Review on 🔌 Eversame USB Power Meter: Accurate 35W Adjustable Constant Current USB Load Tester for Charger & Cable Testing, Power Bank Capacity Analysis - QC2.0/3.0 Trigger by Dwayne Meurer

Let me start with the fact that the product's features look great and should be enough to test most mobile chargers and power banks. However, if you have a power supply that can deliver a higher current, or just a Li-Ion or Lipo battery, this load is useless. The fine adjustment, which allows the current to be set to only 0.2 amps, works perfectly. When you start adjusting the current with the coarse adjustment, it suddenly jumps from about 0.05-07 to 3->5 amps (depending on the input voltage). Once it has jumped to a higher current, turning both current adjustment knobs to the minimum does nothing. The only way is to turn off the power supply. If you are not nearby at this time, it could start a fire or fire. Many may wonder why they never encounter a problem. If you're testing a portable charger or power bank, most of these devices have built-in current limiters that don't deliver enough current to drive the load crazy. You will only experience this if you test it with a lithium battery or lab power supply. Problem with simple design: All current control circuit is purely analog with LM321 and TIP122 Darlington transistor. This behavior occurs because the current loop becomes unstable and begins to oscillate. TIP122 High gain Darlington transistor with no anti-oscillation control. The simple fix is to connect 100k ohms and 0.22uF from the ground base and everything works fine. Not sure if it's missing from my board or even the design. Anyone who sees a problem with current adjustment fluctuations can use this mod. I would like to add that the seller was responsive in communication.