# troubleshooting using electronic formulas

Discussion in 'General Electronics Chat' started by relicmarks, Mar 30, 2008.

1. ### relicmarks Thread Starter Active Member

Oct 13, 2006
355
0
When troubleshooting circuits or understanding a circuit or just in general testing circuits from technical papers from your past jobs

What are the top 10 formulas for electronics to use when troubleshooting?

What are the top 10 formulas to use when understanding a circuit design?

2. ### relicmarks Thread Starter Active Member

Oct 13, 2006
355
0
types of formulas for troubleshooting or Testing:

1.) ohms law
2.) RC= time
3.) Slope= Voltage peak/ time , (used only with triangle waveforms)
4.) duty cycle
5.) frequency = 1/Time
6.) Time= 1/ frequency
7.) output wattage= AC voltages/ output impedance ohms
8.)

These are they ones i used alot when troubleshooting or testing , what other ones have you guys used please or personal use or job related ones?

3. ### beenthere Retired Moderator

Apr 20, 2004
15,808
295
In troubleshooting, generally finding the place where a change in input fails to produce a change in output is what you look for. Besides the obvious things like blackened resistors and tall capacitors.

I would find the formulas more useful when designing a circuit.

4. ### relicmarks Thread Starter Active Member

Oct 13, 2006
355
0
Types of tests and measurments

1.) Measuring from 10% to 90% rise time and fall times, this is in volts not time from 10% to 90%
2.) Biasing the positive cycle and negative cycles symmetry, so they are equal halves
3.) Matching and balancing the positive & negative cycles, so both halves peak at the same time
4.) Measuring the high and low pulse width times , then calculating the duty cycle percentage after,Duty cycle is the ratio of time high to the total period.
5.) Measuring the output wattage of an ampilifier, AC voltages/ the output impedance ohms= wattage
6.) Measuring the Slope of a triangle waveform or integation waveform, Voltage peak or amplitude/ positive cycle time = slope
7.) Time constant is Resistance X's capacitance values
8.) phase measurement- comparing input waveform with the output waveform or comparing 2 waveforms and measuring the time differences between the two
9.) Measuring frequency or time , just take the reciprocal of the waveforms period

What other ones do you guys use or have done?

5. ### techroomt Senior Member

May 19, 2004
198
1
to be honest, eventually i use about every formula i've ever learned for electronics. and then, there comes the time when you need to learn new formulaes on something you have yet to learn about.

6. ### Wendy Moderator

Mar 24, 2008
21,824
3,039
Sense of smell?

Most obvious electronics problems will give clues if you look at the board, for blown or melted parts, or burns. If a circuit was working there is usually a bad reason it quit.

7. ### Dave Retired Moderator

Nov 17, 2003
6,960
171
Why have we missed:

$P = VI$

And the I/V/R variants there of.

Personally the equation I probably use most is that of the Fourier Transform and its inverse (Aside from Matrix equations, but the often just representations of FT equations).

Dave

8. ### relicmarks Thread Starter Active Member

Oct 13, 2006
355
0
Can you guys give some explains of when your using these formulas when testing or troubleshooting a circuit?

9. ### techroomt Senior Member

May 19, 2004
198
1
when troubleshooting a failure, it often requires analyzing the circuit (with formulaes) so that when voltage or current (or whatever quantity) measurements are taken, they can be evaluted as being correct or not.