S
[email protected]
- Jan 1, 1970
- 0
I was using a 12V 1A wall wart yesterday to power a project when I heard something in it go "pop". My project draws approximately 0.5A. Postmortem revealed a dead resistor on the 120V input to the wall wart, which appears to be a 1 ohm 1/2 watt resistor. The wallwart is a swithmode power supply.
1) Am I correct in assuming this 1 ohm resistor was some attempt to save money on a fuse? or does it actually serve some purpose other than as an easypoint of failure?
2) Is there a way to compute how much power was being dissipated across theresistor? I suppose I could replace it and measure the voltage drop acrossit?
3) Was it a bad resistor that popped, or a bad wall wart design? or both?
1) Am I correct in assuming this 1 ohm resistor was some attempt to save money on a fuse? or does it actually serve some purpose other than as an easypoint of failure?
2) Is there a way to compute how much power was being dissipated across theresistor? I suppose I could replace it and measure the voltage drop acrossit?
3) Was it a bad resistor that popped, or a bad wall wart design? or both?