Electronics

 

                        Resistor

A resistor is an electrical component that limits or regulates the flow of electrical current in an electronic circuit. 

Color coding of resistor

Find the value of resistor 

       Value of Resistor :- 

           Resistor value can be found using ohm law

                                          R = V/ I

                here , V = Voltage drop  for the circuit

                           I =  Current requirnment of the load

 

          

         

    Watt of Resistor

            Wattage means how much power the physical resistor is rated to handle. Same value resistor can be in different watt 

 

                    Watt for given resistor can be found using this formula 

       

                                         P = VI                      

                    

                                         P = V^2 / R

                                                     

               

Identification of watt by resistor length

    3mm = 1/8 watt

    5mm = 1/4 watt

    8mm = 1/2 watt

    10mm = 1 watt

    13mm = 2 watt 

    15mm = 3 watt

    16mm = 4watt

    20mm = 5 watt

STANDARD RESISTOR VALUE IN MARKET

Note In the following table, “k” represents kilo-ohms, so 7.5 k translates into 7,500 ohms. Similarly, “M” stands for megohms, so a value of 3.6 M represents 3,600,000 ohms.

Resistor in Parallel and Series

   Series :- 

 Resistance :- R1 + R2 + R3

Voltage :- V1  + V2 + V3

Current :- I1 = I2 = I3

Parallel :- 

Resistance :- 1/R1 + 1/R2 + 1/R3

Voltage :- V1  = V2 = V3

Current :- I1 + I2 + I3

  Conversion of Resistor by combination

Addition Of watt

Addition Of watt decrease the value of Resistor

Resistor with LED

1.  3v LED on 12 v

2. 3v LED on 220v

   

3. 3v , 80 Led in Series

       voltage add in series

      No need of Resistor

4. 3v , 15 Led in Parallel

     

           current add in parallel

                         current id added in parallal and voltage is same ,

                         voltage is addded in series and current same (becouse of kirchoff law)

   Varistor, VDR, MOV

 VDR stand for voltage dependent resistor

 

A varistor/voltage dependent resistor (VDR) is a component which has a voltage – current characteristics that is very much similar to that of a diode. This component is used to protect electrical devices from high transient voltages. They are planted in the devices in such a manner that it will short itself when a high current is produced due to the high voltage. Thus the current dependent components in the device will remain safe from the ki surge.

when Sudden voltage overcome mov voltage  then  it short itself and protect circuit,

Mov mostly used with fusible Resistor when high voltage spikes passed mov shot itself due to which fusible Resistor( Coverd in next topic)  burn out and stop power supply

MOV value Identification

  

here we see  value 07D180K

1. Disc Diameter :- here, 07 is the diameter of disc in mm, or it the length of diagonal in the case of square disc . MOV mostly found in 3D, 5D, 7D, 10D, 14D, 18D, 20D
2.  Shape :- MOV found in two shape circular (D) or Square (S)
3. value :- vale of MOV can have determine by this way in above example we have 180 which written as 18 * 10^0  = 181v
4. Tolerance :-   K = 10%, L = 15% ,M = 20%

     Example :- 

1. 471KD07
2. 07D511K
3. 561KD07

     Table for voltage identification

Fusible Resistor 

      fusiable Resistor are the special type of Resistor which can be used to protect the circuit from over current spikes,

   Fusible Resistor burn on high voltage and protect current

  

 Fusible Resistor can be determine easily becouse in mostly case fuseable resistor have rough surface then of simple resistor 

• Mostly fusible Resistor found between 0ohm to 50ohm , some of common are 0, 1, 2.2, 4.7, 5.6, 10, 15, 18, 22 ohm
• This type of Resistor are of high wattage and low ohms
• They can also returned on pcb as (FR) 0ohm or in smd with R
• The wattage of fusible Resistor must be atleast 1 watt (except Mobile charger circuit in which we can use 1/2 watt also
• For Supply of 220v we can use resistor between 0 - 22 ohm and 1 watt
• Fusible Resistor mostly used with MOV or voltage dependent resistor

Thermistor

A thermistor is a resistance thermometer, or a resistor whose resistance is dependent on temperature. The term is a combination of “thermal” and “resistor”. It is made of metallic oxides, pressed into a bead, disk, or cylindrical shape and then encapsulated with an impermeable material such as epoxy or glass.

Application of resistor 

Voltage devider => 

The voltage divider is a circuit used to create a voltage less than or equal to the input voltage.

Equation

$$V_{out}=V_{in}\ast \frac{R_2}{R_1+R_2}$$

 

Where:

$$V_{out}$$ = Output voltage. This is the scaled down voltage. 

$$V_{in}$$ = Input voltage. 

$$R_1$$ and $$R_2$$ = Resistor values. The ratio $$\frac{R_2}{R_1+R_2}$$ determines the scale factor. 

 

Application of voltage devider :- 

1- potentiometer 

2-  Level Shifters

Another area where voltage dividers are useful is when a voltage needs to be leveled down. The most common scenario is when interfacing signals between a sensor and a microcontroller with two different voltage levels. Most microcontrollers operate at 5V while some sensors can only accept a maximum voltage of 3.3V. Naturally, you want to level the voltage from the microcontroller down to avoid damage to the sensor. An example circuit is shown below:

The circuit above shows a voltage divider circuit involving a 2kΩ and a 1kΩ resistor. If the voltage from the microcontroller is 5V, then the leveled-down voltage to the sensor is calculated as:

$$V_{out}=5\ast \frac{2k\Omega }{2k\Omega +1k\Omega }=3.33V$$

This voltage level is now safe for the sensor to handle. Take note that this circuit only works for leveling down voltages and not leveling up. 

Below are some other resistor combinations used for leveling down commonly encountered voltages:

Resistor Combination	Use
4.7 kΩ and 6.8 kΩ	12V to 5V
4.7 kΩ and 3.9 kΩ	9V to 5V
3.6 kΩ and 9.1 kΩ	12V to 3.3V
3.3 kΩ and 5.7 kΩ	9V to 3.3V

Resistive Sensor Reading

A lot of sensors are resistive devices and most microcontrollers read voltage, not resistance. Thus, a resistive sensor is usually connected in a voltage divider circuit with a resistor in order to interface with a microcontroller. An example setup is shown below:

A thermistor is a sensor whose resistance changes proportionally to temperature. Let us say that the thermistor has a room temperature resistance of 350Ω. The paired resistance is chosen to also be 350Ω. 

When the thermistor is at room temperature, the output voltage is:

$$V_{out}=5\ast \frac{350\Omega }{350\Omega +350\Omega }=2.5V$$  

When the temperature increases, the thermistor resistance changes to 350.03Ω, the output changes to:

$$V_{out}=5\ast \frac{350.03\Omega }{350\Omega +350.03\Omega }=2.636V$$

Such a small change in voltage is detectable by a microcontroller. If the thermistor transfer function is known, the equivalent temperature can now be calculated. 

What Are Pull-up Resistors?

Pull-up resistors are resistors used in logic circuits to ensure a well-defined logical level at a pin under all conditions. As a reminder, digital logic circuits have three logic states: high, low and floating (or high impedance). The high-impedance state occurs when the pin is not pulled to a high or low logic level, but is left “floating" instead. A good illustration of this is an unconnected input pin of a microcontroller. It is neither in a high or low logic state, and the microcontroller might unpredictably interpret the input value as either a logical high or logical low. Pull-up resistors are used to solve the dilemma for the microcontroller by pulling the value to a logical high state, as seen in the follow figure. 

Pull-up resistor circuit

 

Without the pull-up resistor, the MCU’s input would be floating when the switch is open and pulled down to a logical low only when the switch is closed.

Pull-up resistors are not a special kind of resistors; they are simply fixed-value resistors connected between the voltage supply (typically +5 V, +3.3 V, or +2.5 V) and the appropriate pin, which results in defining the input or output voltage in the absence of a driving signal. A typical pull-up resistor value is 4.7 kΩ, but can vary depending on the application, as will be discussed later in this article.

Pull-up Resistor Definition

Pull-up resistors are resistors which are used to ensure that a wire is pulled to a high logical level in the absence of an input signal.

What Are Pull-down Resistors?

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 following figure.

Pull-down resistor

 

In this figure, a pushbutton switch is connected between the supply voltage and a microcontroller pin. In such a circuit, when the switch is closed, the microcontroller 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. The pull-down resistor must have a larger resistance than the impedance of the logic circuit, or else it might be able to pull the voltage down by too much and the input voltage at the pin would remain at a constant logical low value – regardless of the switch position.

Pull-up and Pull-down Resistor Values

The appropriate value for the pull-up (or pull-down) resistor is limited by two factors. The first factor is power dissipation. If the resistance value is too low, a high current will flow through the pull-up resistor, heating the device and using up an unnecessary amount of power when the switch is closed. This condition is called a strong pull-up and is avoided when low power consumption is a requirement. The second factor is the pin voltage when the switch is open. If the pull-up resistance value is too high, combined with a large leakage current of the input pin, the input voltage can become insufficient when the switch is open. This condition is called having a weak pull-up. The actual value of the pull-up’s resistance depends on the impedance of the input pin, which is closely related to the pin’s leakage current.

A rule of thumb is to use a resistor that is at least 10 times smaller than the value of the input pin impedance. In bipolar logic families which operate at operating at 5 V, the typical pull-up resistor value is 1-5 kΩ. For switch and resistive sensor applications, the typical pull-up resistor value is 1-10 kΩ. If in doubt, a good starting point when using a switch is 4.7 kΩ. Some digital circuits, such as CMOS families, have a small input leakage current, allowing much higher resistance values, from around 10 kΩ up to 1 MΩ. The disadvantage when using a larger resistance value is that the input pin responds slowly to voltage changes. This is the result of the coupling between the pull-up resistor and the total pin and wire capacitance at the switching node which forms an RC circuit. The larger the product of R and C, the more time is needed for the capacitance to charge and discharge, and consequently the slower the circuit. In high-speed circuits, a large pull-up resistor can sometimes limit the speed at which the pin can reliably change state.

10k is thumb rule for pullup and pull down 

transistor base resistor :- 

1. To control this current flow, you're using a transistor.

2. Transistors can act like switches in circuits. You're assuming that the transistor you're using typically increases the current by a factor of 50 (this is called the current gain). So, if you want 150mA to flow, you need to push about 3 milliamps (mA) into the base of the transistor to make it work properly.

3. 
   

4. Calculating Resistance: The base of the transistor needs a certain voltage to work properly, typically around 0.7 volts. So, the remaining voltage (1.8V - 0.7V) needs to be across a resistor (let's call it R1). We can use Ohm's law to find the resistance needed. So, R = 1.1V / 3mA, which equals about 366.7 ohms.

Capacitor

A capacitor is a device which hold electrical energy in an electrical field,

Capacitor  in Series And Parallel

series :- 

When capacitors are connected in series, the total capacitance is less than any one of the series capacitors’ individual capacitances. Only voltage will be add up 

Voltage :- V1  + V2 + V3

Current :- I1 = I2 = I3

Parallel :- 

When capacitors are connected in parallel, the total capacitance is the sum of the individual capacitors’ capacitances. But the voltage will unchanged

Voltage :- V1  =  V2 = V3

Current :- I1 + I2 + I3

Create New Capacitor From available

1. For making a 100v, 100uf capacitor from two 50v 50v , 100uf capacitor we should connect them in series

2. For making a 100uf  ,100v capacitor from two 50uf 50uf , 100v capacitor we should add them in parallel

Types Of Capacitor

There are two types of capacitor mostly used

1. Fixed 

2. Variable

Fixed Capacitor

   fixed capacitor are those capacitor which have fixed capistance , fixed capacitor further devided into two types 

1. Polarized Capacitor (- , +)

2. Non- Polarized

1. Polarized Capacitor

      Polarized Capacitors are the ones that have specific positive and negative polarities. While using these capacitors in circuits, it should always be taken care that they are connected in perfect polarities. The following image shows the classification of polarized capacitors.

Let’s start the discussion with Electrolytic Capacitors.

Electrolytic Capacitors

The Electrolytic Capacitors are the capacitors which indicate by the name that some electrolyte is used in it. They are polarized capacitors which have anode +  and cathode −$-$ with particular polarities.

Electrolytic Capacitor Values Chart

0.1 µF	68 µF	480 µF	3900 µF	30,000 µF
0.15 µF	72 µF	500 µF	4000 µF	31,000 µF
0.22 µF	75 µF	510 µF	4100 µF	32,000 µF
0.33 µF	82 µF	520 µF	4200 µF	33,000 µF
0.47 µF	88 µF	540 µF	4300 µF	34,000 µF
0.68 µF	100 µF	550 µF	4600 µF	36,000 µF
1 µF	108 µF	560 µF	4700 µF	37,000 µF
1.5 µF	120 µF	590 µF	4800 µF	38,000 µF
2 µF	124 µF	620 µF	5000 µF	39,000 µF
2.2 µF	130 µF	645 µF	5100 µF	40,000 µF
3 µF	140 µF	650 µF	5400 µF	41,000 µF
3.3 µF	145 µF	680 µF	5500 µF	47,000 µF
4 µF	150 µF	700 µF	5600 µF	48,000 µF
4.7 µF	161 µF	708 µF	5800 µF	50,000 µF
5 µF	170 µF	730 µF	6000 µF	55,000 µF
5.6 µF	180 µF	800 µF	6500 µF	56,000 µF
6.8 µF	189 µF	820 µF	6800 µF	60,000 µF
7 µF	200 µF	850 µF	7200 µF	62,000 µF
8 µF	210 µF	860 µF	7400 µF	66,000 µF
8.2 µF	216 µF	1000 µF	7600 µF	68,000 µF
10 µF	220 µF	1100 µF	7800 µF	76,000 µF
12 µF	230 µF	1200 µF	8200 µF	0.1 F
15 µF	233 µF	1300 µF	8300 µF	0.11 F
16 µF	240 µF	1400 µF	8400 µF	0.12 F
18 µF	243 µF	1500 µF	8700 µF	0.15 F
20 µF	250 µF	1600 µF	9000 µF	0.22 F
21 µF	270 µF	1700 µF	9600 µF	0.33 F
22 µF	300 µF	1800 µF	10,000 µF	0.47 F
24 µF	320 µF	2000 µF	11,000 µF	0.666 F
25 µF	324 µF	2100 µF	12,000 µF
27 µF	330 µF	2200 µF	13,000 µF
30 µF	340 µF	2500 µF	15,000 µF
33 µF	350 µF	2600 µF	16,000 µF
35 µF	370 µF	2700 µF	17,000 µF
36 µF	378 µF	2800 µF	18,000 µF
39 µF	380 µF	2900 µF	20,000 µF
40 µF	390 µF	3000 µF	22,000 µF
43 µF	400 µF	3100 µF	23,000 µF
47 µF	420 µF	3300 µF	24,000 µF
50 µF	430 µF	3400 µF	25,000 µF
53 µF	450 µF	3500 µF	26,000 µF
56 µF	460 µF	3600 µF	27,000 µF
60 µF	470 µF	3700 µF	28,000 µF

Aluminum Electrolytic Capacitors

Tantalum Electrolytic capacitors

Niobium Electrolytic Capacitors

Finding the value of filter capacitor

Super Capacitors

The high capacity electrochemical capacitors with capacitance values much higher than the other capacitors, are called as Super Capacitors. These can be categorized as a group that lies between electrolytic capacitors and rechargeable batteries. These are also called as Ultra Capacitors.

There are many advantages with these capacitors such as −

• They have high capacitance value.
• They can store and deliver charge much faster.
• They can handle more charge and discharge cycles.
• 
  
  

These capacitors have many applications such as −

• They are used in cars, buses, trains, elevators and cranes.
• They are used in regenerative braking.
• They are used for memory backup.

The types of super capacitors are Double-layered, Pseudo and Hybrid ones.

2. Non-Polarized Capacitors

These are the capacitors that have no specific polarities, which means that they can be connected in a circuit, either way without bothering about the placement of right lead and left lead. These capacitors are also called as Non-Electrolytic Capacitors.

The main classification of Non-Polarized capacitors is done as shown in the following figure.

Among the types of capacitors, let us first go through the Ceramic Capacitors.

Tolerance of capacitor

Ceramic Capacitors

Identification

In  three value the first two values are value and last one is the number of zero

For two value both are values in pF

High value ceramic capacitor 

Low value ceramic capacitor

Low value ceramic capacitor with dc motor  used for smoothing the motor speed and reduce noise

Polyster Capacitor (pf capacitor)

• This capacitor is used where maximum levels of peak current need to handle

• Used in different low-frequency pulsating & DC circuits

Used in transformerless power supply

Finding the capacitor value in transformerless power supply 

Capacitor working as resistor to drop voltage 

Difference between these three capacitor

Application

1. Low Pass Filter - 

2. High Pass Filter-

3. Noise Filter - 

4. DC power Supply-

5. Power factor improvement - 

6. Block DC

7.Coupling 

8. Decoupling

Decoupling / Bypass Capacitor

Performance of the IC degrade if the input supply has some people or noise.

 capacitor behave as a open circuit for AC and close circuit for DC supply and it also reserve energy for IC the capacitor must be connected closer to the IC if frequency is lower than 50 megahert then capacitor of value 0.1 UF or 10 and 10 nf is sufficient if more than connected multiple capacitor in paralel is good practice 

electrolyte capacitor used when we have low frequency and ceramic capacitor when we have high frequency we cannot recognise the nature of noise and ripple spikes so it  is good practice to connect multiple ceramic capacitor in parallel

Decoupling allow DC and Block AC, where

Coupling Block DC and allow AC this work on the principal that the ac passed through capacitor and DC block

In decoupling Capacitor connect in parallel where in Coupling capacitor connect in series

Coupling Capacitor

In circuit both AC and DC present the DC mostly used for power supply and AC for transfer the signal ,

So , we use Coupling capacitor in series so DC block and AC passed

Bleeder Resistor :- 

High value register which are used to discharge the capacitor in filter circuit it protect from electric shock after supply off by discharging of capacitor

                      Diode

Diode allow current to flow when connected in forward bias and stop when connected in reverse bias

Rectifier Diode

1N4007 - 1A

1N5389 - 1.5 A

1N5408 - 3A

Application

Zener Diode 

Zener diode work in reverse bias means in forward bias it working as normal diode but for voltage regulating its must be connected in reverse bias 

If voltage overcome zener value it allows passed from it 

Resistor must be connected in series with zener diode

Zener diode values :- 

3. Switching diode

• Used for both General purpose and high speed switching applications

Naming Documents

Transistor

Transistor do basic two works :- 

1. Switching

2. Amplifier

Mostly transistor have three lags collector, base and emitter 

BJT

NPN - required positive voltage on bass or enable switch 

Silicon :- 0.7v

Germanium :- 0.3v

PNP - required negative voltage on base

Common Used Transistor

Common types that were widely used in all types of equipment and by electronics hobbyists included 2N2222, 2N3904, 2N3906, 2N3055, TIP41, 2SC945, BC547, and several others.

BC547 

Followings are the key knowledge of BC547 that you must understand:

• BC547 is a bipolar junction transistor (BJT).
• It is kind of an NPN transistor.
• It has three terminals: Emitter, Collector and Base.
• The maximum current gain of BC547 is 800A.
• The Collector−Emitter Voltage is 65V.
• The Collector-Base Voltage is 80V.
• The Emitter-Base voltage is 8V.

Projects:

1. LED intensity control

2. Water level indicator

3.contectless voltage detector

4. Relay driver 

MOSFET

MOSFET also contain three legs 

Drain - collector , 

Source - emmiter , 

Gate - base 

N- channel : High switching device. (mobility of electrons is high)

P  - channel:  Low switching speed.  (mobility of holes is low)

BJT VS MOSFET

BJT - current control device, 

MOSFET - Voltage Control device, used for high power then bjt and due to high drain capistance it is work for low frequency then of transistor, and it is not general purpose mostly it is specified , mosfet  is better in switching then amplification 

IRFZ44N MOSFET

This is general purpose mosfet ,It also has an extremely low threshold of just 4V, at which the MOSFET will begin conducting. This is why it is often employed with microcontrollers that drive using 5V.The IRFZ44N is a general-purpose device and is ideal for inverters, DC motors lighting, SMPS, load switches, and battery-powered applications.

IRFZ44N Equivalent

You could use IRF2807, IRFB3207, IRFB4710 as IRFZ44N Equivalent. You could find them on easybom.

 

IRFZ44N Application

Switching high power devices

Control speed of motors

Dimmers and flashers for LEDs

Application for high-speed switching

Inverter circuits or converter circuits

MOSFET Regulator

LM317 Voltage Regulator

LM317 Voltage Regulator

It is a type of positive-linear-voltage regulators used for voltage regulation,  which is invented by Robert C. Dobkin and Robert J. Widlar while they worked at the National Semiconductor in 1970. It is a three-terminal-adjustable-voltage regulator and is easy to use because to set the output voltage it requires only two external resistors in the LM317 voltage regulator circuit. It is majorly used for local and on-card regulation. If we connect a fixed resistor between the output and adjustment of the LM317 regulator, then the LM317 circuit can be used as a precision current regulator.

LM317 Voltage Regulator Circuit

The three terminals are input pin, output pin, and adjustment pin. The LM317 circuit is shown in the below figure is a typical configuration of the LM317 voltage regulator circuit diagram including the decoupling capacitors. This LM317 circuit is capable to provide variable DC power supply with an output of 1A and can be adjusted up to 30V. The circuit consists of a low-side resistor and high-side resistor connected in series forming a resistive voltage divider which is a passive linear circuit used to produce an output voltage which is a fraction of its input voltage.

Decoupling capacitors are used for decoupling or to prevent undesired coupling of one part of an electrical circuit from another part. To avoid the effect of noise caused by some circuit elements over the remaining elements of the circuit, the decoupling capacitors in the circuit are used for addressing the input noise and output transients. A heat sink is used with the circuit to avoid the components getting overheated due to more power dissipation.

LM317 Voltage Regulator Circuit

Features

There are some special features of the LM317 regulator and a few are as follows:

• It is capable of providing an excess current of 1.5A, hence it is conceptually considered as an operational amplifier with an output voltage ranging from 1.2V to 37V.
• The LM317 voltage regulator circuit internally consists of thermal overload protection and short circuit current limiting constant with temperature.
• It is available in two packages as 3-Lead Transistor Package and surface mount D2PAK-3.
• Stocking many fixed voltages can be eliminated.

7800 Regulated ic 

7800 VOLTAGE REGULATOR VARIANTS & SPECIFIC SPECIFICATIONS
PARAMETER	IC NUMBER	MIN	MAX	UNIT
Input voltage	7805	7	25	V
	7808	10.5	25	V
	7810	12.5	28	V
	7812	14.5	30	V
	7815	17.5	30	V
	7824	27	38	V
Output current, IO			1.5	A
Operating junction temperature, TJ	7800 series		125	°

Basic 7800 series voltage regulator circuit

The electronic circuit design using 7800 series voltage regulators is very easy. It is almost a matter of putting them in circuit: input, output and ground.

Naturally there are a few additional electronic components that may be required to ensure the correct operation of the voltage regulator circuit.

Basic 7800 series voltage regulator circuit

*     This capacitor is required to ensure the stability of the regulator. Normally if the smoothing capacitor for the rectifiers is close, then this can be omitted, but if there is any length of wire, then it must be included to ensure the circuit remains stable.

**     This capacitor is in circuit to remove noise and transients.

Regulated Power supply

Transformer less regulated power supply

Optocoupler 

Octopus working as a switch like transistor but it will isolated to power supply from each other one power supply cannot effect on another power supply

• Remove electrical noise from signals
• Isolate low-voltage devices from high-voltage circuits
• Allow you to use small digital signals to control larger AC voltages

Optocouplers come in four configurations. Each configuration shares the same infrared LED with a different photosensitive device. These include:

Photo-Transistor and Photo-Darlington, which are typically used in DC circuits, and Photo-SCR and Photo-TRIAC which are used to control AC circuits.

Relay 

Relay is working as switch between two terminals comment terminal is connected to normally open  until we passed current from the coil after passing the current the common terminal connected to normally closed

3V / 5V / 9V / 12V / 24V DC Various

Relay module

Relay module

Without optocoupler

With optocoupler

Ic555

L293D

motor driver is an integrated circuit chip which is usually used to control motors in autonomous robots. Motor driver act as an interface between Arduino and the motors . The most commonly used motor driver IC’s are from the L293 series such as L293D, L293NE, etc. These ICs are designed to control 2 DC motors simultaneously. L293D consist of two H-bridge. H-bridge is the simplest circuit for controlling a low current rated motor. We will be referring the motor driver IC as L293D only. L293D has 16 pins.

Vcc is for motor power it may very 5v, 9v , 12v according to motor requirement

Why 4 grounds in the IC?

The motor driver IC deals with heavy currents. Due to so much current flow the IC gets heated. So, we need a heat sink to reduce the heating. Therefore, there are 4 ground pins. When we solder the pins on PCB, we get a huge metalllic area between the grounds where the heat can be released.

Why Capacitors?

The DC motor is an inductive load. So, it develops a back EMF when supplied by a voltage. There can be fluctuations of voltage while using the motor say when suddenly we take a reverse while the motor was moving in some direction. At this point the fluctuation in voltage is quite high and this can damage the IC. Thus, we use four capacitors that help to dampen the extreme variation in current.

CD4017 – A Decade Counter with Decoded Output

The CD4017 IC is a decade counter that counts to ten. It has 10 outputs that represent the numbers 0 to 9. The counter increases with one for every rising clock pulse. After the counter has reached 9, it starts again from 0 with the next clock pulse.

How To Use The CD4017

First of all, you need a power supply voltage of 3 to 15V. Most versions of the chip support up to 18V. But for instance, the HEF4017 recommends only up to 15V.

Connect the VDD pin to the positive terminal and the GND pin to the negative terminal.

The Clock (CLK) pin increases the counter with one every time the pin goes from low to high. And as the count increases, the output pins (Q0-Q9) get high one by one. After the 10th input pulse, the counter resets and starts from 0 again. Change this pin from low to high to increase the counter.

The output pins Q0 to Q9 goes high one by one as the counter increases. Connect each to a resistor and LED if you want to see pins change state.

The Clock Inhibit (CI) pin disables the counter so that any clock pulse on the CLK pin is ignored. Set this pin to low to enable the counter.

The Carry-out (CO) pin goes from low to high when the counter reaches 10 and resets back to 0. It stays high for 5 clock pulses, then goes low again. Connect this pin to the clock input of another decade counter if you want to count higher than 10.

• The supply voltage of IC 4017 ranges from 3V to 15V, usually +5V
• This IC is well-matched with Transistor-Transistor Logic or TTL.
• The operational speed/CLK speed of this IC is 5 MHz.
• It provides support to10 outputs that are decoded.
• It is available in different packages like 16-pin GDIP, PDIP & PDSO
• Input high time 30 ns
• Output current is 10 mA

Application

4026 IC 

The 4026 is a decade counter integrated circuit (IC) with decoded outputs for driving a common-cathode seven-segment LED display. An advantage of this IC is that it has decade counter functionality together with 7-segment decoder driver.

Since 7-segment LED displays consume much power, this chip has special function Display Enable In (DEI) through pin 3, which is has to be HIGH when a display is required. This is useful if you had many display panels, because you could switch them ON only when required thereby saving power

I would recommend. If you are using the cheap and commonly available red coloured display, then they usually have a voltage drop of 1.8 V. Here is a table showing resistor values for each power supply option for such a display.

Power Supply (Volts)	R (Ω) - E24 Series
3	56
3.3	75
5	160
6	200
9	360
12	510

Circuit diagram

Multiple display 

PiN 5 In  4026 Working as clk for 2nd ic becouse pin 5 is trigger when it complete one decade . Pin 5 of second ic working as clock for  3rd ic and this will continue ..

Logic gates ic

Shift Register

Shift register working as memory when we gave input the input push into register and other shift 1 bit right again we gave another input it also push and first input right shift 1bit with another inputs and this process continues..

Right shift based ic contain 3importent pins 

1. Clock - 1bit input add into regester ic on each clock and shift other one bit 

2. Data - data conain 0 or 1 (vcc or no ) the data present on data pin insert into regester ic with clock 

3. Latch - after enable latch other output pin enable 

Video link for more ..

Multiple Register

We can connect multiple regester ic,

SIPO ic also have 1 series output which gave data as serial output we can connect this pin with the data pin of second ic , both the ic must have common clock 

Multiple Output for Arduino

ATiny 

The ATtiny85 microcontroller is a small 8-pin AVR controller. It has 8 I/O pins, in which 6 I/O pins are used for multiple functions and the other 2 pins are power pins used for VCC and GND. These 6 I/O pins are also known as PORTB pins, which are used as inputs or outputs based on the application.