Dual Digital-Voltmeters/ Ammeters DC 100V 10A Voltmeter Ammeter Blue + Red LED, dsn vc288

How to wire digital dual display volt- and ammeter
Once I bought a popular “Chinese” volt- and ammeter gauge with

100V/10A ratings. Unfortunately, I didn’t find any good resource

about how to wire/connect it. Actually, it’s not rocket science,

but I had waited for it 2-3 weeks and didn’t want to blow it at

first try.
How do these ammeters work?
These meters calculate current flow by the voltage drop across

the shunt resistor. They have built-in shunts that should

withstand measuring as much as 10 amperes. You must see shunt

behind your volt- and ammeter. That small bridge bent from a

thick wire on PCB.
Wiring basics
They are basically the same. There is a connector with thick

wires and connector with thin wires. But coloring of wires vary.

Amperage measurement is done by passing power through thick

wires. Power to the meter itself is fed through thin wires.

They all can be wired such way that you don’t need a separate

power supply for the electronics part. You can use the same power

supply where your measured load gets electricity. But then you

can only use a maximum of 30V since it’s the maximum operating

voltage for the meter itself. Also, you can’t measure voltages

below 4.5V. If using the same power supply you even can leave

thin black wire un-connected since they have common ground/GND.

Reversing polarity on these meters?
You can’t reverse polarity on these meters when measuring

amperages (probably voltage also). I tried this on the first one

in the list. It shorted out. It’s probably because of the common

ground and by reversing you are feeding positive voltage into GND

connection. If someone has some other info please let me know.
Red and black thick wires + thin yellow, black and red
This one makes the most sense to me and it has model number zfx-

VC288 marked on the back.

Видео Dual Digital-Voltmeters/ Ammeters DC 100V 10A Voltmeter Ammeter Blue + Red LED, dsn vc288 канала SHA MEDIA