Ohms Law.
Straight_Man
Geeky, in my own wayNaples, FL Icrontian
Would any of you folks like to discuss how Ohms Law is used to evaluate PSUs and trace faults???? Understanding that is key to isolation of problems that are not software. Discriminating between soft and hard errors\defects\faults is the one hardest thing to do.
I suspect we have engineer level folks here, in the hands-on variety, and a discussion like this is something that can be summarized in simple ways. But getting the grokking of Ohm's Law is a learning stepping stone to really help enable finding out intellectually how to parse and then discriminate between hard and soft faults. Also, understanding Ohm's Law and how computers bus things is a key to know what hardware parts may be failing with soft "failures" that keep reoccuring on only one or a few boxes if they are not traceable to malware.
I know, I lacked that deep grokking understanding for half my career.
John.
I suspect we have engineer level folks here, in the hands-on variety, and a discussion like this is something that can be summarized in simple ways. But getting the grokking of Ohm's Law is a learning stepping stone to really help enable finding out intellectually how to parse and then discriminate between hard and soft faults. Also, understanding Ohm's Law and how computers bus things is a key to know what hardware parts may be failing with soft "failures" that keep reoccuring on only one or a few boxes if they are not traceable to malware.
I know, I lacked that deep grokking understanding for half my career.
John.
0
Comments
I=v/r
R=v/i
P=iv
P=v^2/r
P=i^2r
See here for something you might find fun, and others might be able to understand interactions better with:
http://www.the12volt.com/ohm/ohmslaw.asp
Basicly, folks who understand Ohm's Law need to know when to use it, how to get the measurements to use it right (resistance is not easily measurable HOT directly(base logic says NOT to measure it directly), but is logic-derived mostly if you have a multimeter and not an ocilloscope plus analysis software that can calc this and display this).
But increased resistance beyond wanted resistance is usually core of problem (other major fault cause is too much or two little power to part that has faulted, but that can be directly measured if you know where to look starting from sysmptoms and how to drill down with minimum time and effort), and lack or poor ground is increase of resistance, and wrong ground route is an implicit short. So, understanding Ohm's law in the way non-engineering folks think can be valuable for younger folks and folks who are not hardware engineers.
Lets talk about how to apply it also, from gross generality to howto by computer function....
How is power eval like a river ecosystem??? How can circuit branching be like trees of deciduous kind,and why are there so many detailed diffs as there are between a random forest of all species of tree would have, from tree to tree???
How do you know when the problem is software and when it is more likely to be hardware and which hardware part to swap out or stick in another box??? How can knowing the gross relationships (larger rules explicated by Ohm's Law) help decide these things????
John D.
Ix=(IR)/Rx
Vx=Rx(V/R)
Very helpful if you dont know the total current, its in parallel, or you dont know the total Voltage in parallel.
I am getting towards the end of my AC/DC class so I know how to calculate OHMs Law, CDR, VDR, Power, resistance given the resistor properties, Capacitance given its properties, inductance given its properties, voltage drop across a resistor (VDR), current thru a resistor (CDR), impedance of Capacitors and inductors, RMS and peak values in AC circuits, phasor(complex form) and time domain forms, and current, voltage, resistance, capacitance, and inductance in parallel and series circuits. Man I learned ****ing ****load 11 in weeks already. DAMN I didnt realize until I wrote it all out.
So what would you like to know.:)
Nice link.:)
I see PSU testing done under load, this is a good start. But people use a pure restive load, maybe not too realistic. The talk about voltage drop, this is good too. But they never mention the waveform or harmonic noise involved. I would rather that the filters on my mobo didn't have to work too hard.
The real (and imaginary) world can get so messy.