This tiny and very cheap board allows you to use batteries and rechargeable batteries to power your USB devices.
Even at the "new" prices, the HW-105 board costs less than 30 rubles.
Voltage from 0.9 to 5 volts can be applied to the input, the output should always be 5 volts.
The seller promises that when powered by one AA battery, the load current can be up to 300mA, from two AA batteries up to 600mA. Of course it isn't. :)
Only "HXN-Xh" is written on the chip, so it was not possible to recognize it.
With laboratory power supply and instrument EBD-USB+ I measured the limiting output currents at various input voltages.
The converter produces 5 volts up to a certain load current, then the output voltage begins to decrease quite sharply. The higher the input voltage, the greater the load current the converter can withstand, but at an input voltage above 4 volts, there is a dip in the limiting output currents.
At each input voltage from 0.9 to 4.3 V, I measured the maximum output current at which the output voltage was more than 4.88 V.
The voltage on alkaline batteries decreases from 1.5 to 0.9 V as it discharges, so when powered by one battery (AA or AAA), you can connect to the converter devices with a current consumption of up to 40-65 mA (if the device consumes no more than 40 mA, it will "land" the entire battery if 65 mA is approximately half). When powered by two batteries, the converter can provide 120-180 mA.
The highest efficiency (86%) for the converter at an input voltage of 4.0-4.1 V, the lowest (53%) at 0.9-1.1 V.
At maximum load, the output ripple amplitude is 100 mV, the conversion frequency is about 100 kHz (measured at an input voltage of 2.5 V and an output current of 190 mA).
If you do not load the converter to the full, the ripple drops to almost zero. So with a load of 160 mA and the same input voltage, the ripple could not be fixed at all.
I ordered these converters in order to try to make power "People's ripple meterfrom one or two batteries. Despite the fact that the device consumes 64 mA, it works perfectly with one AAA battery.
The device worked on one AAA battery for more than an hour, which is quite enough.
Although the converter does not provide the promised 300 mA from one battery and 600 mA from two, it can be used to power various low-power devices.
Peace for everyone!
© 2022, Alexey Nadezhin
For twelve years I have been writing about technology, discounts, interesting places and events. Read my blog site ammo1.ru, in Learn, Zen, Mirtesen, Telegram.
My projects:
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