Electronic mosquito repelent ultrasonic frequency generator circuit

Dear friends today we are going to learn how to make a circuit which act as mosquito repellent.

This circuit is very much easy to understand and use. A circuit with minimum components repel mosquito. Large number of things like coils, creams, oils is available in the market to repel mosquito. But these replant is also harmful for the humans . Oils and creams can led to skin disease, while coils or mats produces toxic fumes which can lead to breathing problem and lung cancer.

Our circuit do no harm for human being as it produces frequency which human being can not hear. Mosquito repellent generates a frequency ranges from 20-38 KHz. And mosquito runs away from your house as they irritates from these range of frequency.

Humans are only able to hear frequency which has a range from 20Hz to 20 KHz. All the rest frequency above this is considered as a ultrasonic frequency. Many animals and insects are able to hear this range of frequency. Usually in mosquitoes ultra sound is generated by the males and female one receives that one. While after breeding female mosquito usually used to avoid this frequency. And this circuit produces the same frequency as the male one generates, and these creates a stress on the antennae of the mosquito and these keep them away.

Here the basic principal of this circuit is to connect a such type of buzzer which can produce ultrasonic frequency range. With the help of oscillator in the circuit, buzzer is driven. And in the circuit oscillation is generated by 555 timer IC which is linked as a astablemultivibrator.

The circuit is connected in the closed mode and thus power is received by the 555 timer. In the starting stage voltage in the capacitor is zero volts.

So the voltage at the threshold `as well trigger pin is at zero volts. Now the capacitor starts charging via a resistor R1 and R2.There will be one point when the voltage of capacitor will be higher as compared to threshold voltage. At this stage capacitor starts discharging with the help of resistor R2, which is a discharging pin and it keeps of going downward till it reaches to its original state. Thus the signal at the output pin of IC will be an oscillating signal having 38 KHz frequency. With the help of pin 3 of timer IC 555 which is out pin of IC 38 KHz frequency drives to 38 kHz piexo buzzer. This buzzer will produce a ultrasound at a regular interval.

By altering the value of resistor R2 we can alter the output frequency.

By changing the value of resistor and capacitor, it can also use as an insect replier as insects are also able to hear ultrasound.
From the source ultrasound are transportable only at 45 degree. So in the situation when there is any hurdles in the track signals get diverted. Also it works on the place where population of mosquito are not much more.

Component Description:-

1. Power supply (12V)

2. Resistors (2.7kΩ x 2)

3. Capacitors (0.01µF x 2)

4. NE 555 timer

5. IC Diode (1N4007)

6. Piezo Buzzer

Working principle:-

(1) Here the 555 timer is configured in astable multivibrator mode , specifically devised for generating sound at the ultra frequency levels.

(2) The frequency of this circuit is set to 25 kHz, this frequency falls in the ultrasound region and it is not audible to human beings.
The 1N4007 diode is used to get 50% duty cycle for the frequency generator.

(3) The piezo buzzer converts the output of 555 astable to ultrasonic sound that can be heard by the insects.

(4) This ultrasound frequency cause some irritations and uneasiness to the insects such as mosquitoes. However it will not disturb you if you have installed this circuit of insect repellent for your home.

How to design this circuit:-

We need 25 kHz signal, so the time period will be 40µseconds .

Then T =T =20µSeconds .

use R= 2.7kΩ standard.

Simple real puspose touch switch using transistor circuit

Dear friends, today we are going to learn how to make a Touch Switch ( On and Off switches separated) to use it as a wall socket switch.

There are lot of touch circkts on internet but those ate only one state switch means when you touch they will switch on and when you dont touch they switch off. Our touch switch has separated touch plate for ON and Off and it keep it state until switched off by touching switch off plate. Advantage of this is that you are sure which circuit state you really want, unlike the other touch switch that uses only one plate for on and off. You can replace the bulb with a relay to power up any device.

Part List :-

R1 - 500  kilo ohms 1/4Watt

R2 - 3.9 Mega ohms 1/4Watt

R3, R4 - 5 kilo ohms 1/4Watt

Q1, Q2, Q3 - 2N2222, 9013, or similar NPN transistor

Q4 - 2N4403 or similar (higher the better) PNP transistor

Touch plate - any touch plate for
Lamp - 3V to 6V bulb or relay
DC - 6V battery

Enjoy making such interesting touch switch circkit. If any query arises please ask them in comment section.

Make a 12Volt 10Amp, 20Amp, 30Amp, 40Amp variable transformerless electronic SMPS power supply

How to make a 12v 10Amp to 40Amp (ie 10A, 20A, 30A, 40A) transformerless electronic power supply SMPS based at home at very cheap price and compact.

By: Alok kumar

Today we are going to make a 12volt 5volt 10Amp, 20Amp, 30Amp & 40Amp all in one transformerless electronic power supply which is SMPS (switched mode power supply) which can output tremendous amounts of power in a small form factor. They have overload protection as well built right in, and even a 500W model can be made at reasonably priced with high efficiency. The voltage is incredibly stable. Giving nice, clean DC current even at high loads. 

For making this such amazing circuit you don't need to be from electrical background or either too many tools as weel even you don't have to invest huge money or you don't need to be very smart one.

Today we are going to simply convert a personal computer power supply to a highly stable , efficient, compact and beautiful electronic transformerless power supply SMPS based.

Actually we can buy a computers power supply at very cheap price or even use a old computer power supply ( you might have one in your backyard.) for this project.

Why we are converting a Computer's power supply to a normal general purpose transformerless electronic power supply because
for the same power supply from market you have to pay a 10 times more than the budget we are going to make and also the high wattage power supply you got from market may dont have overload protection and such high efficiency. Thats why we are making it because it saves our huge money as well we got variousbenifits like stable & clean DC, overload protection, high efficiency.

So lets get start this project:

All you need is:

1. Needle-nose pliers  computers "ATX Power Supply" or any power supply used in PC. 
   
   
2. 
   
3. Soldering iron 
   3 x "Banana Jack" Insulated Binding Post sets 
   
   
4. 1 x bag of "#6" Ring Tongue Terminals (16-14 gauge) 
                                                                                       
5. Rubber feet 
   
   
6. Small bit of heat shrink. 
   
   
7. Screwdriver 
   
   
8. Wire strippers

Posts Recommended:

1. Make a 12v 5Amp SMPS transformerless electronic power supply
2. Convert any SMPS to solar battery charger circuit
3. Simple 12 v 1 amp SMPS power supply, battery charger, LED driver circuit
4. Make 0~300V Variable Voltage & Current Transformerless Electronic Power Supply, LED Driver, Electronic Dimmer
5. Make 5V 1Amp Cell Phone battery Charger Circuit from 220/110v

Step 1:

First of all you need to get one  of this compuer's power supply for this project to make a 12volt and 10,20,30Amp...

We shoud first consider safety because project deals with high power capacitors. so forst unplug the Power supply from pc and mains leave it for 2 days to discharge and always put insulating gloves while doing this project.

  

Step 2:

Open up the ATX power supply or any you have to open the power supply it will look like below circuit diahram

opened power supply

Now here come the tiring or daunting task of shorting or identifying the wire from hundreds of different colored wire. Here the only color we care about is BLACK, RED, YELLOW, GREEN. Any other colored wire are not of our use so you can leave it or totally cut those off the supply.

Here the colour we care about represents:

YELLOW = 12 volts
RED = 5 Volts
ORANGE = 3.3 Volts
BLACK = Common Ground.

or you can simply check via a multimeter but be careful.

Step 3:

Now you are done. The only thing you have to do sort all same colour wire and group them together and connect them all. We have to connect all same colored wire together to harness the full amperage and wattage from this supply. Now the wire will look like this figure

Now technically you are done Yello and black wire will give you around 12volt 20Amp, red and black will give you 5volt and 32Amp if you need more amperage just buy a computer power supply of high wattage mine was 240watt (approx.)

Now what you can do is to make it beautiful and compact.

Step 4:

Now make a 4 hole as shown in figure and connect those group of wire according to given in figure and you are done.

enjou your 12v 20 amp, 5v 32amp etc...or more it will depend upon the wattage of power supply

Step 5:

Drill 4 holes like given in figure.

connect group of wires to those pins or any pins you have. But keep caution that these wire don't short with each other

Final transformerless electronic power supply SMPS based compact shoud look like this

Enjoy above beautiful circuit. For any querry please ask them in comment section.

Thank You for reading this post.

Make a 5volt 8-100mAmp transformerless electronic power supply or cell phon battery charger at home

How to make 5volt 8 to 100mAmp transformerless electronic power supply or cell phon battery charger simple compact, efficient and cheap at home.

By:Alok kumar

Almost all of our electronic products or projects, we need a compact cheap power supply for converting mains AC voltage to a regulated DC voltage. For making a power supply designing of each and every component is essential. Here I’m going to discuss the designing of  regulated 5V Power Supply.

To make a transformerless electronic power supply or Capacitor Power Supplies, we use a Voltage Dropping non polar Capacitor in series with the main line. An ordinary capacitor can not be used in these applications because Mains Spikes may create holes in dielectric of ordinary capacitors and the capacitor will fail to work or even may explodes. This may destroy the device connected to such power supply. Thus we use X Rated Capacitor with required voltage is used for this project. X Rated Capacitors rated for 250v, 400v, 600v AC and higher voltage levels are also available. Reactance of the voltage dropping capacitor should be greater than the load resistance to keep constant current through the load otherwise the current may drop when connected to different loads.

make 30volt 1amp transformerless power supply circuit

How to make 30volt 1amp transformerless electronic power supply simple and sleak at home.

By:Alok kumar

Today i am going to post an article about the 30watt power supply which id 30volt and 1Amp transformerless electronic power supply circuit for medium current application. This circuit is not only compact circuit but also cheap and compact circuit.This circuit an be made at home using easily available component at market.

Simple Light Dark Detector circuit using LDR

How to make very Simple Electronic Dark or Light detector circuit using LDR and Integrating a Relay in it for making it a  Automatic Switch.

By: Alok kumar

Today we are going to learn how to make an eletronic dark or light detector circuit because this marvelous piece of gadget can be very useful if integrated with other devices as a switch. It means when a certain predefined intensity of light is reached our device is able to detect that condition and able to switch any device and can be very useful for saving energy and efforts. We can make a Automatic Lawn Light, Automatic Bulb or Tubelight, Automatic Car Head Light switch and many many useful circuit. It can be used in various ways if logically applied.

Intelligent Automatic Battery Carger circuit

How to Make the Intelligent Fully Automatic Fast, Efficient Battery Charger circuit at home.

By: Alok kumar

While i was searching for fully automatic battery charger or fast diehard battery charger what i found on google was only crap but nothing, I dont know either most of the people dont know what exactly fast battery charger is or they dont want to share that with public. Today i am going to explain How to make a intelligent fully automatic battery charger(6v 12v 48v or any) circuit.

First you should know that, we can not charge the lead acid batteries faster because Lead acid batteries are not designed to accept high current level continuously.

How fast charging is Done:

For charging the batteries faster we apply the full dose of  high current specified for that battery and when full charged automatically switch off the charging to prevent battery from overcharge. It works best for Li-ion batteries
.

The bottom line with Lead Acid batteries is that these can not be charged quickly unless a intelligent Automatic circuitary is incorporated.

Fast charging, It should be done in step wise mechanism means initially we charge using X1 rate and then gradually reducing the rate of charging to X1/10
as battery is getting charged we need to slow down the charging rate to prevent battery from damage and overheat. And when battery becomes full charged that need to autocut the charging operation.

Fastest 10minute Battery Charger circuit.

How to make Easiest 10-15 minute fastest Battery Charger

By: Alok kumar

Today i am going to explain how we can make the worlds fastest battery charger circuit at home in 5 minutes. It uses the most basic principle although it should be taken care that battery should not overcharged because it charges faster than any other charger.
The fast chargers out in the market actually is useless because i actually dont understand why their output current is much higher than specification of the battery. it may charge the battery faster like in 10 minutes but battery sooner become dead and useless and expands. They actually have no idea how fast charging works.

so just not wasting our precious time lets get started.

Here the components required is very popular and cheap so just dont worry you will get those components in seconds...

Components Required:

1. One rectifier diode IN5402, or IN5408, any you can find quick.

2. One incandescent bulb, having nearly exact voltage rating as the battery but current rating of the bulb should be 1/10 of the value of battery AH (AmpereHour).