How a Relay Works in Circuits

Jan 27, 2012

If you are wondering how a relay works in order to switch heavy electrical loads through an electronic control circuit, you would need to learn the following article.

Making a Transisor Relay Driver Circuit

Relays are one of the most important components in electronic circuits. Especially in circuits where high power transfer or mains AC load switching is involved, relays play the major role in implementing the operations. Let’s learn more regarding these outstanding devices and how to configure them in electronic circuits through relay driver stage.

How to Save Electricity at Home - General Tips

Saving electricity will not only save you some bucks but also help in a social cause. A little awareness and alertness is all that is required for the purpose.

How to Manufacture Automobile Electronic Parts and Earn a Handsome Income

To set up an auto electrical manufacturing unit, it's important to have a thorough knowledge regarding the various technicalities associated with the field. The article makes a comprehensive approach and explains all the issues related to the subject.

How to Make Any Light a Strobe Light Using Just Two Transistors

If you feel strobe lights very interesting but are disappointed by the fact that these wonderful light effects can be produced only through complex xenon tube then probably you are quite mistaken.

How to Make Your Own Active Loudspeakers - Speaker Amplifier

Jan 26, 2012

With the advent of ultra modern cell phones, now it has become possible to store huge music data and listen to them with just a flick of your finger. But listening to music becomes significantly pleasing only if it’s hugely amplified and reproduced over active loudspeakers or with systems incorporating a speaker amplifier circuit.

How to Understand and Use Capacitors in Electronic Circuits

Seen those colorful, cylindrical and chocolate shaped parts on a PCB? These may be actually the capacitors of different makes and brands used extensively in electronic circuits. To know more regarding what is a capacitor, just go through the article.

How to Understand Diodes and Build a Bridge Rectifier

Jan 23, 2012


Diodes are one of the important electronic components used for rectifying an AC into DC. Diodes have the property of allowing DC through a specified direction and rectifying AC across its pin outs. Let’s learn the components more elaborately.
Diodes are tiny electronic components which are normally recognized by their cylindrical black colored body having a white band at the edge of their body. 

How to Understand and Use Transistors in Circuits

Jan 22, 2012

Transistors are the building blocks of all semiconductor devices found today. If there wouldn’t be transistors there wouldn’t be any ICs or any other semiconductor component. Even ICs are made up of millions of closely knit transistors which constitute the features of the particular chip.

Simple Hobby Electronic Circuits

Jan 20, 2012

A few of the interesting and useful hobby electronic circuit diagrams already published in this blog have been selected and compiled here for quick reference and understanding.


Simple Touch Sensitive Switch Circuit

We all know about this little versatile chip which finds its way in almost all useful electronic circuits, yes our very own IC 555. The following circuit is no exception, it's a sensitive touch switch circuit using the IC 555.
Here the IC is configured as an monostable multivibrator, in this mode the IC activates its output momentarily by producing a logic high in response to a trigger at its input pin#2.
The momentary activation time period of the output depends on the value of C1 and the setting of VR1.
When the touch switch is touched pin#2 is pulled to a lower logic potential which may be less than 1/3 of Vcc. This instantly reverts the output situation from low to high activating the connected relay driver stage.
This in turn switches ON the load attached with the relay contacts but only for the time until C1 gets fully discharged.

Simple Triac Dimmer Circuit

The circuit of a simple triac light dimmer shown below can be used for dimming incandescent lamps directly from AC mains. The circuit is very easy to construct and uses very few components. The pot is used for controlling the load power or the intensity of the light. The circuit can be also used for controlling ceiling fan speeds.
Simple Audio Power Amplifier Circuit

The circuit illustrated here is probably the simplest form of an audio power amplifier. Though the circuit is very crude by its specs yetis able to amplify an audio input up to a powerful 4 watts in a 8 Ohm speaker.The transistor is a 2N3055 is used as a switch for inducing voltages in response to the input signals into one half winding of the transformer. The back emf generated across the winding of the transformer is effectively dumped over the speaker generating the required amplifications. The transistor needs to be mounted on a suitable heatsink.



Simple Water Level Alarm Circuit
Just a couple of transistors are enough for implementing a simple water level alarm circuit and used for getting a warning signal when the water level inside a tank nears the overflowing level. The two transistors are configured as a high gain, high sensitive switch, which also is capable of generating a tone when the shown terminals get bridged through the terminals coming in contact with the water inside the tank. The water offers just about the right resistance value across the specified points of the circuit for initiating high pitched tone or the desired warning alarm.

Simple Temperature Detector Circuit

A very simple temperature indicator circuit can be built using the circuit shown in the diagram. A generally purpose small signal transistor is used here as the sensor and another active device in the form of a1N4148 diode is used for providing a reference level to the sensing operation.The heat source which is to be measured is place in contact with the transistor while the diode is held at a relatively constant ambient temperature level.
As per the setting of the preset P1, if the threshold is crossed by the introduced heat source, the transistor begins to conduct substantially, illuminating the LED and indicating the generation the heat beyond a particular set limit.



Parts List for the above simple transistor hobby circuit
R1 = 1K,
R2 = 2K2,
D1 = 1N4148,
P1 = 300 Ohms,
T1 = BC547
LED = RED 5mm
100 Watt Transistor Based Inverter Circuit


Inverters are devices which have important applications where normal electric supply is not available or difficult to obtain through conventional routes. The simple 100 watt inverter circuit shown here can be built and used for powering many electrical appliances like, lights, soldering iron, heater, fan etc. The whole circuit mainly involves transistors and therefore becomes easier to construct and implement.

Parts List
R1, R4 = 330 Ohms,

R2, R3 = 39K,

R5, R6 = 100 Ohms, 1watt,

C1, C2 = 0.47uF,

D1, D2 = 1N5402

T1, T2 = BC547,

T3, T4 = TIP127,

T5, T6 = 2N3055,
Transformer = 9-0-9V, 10Amp, 220V or 120V

100 Watt Transistor Power Amplifier Circuit




This circuit of a transistor power amplifier is outstanding with its performance and is able to provide a thumping 100 watts of pure music output. As can be seen in the diagram it utilizes mainly transistors for the implementations and a handful of other inexpensive passive components like resistors and capacitors. The required input is not more than 1 V, which gets amplified 200,000 times at the output.

Please refer the article below for the parts list:

http://homemadecircuitsandschematics.blogspot.com/2012/01/how-to-make-hi-fi-100-watt-amplifier.html

Simple Automatic Emergency Lamp Circuit



This simple emergency lamp circuit uses very components and yet is able to provide some useful service. The shown device is able to switch ON automatically when mains power fails, illuminating all the connected LEDs.As soon as power is restored, the LEDs shut off automatically and the connected starts charging through the built in power supply. The circuit employs a transformerless power supply for initiating the explained automatic actions and also for trickle charging the connected battery.

Parts List for the above CIRCUIT DIAGRAM

R1 = 220K,
R2 = 10K,
D1, D2, D3 = 1N4007,
Z1 = 15V 1watt, zener diode,
C2 = 100uF/25V
LEDs = white, high bright type.

Automatic Day Night Light Switch Circuit



This simple transistor circuit can be used for monitoring the dawn and dusk conditions and for switching lights in response to the varying conditions. Thus the circuit can be used for switching ON the connected lights when night sets in and switch it OFF during day break. The threshold tripping point may be set by adjusting the 10K preset.
The capacitors are 100uF/25V, the transistors are ordinaryBC547, and the diodes are 1N4007.

Electronic Candle Circuit




This is a simple hobby project and exhibits all the properties of a conventional wax type candle. Here the LED is used in place of the candle flame, which illuminates as soon as the mains power fails and shuts off automatically when the power is restored. So it also performs the function of an emergency lamp. The connected battery is used for powering the candle”light and it is charged continuously when the unit is not being used and powered through the mains supply.

An interesting “puff off” feature is also included so tatthe “candle” light may be switched OFF whenever desired through a puff of airinto the attached mic which acts as the air vibration sensor.

Simple Emergency Flashlight Circuit

This circuit may be used as an automatic emergency lamp when there’s no power or when mains power fails during night times. As shown in the diagram, the circuit utilizes a cheap incandescent flashlight bulb for the required illumination. As long as the input supply from the mains transformer is present the transistor remains switched OFF and so does the lamp. However the moment the mains power fails, the transistor conducts and switches ON the battery power to the bulb, instantly illuminating it brightly.

The battery is trickle charged for so long as the mainspower remains connected to the circuit.

Parts List
R1 = 22 Ohms,
R2 = 1K,
D1 = 1N4007,
T1 = 8550,
Lamp = 3V flashlight bulb.
Transformer = 0-3V, 500 mA,
Battery = 3V, penlight 1.5 V cells (2nos. in series)

Music operated Dancing Light Circuit




This circuit may be used for transforming music into dancing light patterns. The operation of the circuit is very simple, the music input is fed to the bases of the shown transistor array, each of them are configured to conduct at a specific voltage level in the incrementing order from the top to the bottom transistor.

Thus the uppermost transistor conducts with the input music is at the minimum volume level and the subsequent transistor starts to conduct in sequence as per the volume or the pitch of the music. Each transistor is rigged with individual lamps which light up in response to the music levels in a “chasing” dancing light pattern.

Parts List

All the base presets are = 10K,
All the collector resistors are 470 Ohms,
All the diodes are = 1N4148,
All NPN transistors are = BC547,
The single PNP transistor is = BC557,
All the triacs are = BT136,
The input capacitor = 0.22uF/25V non polar.

Simple Clap Switch Circuit

The interesting clap switch circuit shown here can be used in stairways and passages for illuminating the premise momentarily through clap sound. The circuit is basically a sound sensor circuit with an enclosed amplifier stage. The clap sound or any similar sound is detected by the mic and converted into minute electrical pulses. These electrical pulses are suitably amplified by the subsequent transistor stage.

The Darlington stage shown at the output is the timer stage which switches in response to the above sound interaction and illuminate the connected LEDs for some period of time defined by the 220K resistor and the two39 K resistors. After the time lapses the LEDs are switched off automatically and the circuit returns to its original state until the next clap sound is detected.
The parts list is given in the circuit diagram itself.

A Simple ELCB Circuit



The circuit shown here can be used for detecting earth leakage conditions and for implementing the required shutting off the mains power supply. Unlike usual configurations, here the ground to the circuit and the relay is acquired from the earthing line itself. Also since the input coil is also referenced to the common earthing ground, the entire functioning becomes compatible and accurate.

On sensing a possible current leakage at the input, the transistors come into action and switch the relays appropriately. The two relay have their individual specific roles to play. One relay detects and switches OFF when there’s current leakage through an appliances body, while the other relay is wired up to sense the presence of a the earthing line and switches OFF the mains as soon a wrong or weak earthing line is detected.

Parts List
R1 = 33K,
R2 = 4K7,
R3 = 10K,
R4 = 220 Ohms,
R5 = 1K,
R6 = 1M,
C1 = 0.22uF,
C2, C3, C4 = 100uF/25V
C5 = 105/400V
All diodes = 1N4007,
Relay = 12V, 400 Ohms
T1, T2 = BC547,
T3 = BC557,
L1 = output transformer as used in radio push pull amplifierstage
Simple LED Flasher




A very simple LED flasher circuit is illustrated in the diagram. The transistors and the corresponding parts are connected in the standard astable multivibrator mode, which forces the circuit to oscillate the moment power is applied. The LEDs connected at the collector of the transistors start flashing alternately in wig wag manner. The LEDs shown in the diagram are connected in series and parallel, so that many numbers of LEDs can be accommodated in the configuration. The pots P1 and P2 may be adjusted for getting different interesting flashing patterns with the LEDs.

Parts List
R1, R2 = 1K,
P1,P2 = 100K pots,
C1, C2 = 33uF/25V,
T1, T2 = BC547,
Resistors connected with each LED series = 470 Ohms
LEDs are 5mm type, color as per choice.

Simple Wireless Microphone Circuit


Anything spoken into the mic of the presented circuit cab be clearly picked up and reproduced by any standard FM radio, within a range of 30meters of distance. The circuit is very simple and just requires ther shown components to be assembled and connected with each other as depicted in the diagram.
The coil L1 consists of 5 turns of 1mm super enameled copper wire, having a diameter of around 0.6 cm.
Parts List
R1 = 4K7,
R2 = 82K,
R3 = 1K,
C1 = 10pF,
C2, C3 = 27pF,
C4 = 0.001uF,
C5 = 0.22uF,
T1 = BC547
40 LED Emergency Light Circuit




The shown design of a 40 LED emergency light is driven usingan ordinary transistor/transformer inverter circuit. The transistor and the respective winding of th transformer are configured as a high frequency oscillator stage. The oscillations induce a high voltage across the winding of the transformer. The stepped-up voltage at the output is directly used to drive the LED which are all connected in series for getting the desired balance and the illumination.

Parts List
R1 = 470 Ohms,
VR1 = 47K,
C1, C2 = 1uF/25V
TR1 = 0-6V, 500mA,
Battery = 6V, 2AH,
LEDs = high bright white, 40 nos.

Simple Transistor Latch Circuit

If you are looking for a circuit which can be used to latch the output in response to an input signal, then this circuit can be used for the intended purpose very effectively and also very cheaply.
A momentary input trigger is applied to the base of T1,which switches it for a fraction of a second depending upon the length of the applied signal. The conduction of T1 immediately switches T2 and the connected relay. However at the very instant a feedback voltage also appears at the base of T1 via R3 from the collector of T2. This feed back voltage instantly latches the circuit and keeps the relay activated even after the trigger from the input is removed.

Parts List

R1, R3 = 100k,
R2, R4 = 10K,
C1 = 1uF/25V
D1 = 1N4148,
T1 = BC547,
T2 = BC557
Relay = 12V, SPDT

Simple LED Music Light Circuit
In one of the previous sections we studied a simple music light show circuit using mains operated incandescent lamps, the present design incorporate LEDs for similar intended light show generation. As can be seen in the figure, the transistors are all wired up in sequencing array. The music signal varying with pitch and amplitude is applied at the base of the buffer amplifier PNP transistor. The amplified music is then fed across the whole array where the respective transistor receive the inputs with incrementing pitch or the volume levels and go on switching in the corresponding manner from start to finish, producing an interesting LED light sequencing pattern. This light exactly varies its length according to the pitch or the volume of the fed music signal.

Parts list is provided in the diagram.
A Simple 2-Pin Automobile Indicator Lamp Flasher Circuit with Buzzer
If you want to make a flasher unit for you motorbike then this circuit is just for you. This simple turn signal flasher circuit can be easily built and installed in any two wheelers for the desired actions. The circuit employs just two 2-pins instead of 3 as found in other flasher circuits. Once installed, the circuit will faithfully flash the side indicator lights whenever the intended function is switched ON. The circuit also incorporates an optional buzzer circuit which can be also included for getting a beeping sound in response to the flashing of the lamps.

Parts List

R1, R2, R3 = 10K
R4= 33K
T1 = D1351,
T2 = BC547,
T3 = BC557,
C1, C2 = 33uF.25V
L1 = Buzzer Coil

Simple Relay Motorbike Flasher Circuit


In the above section we discussed a simple three transistor based flasher circuit; here we study another similar design, however here we incorporate a relay for the switching actions of the lamps.
The circuit looks pretty straightforward and employs hardly anything substantial and yet performs the expected functions wonderfully well.
Just build it and wire it in your mo-bike for witnessing the intended functions...

Parts List

R1 = 1K,
R2 = 4K7,
T1 = BC557,
C1 = 100uF/25V,
C2 = 1000uF/25V
Relay = 12V, 400 Ohms
D1 = 1N4007

Simple Door Bell Timer, with Adjustable Timing Facility
Yes this simple transistor circuit can be used as a home door bell and it’s ON time can be set as preferred by the user, meaning if you wanted that the sound of the bell to remain switched ON for a particular period of time, you could easily do it just by adjusting the given pot.
The actual tune is derived from the IC UM66 and the associated components, while all the included transistors along with the relay are configured for producing the time delay for keeping the music switched ON.
Parts List

R1, R2, R4, R5 = 1K
VR1 = 100K,
D1, D2 = 1N4007,
C1, C2 = 100uF/25
T1, T3 = BC547,
T2 = BC557
Z1 = 3V/400mW
Transformer = 0-12V/500mA,
S1 = Bell Push
IC = UM66

Timer Circuit with Independent On and OFF Delay Adjust Facility


The circuit can be used for generating delays at a desired rate. The On time of the relay can be controlled by adjusting the Pot VR1 while the pot VR2 may be used to decide after how long the relay responds once theinput trigger is fed by the switch S1.

The parts list is enclosed inside the diagram.

Simple High and Low Mains Voltage Cut Off Circuit



Are you having problems with your input Mains supply? That’s common problem associated with our input mains AC line, where a high and a low voltage conditions are quite frequently encountered by us. The simple circuit shown here can be built and installed in you house electrical board for getting a 24/7 safety from the possible dangerous AC voltage conditions. The circuit keeps the relay and the wired appliances as long as the mains input stays within a safe tolerable level and switches the load OFF the moment a dangerous or unfavorable voltage condition is sensed by the circuit.

Parts List

R1, R2 = 1K,
P1, P2 = 10K Preset,
T1, T2 = BC547B,
C1 = 100uF/25V,
D1 = 1N4007
RL1 = 12V, SPDT,
TR1 = 0-12V, 500mA
0 – 40 V, 0 – 4 Amp Continuously Variable Power SupplyCircuit



This unique work bench circuit utilizes only a few inexpensive transistors and yet delivers some truly useful features. The feature includes continuously variable voltage from zero to the maximum transformer voltage and current variable from zero to the maximum applied input level. The output of this power supply is also over load protected. The pot P1 is used for setting the maximum current while the pot P2 is used for varying the output voltage level up to the desired levels.

Parts List
R1 = 1K2,
R2 = 100 Ohms,
R3 = 470 Ohms,
R4 = Evaluate using Ohms law.
R5 = 1K8,
R6 = 4k7,
R7 = 68 Ohms,
R8 = 1k8,
T1 = 2N3055,
T2, T3 = BC 547B,
D1 = 1N4007,
D2, D3, D4, D5 = 1N5408,
C1, C2 = 2200uF/50V,
Tr1 = 0 – 35 Volts, 3 Amp

Simple Crystal Tester Circuit

When it comes to frequency generating circuits or rather precise oscillator circuits, crystals become a crucial part, especially because they play an important role for generating and maintaining accurate frequency rates of the particular circuit. However these devices are prone to many defects and are normally difficult to check through conventional DMM units.

The shown circuit can be used for checking all types of crystals instantly. The circuit itself is a small transistor oscillator circuit which starts oscillating when a good crystal is introduced across the indicated points in the circuit. If the crystal is a good one, the bulb lights up showing the relevant results and if there’s any defect in the attached crystal, the bulb remains switched OFF.

Simple Current Limiter Circuit Using two transistors

In many critical applications, circuits are required to maintain a strict controlled magnitude of current through them of at their outputs. The proposed circuit is exactly meant for carrying out the discussed function. The lower transistor is the main output transistor which operates the output vulnerable load and by itself is unable to control the current through it. The introduction of the upper transistor makes it sure that the base of the lower transistor is allowed to conduct as long as the current output is within the specified limits. In case the current tends to cross the limits, the upper transistor conducts and switches OFF the lower transistor inhibiting any further passage of the exceeded current limit. The threshold current may be fixed by R which is calculated with the shown formula.

NiMH, NiCd Battery Charger Circuit

Jan 18, 2012

A single state-of-the-art chip, a transistor and a few other inexpensive passive components are the only materials required for making this outstanding, self regulating, over charge controlled, automatic NiMH, NiCd battery charger circuit. Let’s study the whole operation explained in the article.

How to Make a Simplest Blue, White LED Driver Circuit - Joule Thief

A simple circuit described here explains a principle through LEDs can be driven much more efficiently compared to the traditional methods.

How to Make a Simple Metal Detector Circuit Using IC CS209A

Jan 15, 2012

The principle of operation of the proposed metal detector circuit is quite basic yet very interesting. The detecting function is triggered by sensing the decrease in the Q level of the LC network associated with the circuit in the presence of a metal at a specified proximity level.

How to Understand Proximity Detector IC CS209A Pinouts - Datasheet Explained

The device CS209A is a bipolar monolithic IC specifically designed for metal detecting circuit applications. The IC fundamentally has a built-in oscillator stage, a couple of current regulator stages, a low level feed back circuit, and a few other relevant stages like peak detection/demodulation stage, a comparator stage and  a couple of complementary output blocks.

How to Make a Simple Frequency Counter Circuit

Jan 14, 2012

A very simple frequency counter circuit is shown below and can be easily built by any electronic enthusiast for the intended purpose. The circuit diagram was provided by Mr.Kapital through an order in Fiverr.com, I was asked to explain the functioning by him.

The Circuit can be understood with the following points: 

Simple Ignition Code Lock Circuit for Your Vehicles

Jan 13, 2012

This innovative circuit can be used for locking a vehicle’s ignition by typing a hidden code over the given micro switch keypads. So now you can use this simple code lock ignition circuit for probably securing your car from a possible theft. Alternatively the circuit may be used for any application requiring security or safeguarding from external intrusions and thefts.

How to Make a Ghost Detector Circuit

Do you believe in the existence of ghosts? Well some of you may answer positively while some may just nod their heads showing sheer skepticism regarding the issue. Whatever may be the reactions; nobody just can’t deny or ignore the responses delivered from the circuit explained in this article.

Wireless Li-Ion Battery Charger Circuit

Jan 12, 2012

Charging batteries through inductive wireless charging is one of the applications that’s becoming very popular and getting appreciated by the uses. Here we’ll study how to make a wireless Li-Ion battery charger circuit using the same concept.

How to Make an Outstanding Home Theater System Circuit

Jan 11, 2012

The article discussed here provides a simple, cheap home theater system circuit that may be built at home and used for the desired purpose. The results from this circuit design are outstandingly rich and have the capabilities comparable with the costly hi-end types available in the market.

How to Generate Electricity from Vegetables and Fruits - Making a Potato Battery

Alessandro Volta was probably the first man to devise the method and idea of generating electricity from electrolytic solutions. According to his concept, two dissimilar metals when brought in contact with an electrolytic solution would initiate electron movement across the two metals, joined externally together using a conductor.

Variable Voltage, Current Power Supply Circuit Using Transistor 2N3055

Jan 9, 2012


 A power supply that does not include the features of a variable voltage and current control can by no means be considered truly versatile. A workbench power supply circuit explained in this article is not only specified with a continuously variable voltage control but is also equipped with the feature of overload or continuously variable current control.

How to Make a Light Activated Day Night Switch Circuit – Science Fair Project

Jan 8, 2012

The circuits explained here can all be used for controlling a load, normally a lamp, in response to the varying levels of the surrounding ambient light.

How to Make a Hi-Fi 100 Watt Amplifier Circuit Using 2N3055 Transistors

Jan 7, 2012

The amplifier circuit explained here was built and tested by me and am extremely pleased by its performance and also ruggedness as far as maintenance and handling is concerned.

How to Make Over Head Tank Water Level Indicator cum Controller Circuit

The circuit provided in this article performs a dual function of both, as an over head tank water level indicator as well as a controller. The indications of the rising water are provided by five LEDs, which light up sequentially in response to the rising water level inside the tank.

How to Make an Interesting Random LED Flasher Circuit for Decorating a Christmas Tree

I have already discussed a few interesting applications of the IC 4060 as an oscillator for driving clock input ICs like 4017 and also as a timer for producing variable time delays, ranging from  a few seconds to many hours. The oscillator function of the IC can also be effectively employed for driving colorful LEDs and for creating interesting LED light show. The idea can be used for illuminating vehicles, houses and typically Christmas trees during Christmas.

Simple Timer Circuit Using IC 4060

I have already discussed this IC comprehensively in one of my previous articles, everything regarding its pin outs have discussed there in detail. We studied there that the IC 4060 is specifically suited for timer applications and also as an oscillator. In this article we’ll study how a simple versatile timer can be built using the IC 4060.

Adjustable Timer Circuits Using IC 555

Jan 6, 2012

A timer is a device which produces a delay period after which an external connected electrical load is triggered. The produced time delay is normally adjustable and the user has the freedom to set the time period as desired. There are many ways of making simple timer circuits using different ICs and discrete components; here we discuss one such circuit using the ubiquitous IC 555.

Simple PWM Controlled DC to DC Cell Phone Charger Circuit – Science Fair Project

The explained circuit can be easily made at home by any school kid and used for displaying in his science fair exhibition. The circuit is a simple cell phone charger that may be operated in conjunction with any DC source, from a car or a motorcycle battery or from any ordinary 12 V AC DC adapter.

How to Make a Cell Phone RF Signal Detector Circuit – A Simple Science Fair Project

A simple electronic circuit project is discussed here that may be built by any school student for displaying in a school fair science exhibition.

GSM Based Cell Phone Remote Control Switch Circuit


Now you can control any electrical gadget from any part of the world through your cell phone, that too without spending a penny for the individual commands. Whether it’s you vehicle, your basement door, your mansion gate or simply the air conditioner of your house, everything can now be switched by just a flick of your cell phone button. And mind you, it’s completely fool proof, meaning no false triggering is possible through any other cell phone signals, it works only through the owners cell phone commands.

How to Make an Electronic Toggle Switch Circuit

Jan 5, 2012

A toggle switch refers to a device which is used for switching an electrical circuit ON and OFF alternately whenever required. Normally mechanical switches are used for such operations and are extensively employed wherever electrical switching is required. However mechanical switches have one big drawback, they are prone to wear and tear and have the tendency of producing sparking and RF noise.

Closed Loop Single Phase AC Motor Speed Controller Circuit

The article presented here explains a very simple circuit that may be used for controlling single phase AC motor speeds.

How to Generate Electricity from Sea Water - Simple Experimental Project

Just like wind and sun, sea is another example of massiveness and a potential raw energy source that may be harnessed for acquiring electrical power. Yes, just as solar or wind power, sea surfs can also be effectively dimensioned and converted for generating electricity. How? We’ll learn in this article through one simple experimental set up.

What is Hysteresis in Electronic Circuits

Jan 4, 2012

You might have searched regarding what is hysteresis a number of times through many different posts on different websites, but to no avail.

Make this Wireless Speaker Circuit - Make Your Own Radio Station Science Project

The article explains a very simple circuit of a wireless speaker system which can be used for playing hi quality music wirelessly from your TV set, DVD player, Ipod, cell phone or from any music system.

Rain Sensor Circuit

Jan 3, 2012

This is a simple rain sensor circuit which can be built by a school grade student very easily and can be used for displaying its relatively useful feature, probably among his friends or in a science fair exhibition.

How to Make a Homemade Earth Leakage Circuit Breaker (ELCB) Unit Using IC 324

Jan 2, 2012

An earth leakage circuit breaker is a safety electrical device used for monitoring current leakages through the “earthing” terminal and switching OFF the mains when this leakage exceeds a certain dangerous level.

Simple Low Battery Indicator Circuit Using IC 741

Jan 1, 2012


The proposed circuit was requested by one of the avid readers of my blog. It is a low battery warning indicator circuit and can be used for monitoring a particular low battery voltage threshold.

How to Make Car LED Chasing Tail Light, Brake Light Circuit

The circuit explained here is presented in response to a request sent by one of the avid readers of this blog. The proposed circuit is of a sequential LED light driver, especially designed to suit the application of a multipurpose car tail light indicator.
 

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