Sunday, March 22, 2009

Starting to Electronics Blog

The world is moving ahead. In this time Electronics has become undivided to our modern and comfortable life. Modern world depends on Electronics. It has so much branches. As it is a blog for discussing about Electronics, Now I want to describe you some plans and projects about Electronics. Mainly, this projects are based on IC 555, you will have some descriptions about this IC as well as several projects. The projects are easy to build and nice to use. This matchines help to make comfort our life. Though this matchines are small but they help to remove odds which hampers ours comfort in life

Digital dice


We can easily playing a monopolies playing item with this circuit diagram. This thing is made by two IC and a seven segment. First IC is 555 timer. Seven segment driver IC after press the button this it will played in the display.

Relay on/off Time Adjuster Circuit


This circuit is built around the popular timer IC 555. This circuit is designed to adjust both the on off times of the relay.Here, the IC 555 has been used as an astable multivibrator. Diode D1 and D2 and two preset controls VR1 and VR2 have been used to get separate On and Off timings for the relay. By using this controls VR1 and VR2 the On and off timings of the relay can be adjusted independently.Time period of the On and Off time to relay can be adjusted from 1 second to about 90 seconds by using the given values of VR1, VR2 and the capacitor C1. Take care to use a new IC for this circuit because a used IC may not perfom perfectly. Similarly, the Capacitor C1 should also be from a good and reputed manufacturer such as Keltron, Uptron or Phillips.

Simple Siren


There can be many siren circuits based on the IC 555. These circuits can be operated from 5V to 17V supply.
The circuit given here gives out the tone of a common siren. IC 555 is used in the circuit as an astable mutivibrator. The siren tone can be adjusted by preset VR1(10K). The capacitor used at pin no.3 of the IC, determines the shape of the outform waveform. Sound is received by giving the output to the speaker. If this output signal is amplified by a high power amplifier then a very loud sound can be received from this circuit.
Parts list::::::Resistance :1K, PRESET 10KCapacitor : 10KPfx2, 10MF, 10V, 100MF, 10V, Loue speaker 8E.

Automatic street light controller


This street light controller circuit is designed around a single IC timer 555. This IC has been used in it’s bi-stable mode in the circuit. Two LDRs are also used in this circuit to differentiate between the day light and the darkness of the light. During the day time this bi-stable circuit remains reset by the LDR-2 while in the night time this bi-stable is set by the LDR-1. The output from the timer IC is given to the base of transistor T-2 which drives the relay in turn. Street light connections are given from the N/O contacts of the relay as shown in the figure. The number of lights which can be connected in parallel to this circuit depends directly upon the load rating of the relay contacts.

Automatic time indicator for the Telephone


As, you already know, the telephone calls are charged on the basis of the time duration for which the call has been made. If the call is continued after the standard time is over, then your calling time will be extended and the charges will be added up accordingly. It is very difficult to keep an eye on the time elapsed while you are busy in talking on the phone. This novel circuit does just this for you while you are talking on the phone. The circuit gives out a warning signal after 2.5 minutes of starting the call.The On/Off touch plates are made from the conducting silver paper strips and fixed in a suitable position on the cabinet

MOSQUITO REPELLENT


This circuit is based on the popular timer IC 555. This is a unique circuit that sends the mosquitoes flying away from your room. In this circuit, the IC 555 works as an oscillator that outputs a frequency range of minimum 200Hz to a maximum frequency range of 62 KHz. The output frequency can be adjusted by the preset R-2 connected in the circuit. A high quality speaker should be used with this circuit.

PARTS LIST::::1/ IC 5552/ Resistance : 220E, 1ME, Control- 5K3/ Capacitor :0.005, 0.1, 100MF/10V, Loud speaker.

Melody door bell



Melody door bell circuit circuit. After pressing this musical stared. 1.5 volt will required to move this circuit is made by UM66 IC and two transistor. There is a push button at this

Telephone line monitor


You can easily record your telephone conversation with this little circuit. First time you have to attach your circuit remote jack with recorders. Seconds mikes input when you will draw the receiver from telephone set. Conversation will record in the both side automatically. This hole circuit is made by two transistor. It may be kept at any place with phone.

Self reset touch switch


Here a self reset touch switch is made by timer IC. When you touch the plate no.3 pin will be high and it will on the load at the perfect time load will be off automatically. Here time is delayed by R1, R2,and C2.

Multi Tester


Transistor, Led, Diode, Capacitor may be checked by multi tester. To check the diode attach the point d and c. The if you get off LED. It will be under stood that its opened and you get twice on LED. It will be proved short circuit. If you want to proved diode is ok. You will get LED on at the same procedure may be checked.

Sound operated switch


This circuit diagram is a little sound operated switch. Here microphone is used to get the sound, transistor is used to amplify the sound. After receiving sound into the microphone it trigger SCR and switch the relay by using transistor. At the result loads press S1. becomes on/off. If you want to deactivate the load you have to 6v DC will be required to move the circuit

TURN INDICATOR



The circuit given here can be used as a turn indicator which you can connect to your vehicle.In this circuit IC 555 is used for frequency oscillation. When we keep switch S1 in center position of 1-pole 3 way switch then both indicator bulbs remain in OFF. When the switch S1 is brought in left position then left indicator blinks and when the switch S1 is brought in right position then right indicator blinks.

Automobile flasher


Electromechanical methods are still used switching the blinkers in the automobiles. Electronic automobile flashers are made by using transistors. In the circuit given here an IC has been used for the same purpose. The circuit is built around the popular timer IC 555 which is used in the as table mode. This is a free running multi vibrator. Here, the output pin no 3 of the IC 555 is connected with the base of the transistor T1( AD149 ). This transistor works as an electronic switch. The panel Leds connected on the dashboard indicate the working of the flasher bulbs. Rate of the flashing of the bulbs is kept at 95/min. This rate can be changed by changing the value of the capacitor C1. When the value of this capacitor is increased then the rate of flashing becomes faster. Transistor T1 ( AD149 ) is a power transistor and it is necessary to mount it on a heat sink. The LED indicates should be mounted at a convenient position on the dash board.