Friday, June 22, 2012
Sunday, March 18, 2012
Diodes and Transistors
Diodes
Today im going to talk about diodes first.
There is a few components which is getting called Diodes. Like Diodes, ZenerDiodes and L.E.D. ( Light Emitted Diodes).
Normal Diode has a voltage drop of 0.6v, 0.538v from a practical. And if you have a look on the picture, a silver line on the diode means a negative side and a black side is a posetive.
On the practical i had to find out the voltage drop of the diode, so i did switch my multimeter on a diode selection and used my posetive and a negative probes to connect to the diode. By doing that, i did found a reading of 0.538v, thats a voltage drop of it. When i have connected my probs at other way, i had a reading of .OL. That means, no voltage going this way and cant get a reading.
Thats a forward voltage drop of diode.
L.E.D. ( Light Emitted Diode) has a voltage drop of 1.7v, 1.734v from a practical. It has two legs, one is a short one, which is a negative and a longer one, which is a posetive. Inside it has a small pin, which is a posetive and a bigger flat pin, which is a negative side.
On practical i have used a small board, to place my components so i can test them and use them. Ive tested one of the L.E.D.s. By switching my multimeter to the Diodes mode and placing the probs on the L.E.D.d Legs. Ive got a reading of 1.734v, thats a voltage drop of it. And when i did connect my probs the other way, the reading was .OL. So cant get the reading this way.
The L.E.D. has a higher voltage drop then a diode and that means that it has a lower current flow.
Zeners diodes is the same as a normal diodes but has a slightly higher voltage drop of a 0.8v. Zener diodes allows the current to pass in one direction and reverse position. It used to protect the circuit from a high voltage surges and to regulate the voltage. The voltage drop of the zener diode can be even 5v. It does depend on it and for what voltage it is made.
Reverse the polarity of the zener diode.
When ive connected the Zener Diode to test it, the measurement was 0.86v. The zener diode allows the current to flow but it does not regulates it. When you put it in a reverse position. It acts like a normal diode.
Cathode = is a NEGATIVE -
Anode = is a POSETIVE +
Sides of the diodes.
I had no problems with that and it was easy to understand, the only fault i had with a zener diode, plugging it in a wrong way in my circuit on the board, Which end up of my resistor to heat up and smoke a little. After that, ive started to knew what and how to do it right.
At this subject, ive learned about a different types of diodes, their voltage drops and function. But the main one, is how to indentify which ine is what and what side is a negative and which is a posetive.
Transistors
There is a few types of transistors and now i will write some information of my theory and practical lessons i have done in class.
BJT- Bipolar Junction Transistor
Here is some easy ways to remember a right transistor.
PNP is Park Now Please
NPN is No Park Now
The NPN Transistor has a Base, Collector and an Emitter. The arial will be down on an emitter side. To measure the voltage drop and to find out which transistor is it. There is a way of doing it with a multimeter. By using your probs and place it on one or two legs of the transistor. Each transistor has three legs.
So NPN has a negative which is a collector, posetive which is a base and a negative which is an emmiter.
The PNP has a collector, base and an emitter, same way to test it as a NPN transistor but the collector is posetive, base is a negative and an emitter is a posetive.
You always have to connect a resistor on the base of the transistor. Collector side will have a smaller voltage. And a Emitter side will have a higher voltage.
The voltage the transistor needs to be operating is 0.6-0.7v.
On my practical, i had to find a voltage drop of the NPN transistor, which was 0.754v because the transistor has a diode inside of it, which needs a voltage of 0.6-0.7v to be operating.
Transistors has three different types of the Region:
Saturation region is when the transistor is fully on and operating the current levels.
Cut off region is when the transistor has hardly any current or none at all.
Active region is when the transistor is operating in a middle between the saturation and a cut off regions.
Thats a better description of how to indentify the terminals on a Transistor.
You have to find the base, set your multimeter to the siodes function mode. Then play around with the probes between three legs of the transistor. When you get a reading between one pin to both other two pins. This pin will be your base, if your red probe on the base, thats NPN one and if its on a black probe, thats a PNP one.
If there will be more current going thrue the base, it will be more in a saturation mode. But if there is less current thrue the base, it will be more in an anplification mode, so in a cut off region.
I found no faults with the transistors, as it was easy to understand and to learn how and what they does. The only mess around is to find what leg is what. For that, you will have to use a multimeter. Any one will need to use it, as if you connect the legs in a wrong way, the circuit will not work good or even not going to be working.
If the transistor is getting shorted, nothing will happen to the transistor when you shorten C with E, but components around it may be damaged due to unlimited currents (short means 0 ohm).
However, when you release the short and damage has occurred to a components connected to it, there is a good chance that it also will be damaged.
All photos have been taken of google images by tiping. Diodes and Transistors. Here is some links:
http://ram-e-shop.com/oscmax/catalog/index.php?cPath=141
http://www.markallen.com/teaching/ucsd/147a/lectures/lecture3/5.php
http://www.google.com/imgres?um=1&hl=ru&biw=1280&bih=600&tbm=isch&tbnid=zVvYRRhpPtMypM:&imgrefurl=http://www.simplemotor.com/tmotor.htm&docid=UO6dbGgE4OdEYM&imgurl=http://www.simplemotor.com/images/transistors.gif&w=393&h=193&ei=OolvT9v0EqqOmQXEwdWkBg&zoom=1&iact=hc&vpx=919&vpy=328&dur=190&hovh=154&hovw=314&tx=181&ty=95&sig=101673499850352112935&page=1&tbnh=83&tbnw=168&start=0&ndsp=18&ved=1t:429,r:17,s:0
http://www.reuk.co.uk/What-is-a-Transistor.htm
Today im going to talk about diodes first.
There is a few components which is getting called Diodes. Like Diodes, ZenerDiodes and L.E.D. ( Light Emitted Diodes).
Normal Diode has a voltage drop of 0.6v, 0.538v from a practical. And if you have a look on the picture, a silver line on the diode means a negative side and a black side is a posetive.
On the practical i had to find out the voltage drop of the diode, so i did switch my multimeter on a diode selection and used my posetive and a negative probes to connect to the diode. By doing that, i did found a reading of 0.538v, thats a voltage drop of it. When i have connected my probs at other way, i had a reading of .OL. That means, no voltage going this way and cant get a reading.
Thats a forward voltage drop of diode.
L.E.D. ( Light Emitted Diode) has a voltage drop of 1.7v, 1.734v from a practical. It has two legs, one is a short one, which is a negative and a longer one, which is a posetive. Inside it has a small pin, which is a posetive and a bigger flat pin, which is a negative side.
On practical i have used a small board, to place my components so i can test them and use them. Ive tested one of the L.E.D.s. By switching my multimeter to the Diodes mode and placing the probs on the L.E.D.d Legs. Ive got a reading of 1.734v, thats a voltage drop of it. And when i did connect my probs the other way, the reading was .OL. So cant get the reading this way.
The L.E.D. has a higher voltage drop then a diode and that means that it has a lower current flow.
Zeners diodes is the same as a normal diodes but has a slightly higher voltage drop of a 0.8v. Zener diodes allows the current to pass in one direction and reverse position. It used to protect the circuit from a high voltage surges and to regulate the voltage. The voltage drop of the zener diode can be even 5v. It does depend on it and for what voltage it is made.
Reverse the polarity of the zener diode.
When ive connected the Zener Diode to test it, the measurement was 0.86v. The zener diode allows the current to flow but it does not regulates it. When you put it in a reverse position. It acts like a normal diode.
Cathode = is a NEGATIVE -
Anode = is a POSETIVE +
Sides of the diodes.
I had no problems with that and it was easy to understand, the only fault i had with a zener diode, plugging it in a wrong way in my circuit on the board, Which end up of my resistor to heat up and smoke a little. After that, ive started to knew what and how to do it right.
At this subject, ive learned about a different types of diodes, their voltage drops and function. But the main one, is how to indentify which ine is what and what side is a negative and which is a posetive.
Transistors
There is a few types of transistors and now i will write some information of my theory and practical lessons i have done in class.
BJT- Bipolar Junction Transistor
Here is some easy ways to remember a right transistor.
PNP is Park Now Please
NPN is No Park Now
The NPN Transistor has a Base, Collector and an Emitter. The arial will be down on an emitter side. To measure the voltage drop and to find out which transistor is it. There is a way of doing it with a multimeter. By using your probs and place it on one or two legs of the transistor. Each transistor has three legs.
So NPN has a negative which is a collector, posetive which is a base and a negative which is an emmiter.
The PNP has a collector, base and an emitter, same way to test it as a NPN transistor but the collector is posetive, base is a negative and an emitter is a posetive.
You always have to connect a resistor on the base of the transistor. Collector side will have a smaller voltage. And a Emitter side will have a higher voltage.
The voltage the transistor needs to be operating is 0.6-0.7v.
On my practical, i had to find a voltage drop of the NPN transistor, which was 0.754v because the transistor has a diode inside of it, which needs a voltage of 0.6-0.7v to be operating.
Transistors has three different types of the Region:
Saturation region is when the transistor is fully on and operating the current levels.
Cut off region is when the transistor has hardly any current or none at all.
Active region is when the transistor is operating in a middle between the saturation and a cut off regions.
Thats a better description of how to indentify the terminals on a Transistor.
You have to find the base, set your multimeter to the siodes function mode. Then play around with the probes between three legs of the transistor. When you get a reading between one pin to both other two pins. This pin will be your base, if your red probe on the base, thats NPN one and if its on a black probe, thats a PNP one.
If there will be more current going thrue the base, it will be more in a saturation mode. But if there is less current thrue the base, it will be more in an anplification mode, so in a cut off region.
I found no faults with the transistors, as it was easy to understand and to learn how and what they does. The only mess around is to find what leg is what. For that, you will have to use a multimeter. Any one will need to use it, as if you connect the legs in a wrong way, the circuit will not work good or even not going to be working.
If the transistor is getting shorted, nothing will happen to the transistor when you shorten C with E, but components around it may be damaged due to unlimited currents (short means 0 ohm).
However, when you release the short and damage has occurred to a components connected to it, there is a good chance that it also will be damaged.
All photos have been taken of google images by tiping. Diodes and Transistors. Here is some links:
http://ram-e-shop.com/oscmax/catalog/index.php?cPath=141
http://www.markallen.com/teaching/ucsd/147a/lectures/lecture3/5.php
http://www.google.com/imgres?um=1&hl=ru&biw=1280&bih=600&tbm=isch&tbnid=zVvYRRhpPtMypM:&imgrefurl=http://www.simplemotor.com/tmotor.htm&docid=UO6dbGgE4OdEYM&imgurl=http://www.simplemotor.com/images/transistors.gif&w=393&h=193&ei=OolvT9v0EqqOmQXEwdWkBg&zoom=1&iact=hc&vpx=919&vpy=328&dur=190&hovh=154&hovw=314&tx=181&ty=95&sig=101673499850352112935&page=1&tbnh=83&tbnw=168&start=0&ndsp=18&ved=1t:429,r:17,s:0
http://www.reuk.co.uk/What-is-a-Transistor.htm
Sunday, March 11, 2012
Resistors
Resistors
Ohms Law
Ohms Law
The way of an ideal resistor is dictated by the relationship specified by Ohms law:
Which is: V=I x R
Ohms law states that the voltage V across a resistor is proportional to the current I, where the constant of proportionality is the resistance R.
Equivalently, Ohms law can be stated:
I = V divided by R
Firstly im going to talk about the resistors, there is a lot of them. So there is a few ways to identify, test and combine them.
1) First two or three bands may be the numbers to write down.
2) Next band is the multiplier (how many zeros to add to the number).
3) Gold multiplier makes one decimal place smaller, Silver makes two decimal places smaller.
4) Last band to right may be tolerance values
Here is some examples of my calculations:
1) Brown, Black, Red, Gold thats 1000 Ohm with 5% tolerance, so the min tol is 950 Ohm and the max tol is 1050 Ohm. The multimeter value that ive got is 989 Ohm
2) Orange, white, brown, gold thats 380 Ohm with 5% tolerance, so the min tol is 361 Ohm and the max tol is 399 Ohm. The multimeter value that ive got is 381 Ohm
3) Yellow, purple, black, black, brown thats 470 Ohm with 1% tolerance, so the min tol is 465 Ohm and the max tol is 474.7 Ohm. The multimeter value that ive got is 469 Ohm
To measure the voltage by the multimeter, ive switch it to the Ohms and connected my positive and negative leads to the resistors legs from both sides. It does not matter what side is a positive and a negative leads as from both ways, it would have the same resistance.
Here is a resistors color code, tolerance and how many zeros add to the number charts.
0 BLACK
1 BROWN
2 RED
3 ORANGE
4 Yellow Color Code
5 GREEN
6 BLUE
7 Violet
8 Grey
9 WHITE
Gold 5%
Silver 10% Tolerance
Brown 1%
0x1
1x10
2x100
3x1000
4x10000 Zeros to the number
5x100000
6x1000000
When you connect your resistors in a series, the resistors values are just added together. Connect them end to end, one right after another.
RT=R1+R2, example 470 Ohm + 820 Ohm is 1290 Ohm
For the series the current will be the same but the voltage will change.
When you connect your resistors in a parallel, you have to use a formula of 1/RT=1/R1+1/R2 to get the parallel calculations and which will be the total resistance value is lower than the lowest resistor value.
To get the reading you will have to connect both ends when they are side by side.
For the parallel the current will change but the voltage will stay the same.
The results were good and correct at the time when i did check them. They could of be wrong by a few things like not touching the leads from the multimeter properly to a resistor or switching it wrong, not to the Ohms.
This calculation here is to show of the electricity in these two exercises is that, when the resistor is connected in series, the Ohms are combined together and it does add up the value. But when it is in a parallel circuit, the Ohms are divided equally between the resistors and giving all the components an equal measured value.
The results were good and correct at the time when i did check them. They could of be wrong by a few things like not touching the leads from the multimeter properly to a resistor or switching it wrong, not to the Ohms.
Ive seen the study about resistors easy to understand and use in a real life. As when you make a board, or some circuit when you will have to use a resistor, you must be sure what resistens it has and doing that by checking the color code and resistens by the multimeter.
Here is an explanation of the component Voltage Drop.
The Voltage Drop is the reduction of the voltage in the circuit.
As the current passes through a longer and longer conductor, more voltage is getting lost and that’s due the voltage drop developed across the resistance of the conductor and the wires.
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