PWM using 555 Timer

Here is very simple circuit but very important in electronics specially in inverters science and you can say its basic hobby project for beginners in electronics.

PWM (Pulse Width Modulation) using 555 timer. Pulse width modulation is use to control the output of inverter circuit by the switching of H bridge transistors for increasing and decreasing ON/OFF time. 

PWM is also use for SMPS to control the output voltage or regulate the voltage.

Components required:

555 timer IC

Resistors (for calculation see here)

Capacitors

Pot-meter

LED

Breadboard

Battery

Jumppers

Circuit:

If we remove the Pot_meter from pin 5 (Control voltage pin) of 555 timer then its same as AMV of 555 timer which give the fixed output pulses like as

Here you can see having twice resistors (Charging and discharging) having same value. A diode is connected in parallel to 2.2k resistor (Discharging) so that it maintains 50% duty cycle of output pulses.

GIF simulation:

Thanks if you like my post then comment me and share it 

 

 

555 Timer AMV Flasher Circuit

 

Hi here i am sharing a simple but interesting circuit of flasher circuit by using 555 timer with the application of AMV (Astable Multi-vibrator). I have already shared a 555 timer police siren project you can see that also interesting project for students.

In this circuit we use following components.

• 555 timer IC
• 4.7 K Ohm resister
• 47 uf capacitor
• LED
• 9V battery 

Connect all the components as per diagram

Circuit diagram:

Here is simple circuit designed in Livewire Circuit simulator.

here is the PIN diagram of 555 timer IC.

Data sheet of 555 timer

This little Project is tested on hardware so can directly go for hardware with given values.

Thanks if you like the project then please comment and share.
 

Transistor Flasher Circuit

Transistor is the revolutionary component in electronics field its major property that is to control the current flow. Here is one of the best example on this property that Transistor Flasher circuit.

Basically there is the field of multi-vibrators in analog electronics and MV has three types.

1. Mono Stable Multivibrator (MMV):

    That type of Mutli-vibrators which has one stable state that may be 0 (Low voltage) are 1 (high voltage) and required a trigger pulse to change its state from stable to unstable. After some time (T = RC) MMV come back to its stable state.

2. Bi-stable Multivibrator (BMV):

    That type of Multivibrator which has two stable states 0 (low voltage) and 1 (high voltage) and required a trigger pulse to change from low to high or high to low (example Flip flops).

3. Astable Multivibrator (AMV):

    Such type of multivibrator which has no stable state but its free running multivibrator between 0 and 1 without any trigger pulse. So its use for flasher circuit and as clock generator.

here i am sharing transistor AMV. 

 

Proteus 8 Preview

Components:

1. 2 BJT (2N3904)

2. 2 Resistor (1k ohm)

3. 2 Capacitor (47uf)

4. 2 LEDs 

5. 5v adopter

Working Idea:

Current I1 flow through R1 and first charge C1 and at that time there is no current flow toward base terminal of Q2, So Q2 remain Off and LED 2 Off.

at that time C2 already Complete Charged and Current I2 flow through R2 toward base terminal of Q1 So Q1 start conduction (Turn ON) then LED 2 turn ON.

when C1 full chaged and C2 discharges then reverse the action.

• 555 timer Flasher

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Configure bits for PIC microcontroller in Genious 540 Universal IC burber

PIC microcontroller Configures bit:
Its very hard and hot topic of Configures bits of PIC microcontroller during Programming using Genius 540, 530
I am sharing my practical examples of PIC microcontroller Programming using PIC 16f877A, PIC 18F452

Configure bits Register:

Configures bits PIC16f877A:

Configures bits PIC18F452:

Now follow my group if you like this information.

Zener Diode

I am starting a series of electronics devices theory for students and my first topic is Zener diode. 

Zener diode:

Zener diode is two terminal device and have one PN highly doped junction use for voltage regulation in reverse bias to parallel at input of device or at output of DC power supply.

Physical shape: 

Symbol:

Characteristic (V-I) curve:

Forward bias:

when we connect anode with + terminal of the battery and cathode with - terminal of the battery then current flow start anode to cathode after 0.7 junction volt as shown in V-I curve.

Reverse bias:

When we apply cathode with + terminal and anode with - terminal then after zener voltage diode will start conduction in reverse bias (its called Zener break down).

When voltage more increase then a lot of current flow through zener diode and diode will burn out (its called avalanche break down) as shown in V-I curve.  

Load Regulation:

This is very simple science fixed input voltage and load is variable

load current increase:

when load current increase the zener current decrease and extra voltage drop across R1  and output voltage remain same.

Load current decrease:

when load current decrease then zener current increase and voltage at output remain same. and total current remain same.(will see one more post with solve examples)

Line Regulation:

In line regulation Vin (Line voltage) are variable and load is at fixed value.

Vin increase:

when input voltage increase then load voltage remain constant according to zener voltage and remaining Max voltage drop across R1.

Vin decrease but > Vz:

when vin decrease then Vz and load voltage also remain constant due to conduction of zener diode and renaming min voltage drop across R1.

Vin < Vz:

when Vin decrease then Vz then applied divide at R1 and RL. (No need this case) 

lecture watch on YouTube: 

Common Collector Amplifier

Here is new one topic of BJT that is Common Collector Configuration circuit. In this circuit collector terminal of BJT is common for input and output loop.

INPUT Loop:

Input loop of CC is base collector where we apply the Vin as shown in circuit diagram.

OUTPUT Loop: 

where as the output loop of the this circuit is emitter collector as shown on diagram. and we get Vout as VEC.

when Vin increase then conduction of BJT increase and max current flow through Collector to emitter and high current will appear at output. 

When Vin go down then conduction of BJT decrease and we get reverse current at output loop, means CC has high current gain but Voltage gain approximately unity.

have some following Properties:

Properties:

Av ------- Unity

Ai -------- High

Zi --------- High

Zo --------- low

Application:

use for Impedance matching

use for Current amplification

Common base Amplifier

Hi
here is one more topic related to BJT Configuration. There are three types of configurations
1. Common Base
2. Common Collector
3. Common Emitter
Common Base:
In this type of configuration base terminal of BJT is common between input loop and output loop. Input loop of BJT CB is emitter to base and output loop is collector to base.

when input applied across RE then there are two case 

1. when Vin > 0 then BJT Conduction reduce toward off and then max Ic flow through output.

2. & when Vin < 0 then BJT Conduction increase toward saturation low Ic flow through output and Vout reduce.

and we can find the Vout = Vcb = Vcc - IcRc 

Introduction to BJT

As'salam o alaikm

Dear students here today I am discussing about BJT from the part of Chapter 09. In which we will discus about Some following topic in giver video lecture.

1. Introduction to BJT
2. Types of BJT
3. Construction of BJT
4. Current equations of BJT

 

Two Digit Token Counter as UART Application

As'salam o alaikm

Today here is new application of PIC controller that is "Token Counter" basically the application of UART (Universal Asynchronous Receiver Transmitter).

Description:

Here is the block diagram of mentioned project.

1. Tx End

In this end of microcontroller have a keypad use to enter preset value of visitor. Press * to enter in keypad then press two digit then press # to exit from keypad. Then Tx end display that number and send to Rx end.

If you want to increment then push Up push button, for decrements press Down and for start 00 then press RST (Reset).

2. Rx End 

UART receive the number and display on 7 segment display and blink twice with beep (buzzer).

Circuit diagram of token counter

Youtube link:

For Code & Circuit

Making PCB at Home (Step by Step)

اسلام علیکم

Here is an other one article related to PCB (Printed Circuit board) designing. PCB designing is very important for Circuit designing engineers. PCB Making at home is the need of Students or hobbyist persons because they are making some samples of circuit. But some Professionals and businessman engineers order the for PCB making companies like JLC PCB, PCB cart etc. they received bulk order as well for some mini 5 samples also but 5 sample is costly more then bulk quantity. 

But here is my MSc course Project at ISRA Uniersity Islamabad {Control Home appliances using Mobile (cell phone)} this project was DTMF based (here is not required to discus more about Project but PCB).

Description:

Here PCB method is iron based by transforming toner on transparent sheet then etching by ferric chloride. 

I am explaining method step by step.

1. Take a Copper sheet of specific area and rub that by zero size sand paper.

2. Take a mirror Print of PCB layout on Transparent sheet

3. First to little heat up to Copper sheet which rubbed by sand paper then adjust PCB layout Print on Copper sheet, then set a double paper on that and heat up by iron approximately 10 minuets.

4. Peel out the transparent sheet after above time

5. Make a ferric chloride 2:1 solution in a tub then do etching

6. You will see the results like that

7. Do manual drilling by small drilling macine

8. Insert Components and do Soldering

9. Circuit Board is ready 

the above Layout was not Professional because I was not PCB expert but now I am designing professional PCBs also, if any one want my services the connect me by email.

if you like this article then like and share it.

  

  

   
 

Password based Door Lock Using PIC Microcontroller

Password based door lock is also a very interesting and important Project for Students learning. This project is useful for domestic and as well industrial application. Its not only for door lock but you can use for any sensitive machine ON by entering password to Activated load.

Description:

In this Project some following Components are used.

1. PIC16877A Microcontroller

2.LCD 16x2

3.Crystal of 10MHz with 22pf Non Pol capacitor

4. 3x4 Numerical keypad

5. Resisters

Connection of the circuit is as following diagram.

Function: of the circuit is very simple 

1. When you would like to Unlock the door then press * from the keypad to enter the Password receiving environment, LCD will Show the message to "ENTER CODE:     ".

2. Then enter the password of four digit, here password is 2636. (2636/3350 my marks of DAE) 

when you will enter the last 4th digit then there will two cases 

        if password is correct then it will show the message "  OK- DOOR OPEN   " and Activate the lock to open.

         if password is wrong the it will show the message " *** WRONG *** ".

3. Then enter # to exit the password entering environment.   

Download Files:

Proteus and MikroC

Youtube link:

Automatic Street Lights Control using LDR And BJT

Automatic Street Lights Control using LDR And BJT

To control Street lights automatically is a very interesting and very basic components Project for students and daily life hobby engineers.

This Project sense the light intensity through LDR (Light Dependent Resistor) which control the Biasing of BJT to ON or OFF Transistor as switch. One SPDT (Single Pole Double Through) is connected at collector terminal of the transistor. When BJT ON the pass a required and calculated current (Ic) through Relay and Relay activate to ON Street light which operating on AC 220v.
We can use any other type of load also here like Main gate light etc.
All values of the components mentioned in the circuit diagram. 

• Circuit diagram:

   

Police Siren Using 555 Timer

Police Siren Using 555 Timer

Police Siren using 555 timer is a very interesting project for DAE or Engineering students. In this project we will produce the out signal which produce the sound like police siren. 

In this Project we are using very basic and simple components like as 

1. Two 555 timer ICs 
2. Some resistors values are mentioned on diagram
3. Capacitors
4. Simple diode 1N4001
5. One Pot-meter 5K
6. Buzzer
7. 9v battery 

• 555 Timer

555 timer belongs to the category of mixed ICs means digital and analog. 555 timer internal circuit is cconsist on two Op-Amp Comparators and one RS latch and three 5k resister network. Physical shape, internal circuit and Pin out of the IC is as under.

• Internal circuit:

• Pin Out:

• Pins Description:

1.       Ground
2.    Trigger: In case of 555 as MMV we apply trigger pulse at this pin to unstable the output of                  MMV.
3.     Output
4.     Reset: Pin#4 is mostly on +v when we want to reset the MV then we apply 0 level on this pin.
5.     Control Voltage: In case of 555 timer VCO(voltage control oscillator) variable voltage applied          on this pin to vary the output frequency.
6.     Thresh Hold: At this pin an external capacitor connected to change the output by charging and          discharging.
7.     Discharging: This pin provides the short path to external capacitor for discharging.
8.     +Vcc

• Circuit Diagram:

In above Diagram (which is the simulation view of Livewire you can simulate it in proteus as wel) IC1 timer IC is behaving as AMV (Astable Multi-Vibrator) and 2nd one is behaving as VCO (Voltage Control Oscillator). AMV is just making voltage out put high and low and VCO out put frequency changing according to AMV voltages up down. So when Out1 will high then Out2 frequency go down and when Out1 voltages goes to zero then Out2 frequency go high. Accroding to this frequency variations Buzzer produce sound like Police Siren. look at wave form.