opto coupler feedback.

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The four usb outputs are in parallel and there is some resistors to control the voltage on the data pins, probably to make it compatible with Apple.

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It does also have a capacitor between primary and seconday, this is used to reduce noise and due to safety it MUST be a Y capacitor. The capacitor looks like it is.

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This ps uses a real chip for control, it is called THX203H

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There is a good distance between mains and low voltage. At the usb connectors it looks like the distance is short, but when the pcb is in the box, there is a plastic shield between the mains and the low voltage section.



USB Power Supply #5 Skross

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From: www.batteribyen.dk
Name: Euro USB Charger

Official specifications:
  • Ideal for iPad, iPhone and all other USB devices
  • Suitable in all countries with Euro plug standard and modularly compatible with all SKROSS Adapters worldwide
  • 2 USB ports for simultaneous powerful charging
  • Input range: 100 – 250V
  • USB Output: 5V / 1300mA
  • Colour: white




Measurements

This ps has two usb output, that can deliver a total of 1.3A according to the specifications, lets check:

USB%20PS%20%235%20load%20sweep

Between 1.2A and 1.3A and then it shuts down, this is very nice doing.

USB%20PS%20%235%201.2A%20load%20test

Running a load test for 1 hour is no problem, it has perfectly stable output.

How does the output look at 1.2A:

Trace%205a

Only a little noise, can be used for anything.



Tear down

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This adapter does not use wires to connect from the plug to the pcb, but some custom clips.

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This ps is designed with a bridge rectifier and a control IC. I cannot see any feedback, but it has a very good regulation anyway (It is probably using a extra winding on the transformer for regulation).

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The distance between mains and output is not that long, part of it is protected by the plastic shield.
Note: There is something that looks like a PCB trace near the wide slot, but it is not.

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Nothing is hidden under the USB connectors.



USB Power Supply #6, KY-738

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The charger was rattling when I got it, that turned out to be some loose plastic pieces inside the charger.

From: ebay:boutique_uno/360542144761
Name: MP3 MP4 Mobile Cell Phone EU Plug USB Power Adapter AC Wall Charger

Official specifications:
  • Product Name: USB Power Adapter AC Wall Charger
  • Input: AC 110-240V 50/60Hz
  • Output: DC 5V 500mA
  • Plug Type: USB to EU Plug
  • External Material: Plastic
  • Color: Black
  • Overall Size: 60 x 36 x 56mm / 2.4" x 1.4" x 2.2" (L*W*H)
  • Weight: 27g
  • Package Content: 1 x USB Power Adapter AC Wall Charger




Measurements

This ps has one usb output, that can deliver a total of 0.5A according to the specifications, lets check:

USB%20PS%20%236%20load%20sweep

About 0.4A, then the voltage goes below the minimum limit, this is below specifications.
The green led on the power supply turns on at about 90 to 100mA load, the red is on when it has power.

USB%20PS%20%236%200.35A%20load%20test

With a 0.35A load there is no problem running for 1 hour.

USB%20PS%20%236%200.4A%20load%20test

Increasing the load to 0.4A does not look good, the voltage is way to low.

How does the output look at 0.35A:

Trace%206a

It has some noise in the output.



Tear down

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The ps has a single rectificer diode, that charges a 2.2uF capacitor. It has two transistors and a opto coupler for feedback. This opto coupler does keep the output fairly stable, but because the ps cannot deliver much power, the output will drop at around 0.4A.

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USB Power Supply #7

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From: ebay:lotsgoods88/110740713894
Name: USB AC Power Supply Plug Adapter for MP4 MP3 Charger EU

Official specifications:
  • Output Voltage: DC5V
  • Charges most USB devices and MP3 Players
  • Works with most devices that can be charged with the USB Port
  • Save the hassle of finding a computer to charge your USB devices
  • People who needs to charge their MP3 players frequently necessary to have one
  • Color:White
  • 1x USB AC Power Supply Plug Adapter




Measurements

This ps has one usb output, that can deliver a total of 1 according to the specifications, lets check:

USB%20PS%20%237%20load%20sweep

About 0.6A, then the voltage goes below the minimum limit.

USB%20PS%20%237%200.55A%20load%20test

The output at 0.55A looks nice.

USB%20PS%20%237%200.6A%20load%20test

At 0.6A the voltage varies a bit, probably due to temperature changes

USB%20PS%20%237%200.65A%20load%20test

Increasing the current a bit more and the voltage is far below specifications and not very stable.

How does the output look at 0.55A:

Trace%207a

There is a lot of noise in the output.



Tear down

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The ps has a four rectificer diode (i.e. a bridge), that charges a 2.2uF capacitor. It has two transistors (one of them a power transistor) and a opto coupler for feedback. This opto coupler does keep the output fairly stable.
It does also have a capacitor between primary and seconday, this is used to reduce noise and due to safety it MUST be a Y capacitor, but the used capacitor is not.

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The distance between mains and low voltage is way to short on this ps.



USB Power Supply #8

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From: ebay:sinedy/180653247293
Name: BlackBerry Power AC Charger Mini Micro USB Adapter EU

Official specifications:
  • Compact, lightweight, and portable.
  • Easy to operate, carry around and store, very convenient indeed.
  • Powers handset and charges battery.
  • Rapid Charge.
  • Single USB Port.
  • Compatible with any Blackberry device with the appropriate USB Cable (mini or micro):
  • Blackberry Torch 9800 Bold 9700 Style 9670 Bold 9650 Tour 9630 Storm2 9550 9520 Storm 9500 9530 Blackberry Curve 8300, 8310, 8320, 8330, 8350i, Pearl 8100, 8110, 8120, 8130, 7250, 7520, 7100 and more.
  • Input Voltage: 100-240 Volt.
  • Output: 5V.
  • Size: 3cm x 3cm
  • Color: black.
  • 1 x BlackBerry Power USB AC Adapter EU




Measurements

This ps has one usb output, that can deliver a total of 0.75A according to the specifications, lets check:

USB%20PS%20%238%20load%20sweep

About 0.65A, then the voltage goes below the minimum limit.

USB%20PS%20%238%200.65A%20load%20test

The output at 0.65A looks acceptable.

USB%20PS%20%238%200.7A%20load%20test

At 0.7A the voltage is way to low.

How does the output look at 0.65A:

Trace%208a

There is a lot of noise in the output.



Tear down

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The ps has a single rectificer diode, that charges a 4.7uF capacitor. It has two transistors (On smd and one power) and a opto coupler for feedback. This opto coupler is the reason for the stable voltage during load sweep.

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The main capacitor is mounted very close to the usb connector, this is not very safe.

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It looks like there is a white line between mains and low volt on the pcb, but this does not help with the distance, that is very short.



USB Power Supply #9

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From: av-cables.dk/44004
Name: 230V til 1 x USB lader - 1000 mA

Official specifications:
  • Charge function by 100-240 V / AC
  • Input Voltage: 100-240V AC
  • Output Voltage: DC 5,0V
  • Output current: max.1000mA




Measurements

This ps has one usb output, that can deliver a total of 0.75A according to the specifications, lets check:

USB%20PS%20%239%20load%20sweep

Looking at this curve, the ps can deliver 1.4A, this looks very good.

USB%20PS%20%239%201A%20load%20test

The first test at 1A does not work as expected, after 23 minutes the ps begins doing funny stuff.

USB%20PS%20%239%200.9A%20load%20test

Doing a test at 0.9A works much better.

USB%20PS%20%239%201.4A%20load%20test

I was curious about 1.4A load, as can be seen above it can do that for about 5 minute.

How does the output look at 0.9A:

Trace%209a

It has some noise in the output.



Tear down

No tear down for this charger (It requires a Dremel to open).



USB Power Supply #10

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From: av-cables.dk
Name: 230V til 2 x USB lader - 2000 mA.

Official specifications:
  • Input Voltage: 100-240V AC.
  • Output Voltage: DC 5,0V.
  • Output current: max. 2000mA (1xUSB).
  • Max. 1000mA (2xUSB).
  • Dimensions: 64.5 x 40.7 x 62.4 mm.




Measurements

This ps has two usb output, that can deliver a total of 2A according to the specifications, lets check:

USB%20PS%20%2310%20load%20sweep

Looking at this curve, the ps can deliver more than 3A, this looks very good.

USB%20PS%20%2310%202A%20load%20test

A test at 2A looks very good.

USB%20PS%20%2310%202.5A%20load%20test

A 2.5 test does also look very good. I am not going to test at higher current, I do not want to risk damaging this ps.

How does the output look at 2A:

Trace%2010a

The ps has a very nice output voltage with low noise.



Tear down

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The ps has input noise filter, a rectificer diode, that charges three 6.8uF capacitor. It has an IC and a power transistors. There is no opto coupler, but it has a fairly stable output anyway.
It does also have a capacitor between primary and seconday, this is used to reduce noise and due to safety it MUST be a Y capacitor and it is.

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There is a very good isolation distance between mains and low voltage on this charger.



USB Power Supply #11

This ps is the same as #3, but from another dealer.

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From: e.beautyshop24 / 180973732363
Name: EU PLUG USB POWER ADAPTER TRAVEL HOME WALL CHARGER FOR IPHONE 4G 4 4S IPOD

Official specifications:
  • Color: 8 colors ( blue/white/orange/black/green/purple/rosy/red)
  • Plug: EU plug.
  • Input: 100V-240V 50/60Hz 0.15A.
  • Output: 5V 1A.
  • USB AC Adapter Charge for iPhone 3G 4G 4S 4GS/iPod
  • 1 x USB Charger




Measurements

This ps has two usb output, that can deliver a total of 1A according to the specifications, lets check:

USB%20PS%20%2311%20load%20sweep

Looking at this curve, the ps can deliver about 0.5A.

USB%20PS%20%2311%200.5A%20load%20test

Doing a actual load at this current, shows that 0.5A is a bit too much for this ps.

USB%20PS%20%2311%200.45A%20load%20test

Reducing the current to 0.45A looks much better.

How does the output look at 0.45A:

Trace%2011a

There is a lot of noise in the output.



Tear down

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The ps has a single rectificer diode, that charges a 2.2uF capacitor. It has two transistors and a opto coupler for feedback. This opto coupler is the reason for the stable voltage during load sweep.

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DSC_1576DSC_1578



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There is a good distance between mains and low voltage side.



USB Power Supply #12

This ps looks the same as #2, but when looking at the tear down it is easy to see that the construction is different.

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From: zyy123087/400308826772
Name: USB AC Power Supply Plug Adapter for MP4 MP3 Charger EU

Official specifications:
  • Compact and exquisite design, convenient to carry
  • USB interface
  • Fast charging speed and low power consumption
  • Suitable for DVs, cell phones, MP3 players, PDAs and etc.
  • Input Voltage:100-240V 50/60Hz 0.1A
  • Output Voltage: 5V 500mA
  • LED power indicator.
  • Build-in Smart IC chip can recognize a full battery and automatically switch to stand-by mode to protect your cell phone's battery from over charging
  • Color: Black
  • 1x EU Europe USB Wall Charger Adapter for PDA DV Mp3 Mp4




Measurements

This ps has two usb output, that can deliver a total of 1A according to the specifications, lets check:

USB%20PS%20%2312%20load%20sweep

Looking at this curve, the ps can deliver about 0.35A.

USB%20PS%20%2312%200.35A%20load%20test

Doing a actual load this, shows that 0.35A is a tiny bit too much for this ps (the voltage goes below 4.75 volt).

How does the output look at 0.35A:

Trace%2012a

There is a lot of noise in the output.



Tear down

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The ps has a single rectificer diode, that charges a 2.2uF capacitor. It has two transistors and a opto coupler for feedback. This opto coupler is supposed to stabilize the output voltage, but does not really work.

DSC_1504


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There is some isolation distance.



USB Power Supply #13

This ps is nearly the same as #1, but from a different dealer.

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From: wwwdot999/390512458592
Name: EU Plug USB Wall Charger AC Power Adapter For iPhone 3GS ...

Official specifications:
  • USB adapter wall charger for iPhone & iPod, except iPod Shuffle
  • Suitable for home, office or on travel use
  • Easy to use, plug and play. No installation needed.
  • This item with protective circuit to prevent overcharging (IC chip)
  • Compact and exquisite design, easy to carry
  • Fast charging speed and low power consumption
  • Color: Green
  • Input: 100-240V, 50/60Hz, 0.15A
  • Output: 5V, 1A
  • Plug: EU Plug
  • Size: About 4.5 x 2.5 x 2.5cm




Measurements

This ps has one output, that can deliver a 1A according to the specifications, lets check:

USB%20PS%20%2313%20load%20sweep

Looking at this curve, the ps can deliver about 0.6A.

USB%20PS%20%2313%200.6A%20load%20test

Doing a actual load this, shows that 0.35A is a tiny bit too much for this ps (the voltage goes below 4.75 volt).

USB%20PS%20%2313%200.65A%20load%20test

Trying to draw slight more current does not work.

How does the output look at 0.6A:

Trace%2013a

There is a lot of noise in the output.

High voltage test failed.



Tear down

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The ps has a single rectificer diode, that charges a 2.2uF capacitor. It has two transistors and a opto coupler for feedback. This opto coupler is the reason for the stable voltage during load sweep.

DSC_1594


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I have marked the mains connected parts with red and the low volt parts with blue. There is less than 0.5 mm between them.
This is extremely unsafe.



Conclusion

With the cheap chargers I had not expected much and the result proved that. The isolation distance is seldom large enough and many of the chargers has a lot of noise in the output. There is also a problem with the output current, it is often considerable lower than rated.

comparison

Looking at the result, the only ones I will be using are 4, 5, 9 and 10.
Number 1 and 13 is way to dangerous to use



Notes

5, 9 and 10 are bought in Denmark, this means higher price (Denmark is very expensive) and probably better safety due to EU regulations.
Efficiency and noise is measured at the "Measured current"

In the tear down section for each ps, it is possible to click on some of the pictures to get larger versions.

One important aspect of safety is the transformator, in the above I have not disassembled it to see if it is safe, but anything that can handle 5kV will be mostly safe.

Read more about how I test USB power supplies/charger

My website with reviews of many chargers and batteries (More than 1000): http://lygte-info.dk/

Edited by: sb56637 on 06/25/2015 - 11:41
NightCrawl
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Last seen: 1 year 2 months ago
Joined: 01/22/2012 - 08:20
Posts: 3071
Location: Karlsruhe, Germany

Wow, awesome comparison, thank you very much!

I think I'll have to replace one or two USB power supplys I currently use. Those teardown pictures are very helpful and really show the weak links.

Do you have a plan on testing some 12V USB power supplys used in cars? Smile

fyesilova
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Last seen: 1 day 9 hours ago
Joined: 01/31/2012 - 18:33
Posts: 590
Location: Istanbul - Turkiye

Great and informative test, Thank you HKJ

Istanbul New YSM Bridge
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HKJ
HKJ's picture
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Last seen: 21 min 36 sec ago
Joined: 05/24/2011 - 12:23
Posts: 5048
Location: Copenhagen, Denmark

NightCrawl wrote:
Do you have a plan on testing some 12V USB power supplys used in cars? :)

Not at this time.

My website with reviews of many chargers and batteries (More than 1000): http://lygte-info.dk/

Ratpie
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This is awesome, thank you!

I’ve always been wondering about that ioncell ps, but I’ve been so sceptical to chinese knock-off supplies, that I’ve just let it be until now – ordered!

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Very useful review – thanks for taking the time. Good to know that Intl Outdoor have a readily available safe model I can get should I need a replacement.

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Thanks again HKJ. The amount off effort put into this is amazing. Cheers.

My current and or voltage measurements are only relevent to anything that I measure.

Budget light hobby proudly sponsored by my Mastercard and unknowingly paid for by a hard working wife. 

djozz said "it came with chinese lettering that is chinese to me".

old4570 said "I'm not an expert , so don't suffer from any such technical restrictions".

Old-Lumens. Highly admired and cherished member of Budget Light Forum. 11.5.2011 - 20.12.16. RIP.

 

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As others have said, thanks for all the time/effort to bring this kind of information to us. It’s much appreciated.


 

scaru
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Great tests, I guess I'm retiring my green one that looks like yours. Yell

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HKJ
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nekdo12 wrote:
"Another test":http://www.righto.com/2012/10/a-dozen-usb-chargers-in-lab-apple-is.html here

That test does include many brand name chargers and very few cheap charger. Notice that the KMS is not the same 4 port ps as I have tested, this is very obvious if looking at his tear down.

My website with reviews of many chargers and batteries (More than 1000): http://lygte-info.dk/

ChangchungLeds
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Thanks for this big job that you do for us… It is amazing that the most best looking PS are the worts…

Zebralight Spark Princeton Inova Petzl Maglite Bushnell a lot of Cree XM-L Lights 18650's Intl-outdoor 3400 Panasonic 3100 Hobby Charger

texaspyro
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In the noise plots for chargers 1, 6, 12, and 13 you clearly see what are commonly called “hanging bridges”. These are highly indicative of the waveform sampling frequency being less than twice the noise frequency (under-sampling). This causes aliasing and distortion of the waveform. The noise level of those devices is probably quite a bit higher than what is indicated.

HKJ
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texaspyro wrote:
In the noise plots for chargers 1, 6, 12, and 13 you clearly see what are commonly called "hanging bridges". These are highly indicative of the waveform sampling frequency being less than twice the noise frequency (under-sampling). This causes aliasing and distortion of the waveform. The noise level of those devices is probably quite a bit higher than what is indicated.

That might be the case, but I doubt the result would be that much different if I sampled at a higher frequency. I sampled at about 100kHz, i.e. each point on the curve is about 120 samples.

The expression "hanging bridges" is not common around here, I have never heard it before. I tried using google, but did not have much success (There is a surprising number of pages about Brookling bridge and oscilloscopes Smile).

My website with reviews of many chargers and batteries (More than 1000): http://lygte-info.dk/

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Awesome teardowns and reviews. Always wondered what had to give in those tiny little cube chargers, now I know!

Hesitant to use my Samsung cube charger now, assuming similar isolation and noise issues.

Makes me wonder how the built-in USB charging ports on my surge protector fare, hoping they are better than these little chargers

HKJ
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M1K3Z0R wrote:
Hesitant to use my Samsung cube charger now, assuming similar isolation and noise issues.

Do not worry about the Samsung charges, check the link nekdo12 posted, there is a test of two Samsung chargers and works fine.

 

M1K3Z0R wrote:
Makes me wonder how the built-in USB charging ports on my surge protector fare, hoping they are better than these little chargers

Hopefully they are.

My website with reviews of many chargers and batteries (More than 1000): http://lygte-info.dk/

kreisler
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i dont know what these ps are good for, are they employed for powering Apple ipads during a work day or for charging Apple liion cells in iphones during the night? never mind.

the 4 most expensive ps were the 4 best? i see Smile

goobay .. i think it's German stuff (goobay.de).

Thanks for the superb review!!

*FMI* i got 4 i/o sh
HKJ
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leaftye wrote:

Thank you for the review HKJ.  I have the first charger.  The size and weight were very attractive to me.  It's too bad it's not as fast as it's supposed to be.  I wonder if this 1.5A version is any faster.  If nothing else, I hope it's safer.  I have one on the way.

https://www.fasttech.com/products/1235601[/quote]

The #1 in my test? I will recommend that you break it apart and throw it out, with 0.5 mm in isolation distance it is not something to have laying around.

On the one you linked to, try reading the text on the bottom of it, there it says 1A. It is probably just as unsafe and weak.

If you really want a small ps, buy the Apple one, it is safe.

My website with reviews of many chargers and batteries (More than 1000): http://lygte-info.dk/

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Yet another quality review by HKJ! Been reading your reviews on chargers and batteries! Reviews are always packed with nice charts and high quality pictures!

Thanks HKJ!

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Very interesting and useful, thanks a lot for the effort

Mooooooo

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HKJ wrote:

leaftye wrote:

Thank you for the review HKJ.  I have the first charger.  The size and weight were very attractive to me.  It’s too bad it’s not as fast as it’s supposed to be.  I wonder if this 1.5A version is any faster.  If nothing else, I hope it’s safer.  I have one on the way.

https://www.fasttech.com/products/1235601

The #1 in my test? I will recommend that you break it apart and throw it out, with 0.5 mm in isolation distance it is not something to have laying around.

On the one you linked to, try reading the text on the bottom of it, there it says 1A. It is probably just as unsafe and weak.

If you really want a small ps, buy the Apple one, it is safe.

I just received 1 of the 1.5a chargers today…and it is 1A. Thanks for the testing, great info!

Dave

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soytnly wrote:
I just received 1 of the 1.5a chargers today…and it is 1A. Thanks for the testing, great info!

As appreciated as your tests have been for me, this is the best.

So many of these cheap chargers… I feel like you’re driving a car steering me to the good stuff.

GREAT work HKJ!

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Great review, very important safety facts!

Highly appreciated!

Insipred by this thread, I tore down one (failed) Xtar WP2 II power supply unit.
Since I’m no-pr0, I will post pics to another thread and let You guys decide “what it has eaten” :bigsmile:

Here is a link to tear down: http://budgetlightforum.com/node/18797

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Awesome review, thanks HKJ!

BLF ≠ B-grade Flashlight Forum

Ongoing projects:

<span style="font-size: small; line-heigh

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If you look at the myriad of PCBs out there in electronic devices the distances separating circuitry apart from disaster is likewise as these USB units. The point being is don’t get these type of things wet or for that matter any other similar device, nor mess around in there unless you know what you’re doing and you should be fine. Even if gaps somehow connected with the AC voltages involved the result would most likely be a fried connection, a strong smell, and a device that doesn’t work.

The tests here IMO would have more credence if the author subsequently bridged these gaps, submerged the units, or some similar test to see what actually happens if said gap was bridged. Think UL Labs testing.

IOW, overeaction IMO.

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nottawhackjob wrote:
If you look at the myriad of PCBs out there in electronic devices the distances separating circuitry apart from disaster is likewise as these USB units. The point being is don't get these type of things wet or for that matter any other similar device, nor mess around in there unless you know what you're doing and you should be fine. Even if gaps somehow connected with the AC voltages involved the result would most likely be a fried connection, a strong smell, and a device that doesn't work. The tests here IMO would have more credence if the author subsequently bridged these gaps, submerged the units, or some similar test to see what actually happens if said gap was bridged. Think UL Labs testing. IOW, overeaction IMO.

The safety standards says 4 mm distance in air, on a pcb it will be longer, except if it has a special isolating coating. This distance has two purposes, one is to withstand humidity and dirt, the other is to withstand transients on the mains.

I did not open the transformer, but it will probably also fail the safety standards on the cheap units.

Read this article from BBS, especially the bottom part, that is what can happen with the worst of these chargers.

My website with reviews of many chargers and batteries (More than 1000): http://lygte-info.dk/

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What’s the gap safety spec if they did have it?

A UL Labs style torture test would be interesting. Do they catch on fire, go into electrocution mode, etc. IMO, any electrical device that’s abused whether by liquid, cord yanking, what have you, is potentially dangerous. The construction of the units claimed as being unsafe on the surface seems pretty robust. I don’t see dangling bare wires or particularly shoddy soldering IOW.

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nottawhackjob wrote:
What's the gap safety spec if they did have it? A UL Labs style torture test would be interesting. Do they catch on fire, go into electrocution mode, etc. IMO, any electrical device that's abused whether by liquid, cord yanking, what have you, is potentially dangerous. The construction of the units claimed as being unsafe on the surface seems pretty robust. I don't see dangling bare wires or particularly shoddy soldering IOW.

 

The safety standard is called IEC60950-1 and is implemented in many countries (including US). One important aspect of it is that any vital to safety isolation must be double thickness or two layers normal isolation. There is also different requirements in US and EU, because the mains voltage is different (110VAC vs. 230VAC).

For US indoor equipment with safety earth only needs 1 mm safety distance, without earth 2mm, in "Polluted degree 3" environment it is 2.6 mm and all these distances can be reduced if the factory does a high voltage test on equipment, before shipping.

The standard does list many other safety requirements, including detailed specifications on how solid the equipment must be.

My website with reviews of many chargers and batteries (More than 1000): http://lygte-info.dk/

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IOW not three pronged like you typically see on most power tools? If they had it then the 1mm distance would be ok? I was also thinking about US and EU voltages and their respective different safety guidelines as you wrote the reply.

I think if we dissected most Chinese inexpensive electronic devices a good many of them would also fail under stringent wide safety criteria as well. Wink

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nottawhackjob wrote:
IOW not three pronged like you typically see on most power tools? If they had it then the 1mm distance would be ok?

As air distance yes, not on a pcb.

nottawhackjob wrote:
I was also thinking about US and EU voltages and their respective different safety guidelines as you wrote the reply.

Because both EU and US uses the same safety standard, the differences are probably minor, and all equipment that can work on bot 110 and 230VAC, needs to use the larger distances.

nottawhackjob wrote:
I think if we dissected most Chinese inexpensive electronic devices a good many of them would also fail under stringent wide safety criteria as well. ;)

I do believe that.

My website with reviews of many chargers and batteries (More than 1000): http://lygte-info.dk/

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HKJ wrote:

M1K3Z0R wrote:
Hesitant to use my Samsung cube charger now, assuming similar isolation and noise issues.

Do not worry about the Samsung charges, check the link nekdo12 posted, there is a test of two Samsung chargers and works fine.

 

M1K3Z0R wrote:
Makes me wonder how the built-in USB charging ports on my surge protector fare, hoping they are better than these little chargers

Hopefully they are.

Thanks! Glad it was tested and found to be different from the Apple chargers. Hard to tell these days who builds what for whom and to what standards

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