For posterity and myself, I'm leaving some tips and tricks of PC Power Supply Unit (PSU) whcih is an SMPS (Switched Mode Power Supply). There are a variety of uses of a +12V, +5V and +3V DC power supply like lighting up an LED strip or powering a raspberry pi. There are various colored cables in a typical ATX 12V SMPS. I'll list out the various color lines and what they mean, Sr. No Cable color Number of cables in a PSU Use 1 Green exactly one (1) Wake up signal from motherboard. Pressing PC power button makes this signal carry wake up signal to PSU to start. Green needs to be touched with the any ground to make the SMPS start. For self-starting PSUs, green needs to be connected with one black all the time. 2 Blue exactly one (1) -12V 3 Purple exactly one (1) +5V standby. When power supply is on standby mode (not on by signalling green), this line can give 1-2 A current. 4 Gray exactly one (1) Power good signal. When PSU levels has reached specificati...
Universe from my perspective..