17mm 7135x3 AK47A MCU Dimming 1000mAh 5Mode





Driver is from banggood.com

• Product name: 7135x3 AK47A Circuit Board
• Model:AK47
• Size: Board diameter:17mm
• PCB thickness: 1.2mm
• Input voltage:3.0v-4.2v
• The maximum current:1A
• 2-Mode: Low 10%--High 100%
• 3-Mode: Low5%--Middle30%-High100%
• 5-Mode: Low5%—Middle30%—High100%—Strobe---Police Flash—SOS
• Suitable LED:Single core LED flashlight(white/blue/purple light)

Features:
It’s with reverse polarity protection.
Low voltage indication function. If the voltage is lower than 2.9V-3V, it will reduces the minimum brightness automatically. And will prompt you by flash once a second.
Power supply by Single lithium battery or 3xAA battery. It’s the best when Input is more than Output about 0.2V-1V. This section can be efficient, and can also constant current.

Please note:
The drive current is not higher than the maximum current of LED lamp.




Measurements

The description of this driver is wrong, the software is different
Multi mode linear driver
Tested with Cree XP-G2 led
Diameter: 17mm
Thickness: 3.2mm
The modes are: 10%, 20%, 30%, 40%, 60%, 80% and 100%
The driver remembers last selected mode.
If the driver voltage get below 2.95 volt the driver changes to warning mode.
When the driver goes into warning mode, it stays there until another mode is selected.
Pwm frequency is 4.75 kHz

The percent names I uses for the modes are not entirely accurate, I have rounded them.
For 100% mode power and efficiency calculations are fairly accurate, for all other mode they are only valid above 3.3 volt to 3.4 volt.



100%



Full brightness is depends on the Vf of the led. Warning mode is activated if the voltage drops below 2.95 volt.
As usual with linear drivers the efficiency is best when the battery voltage is only slightly above led voltage.






When the voltage starts at a low value the driver will switch to warning mode and stay there until another mode is selected.



High mode is not without pwm. It is just adjusted very close to 100% on time.



80%








60%









40%









30%








20%









10%









Warning mode



If the voltage gets below 2.95 volt the driver will switch to warning mode and also remember it. In warning mode the light turns off/on shortly each 1.2 second.
To get out of warning mode, do a fast power cycle, this will select another mode.



The pwm is at 10%.



Conclusion

The hardware of the driver works as well as any 7135 driver, but I do not like the program. There is too many modes with to little difference between them and it does not disable pwm at 100% (This is a very minor detail).



Notes

How do I test a led driver
List of all tested drivers