Basic Electronic Components to create your own bots

Basic Electronic Components to create your own bots
Equipment’s, Elements (Components) and Tools of Electronic to create your own Bot.

Before starting create your first own bot. Knowledge of basic Electronic elements, Equipment’s and tools is very important. Let’s us study one-by-one all basic elements and tools for our bot.

In this post we will study about all Basic Electronic Components will help to create your bots

1. Resistors:- resistors are electronic components that offer resistance to the flow of an electric current through them. The magnitude of resistance offered is measured in ‘ohms’. The higher the ohmic value of a resistor, the more resistance it offers to the flow of current.

One of the precautions you should take while using a resistor is not to bend its terminals too close to its body Generally, along with the ohmic value of a resistor, the power rating of resistors is also used to classify them. The resistors available in the market have resistances in range of 1 ohm to 64 mega ohm and the power rating varies from 1/8 W to 20W. However if you want, you could get resistors of ratings outside this range also. For To measure the value of resistance of a given resistor,

you could use two methods. First one is to read the color code given on the value of resistance. The other method, and also the easier and faster one is to use a multimeter. 

2. Capacitor:- A capacitor is a device used to store electric charge. Their ability to store charge is measured in ‘Farads’. The more the ‘Farad’ rating of the capacitor, the more charge it can store. But, Farad is a very large unit, so we commonly use smaller unit such as ‘microfarads’ to denote the capacitance of a capacitor. 

Polar Capacitors:-These capacitors have fixed positive and negative terminals. These capacitors have to be connected in the correct way in the circuit. If you connect it in reverse polarity (connecting positive terminal where negative is to be connected and vice versa), an explosion may occur and you may spoil quite a few electronic components of your circuit.The most widely available polar capacitors are electrolytic capacitors. You can identify the polarity of the terminals of an electrolytic capacitor by comparing their lengths. The longer terminal is electrolytic capacitors are polarised always positive. Also, on the body of the capacitor, there is a negative sign mentioned above the negative terminal.
Non Polar Capacitors:-These capacitors do not have any polarity and can be connected in either way in a circuit. Most commonly used non polar capacitors are mica and ceramic capacitors. Also, because both the terminals of the non-polar capacitor are identical, the symbol for them is slightly different than that for polar capacitors.

Now a very common question in every innovative mind.

How we can identify value of a capacitor?

Ans. Identifying capacitance values.

A polar capacitor has both the capacitance value and the voltage rating clearly written on its body. However, for mica capacitors, they are written on the body in encoded form, generally a three digit number. So 474 is equal to 47 x 104 pf and 342 is equal to 34 x 102 pf. 

3. Diodes:-Diodes are two terminal devices just like the resistors, but they conduct electricity only in one direction. A resistor offers same resistance to the flow of electricity irrespective of its direction through it.

 On the other hand, a diode offers very large resistance to flow of electricity through it in one direction, and negligible resistance in other direction. Essentially, it means that a diode behaves as an open circuit (allowing no current flow) in one direction and as a closed circuit (allowing all the current to pass through it) in other direction. The condition of maximum current flow (or closed circuit) happens when the positive terminal of diode is connected to a point which is at higher potential than the point to which negative terminal is connected. This condition is called forward biasing. On the other hand, the condition of minimum or zero current flow happens when positive terminal of diode is connected to a point which is at lower potential than the point to which the negative terminal of diode is connected.

Before using any diode, you should always check if it is working fine by doing continuity test using a multimeter. The a diode and its symbol diode must offer continuous flow of current when its positive terminal is connected to red (positive) probe and its negative terminal is connected to black (negative) probe. The diode should offer discontinuity when multimeter is connected in opposite direction (that is Red probe to negative terminal of the diode and Black probe to positive terminal of the diode). Most commonly used diodes in electronics are 1N4001 and 1N4007.

4. LEDs:- light emitting diodes is a special category of diodes that emits light when forward biased. Generally, LEDs are of two types: Visible light emitting LEDInfrared light emitting LED (IR LED)Visible light emitting LEDA typical LED has a current rating of 20 mA, life time of 2 lakh working hours, and can tolerate a maximum voltage of around 4 V. 

There are also coloured LEDs available in the market, and there color is due the doping in the semiconducting material used to make them.All LEDs have two terminals, one positive and the other negative. The negative terminal is of shorter length, but there are some LEDs with a longer negative terminal which may be due to manufacturing defect. Also, once you cut the lengths a LED to use it in a circuit, the identification by comparing lengths of terminals is not useful. Another way of identifying the positive and negative terminal is to compare the filament. Again, due to manufacturing defects, some LEDs have a broader positive terminal. So none of the ways mentioned can be relied upon completely. The best way is to use the multimeter. Set the multimeter to continuity checking mode and touch red probe to one terminal of LED and black probe to other terminal of LED. If the LED glows, the terminal in contact with the red probe is the positive terminal and other is the negative one. If the LED doesn’t glow, change the polarity. Now, if the LED glows, the terminal now in contact with the red probe is positive and the other negative. However, if the LED still doesn’t glow, it means the either the LED or the multimeter is faulty.An LED, with the LEDs are generally used in large number in circuit. They are cathode on the left and anode on the used in parallel with a regular connection in a circuit, and this right helps a lot during troubleshooting (that is finding the error in the circuit if it doesn’t work).

An LED glowing in parallel of a connection suggests that the current is flowing through the connection in the direction of the negative terminal from the positive terminal of LED. However, if the LED doesn’t glow, it suggests that either the current is flowing in the opposite direction, or the current is not flowing at all in that part of the circuit. A thumb rule to be followed while using LEDs is to use a resistor of around 100 ohm in series with LED, so as to avoid the LED getting burnt in case the voltage across it exceeds 4V or current exceeds 20mA.Infrared light emitting LED (IR LED).

There are two differences between a normal LED and an IR LED. The first one, of course, is that an IR LED emits infrared radiations which cannot be seen with the naked eyes, whereas a LED emits visible light. Another difference is that IR LED consumes a lot of current and thus they get damaged very fast. They do not have lives as long as LEDs.An important precaution to be taken while using an IR LED is to not allow it to be forward biased for a very long time as we know that infrared radiations carry a lot of heat. Continuous IR radiations may heat the body or shell of the IR LED too much and can damage it also. Be careful not to touch IR LED after it has been forward biased for a long time since it may have become very hot.

5. Op-amp:-Op-amp stands for operational amplifier. It is just like an amplifier which you use while listening to music. 

It performs the function of amplifying the voltage signal input to it, converting it into a voltage of significantly higher magnitude. Generally, it comes in form of an IC and it has multiple ports to take multiple signals and amplify them simultaneously. The most popular Op-amps among hobbyists are MCP series and LM series Op-amps. We are going to use LM358N Op-amp for our purpose.

6. Sensors:- Robots are very similar to human body. Human body has senses to receive information from the external environment. Robots have sensors. Human body has brain to process the information; robots have processors to do the same. Human body have the external organs to execute decisions given by mind, in robots the wheels or legs or arms does it.

There are two broad categories of sensors:

Digital sensors: They provide discrete or stepped binary results.  A switch an example of a digital sensor: It can either be open or closed. Also, an ultrasonic ranger, which returns a different binary value for distances, is also a type of digital sensor.

Analogue sensors: They provide a continuous range of values, usually in form of voltage.Generally, in both digital and analogue sensors, the input to the processing unit is voltage. In the case of a digital sensor, the processing unit is interested in knowing whether the voltage input given by the sensor is a logic low(usually 0 V) or logic high (usually 5 V). Most of the digital sensors can be directly connected to the processing unit without any additional interfacing electronics, but in case of an analogue sensor, you need additional circuitry to convert the varying voltage levels into a form that the processing unit can use. Also, circuitry is required to amplify the output of the analogue sensor, since this output may not be adequate to be interpreted by the processor. This is basically achieved by using operational amplifiers or op-amps as we have discussed.Types of SensorsIn robotics projects, the following types of sensors are widely used:Bump or touch sensors: These are those sensors which are activated when there is touch or bump.Temperature sensors: These are just like thermometer, and they respond to change in temperature by changing voltage across their terminals. Commonly available temperature sensors are LM35, DS1621 and a thermistor.Light sensors: These are those sensors which are activated whenever there is significant change in the intensity of light. The most commonly used light sensors are the IR (Infrared) sensors and LDR (Light Dependent Resistor) sensors.IR SensorsAppliances such as TVs, music players and ACs have IR transmitter-receiver pairs to transmit signals.Colour sensors: These are advanced light sensors that can sense even the slightest change in the intensity of light falling on them and thus can detect colours. This is because each colour reflects a different intensity of light when light falls on them. So when there is a change in the intensity of light falling and light reflected, the sensor senses it and sends the signal.Sonar proximity detector: In this, the reflected sound waves are used to judge distances between the robot and obstacle, with the aid of sound signals.Speech input or recognition: Various sound/speech patterns or even a human voice can be used to command the robot.

Gas or smoke sensor: These detect noxious or toxic fumes once their concentration in air increases beyond a certain limit.

Pyro electric infrared sensor: It detects changes in heat patterns over period of time and is thus used as motion detectors.

Sound sensor: Robot responds to sound patterns like a clap or drum beat. The robot can also be tuned to listen to only certain sound frequency (which may also lie outside a human’s audible range) or to those sounds having a certain minimum volume level.

Accelerometer: These are used to detect changes in inclination or speed of the robot.Most of these sensors are available in the ready to use form in the market,

but they are quite expensive because they offer very good precision. But for robotics enthusiasts, buying them is not always a good deal because you can construct majority of them on your own and those too offering reasonably good precision and efficiency.

help:-thinkdigit.com