I am working my way through a number of theory books and they all seem to seperate d.c. theory and a.c. theory.
Generally speaking DC is less complex than AC, so DC comes first, and when you have got the idea, move on to AC.
At the moment i would'nt risk using the a.c. mains to do any tests for fear of my own safety.
At this stage i am doing basic d.c. experiments with a breadboard using a 6v battery source.
Very wise to keep away from the mains for basic experiments.
When you want to move on to AC, use a transformer which converts the mains down to 12 or 24volts and experiment with that, safely.
So my question is if i am only using a d.c. voltage source for my experiments does a.c. theory come into play?
If so can you give me examples please.
DC could be considered as a special case of AC where the frequency is zero.
As an example, consider an inductor, it has resistance and inductance. Both of these properties affect the behaviour in a DC circuit, but only the resistance will affect the steady state of the circuit after switch on and before switch off.
In an AC circuit, because of the inductance, there is reactance which opposes the current flow as well as the resistance.
If the frequency is high enough, there will also be AC resistance, in addition to the DC resistance.
(This can get complicated!)
Also when using a 555 timer as an oscillator is the output signal classed as a.c. or does the direction of the conventional current have to move from negative to positive?
This is one of those questions which will cause a thread to run for 10 pages here on ETO!
Yes it is AC, but it has a DC offset so that the polarity of the output is always +ve (with respect to the circuit 0v line).
By the way, the output of a 555 is not a good source for simple AC experiments, it is a square wave not a sinewave, it does not have a 50:50 mark-space ratio and is unipolar.
JimB