Bimbingan Skripsi TEKNIK ELEKTRO

Function Generator Circuit

Description.
The ICL8038 is a function generator chip, able of generating triangular, square , sine, pulse and sawtooth waveforms . From these sine, square & triangular wave forms can be made simultaneously.There is the option to control the parameters like frequency ,duty cycle and distortion of these functions.This is the best function generator circuit for a beginner to start with and is of course a must on the work bench of an electronics hobbyist.The circuit here is designed to produce waveforms from 20Hz to 2o kHz.The ICL 8038 has to be operated from a dual power supply.

Circuit Diagram & Parts List.

Notes .

The circuit needs a dual power supply . A +15 -15 power supply as shown in the circuit is enough for the purpose.
The frequency of the output wave form can be adjusted using R7.It must be a 100K Log POT.
The duty cycle can be adjusted using R3 , a 1K POT.
The distortion of the wave form can be adjusted using R5 , a 100K POT.
Square,triangle & sine waveforms can be obtained simultaneously at pins 9,3,2 respectively.

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LED based transistor tester

Description.

Here is the circuit of a very simple transistor tester which used two LEDs for displaying the condition of a transistor. Both PNP as well as NPN transistors can be tested using this circuit. Quad 2 input CMOS NAND gate IC CD4011B is the heart of the circuit. Out of the four NAND gates inside the IC, only three are used here and they are used as NOT gates by shorting their input terminals. Gates U1a, U1b, resistor R1 and capacitor C1 forms a square wave oscillator. The frequency of this oscillator can be adjusted by using R1. The output of the oscillator is inverted using the gate U1c. The inverted oscillator output is connected to the base of the transistor under test through the resistor R2 and the non inverted oscillator output is connected to the emitter of the transistor under test using the resistor R3.

The status of the LEDs D1 and D2 reveals the condition of the transistor under test. If red LED is ON, It indicates that the transistor under test is a good NPN. If green LED is ON, it indicates that the transistor under test is a good PNP. If both LEDs are ON, it indicates that the transistor under test is short. If both LEDs are OFF, it indicates that either the transistor is bad or you may have connected it incorrectly.

Circuit diagram.

Notes.

The circuit can be easily assembled on a Vero board.
Use 5V DC for powering the circuit.
All unused pins of the IC must be connected to ground.

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USB sound card

Description.
Designing and building a USB sound card is no longer a head ache because we have got the PCM 2702 integrated circuit from Texas Instruments. The PCM2702 is an integrated 16 bit digital to analog converter that has two digital to analog output channels. The integrated interface controller of PCM2702 is compliant to the USB 1.0 standards. The IC can handle sampling rates of 48 KHz, 44.1 KHz and 32 KHz. The IC also has a number of useful features like on-chip clock generator, digital attenuator, play back flag, suspend flag, zero flag, mute function etc. The most interesting thing is that this circuit is plug & play and doesn’t need any driver software for Windows XP and Windows Vista operating systems.

The circuit gets control data and audio data from the USB through the D+ and D- pins of the PCM2702 all the data transferring is carried out at full speed. The decoded audio signals will be available at the VOUTL and VOUTR pins of the IC. The 12MHz crystal is connected between the XT0 and XT1 pins of the IC. The VBUS (USB bus power) pin and DGND (digital ground) pins of the IC are connected to the +5V and ground pins of the USB respectively. The circuit requires +5V DC and +3.3V DC for operation and both of these voltages can be derived from the USB port using LDO (low drop out) voltage regulators (not shown in circuit).

Circuit diagram.

Block diagram of PCM2702.

Notes.

+5V DC supply can be derived from the USB port using a +5V LDO regulator.
+3.3V DC supply can be derived from the USB port using a +3.3V LDO regulator.
Audio signals (output) available at VOUTL and VOUTR requires further amplification for driving low impedance head phones or loud speakers.
The PCM2702 is available only in SSOP28 package and requires special care while assembling.
Before attempting this circuit please go through the datasheet of PCM2702 and get a clear idea about the device.

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Scoring game circuit

Description.
A simple scoring game circuit that can be used for all occasions when a dice is needed.The circuit is based on a NE555 timer,a 74LS192 counter,a74LS247 decoder and a & segment LED display.The timer IC1 will produce the clock for the counter IC(IC2) whose frequency is determined by R1 and C2.When S2 is pressed the IC2 will count in up mode and when S3 is pressed the IC2 will count in down mode.The IC 3 will decode the count to display it on the seven segment LED display .Thats about the working of the circuit.The circuit is designed strictly sticking on to the basics of counters and is a good one for beginners.There is nothing big deal.
Circuit diagram with Parts list.

Notes.

To play the game switch the power ON and press S1 to reset the counter.
Now press S2 or S3 and release .The IC2 will hold the last count .Now press S4 to see the score on display.That’s your score.Now the second person can try.
Each time one tries, he should press the S1 to reset the count and then press S2 or S3 and then S4 to see the score.
Circuit can be powered from a 9V radio cell or a 9V regulated DC power supply .

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Digital code lock

Description.
This is a simple but effective code lock circuit that has an automatic reset facility. The circuit is made around the dual flip-flop IC CD4013.Two CD 4013 ICs are used here. Push button switches are used for entering the code number. One side of all the push button switches are connected to +12V DC. The remaining end of push buttons 2,3,6,8 is connected to clock input pins of the filp-flops. The remaining end of other push button switches are shorted and connected to the set pin of the filp-flops.
The relay coil will be activated only if the code is entered in correct sequence and if there is any variation, the lock will be resetted. Here is correct code is 2368.When you press 2 the first flip flop(IC1a) will be triggered and the value at the data in (pin9) will be transferred to the Q output (pin13).Since pin 9 is grounded the value is “0” and so the pin 13 becomes low. For the subsequent pressing of the remaining code digits in the correct sequence the “0” will reach the Q output (pin1) of the last flip flop (IC2b).This makes the transistor ON and the relay is energised.The automatic reset facility is achieved by the resistor R11 and capacitor C2.The positive end of capacitor C2 is connected to the set pin of the filp-flops.When the transistor is switched ON, the capacitor C2 begins to charge and when the voltage across it becomes sufficient the flip-flops are resetted. This makes the lock open for a fixed amount of time and then it locks automatically. The time delay can be adjusted by varying the values of R11 and C2.

Circuit diagram with Parts list.

Notes.

Assemble the circuit on a good quality PCB.
The circuit can be powered from 12V DC.
Mount the ICs on holders.
The L1 can be a 12V, 200 Ohm SPDT relay.
Capacitor C1 should be tantalum type.
The C1 and C2 must be rated at least 25V.

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FM Radio jammer

Description.
Circuit shown here can be used to jam FM radios in its vicinity. The circuit is nothing but a classic single transistor oscillator operating in the VHF region. Working principle of the circuit is very simple and straight forward. Powerful VHF oscillations from the circuit will interfere with the FM signals to nullify it. Jammer circuits like this are illegal in many countries and you must assemble this circuit on your own responsibility. This circuit is intended only for fun and i request you not to misuse it.
Circuit diagram.

Notes.

For L1 make 6 turns of 16AWG enamelled copper wire on a 9mm plastic former.
The circuit can be powered using a 9V PP3 battery.
For extended range, use an antenna.
A 30cm long wire connected anywhere on the coil will do for the antenna.
For better performance, assemble the circuit on a good PCB.

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Water Level Control

A Water detector is a small electronic device that is designed to detect the presence of water and alert humans in time to allow the prevention of water damage. A common design is a small device that lays flat on a floor and relies on the electrical conductivity of water to decrease the resistance across two contacts. A 9 volt battery then sounds an audible alarm in the presence of enough water to bridge the contacts. These are useful in a normally occupied area near any appliance that has the potential to leak water, such as a washing machine, refrigerator with icemaker, dehumidifier, air conditioner, or water heater.

Many thing in our daily need that can be easily by implement a simple applied technology. So our life become easy and comfort. We can make anything work automatic, or work without our intervention so if we forget to run it, or to turn off it, they will be done by their shelf.

By a simple applied technology, such as electronics, we can solve many simple problem as mentioned above. With the small dimension of electronic component and small power too, we can realize our need, such as automatic lamp, remote controller, water tank level controller.

Beside all that mention above, we can make many device that valuable to our need, such as decorative lamp, amplifier, detector etc. The simple applied electronic circuits are divided in to two groups, analog and digital circuitry.

Analog electronic circuits are those in which signals may vary continuously with time to correspond to the information being represented. Electronic equipment like voltage amplifiers, power amplifiers, tuning circuits, radios, and televisions are largely analog (with the exception of their control sections, which may be digital, especially in modern units).

In digital electronic circuits, electric signals take on discrete values, which are not dependent upon time, to represent logical and numeric values. These values represent the information that is being processed. The transistor is one of the primary components used in discrete circuits, and combinations of these can be used to create logic gates. These logic gates may then be used in combination to create a desired output from an input. In this page you can find one of the circuit.

indonesia: Dengan menggunakan rangkaian pendeteksi air serta komponen inverter, D flip-flop dan rangkaian relay, maka dapat dibangun sistem kontrol pompa air untuk menjaga kondisi tangki tetap terisi air. Ketika air berada di bawah level terbawah, maka pin set dari D flip-flop akan diberi sinyal rendah sehingga keluaran Q akan tinggi dan membuat saklar relay menutup dan pompa air bekerja. Ketika air mencapai level tertinggi, maka pin clear akan diberi sinyal rendah yang akan mematikan pompa. Dengan demikian maka tangki air akan terjaga selalu dalam kondisi terisi.

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Air Ionizer

An air ionizer (or negative ion generator) is a device that uses high voltage to ionize (electrically charge) air molecules. Negative ions, or anions, are particles with one or more extra electrons, conferring a net negative charge to the particle. Cautions are positive ions missing one or more electrons, resulting in a net positive charge. Most commercial air purifiers are designed to generate negative ions.

The Geophysical Institute of the University of Alaska Fairbanks has published a paper reporting that cosmic rays normally create around 1000 negative ions and positive ions per cubic centimeter of outdoor air, the concentration being higher at higher altitudes and also near the sea. But indoor city environments may typically have half that concentration. Controlled studies have reported greater subjective well-being in an artificially negatively-ionized environment, though the reason for this is unknown.

The high electric potentials used to create air ions are achieved by using capacitors to develop a high voltage (c.20,000 volts), low-current charge at an electrode. Such voltages can also generate ozone (an energetic allotrope of oxygen), and NOx, which, even in relatively low concentrations, may irritate lung tissues, causing chest pain, coughing, throat irritation and aggravated asthma.

However, the Cedars-Sinai Medical Center, Los Angeles has stated its acceptance of anecdotal doctor's reports that the use of ionizers produces only neutral to positive reports when tried by patients suffering from respiratory problems and allergies.

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Combination Lock

D-type bistables can easily be used to make a combination lock. Using two 4013 integrated circuits, you can make a 4-digit combination lock in which the keys representing the code digits must be entered in the correct order. Pressing the key for any digit which is not part of the code RESETs all four D-types:

The D-input of the first D-type is held HIGH. When the first digit of the combination is pressed, output Q goes HIGH. If the second digit is the next key presssed, the second D-type will be SET and so on. Pressing any of the unselected keys gives a HIGH at the RESET inputs of all four bistables, and all the Q outputs revert to LOW.

Once the four digits of the code have been entered in the correct sequence, the lock ouptut goes HIGH and will remain HIGH until an unselected key is pressed. The system could be extended to provide an automatic RESET after a delay. Which type of subsystem could you use?

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Electronic Fuse

Circuit of fuse (sekring) electronic designed to operate on 230V AC with an adjustable trip current. When the current through the load exceeds a level determined by the position of the wiper on the 1k wire-wound pot, this circuit cuts off the load immediately. If S1 is open, the range is approximately 300-650 mA, and 0.8-2A when it is closed.

Note:
This circuit connects directly to 220-230V AC which can be lethal! Please do not attempt to build any of the circuits/projects unless you have the expertise, skill and concentration that will help you avoid an injury.

D1: 1N4001
T1: TIC225M
T2: BTA12-600CW

The key variable in the operation of the fuse is the voltage drop across the power resistor(s) which are connected in series with the load. This voltage drop is directly proportional to the current the load draws. When this current is low, the voltage across the resistors is also small and cannot trigger T1. At the same time the gate of T2 is fed from a little power supply built around a negative voltage regulator. T2 is conducting and the load is on.

If the current through the load then gets too high, so that the voltage created across the resistor(s) can trigger the gate of T1 through the 330R resistor and the pot: T1 starts to conduct, swiftly taking away all the current from the gate of T2. The voltage drop across T1 (MT1-MT2) will then be only 0.7 V and T2 will be firmly off. T1 stays this way all until the momentary (normally closed, "push-to-break") Reset push-button is pressed: this causes the current through T1 to drop below the hold level and forces this triac to turn off. Releasing the Reset button re-enables the current flow to and through the gate of T2, switching it on.

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Infra Red Remote Control Tester

The circuit is very effective to test the remote controls what still works or not, the remote record will be tested using infra red. Examples of the TV remote, AC and others. Please try I am sure 100% will be successful.

The workings of the circuit is very simple, when the infra red sensor receive infrared signals pin 2 sensor will produce a voltage, this voltage will drives the PNP transistor so that the LED lamp and piezo disc (BZ) is active. for the power supply you can use a 9 volt battery and then use IC 7805 or use 1.5 volt batteries x 3

Following the specification of components installed