Koyot Dual car charger 2.4A

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Official specifications: I got it from Aliexpress dealer: Miss shen Wonderful Store

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No fancy box for this charge, just an envelope and a plastic bag.

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Measurements

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The 1A output can deliver about 2.8A

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The 2.4A output can also deliver about 2.8A

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And when run in parallel the maximum current is also 2.8A

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Higher input voltage do not change it.

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The output can maintain voltage until about 7V, also note the efficiency goes down when used at 24V

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The chargers own current consumption varies with voltage.

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There was no problem running 1 hour with full load (2.4A).
The temperature photos below are taken between 30 minutes and 60 minutes into the one hour test.

Temp5681

M1: 45.3C, HS1: 50.3C

Temp5681

M1: 45.7C, HS1: 56.9C

10ohm

At 0.5A the noise is 33mV rms and 170mVpp

5ohm

At 1A the noise is 39mV rms and 191mVpp

2ohm

At 2.5A the noise is 68mV rms and 269mVpp



Tear down

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I could not pull or unscrew the metal and decided to cut.

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The back has some heat shrink on it.

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At the input is a "fuse" in the form of a 0ohm resistor, the voltage converter is a single IC (U1: marked VS2886) and it must have build in synchronous rectification (I do not see any diode).

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There is no parts on this side of the circuit board.

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The front circuit board has resistors for coding the two usb output, but there is also an empty space for a auto coding IC

Being a 12V device there is no need to test with high voltages.



Conclusion

This charger works, but is not perfect. The power is enough for one high power output, not for two. Why is a 2.4A output coded for 2.1A, using a auto coding chip for both outputs would have been nicer.



Notes

Index of all tested USB power supplies/chargers
Read more about how I test USB power supplies/charger