1. BM-305 Mikrodenetleyiciler Güz 2015 (2. Sunu)
(Yrd. Doç. Dr. Deniz Dal)

2. Akım, Gerilim, Direnç ve Ohm Kanunu
An electric circuit is formed when a conductive path is created to allow free electrons to continuously move. This continuous movement of free electrons through the conductors of a circuit is called a current, and it is often referred to in terms of “flow,” just like the flow of a liquid through a hollow pipe. The force motivating electrons to “flow” in a circuit is called voltage. Voltage is a specific measure of potential energy that is always relative between two points. When we speak of a certain amount of voltage being present in a circuit, we are referring to the measurement of how much potential energy exists to move electrons from one particular point in that circuit to another particular point. Without reference to two particular points, the term “voltage” has no meaning. Free electrons tend to move through conductors with some degree of friction, or opposition to motion. This opposition to motion is more properly called resistance. The amount of current in a circuit depends on the amount of voltage available to motivate the electrons, and also the amount of resistance in the circuit to oppose electron flow. Just like voltage, resistance is a quantity relative between two points. For this reason, the quantities of voltage and resistance are often stated as being “between” or “across” two points in a circuit.

3. Ohm Kanunu
Ohm's Law (named after German physicist Georg Ohm, 1825) deals with the relationship between voltage and current in an ideal conductor. This relationship states that: The potential difference (voltage) across an ideal conductor is proportional to the current through it. The constant of proportionality is called the "resistance", R. Ohm's Law is given by: V = I.R where V is the potential difference between two points which include a resistance R. I is the current flowing through the resistance.

4. Kirşof Kanunları
In 1845, a German physicist, Gustav Kirchoff developed a pair or set of rules or laws which deal with the conservation of current and energy within Electrical Circuits. These two rules are commonly known as: Kirchoff’s Circuit Laws with one of Kirchoff’s laws dealing with the current flowing around a closed circuit, Kirchoff’s Current Law, (KCL) while the other law deals with the voltage sources present in a closed circuit, Kirchoff’s Voltage Law, (KVL).

5. Kirşof’un Akımlar Kanunu
Kirchoff’s Current Law or KCL, states that the “total current or charge entering a junction or node is exactly equal to the charge leaving the node as it has no other place to go except to leave, as no charge is lost within the node“. In other words the algebraic sum of ALL the currents entering and leaving a node must be equal to zero, I(exiting) + I(entering) = 0. This idea by Kirchoff is commonly known as the Conservation of Charge. We can use Kirchoff’s current law when analysing parallel circuits.

6. Kirşof’un Gerilimler Kanunu
Kirchoff’s Voltage Law or KVL, states that “in any closed loop network, the total voltage around the loop is equal to the sum of all the voltage drops within the same loop” which is also equal to zero. In other words the algebraic sum of all voltages within the loop must be equal to zero. This idea by Kirchoff is known as the Conservation of Energy.
Starting at any point in the loop continue in the same direction noting the direction of all the voltage drops, either positive or negative, and returning back to the same starting point. It is important to maintain the same direction either clockwise or anti-clockwise or the final voltage sum will not be equal to zero. We can use Kirchoff’s voltage law when analysing series circuits.

7. Dirençler İçin Renk Kodları

8. Dirençlerde Tolerans
The tolerance of a resistor is the deviation that a resistor may vary from its nominal value resistance, measured at 25°C with no load applied. In other words, the resistor tolerance is the amount by which the resistance of a resistor may vary from its stated value. The larger the resistor tolerance, the more it may vary, either up or down, from its nominal value. The smaller the resistor tolerance, the less it varies from its nominal value and, thus, the more stable it is.
The most common way of specifying resistor tolerance is by percentage. When specified by percentage value, this percentage means the amount by which a resistor may vary from its nominal value. For example, a resistor which has a tolerance of 10% may vary 10% from its nominal value.
Typical resistor tolerances are 1 percent, 2 percent, 5 percent, 10 percent and 20 percent. The value can even be lower than 1 percent with high-precision resistors.
Consider a 500 ohm resistor with a 10 percent tolerance. This means that the resistance of it can be anywhere from as low as 450 ohm to as high as 550 ohm. On the other hand, if the same 500 ohm resistor has a 1 percent tolerance, its resistance can be between 495 ohm and 505 ohm. Lower percent tolerances equal more precision (less variance) in resistance values.

9. Gerilim Bölücü

10. Değişken Direnç (Potansiyometre)
A potentiometer, informally a pot, is a three- terminal resistor with a sliding or rotating contact that forms an adjustable voltage divider. Potentiometers are commonly used to control electrical devices such as volume controls on audio equipment. Potentiometers operated by a mechanism can be used as position transducers, for example, in a joystick.

11. Geçici Anahtar Normalde Açık veya Normalde Kapalı
Momentary switches are switches which only remain in their on state as long as they’re being actuated (pressed, held, magnetized, etc.). Most often momentary switches are best used for intermittent user-input cases; stuff like reset or keypad buttons.

12. Kalıcı Anahtar
DIP switches are through-hole switches designed in the same mold as a through- hole DIP IC. They can be placed in a breadboard, in the same manner a through-hole IC might, by straddling the center area. These switches often come in arrays of eight or more separate SPST switches, with tiny little sliding levers. They were widely used in the olden days of computing, but they’re still useful for configuring devices via hardware.
An 8-position DIP switch

13. Pull-up Direnci (Resistor to Vcc)
User input is one of the most common applications for switches. For example, if you want to connect a switch to a microcontroller input pin, a simple circuit like this is all you would need. When the switch is open, the MCU pin is connected through the resistor to 5V. When the switch is closed, the pin is tied directly to GND. The resistor in that circuit is a pull-up resistor, required to bias the input high, and prevent a short to ground when the switch is closed.

14. Pull-down Direnci (Resistor to Gnd)
Pull-down resistors work in the same manner as pull-up resistors, except that they pull the pin to a logical low value. They are connected between ground and the appropriate pin on a device. An example of a pull-down resistor in a digital circuit can be seen in the figure. A pushbutton switch is connected between the supply voltage and a microcontroller pin. In such a circuit, when the switch is closed, the micro-controller input is at a logical high value, but when the switch is open, the pull-down resistor pulls the input voltage down to ground (logical zero value), preventing an undefined state at the input.

15. Işık Yayan Diyot (LED)
A light-emitting diode (LED) is a semiconductor device that emits visible light when an electric current passes through it. LEDs, being diodes, will only allow current to flow in one direction. And when there’s no current-flow, there’s no light. Luckily, this also means that you can’t break an LED by plugging it in backwards. Rather, it just won’t work. The positive side of the LED is called the “anode” and is marked by having a longer “lead,” or leg. The other, negative side of the LED is called the “cathode.” Current flows from the anode to the cathode and never the opposite direction.
A LED is a diode that generates a specific wavelength of light when a voltage is applied across its leads. This voltage is known as the forward voltage of the LED. The brightness of the light varies as the current is varied.
An LED has no inherent current limiting, so applying voltages higher than the forward voltage will usually result in overheating or burning out the LED. Often the LED is damaged by this and will still light up, but never be as bright as its original specification.

16. Akım Sınırlayan Direnç
If you connect an LED directly to a current source it will try to dissipate as much power as it’s allowed to draw, and it will destroy itself. That’s why it’s important to limit the amount of current flowing across the LED. For this, we employ resistors. Resistors limit the flow of electrons in the circuit and protect the LED from trying to draw too much current.
The simplest way to limit current to an LED is to use a resistor in series with the LED. To calculate the proper value of resistor, it is easier to use Ohm's Law to calculate the electrical current through the resistor, and not the LED. This works out well because the current through a series circuit is the same at every point in a circuit, meaning the current will be the same through the LED as the current through the resistor.
Here's an example: An LED is going to be powered from a 5 volt supply. Checking the LED's datasheet, the forward voltage is 3 volts. So a resistor in series with the LED would have 5 volts - 3 volts = 2 volts across the resistor.
To put 20 milliamps through the LED (a typical specification for a brightly lit LED), Ohm's law would look like this.
E = IR
E = voltage in volts I = current in amps R = resistance in ohms
2 volts / .02 amps = 100 ohms, so using a 100 ohm resistor in series with the LED will light it at a current of .02 amps (20 milliamps).

17. RGB (Red-Green-Blue) LED Ortak Katot ve Anot
At first glance, RGB (Red, Green, Blue) LEDs look just like regular LEDs, however, inside the usual LED package, there are actually three LEDs, one red, one green and yes, one blue. By controlling the brightness of each of the individual LEDs you can mix pretty much any color you want.

18. Işığa Bağımlı Direnç (LDR)
A photoresistor or light- dependent resistor (LDR) or photocell is a light-controlled variable resistor. The resistance of a photoresistor decreases with increasing incident light intensity; in other words, it exhibits photoconductivity. A photoresistor can be applied in light-sensitive detector circuits, and light- and dark- activated switching circuits.

19. Diyot
A diode is a device that only allows for the flow of electricity to pass in one direction. These components are often used to isolate the effect of one component from another.
Flyback diodes do a similar job of suppressing voltage spikes, specifically those induced by an inductive component, like a motor. When current through an inductor suddenly changes, a voltage spike is created, possibly a very large, negative spike. A flyback diode placed across the inductive load, will give that negative voltage signal a safe path to discharge, actually looping over-and-over through the inductor and diode until it eventually dies out.

20. Kapasitör
A capacitor is a device that can store and release electrical charge in a circuit. Typically a capacitor consists of two charging plates with a material in between that prevents electrical discharge. These devices can be used to smooth out signals in a circuit. Additionally, large capacitors can be used as storage systems for current. Their ability to store charge is measured in Farads [F].

21. Tranzistör
A transistor is a device that restricts or allows the flow of current between two contacts based on the presence or absence of current on a third contact. A transistor has three leads: collector, emitter and base. The collector and emitter act as the input and output for the transistor. While the base is the trigger for the signal. Two common types of transistors are: PNP - If the base voltage is less than the emitter voltage, then current flows from the emitter to the collector. NPN - If the base voltage is greater than the emitter voltage, then current flows from the collector to the emitter. Note: The P stands for P-type semiconductor and the N stands for N-type semiconductor
Two common uses for transistors are to act as an electrically activated switch. Also transistors can be used to increase (amplify) the output current.

22. 7 Parçalı Gösterge (Ortak Katot veya Anot)
A seven-segment display (SSD) is a form of electronic display device for displaying decimal numerals that is an alternative to the more complex dot matrix displays. Seven-segment displays are widely used in digital clocks, electronic meters, basic calculators, and other electronic devices that display numerical information.

23. Sıvı Kristal Gösterge (LCD)
LCD (Liquid Crystal Display) screen is an electronic display module and find a wide range of applications. A 16x2 LCD display is very basic module and is very commonly used in various devices and circuits. These modules are preferred over seven segments and other multi segment LEDs. The reasons being: LCDs are economical; easily programmable; have no limitation of displaying special & even custom characters (unlike in seven segments), animations and so on.
A 16x2 LCD means it can display 16 characters per line and there are 2 such lines. In this LCD each character is displayed in 5x7 pixel matrix. This LCD has two registers, namely, Command and Data.
The command register stores the command instructions given to the LCD. A command is an instruction given to LCD to do a predefined task like initializing it, clearing its screen, setting the cursor position, controlling display etc. The data register stores the data to be displayed on the LCD. The data is the ASCII value of the character to be displayed on the LCD.

24. Breadboard
A breadboard is a construction base for prototyping of electronics. In the 1970s the solderless breadboard became available. "Breadboard" is also a synonym for "prototype". Because the solderless breadboard does not require soldering, it is reusable. This makes it easy to use for creating temporary prototypes and experimenting with circuit design. For this reason, solderless breadboards are also extremely popular with students and in technological education. A variety of electronic systems may be prototyped by using breadboards, from small analog and digital circuits to complete central processing units (CPUs).

25. Fritzing Yazılımı
Fritzing is an open-source software initiative to support designers and artists ready to move from physical prototyping to actual product. It was developed at the University of Applied Sciences of Potsdam. The software is created in the spirit of the Processing programming language and the Arduino microcontroller and allows a designer, artist, researcher, or hobbyist to document their Arduino-based prototype and create a PCB layout for manufacturing.