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Tuesday 25 June 2013

Game Circuit for Steady Hand

Hi, friends here I am presenting a game named Steady Hand which is can be use to check the state of sobriety. This is the electronics games that you can built for your birthday party, friends outs or even for your mid term project or final project too. I have develop a simple formula which help you to understand the game that is :
 Percentage of Soberness = K(n/(1-n)x S)
Where,
K = a constant
n = clever factor (< 1)
S = steady factor

Now, let us talk about the game. Let me warn you here! A good (I repeat good) skill is required to prepare this module. So far as the electronic part is concerned, you can jump at it with your n 0.5 and above, but there is a good deal of craftsmanship involved in it which is not at all electronic. In fact, this latter part is the thing that really matters. The electronic part gives only the audio measure of the steadiness factor achieved. Let us start now.
This is somewhat similar to the age-old steady hand testing game with, of course, a bit of improvement. There are four test sectors in it, each being more than the other successively. Then, there are stoppers, called end_ sectors, to recognise the win of each sector. (These sectors or hurdles will’ tickle your imagination—of course, if you don‘t copy the ones given here). A probe has to be passed through these sectors. Whenever an unsteady hand lets the probe touch any of these sectors, an audio-visual signal announces the failure. The pitch of the audio signal (well, of course not the visual one) increases with the degree of complexity of each sector. The end sectors give the lowest pitch; announcing the win.
 

PARTS LIST

RESISTORS
R182 KΩ
R218 KΩ
hmR333 KΩ
R422 KΩ
R5120 KΩ
R610 KΩ
R7820 Ω
R82.2 KΩ
CAPACITORS
C10.015 μF  Ceramic disc
C210 μF 10V electrolytic
C30.01 μF ceramic disc
ICs
IC1NE555 Timer
IC2CD4016 quad analogue switches
DIODES
D1 to D51N4001
D65mm LED
MISCELLANEOUS
LS8-ohm Loudspeaker
-aluminium rods, aluminium angles, IC sockets, enclosure and hardware…etc


Description

The electronic part of the project is an oscillator built around IC 555. The reset pin 4 of 555, is not connected directly to the positive bus. Rather, it is connected to ground through R8 on one hand and to the sectors on the other hand. There is a probe, connected to the positive of the supply which has to be passed through the sectors. Whenever the probe touches any of the sectors, the positive rail of the supply is applied to the pin 4 of IC1 (NE555) via D1 to D4 and it starts oscillating.
The frequency of this oscillation, and hence the output tone, is controlled by the resistors R1 through R5 between pin 6 and pin 7 of 555. Analogue switches, S1 to S4 (in IC2 CD 4016) are connected across the resistors R1 to R4 in a manner such that S1, when operated, S2 shorts both R1 and R2 and so on. Thus, by activating switches S1, S2 etc the effective resistance between pins 6 and pin 7 of 555 is reduced. The control pins of the switches are connected to the four sectors of the model. Thus, whenever the probe touches the sectors, a control voltage is applied to the corresponding switch, and it is activated. The combination of sectors, switches and resistances is arranged in such a way that the frequency of the output increases with the complexity of the sectors. The circuit can be easily assembled on a veroboard. But if desire , a small PCB can also be made

Microphone Amplifier

If you are looking for the sensitive sound pick-up circuit then here is exactly what you are looking for. The circuit given in this site can be used as a different devices. It can be used as a simple microphone as well as with more exotic device as a sound operated alarm. This circuit is equally effective for a bugging device.

PART LIST

RESISTORS
R11.2 KΩ
R22.7 KΩ
R333 KΩ
R46.8 KΩ
R53.3 KΩ
R6100
R7560 KΩ
R84.7 KΩ
R910 KΩ
VR11 KΩ
TRANSISTORS
T1BC149C
T2BC147B
Capacitors
C147μ  10V
C2,C30.1μ
C4220μ  10V
C510μ
Miscellaneous
BATT 6VOLT Battery
MICCondenser Microphone
OTHERsPCB ,Connecting  wires, hardware etc…

 Microphone Amplifier
Here in the circuit diagram you can see that microphone is employs as the transducer. The output of the condenser microphone is quite low it has to connect with an FET amplifier. This amplifier circuit is power by the R1,R2 resistor network. The output of condenser microphone is fed to a two-stage amplifier. Transistor T1 (BC149C) utilise current series feedback the first stage. The second stage comprising transistor T2 is connected in the voltage shunt feedback configuration. These two stages provide sufficient gain to pick up even the slightest whisper. The amplifier circuit in the site requires  4.2 volt supply which can be obtained with a resistor R9 [1k]. The value of this resistor may be altered to suit a supply voltage other than 6 volts. Output of the microphone amplifier can be made variable by connecting a 10k potentiometer as shown in the circuit. Circuit‘s gain can be increased by reducing the value of R6 to 47 ohms or 22 ohms. depending on the input sensitivity of the main amplifier system. Increase in gain was also observed by using 3V supply and eliminating R9 altogether. The microphone should be housed in a small round enclosure.

Sound Operated Music Bell

Sometimes ringing the bell manually becomes difficult, especially when you are holding something in your hands. The sound-operated music bell takes care of the problem
In this circuit, the use of an external relay has been eliminated. The circuit comprises a trigger stage (around BC548B), a timer stage (NE555) and a melody stage (around UM66 and SL100).
Transistor BC548B is biased inn class C operation. Every second sound cause triggering at pin 2 of 555 timer IC.
When VR1 is at maximum, the hold-on time of NE555 is around 30 seconds. But this time period can be set to a lower value by VR1, as per requirement, using the relationship.
T = 1.1*VR1*C1
Where VR1 is the actual resistance of the preset in circuit. UM66 IC has  ROM memory of 64 notes which are produced one by one and then over with a sound of a clap, the timer is triggered and the output at pin 3 of IC NE555 goes high which gets applied through diode 1N4001 to pin 2 of musical IC UM66. S UM66 gets the positive supply, it starts giving electrical fluctuations of the music to the base of SL100, and the charming music comes and fed to 4-ohm speaker.

PARTS LIST

Resistors (all ¼-watt, ± 5% Carbon)
R1 = 10 KΩ
R2 = 470 KΩ
R3 = 2.2 KΩ
R4 = 150 KΩ
R5 = 100 Ω
VR1 = 1 MΩ
Capacitors
C1 = 22 µF/16V
C2 = 0.1 µF
C3 = 0.22 µF
C4 = 220 µF/10V
C5 = 0.01 µF
Semiconductors
IC1 = NE555
IC2 = UM66
T1 = BC548B
T2 = SL100
D1 = 1N4001
Miscellaneous
MIC1 = Condensers microphone 34 LOD
SW1 = On/Off switch

Monday 24 June 2013

Make a dc power supply variable

The project “VARIABLE REGULATED POWER SUPPLY” plays a very important role in the laboratory functions and that is mainly to the electronics labs. As in electronics all the instruments, components work on a particular regulated dc supply ,so a project which can provide this supply by converting the alternating current to direct current that too into a great range of regulated power keep its own preference. As it can produce a range of 0-30 v direct current by regulating and converting alternating current is has a vast application too. Such converters are also known as “Switch Mode Power Supply” (SMPS). AC to DC converters generally comprise a rectifier bridge to rectify the AC current of the input line and a regulating device supplying on output of one or more regulated DC voltages.
Just the simple ac current is applied and through potentiometer you get the desired regulated dc power supply.

Following is the list of parts or the components required to design this circuit:
1.      BR1 = Bridge Rectifier, 100V – 3A
2.      C1 = 2200 µF, 63V
3.      IC1 = LM317, adjustable regulator
4.      C2 = 0.1 µF
5.      V = Meter, 30V, Ri = 85 ohm
6.      C3 = 1µF, 40V
7.      TR1 = Transformer, 25V, 2A
8.      Plug = 3-wire plug & cord
9.      R1 = 18K, 5%
10.  S1 = On-Off toggle switch
11.  R2 = 220 ohm, 5%
12.  D1 = 1N4001
13.  R3 = 27K, 5%
14.  Fuse = 110V, 500mA, slow-blow
15.  P1 = 5K, potentiometer
16.  P2 = 10K, 10-turn trim-pot
17.  Fuse Holder, wire, solder, case, knob for P1
18.  Red & Black Banana Jacks
WORKING:-
The 110V-AC coming from the powercord is fed to the transformer TR1 via the on-off switch and the 500mA fuse. The 30v ac output (approximately) from the transformer is presented to the BR1, the bridge-rectifier, and here rectified from AC (Alternating Current) to DC (Direct Current). If you don’t want to spend the money for a Bridge Rectifier, you can easily use four general purpose 1N4004 diodes. The pulsating DC output is filtered via the 2200µF capacitor (to make it more manageable for the regulator) and fed to ‘IN’-put of the adjustable LM317 regulator (IC1). The output of this regulator is your adjustable voltage of 1.2 to 30 volts varied via the ‘Adj’ pin and the 5K pot meter P1. The large value of C1 makes for a good, low ripple output voltage.
Why exactly 1.2V and not 0-volt? Very basic, the job of the regulator is two-fold; first, it compares the output voltage to an internal reference and controls the output voltage so that it remains constant, and second, it provides a method for adjusting the output voltage to the level you want by using a potentiometer. Internally the regulator uses a zener diode to provide a fixed reference voltage of 1.2 volt across the external resistor R2. (This resistor is usually around 240 ohms, but 220 ohms will work fine
without any problems). Because of this the voltage at the output can never decrease below 1.2 volts, but as the potentiometer (P1) increases in resistance the voltage across it, due to current from the regulator plus current from R2, its voltage increases. This increases the output voltage.
D1 is a general purpose 1N4001 diode, used as a feedback blocker. It steers any current that might be coming from the device under power around the regulator to prevent the regulator from being damaged. Such reverse currents usually occur when devices are powered down.
The ‘ON’ Led will be lit via the 18K resistor R1. The current through the led will be between 12 – 20mA @ 2V depending on the type and color Led you are using. C2 is a 0.1µF (100nF) decoupler capacitor to filter out the transient noise which can be induced into the supply by stray magnetic fields. Under normal conditions this capacitor is only required if the regulator is far away from the filter cap, but I added it anyway. C3 improves transient response. This means that while the regulator may perform perfectly at DC and at low frequencies, (regulating the voltage regardless of the load current), at higher frequencies it may be less effective. Adding this 1 µF capacitor should improve the response at those frequencies.
R3 and the trimmer pot (P2) allows you to ‘zero’ your meter to a set voltage. The meter is a 30Volt type with an internal resistance of 85 ohms. I you have or obtained a meter with a different Ri (internal resistance) you will have to adjust R3 to keep the current of meter to 1mA. Just another note in regards this meter, use the reading as a guideline. The reading may or may not be off by about 0.75volts at full scale, meaning if your meter indicates 30 volts it may be in reality almost 31 volts or 29 volts. If you need a more precise voltage, then use your multimeter.

Sunday 23 June 2013

FOUR IN ONE SIREN CIRCUIT

The UM3561 contains programmed mask ROM to simulate siren sound. Power consumption of IC is low.It is powered by 3 Volt. One NPN Transistor is used for amplification of audio signal.

This circuit gives sound of Police siren, Ambulance siren, Fire brigade siren and Machine gun sound. 
Part List :

IC UM3561
Resistance = 220 Ohms
Condenser 100Mfd
Transistor BC548
Battery Container 3V
Switches

UM3561 IC includes  oscillator and selector circuits so few external component is used for construction of four tone siren.

UM3561 is an excellent ROM IC that can generate Multi siren tones simulating Police siren, Ambulance siren, Fire brigade siren and Machine gun sound. This 8 pin low power IC can work down to 2.4 volts.

The UM 3561 is a low cost siren generator designed for use in toy applications. The IC has an inbuilt oscillator and tone selection pins. It is easy to make a siren generator with only a few external components. Only one external resistor and a speaker driver transistor are sufficient to make a simple siren generator.

Inside the UM3561
Inside the IC, there is an oscillator circuit and the frequency of oscillations is controlled by the external resistor connected to OSC 1(Pin 7) and OSC2 (Pin 8). A 220 K resistor will give satisfactory results. The oscillations thus generated will be then transferred to a control circuit which function based on the tone selection through the connections of SEL 1 (Pin 6) and SEL2 (Pin 1) . The control circuit passes the signal to an address counter and then to the ROM. The tone pulses thus generated will be available from the output pin 3. Since the sound is weak, an amplifier is necessary to get loud sound. A single NPN transistor will amplify the sound.

Pin 1 Tone Sel.2
Pin 2 Gnd
Pin 3 Output
Pin 4 NC- Used for testing purpose
Pin 5 +3V
Pin 6 Tone Sel .1
Pin 7 Osc 1
Pin 8 Osc 2

Make the following changes which can result in siren sound.

Saturday 22 June 2013

USES AND ABUSES OF SCIENCE

                                                 
Introduction:
In the primitive age, man was living like a savage. he did not know how to wear a cloth. He did not know how to make fire and cook his food. He did not know how to make a hut or a house.
He did not know how to speak. He did not know how to read and write. But gradually by the use of science he developed a great civilization.
Use of science brought about a great change:
At the dawn of civilization man developed a scientific outlook. With the help of science he made observation and experiment, though they were crude at first. he discovered the relationship between a cause and its effect. He discovered some secrets of nature. He came to know the use of fire. With the help of it, he cooked his meal and scared the wild animals. Then he came to know sowing and planting. He discovered the conditions for seeds to sprout. He discovered the process for tending plants. He grew crops and stored the surplus. He came from cave to cottage and from cottage to pucca house. He knew the tending of useful animals and put them to his service. He made many works of invention. He grew cotton were due to proper uses of science.
Modern use of science:
Uses of science are now inseparable even from out day-to-day life. With the help of science and technology we have made pin to space-craft. We have made highly complicated machines for large-scale productions. We have conquered over time and distance. We are conquering disease and sickness. Radio and telecommunications, X-Ray and electricity, rotary and railways are all the works of science. So at present the uses of science are many and varied.
Abuses of science:
Modern man has begun to abuse his scientific knowledge, invention of atom bomb is the burning example of it. Abuse of science will lead to destruction of mankind.
Conclusion:
Abuse of science can be checked by creating a strong public opinion all over the world. Leaders of peace should keep alert and active to do the needful in this respect.