The trick is to put a tiny dummy load on the USB charger. Just buy the cheapest USB cable, cut the end off, and solder (or twist) a resistor between red and black. Boom.
Had a whiny USB power strip at my office desk that stopped whining when my phone was plugged in. Small resistor took care of that perfectly, cheaply, and nondestructively. Got a kick out of confused colleagues asking why I had a dangly cable plugged in with nothing but electrical tape on the end.
USB is 5V so I suppose a 10 mA draw (500 ohm resistor) would be sufficient. 20ohm would be 250 mA/1.25W which is certainly overkill for a dummy load. I don’t recall exact values but mine barely needed any load to shut up.
The trick is to put a tiny dummy load on the USB charger. Just buy the cheapest USB cable, cut the end off, and solder (or twist) a resistor between red and black. Boom.
Had a whiny USB power strip at my office desk that stopped whining when my phone was plugged in. Small resistor took care of that perfectly, cheaply, and nondestructively. Got a kick out of confused colleagues asking why I had a dangly cable plugged in with nothing but electrical tape on the end.
What are we talking here when you say “small”. 20 ohm? 50 ohm?
USB is 5V so I suppose a 10 mA draw (500 ohm resistor) would be sufficient. 20ohm would be 250 mA/1.25W which is certainly overkill for a dummy load. I don’t recall exact values but mine barely needed any load to shut up.