Power meter (TS-836)

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Official specifications:

This is a no-name power meter from Aliexpress dealer repairmall2013, how well do it work?

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Being no-name the box is also without a name, but the label says TS-836

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The box contained the meter and a instruction sheet.

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User interface

This power meter has a very simple user interface, most of the time only one button can be used. Only exception is when the electricity price must be configured and to reset the device.

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Pressing the FUNCTION key will change between a couple of screens with different information on them. The screens are:
Time is only counting when drawing power, either in mm:ss or hh:mm, when passing 24 hours the days count will be incremented.

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Holding down the COST button will change to the "price for one kWh" display and start the price setting mode:
Use FUNCTION to select digit and UP/DOWN to adjust digit.
When done press COST again.



Measurements

Measurements

The precision looks acceptable and it gives indication down to 0.3 watt, that means it can measure standby power for many older devices.

Temp4531

M1: 46,7C, M2: 41,7C, HS1: 48,8C

With only about half a watt in power consumption the heat is limited. Only the area where voltage is dropped from mains to lower values generates any heat.



Tear down

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3 screws and I could open it.
The circuit is directly connected to mains, it do not use any transformer.

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The electronic is fairly simple, because everything is stuffed into one IC.
The internal power supply is done with a capacitor (CX1) and a voltage regulator (U1:78L05). The voltage measurement is done with a resistive dropper (R2, R3, R4). As usual the current is measured over a piece of wire (Rs1). For the battery backup is a small NiMH battery with 3 cells in series (3.6V 20mAh).

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The connections to the plug looks very nicely designed.

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Display and keyboard driver s a COB (Chip on board), this means a chip mounted and bounded directly on the circuit board and then covered with some stuff, usual a black blob.

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The other side of the board do not have anything.

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Display and buttons, both uses rubber connections.



Conclusion

For a cheap power meter this one is good, it works fairly well at low power.
The meter are lacking some features:
It only has one electricity price, it cannot vary depending on time of day.
There is no log, it only shows current consumption and total consumption since reset.



Notes

The build in NiMH battery will probably die after some years, preventing it from maintaining values when there is no power.