First, thank you for your time of reading my questions. As the title suggested, my questions are about turning a computer power supply into a lab power supply. I already did my homework and read pages and pages, and also tested the power supply unit itself while took great caution not to get executed by electricity doing so, yet I still have few doubts that I want to get a precise answers before moving on.
1, some say that it will explose; some say that it will be fine; some just doesn't really know. Will it be okay if there is no load connected to the psu? As far as I know, my tested unit didn't explose, but it could be an exception. I need to know this because I don't like the idea of a dummy load that wastes 5 watts.
2, I don't see manual switch, and I used to see those in older units. I love the idea that it's possible to switch the unit on/off using a simple signal. Here is my observation: With no load and with ps-on not connected to ground, after removing the power, I connect ps-on to ground while got a voltage reading on my meter for a brief moment. Here is my question: is the capacitor still hold a high voltage when ps-on is off after removing the ac plug? I think it probably is. The main doubt for me is when I connected ps-on to ground after the removal of the ac plug, will that discharge the lethal high voltage capacitor to a safe level?
3, I notice there are 2 small yellow pots on the board. I think it is use to change the voltage of 2 of the output. if I am correct, can I turn it as a variable voltage source?
4, I notice that there is a small blue capacitor connected between one ac input line to the ground/metal case (shield). I know it's for filtering high frequency noise, but is it safe for me to touch the metal case when I don't have ground connected to anything? Ac does go through capacitors and metal does go through me, I think. Interestingly, when measuring the voltage difference between that metal case and a water pipeline, it reads 65v ac, so it's not safe? should I remove that capacitor?
again, thank you for your time, and please have a nice day.