We can summarize this resistor tutorial section and what we have learnt as follows:
The job of a Resistor is to limit the current flowing through an electrical circuit.
Resistance is measured in Ohm’s and is given the symbol Ω
Carbon, Film and Wirewound are all types of resistors.
Resistor colour codes are used to identify the resistance and tolerance rating of small resistors.
The BS1852 Standard uses letters and is used to identify large size resistors.
Tolerance is the percentage measure of the accuracy of a resistor from its preferred value with the E6 (20%), E12 (10%), E24 (5%) and E96 (1%) series of tolerance values available.
Series Resistor Tutorial
Resistors that are daisy chained together in a single line are said to be connected in SERIES.
Series connected resistors have a common Current flowing through them.
I_{total} = I_{1} = I_{2} = I_{3} …. etc
The total circuit resistance of series resistors is equal to:
Total circuit voltage is equal to the sum of all the individual voltage drops.
V_{total} = V_{1} + V_{2} + V_{3} …. etc
The total resistance of a series connected circuit will always be greater than the highest value resistor.
Parallel Resistor Tutorial
Resistors that have both of their respective terminals connected to each terminal of another resistor or resistors are said to be connected in PARALLEL.
Parallel resistors have a common Voltage across them.
V_{S} = V_{1} = V_{2} = V_{3} …. etc
Total resistance of a parallel circuit is equal to:
Total circuit current flow is equal to the sum of all the individual branch currents added together.
I_{total} = I_{1} + I_{2} + I_{3} …. etc
The total resistance of a parallel circuit will always be less than the value of the smallest resistor.
Resistor Power Rating
The larger the power rating, the greater the physical size of the resistor to dissipate the heat.
All resistors have a maximum power rating and if exceeded will result in the resistor overheating and becoming damaged.
Standard resistor power rating sizes are 1/8 W, 1/4 W, 1/2 W, 1 W, and 2 W.
Low ohmic value power resistors are generally used for current sensing or power supply applications.
The power rating of resistors can be calculated using the formula:
In AC Circuits the voltage and current flowing in a pure resistor are always “in-phase” producing 0^{o} phase shift..
When used in AC Circuits the AC impedance of a resistor is equal to its DC Resistance.
The AC circuit impedance for resistors is given the symbol Z.
this page is of great help to me,.now, i can study in my own time w/the help of this page even w/o going to electronics/vocational school….thanks a lot…
R (ohms) = Voltage/Current, (R = V/I). If you know the voltage across the resistor and the current expected to flow through it you can calculate the required resistance.
Today in my tutorial i got resistor basics very well and i want to review my knowledge of electronics as i worked for about 20 years as electronics technician and in coming days going to search another job as electronics technician.
I want to study about electronics. I want to purse my goal to become a technician in the future. I am a hearing-impared person and am 48 years old. I have not completely finished this courses in the colleges and not getting it successfully. I want to learn what the electronics work.
Can someone please tell me that how does a rheostat control the amount of current in a circuit?
You can find more info here about Rheosats
i learn a lot of things in this tutorial… thanks guys….
this page is of great help to me,.now, i can study in my own time w/the help of this page even w/o going to electronics/vocational school….thanks a lot…
i can design one circuit but how much of resistor value used i don’t no please tell me
u wil only one resister
R (ohms) = Voltage/Current, (R = V/I). If you know the voltage across the resistor and the current expected to flow through it you can calculate the required resistance.
Today in my tutorial i got resistor basics very well and i want to review my knowledge of electronics as i worked for about 20 years as electronics technician and in coming days going to search another job as electronics technician.
I want to study about electronics. I want to purse my goal to become a technician in the future. I am a hearing-impared person and am 48 years old. I have not completely finished this courses in the colleges and not getting it successfully. I want to learn what the electronics work.
Hello Philip, Everything you need to learn Electronics is right here. Good look with your studies.