12 in 1 USB Tester Voltage Current Meter
I bought this from Aliexpress dealer HATCRPin Store
- Voltage measuring range: 4V ~ 30V
- Resolution precision: 0.01 V
- Current measuring range: 0.00A ~ 5.00A
- Resolution precision: 0.01A
- Power cumulative range: 0 ~ 999999Wh
- Resolution precision: 0.001Wh
- Capacity range: 0 ~ 999999mAh
- Resolution precision: 0.001Ah
- Temperature: 0?~ + 80?
- Resolution precision: 1 ?
- D+Voltage: 0.000V ~ 2.999V
- Resolution precision: 0.001V
- D-Voltage: 0.000V ~ 2.999V
- Resolution precision: 0.001V
- Load impedance: 0~ 999 ohm
- Resolution precision: 1 ohm
- Power metering range: 0 ~ 299.999W
- Resolution precision: 0.001 W
- Timing maximum time: 999 H 59 M 59 S
- Resolution precision: 1 S
- Time to refresh: > 500 ms/time > 500 ms/times
- Product size: 65 x 24 x 14 mm
- Since the power flow: < 0.003 A(< 3mA)
- Working temperature: - 10 ~ + 60?
- Working humidity: 10 ~ 80 (no doubt)
- The pressure of work: 80 ~ 106 kpa
- Measurement rate: 0.5 times/s
- Use large equipment of the same metal manganese bronze sampling resistor(1.0 mm diameter metal manganese bronze material < 0.05R)
- Cumulative capacity range: 0-99999 mah precision: 0.001 Ah (New features or D+ D- Voltage )
I got it in a plastic bag in a plastic envelope, without any instructions.
It has a single button for user interface, clicking on it will change screen.
Display and functions
Power on welcome screen.
Standard display with voltage, current, power, capacity, energy, time and internal temperature.
Double click will reset Wh, triple click will reset time, holding down button will reset mAh
Another readout with less information.
Here voltage on the data pins is shown, this can be used to guess some fast charge schemes. It also shows the resistance of the load.
The backlight adjustment screen, if can be adjusted from off, 1-59s and on. Off means it goes off immediately and makes it fairly hard to use the meter.
Double clicks will increase the value, triple clicks will decrease the reading, holding the button down on the last click will make it auto repeat.
Measurements are done on usb port.
The meter do not like low voltage, it will show wrong results.
The current do not work at low value, but the precision is good when the voltage is 5V or higher.
- Own current consumption is 11mA and 5mA when display is off.
- Internal resistance is about 0.14ohm including connection resistance.
- Minimum displayed current is 0.06A.
- Remembers Wh and Ah when power is off
- Voltage display is within 0.1 volt in the 4.0 to 30.0 volt range.
- Current display is within 0.01 ampere in the 0 to 5.0 ampere range with 5 volt supply.
M1: 60.1°C, HS1: 96.5°C
The resistor gets very hot at 5A, but then 5A is also too much for regular USB connectors, they are rated for maximum 3A
The display is affected by the heat. The temperature sensor to not measure the resistor, but is probably inside the microprocessor.
I could just pull it apart.
The circuit is very simple with a microprocessor and a voltage regulator (M5336B)
The series resistor and the button are on this side.
This is a simple USB meter, but it do the job with both capacity and energy measurements, the heat at 5A is a minor problem, correctly working USB equipment will not draw above 3A.
Except voltage and current on some screens the text is on the small side.
How do I make the test