## How to Make 10V DC Power Supply (PCB included)

Hi friends, in this short tutorial we are going to learn how to make 10V DC power supply using LM350 IC. You can use this circuit as your first or second year engineering electronics mini project. This circuit is capable of producing 10V DC output at a current rating of maximum 3A. It uses LM350, a three terminal positive voltage regulator. It can produce an output voltage ranging from 1.2V to 33V for the input voltage of 14V to 24 V obtained from the AC mains through a step-down transformer. The capacitor C2 ensures the stability of the output from the regulator. To get different levels of the output voltage, the values of R2 and C3 can be varied accordingly.

### Components required

• C1 = 0.1uF
• C2 = 1uF
• C3 = 10uF
• D1,D2,D3,D4 = IN5001
• F1 = 3A
• J1,J2 are screw terminals
• R1 = 240Ω
• R2 = 1.65K
• U1 = LM350

### Features of 10V DC Power Supply

Input(V): 14VAC to 24VAC
Output(V): 10 VDC
PCB:68mmX35mm

Note: Use a ccl with 2oz Cu thickness for PCB fabrication.

## Interfacing 433MHz RF Modules with 8051 Microcontroller

Hello Friends Today I am going to show you how to use a 433MHz RF module in your 8051 Projects. The 433MHz RF module is one of the cheapest ways of wireless communication other than IR that you can use in your 8051 projects.There is a receiving and Transmitting module that we will need. You can easily find them online for3-4\$(150-200 Indian Rs).

### Components required

• Microcontroller (P89V51RD2) (2)
• Resistor 10K (1)
• Capacitor 33pF (2)
• Capacitor 10uF (1)
• 11.0592MHz Crystal (1)
• 433MHz RF Transmitter (1)
• Buzzer(optional) (1)

### Circuit Diagram and Description

Connections of the Transmitter Module:

The smaller module of the two with a crystal on it is the Transmitter module. The Pin connections for the module are as below

Pin on Module            Connection

GND               GND on 8051 Board

DATA             P3.1 on 8051 Board

Vcc                  Vcc on 8051 Board

ANT                Connected to 17.25cm long wire

The Larger module of the two is the Receiver module.The Module has multiple GND and Vcc pins which need to be connected externally. The Pin connections for the module are as below

Pin on Module            Connection

GND              GND on 8051 Board

DATA            P3.0 on 8051 Board

Vcc                 Vcc on 8051 Board

ANT               Connected to 17.25cm long wire

In this particular program, we are using UART to transmit 8-bit data over the RF module. The data pin of the transmit module is connected to the transmit pin of the 8051. When the Switch 4 is pressed on the 8051 Board then the ASCII value of character t is sent over the RFmodule.If this is received at the receiving 8051 then the Buzzer will turn on for 5 Seconds.

I hope you liked this microcontroller project. If you have any queries feel free to ask in the comment section below. Like our facebook page and subscribe to our newsletter for future updates. Hava a nice day!

## MATLAB Program for Maclaurin Series

Hi friends, in this MATLAB tutorial we are going to calculate Maclaurin Series of order n. We know that A Maclaurin series is a Taylor series expansion of a function about 0,

Let’s see a MATLAB program to calculate Maclaurin Series of order n.

### MATLAB Program for Maclaurin Series

Initially, it will take input x as theta of cos. Then it will ask how many terms the series should expand. By using for loop and Maclurin Series formula it will generate the series up to the terms required.

```%Maclurine series%
x = input('enter value of cosx :');
n=input('enter last value:');
for i=1:n
series=(((-1)^n)/(factorial(2*n)))*(x^(2*n));
series=series+series;
end
series```

## Objects in JavaScript – Tutorial 23

Hello friends, in previous JavaScript tutorial, we have seen different event handlers in JavaScript. Today we are going to discuss object-oriented programming. What is mean by Object? What are some built-in objects in JavaScript? etc.

Objects are one of the coolest features in JavaScript as well as it is little confusing for most of the JavaScript learners. Let’s make it simple with some examples. The object is that piece of weird data which has some properties or methods. Don’t be confused now about what the heck are these properties and methods. Be calm, that’s what we are going to learn in next few minutes.

Let us first consider a real life example. If we consider a mobile phone as an object, then it would have properties like weight, color, size, etc. Methods are those things which object does. Methods for a mobile phone would be making a phone call, play game, listen to music, etc.

I hope now you have some basic idea about what object is and what properties & methods are. So let’s go ahead and see what are some built in JavaScript properties and methods.

In this example, we have created a variable named “mobile”. Did you know, this variable mobile is indeed an object with its own properties? To get some of the built in javascript properties we need to use a dot separator. In this example, we have checked the length of a variable using “length” property.

In the following example, we are going to learn what are methods in JavaScripts. For understanding methods, we don’t need to do anything new. We are already using the methods from beginning of this course.

For example, We have used document.write(“Some text goes here”); many times. So in this statement, the document is an object and write() is its method.

That’s what I wanted to discuss in this tutorial so far. To summarize it we can say there are some built in javascript objects. In order to use them, we can write it with our separator along with its properties or methods. See the following picture for clear understanding.

I hope you liked this tutorial. In the next tutorial, we are going to learn how to create our own JavaScript objects. If you have any queries feel free to ask in the comment section below. Please like our facebook page and subscribe to our newsletter for future updates. Have a nice day!

## Shunt Voltage Regulator – Working Principle

A zener diode forms an integral part of any voltage regulator. Before we go ahead, we know, that in all cases, the voltage across a zener diode will remain constant. i.e. ∆VZ = 0. In all cases, we indicate load resistance by RL.

### Regulator using zener diode only

• Across RL we have: V = VZ = ILRL                                                                (Equation 1)
• From current law: I = IZ + IL                                                              (Equation 2)
• From KVL along indicated path: VS = I*R + VZ                             (Equation 3)

Equation 1 tells that output voltage VO will always be constant = VZ.

Assume two cases:

• Assume supply current I change by dI
From Equation 2: ∆I = ∆IZ + ∆IL
From Equation 1: ∆VZ = ∆ILRL ; or, ∆IL = 0 (since ∆VZ = 0)
Thus ∆I = ∆IZ. This shows that excess current is bifurcated through the zener diode.
• Assume load RL changes by ∆RL (with VS constant)
Output voltage VO will remain constant, but change in IL will be compensated by change in IZ
From Equation 3: ∆VS = ∆I*R+ ∆VZ ;      or, 0 = ∆I*R + 0 ;               or, ∆I = 0
From Equation 2: ∆I = ∆IZ + ∆IL ;            or, 0 = ∆IZ + ∆IL  ;             or, ∆IL = – ∆IZ

Thus if IL increases, IZ decreases and vice versa.

### Regulator using transistor and zener diode

Few points:

Correlating VO and indicated path from point X to GND: VO = VX = VZ + VBE          (Equation 1)

I = IB + IC + IL ;   or, I = IC + IL(since IB is very small)                                                     (Equation 2)

The increase in VBE causes more collector current IC to flow.

• Assume current I increase by dI keeping VS constant (opposite analysis will take place of I decreases)∆I is positive. VS – I*R = VX ;         or, 0 – ∆I*R = ∆VX ; (since VS is constant)
i.e. VX = VO  decreases on increase in I.                                                                  (Effect 1: VO tends to decrease)

Next, from Equation 1: ∆VO = ∆VZ + ∆VBE ;            or, ∆VO = 0 + ∆VBE ;
i.e VBE also decreases on decrease in VO
As VBE decreases, IC decreases.

From Equation 2: ∆I = ∆IC + ∆IL
If ∆I = positive (assumed);           ∆IC = negative (as VBE decrease);           so IL must increase.
The voltage across load VL = IL*Rincreases.                                                       (Effect 2: VO tends to increase)

The Effect 1 and Effect 2 neutralize and VO is constant.

• Assume supply voltage VS is increased keeping current I constantThe analysis will take place just as done previously.
VS – I*R = VX ;    or, ∆VS – 0 = ∆VX ; (since I is constant)
i.e. VX = VO increases on increase in VS.                                                                 (Effect 1: VO tends to increase)

Next, from Equation 1: ∆VO = ∆VZ + ∆VBE ;            or, ∆VO = 0 + ∆VBE ;
i.e VBE also increases on increase in VAs VBE decreases, IC increases.

From Equation 2: ∆I = ∆IC + ∆IL
If ∆I = 0 (assumed);         ∆IC = positive (as VBE increase);  so IL must decrease.
The voltage across load VL = IL*RL decreases.                                                     (Effect 2: VO tends to decrease)
The Effect 1 and Effect 2 neutralize and VO is constant.

## Linear Voltage Regulator – Series and Shunt type

Hi friends, in this article, we will take a basic overview of a linear voltage regulator and its types. This includes the block diagram and working principles.

### What is voltage regulator?

A voltage regulator prevents the varying of the voltage across a load in spite of variation in the supply. It is also used to regulate or vary the output voltage of the circuit.

Two terms:

• Regulation: compensates for variation in the mains (line voltage)
• Stabilization: compensates for variation in load current

However, in practice, both the terms loosely used for the same meaning of voltage regulation.

### Types of voltage regulator

There are mainly two types:

1. Series voltage regulator
2. Shunt voltage regulator

### Series voltage regulator:

A simple block diagram is as follows

The series voltage regulator controls variation in voltage (DVS) across the load by providing a voltage in series with the load.

A further more detailed block diagram is shown. A series regulator has its regulating unit in series with the load.

There is always a voltage drop in the regulating unit (VR). The output voltage VO (or VL) is:

VL = VS – VR

Series voltage regulator usually has a negative feedback system. If load voltage (VL) tends to fall, smaller feedback decreases controlling unit resistance thereby allowing more current to flow in the load (VR decreases) and increasing VL. Opposite happens when VL increases.

### Shunt voltage regulator

Block diagram is as follows

Shunt voltage regulator controls the voltage across the load by varying the current flowing through the load (IL) and through the regulating unit (IR).

A further detailed block diagram is shown below. A shunt regulator has its regulating unit in parallel to the load.

I = IR + IL

The stability in the voltage across the load RL is brought about by ensuring a steady current flow through it.

When the current across RL tends to increase, regulating unit prevents it by allowing the excess current to flow through it. Since current I is constant, IL decreases.

Same happens when current IL tends to decrease. Regulating unit prevents it by decreasing current flow (IR) through it, thereby increasing IL.

Tags: LM317, adjustable voltage regulator, zener diode voltage regulator, voltage regulator 7805, vrm, avr, ldo.

## Event Handlers in JavaScript – Tutorial 22

Hi friends, In previous JavaScript tutorial, we have seen do while loops. Today we are going to learn about event handlers in JavaScript. Event handlers are very important in JavaScript to create more interactive and dynamic web pages. Event handlers basically used to run a bit of code based on user action. For example, pop up a message when the user clicks on a button.

We don’t need to write event handlers in those special script tags. We can use event handlers inline to HTML tags. Let us see one simple example for clear understanding.

In this example, we have used onclick event handler. This event handler will pop up a message “Submitted successfully” whenever the user clicks on a button.

Note: We can add more than one statement in inline event handlers also. For example, in above example, we have the user only one alert statement with the semicolon, so if we have to add more statement just write them after that semicolon.

Following is the list of all event handlers available in JavaScrit.

 Event Handler Used In onAbort image onBlur select, text, text area onChange select, text, textarea onClick button, checkbox, radio, link, reset, submit, area onError image onFocus select, text, testarea onLoad windows, image onMouseOver link, area onMouseOut link, area onSelect text, textarea onSubmit form onUnload window

Just try now with some event handlers and let me know about your outputs. In next JavaScript tutorial, we are going to learn about objects in JavaScript. If you liked this article then share it with your friends. Like our facebook page and subscribe to our newsletter for future updates. If you have any questions, feel free to ask in the comment section below. Have a nice day!

## do while Loop in JavaScript – Tutorial 21

Hi friends, in previous JavaScript tutorials, we have seen for loop and while loop. Today we going to learn do while loop in JavaScript. As discussed in an earlier tutorial, all loops work similarly with some minor changes. similarly, do while loop works similar to a while loop. Only the difference is that do while loop first runs the code and then it check the condition. If the condition is true, it again runs a bit of code unless condition becomes false.

In short, do while loop performs an action at least one time. Let us see one simple example of do while loop in javaScript. In this example also, we will print a table of 21.

In next JavaScript tutorial, we are going to learn event handlers in JavaScript. If you liked this article then share it with your friends. Like our facebook page and subscribe to our newsletter for future updates. If you have any questions, feel free to ask in the comment section below. Have a nice day!

## while Loop in JavaScript – Tutorial 20

Hi friends, in previous JavaScript Tutorial we have seen for loop. In today’s JavaScript tutorial, we are going to learn one more loop in JavaScript which is while loop. While loop in JavaScript does the same job like for loop with some little changes.

The main difference between while and for loop is that we directly write some condition in while loop unlike for loop. In for loop, we first initialize some variable and then we increment it for a number of times. In while loop, we already have a variable and we just check the condition for it. while loop stops only when a condition becomes false.

Let us see one simple example of for loop in JavaScript for clear understanding. In this example, we will print a table of 21 using a while loop. It’s very simple to understand.

In next JavaScript tutorial, we are going to learn do while loop in JavaScript. If you liked this article then share it with your friends. Like our facebook page and subscribe to our newsletter for future updates. If you have any questions, feel free to ask in the comment section below. Have a nice day!

## For Loop in JavaScript – Tutorial 19

Hi friends, in the previous JavaScript tutorial we have seen Switch case statement in JavaScript. In this JavaScript tutorial, we are going to learn about for loop in JavaScript.

A loop is extremely helpful in any computer programming language. Whenever you want to do a repetitive task, a loop comes in handy. It saves time. I think we don’t need to waste more time on for loop, as most of you are already have some basic idea about it.

Let us directly see one example for printing table of 9. In this example, if you want to write a statement 10 times we can use a for loop. For loop will save time as we don’t need to write the statement 10 times in the code.