USB Load resistor 1A

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Official specifications:
I bought it on ebay some time ago.

The most interesting detail about this type of load is how hot they get, some power resistor has a working temperature between 200C and 300C when fully loaded.

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This type of load is very simple, two big power resistors and a led to show if there is any power supplied to it.

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Load testing

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Being a resistor the current will depend on voltage.

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As expected the load current and power is stable with a resistor, except for a small drop due to temperature.

Temp3105

M1: 165,5C, M2: 87,0C, M3: 57,4C, M4: 171,9C, HS1: 181,2C
The resistors gets fairly hot.
The correct way to mount power resistors is a bit above the board with some distance between. These resistors are only running at half their rated power, but they cannot get rid of the heat.

Temp3107

M1: 124,5C, M2: 63,8C, HS1: 132,1C



Conclusion

The load works as expected and is an easy way to test usb power banks (together with a usb meter), but this model need an external fan to supply lots of cool air.
It is a bad idea to touch it when it is working.



Notes

Expect very similar performance from all resistive loads with two square white 5W 10ohm resistors.