I have a wall wart that is marked as 9V DC output and 300mA. I used it to power a simple circuit on a breadboard with a DC barrel jack. I connected my multimeter to +ve and ground pins of the barrel jack and got a reading of 15V. Is there a chance (likely!) that I'm doing something wrong or misunderstanding something, or should I not trust this wall wart?
The circuit is a slide switch, a resistor and an LED.
Thanks
I'm not the circuit guy but ya voltage drops on load.. not sure about 330mA dropping 6 volts tho..
It says "9V 330mA", so who knows what miracles may occur! 😀
They are regulated so it should be 9v from no load to 330 ma.
If your power supply is not regulated and you have no load than it can happen that the output voltage is much higher than the nominal. But try to have a load with p.e. 100 mA ( a power resistor with 100 Ohm and 2 W) and check the voltage again. One question is: did your LED get bright with the 14 V OUTPUT?
The LED did get bright.