Ultrasonic transmitter 40kHZ for your Robot

40kHZ ultrasonic transmitter circuit (1)

40kHZ one ultrasonic transmitter circuit, the F1 ~ F3 three oscillators in the F3 is 40kHZ square wave output, frequency mainly by C1, R1 and RP decided to adjust the adjustable resistance with a frequency of RP. F3 transducer excitation output T40-16 at one end and the inverter F4, F4 transducer excitation output T40-16 the other end, therefore, join F4 doubling the excitation voltage. Capacitors C3, C2 and F4 F3 balance the output of the waveform is stable. Inverter circuit, F1 ~ F4 with the CC4069 in four of six inverter inverter, and the remaining two do not (input should be grounded.) Power Supply 9V laminated battery. F3 output frequency measurement should be 40kHZ ± 2kHZ, or should be adjusted RP. Transmitting ultrasonic signals greater than 8m.

40kHZ ultrasonic transmitter circuit (2)  

  40kHZ second ultrasonic transmitting circuit, the circuit transistors VT1, VT2 form strong feedback resonator oscillator, the oscillation frequency equal to the ultrasonic transducer T40-16 resonant frequency. T40-16 is the feedback coupling element, the circuit is the output for the transducer. T40-16 is similar at both ends of the square wave oscillation waveform, voltage amplitude close to the power supply voltage. S is the power switch, click S, T40-16 can drive a string of 40kHZ emitted ultrasonic signals. Circuit voltage of 9V, the operating current of about 25mA. Transmitting ultrasonic signals greater than 8m. Circuit can work without debugging.

40kHZ ultrasonic transmitter circuit (3)  

   40kHZ ultrasonic transmitter circuit, produced by the VT1, VT2 positive feedback form feedback oscillator. Circuit oscillation frequency depends on the feedback element of the T40-16, the resonant frequency of 40kHZ ± 2kHZ. Frequency stability, no need to make any adjustment by the T40-16 as a transducer of the ultrasonic signals emitted 40kHZ. Inductor L1 and capacitor C2 for resonance tuning role played in the 40kHZ. Voltage of the circuit to adapt to a wide (3 ~ 12V), and the frequency change. Using fixed inductors, inductance 5.1mH. Machine operating current of about 25mA. Transmitting ultrasonic signals greater than 8m.

40kHZ ultrasonic transmitter circuit (4)  

   40kHZ four ultrasonic transmitter circuit, which consists of four complete and non-oscillation, and gate drive functions CC4011 by ultrasonic transducer T40-16 to control the receiver, the ultrasound radiation. Which formed the door YF1 controlled oscillator with the door YF2, when S is pressed, the oscillator start-up, adjust the RP change the oscillation frequency, should be 40kHZ.Oscillations are controlled by YF4, YF3 drive differential phase composition of the work, when YF3 output goes high, YF4 certain output low; YF3 output low, YF4 output high. The T40-16 level control issue 40kHZ ultrasonic transducer. Circuit YF1 ~ YF4 four high-speed CMOS circuit 74HC00 NAND gate circuit, the output drive current is characterized by large (greater than 15mA), high efficiency. Circuit voltage of 9V, operating current greater than 35mA, transmitting ultrasonic signal is greater than 10m.

40kHZ ultrasonic transmitting circuit (5)  

  40kHZ five ultrasonic transmitting circuit, time base circuit by the LM555 and the external components, the 40kHZ multivibrator circuit, adjust the resistance of resistor RP can change the oscillation frequency. 3 feet from the LM555 output drives ultrasonic transducer T40 -16, so that emit ultrasonic signals. Circuit is simple and easy system. Circuit voltage of 9V, working current 40 ~ 50mA. Transmitting ultrasonic signals greater than 8m. LM555 NE555 direct replacement is available, the effect is the same.

Ultrasonic reciever for your Robot

Hi friends!
    Here is a common problem for all the electrical engineering students who have interest in the field of robotics and are pretty much into it. You always want to know where the hurdles or obstacles are located in the path of the robot so that it may not be collided with it or you may get some observations about the location of the walls etc.
    Here is a simple electronic project which describes the ultrasonic receiver circuit and its working. get a pair of ultrasonic transducers from market. these are pretty cheap and easily available. And get 2 Op amps 741.  Circuit is very easy to understand as shown in the diagram. Initial stage couples the received signal from the receiver to op amp input. We assume here that the ultrasonic receiver receives a signal of 40 kHz reflected from an obstacle in the path of the robot. And this signal was generated from an ultrasonic transmitter of 40 KHZ. Now the first op-amp stage amplifies the received signal an the second stage compares the receive signal with a particular signal level. You can adjust this level by changing resistors values for the desired signal level. This reflects the distance of obstacle from which the ultrasonic wave is reflected. By attaching several comparators set at different signal levels you can find different range calculations.

Quiz project using IC 555

This project can be used to understand and develop an application of ic 555 timer. The project can be used for a quiz with up to 5 contestants (or teams). Each of the contestant have a trigger push-switch in his/her hand. And an LED is fitted on the table. When a trigger switch is pressed the corresponding LED lights , sounds the bleeper and it keeps other trigger switches away from triggering or working. So this shows which contestant was the first to press the switch. A reset push switch which is operated by quiz master, is used to cancel the bleeper and switches of the LED so that the next question may b asked and the switches can be operated again.
See the circuit diagram. It consists of four ic 555 timer operated in bistable mode( stable in both high and low outputs) which are triggered or reset when their inputs are low. The reset input of all the ic 555 is joined together and operated by a single reset push-switch. The trigger switches are connected to the bistable trigger( pin2) through a 0.1 uF capacitor so that only the initial press triggers the bistable; and continying to hold the switch closed will have no effect. Now the switch is directly connected to the bistables. This prevents the quizmaster from resetting the circcuit until the trigger swicth was released. As it has been observed that some contestants hold the switch until they are asked to give their answer.  When a trigger switch triggers a bistable output (pin 3) lights an LED and makes the trigger line 'high', this prevents any other bistable being triggered and sounds the bleeper. We have used a diode to link the output to the trigger line.

Microcontroller 8051 based Visitor Counter

This is one of the basic and easily implementable circuit for the basic knowledge and practice of an electrical engineer and engineering student using microcontroller 8051. Visitor counter can be used on numerous places where the data for the persons at a perticular place need to be kept such as banks, private places etc.
    Here i have designed a basic circuit using 555 timers. And basic infrared reciever TSOP1736 are used as sensors for the detection of the persons entering and leaving. There are two sensors placed at some distance so that when a person enters the room, the sensor output cuts when the person passes in front of one of them. so when a person leaves, the order in which sensors give low pulse reverses.
            555 is used in monostable operaton as can be seen from the diagram. In monostable operation, 555 gives output only when input trigger pulse goes down. This happens when a person passes in front of the sensor.
Both outputs from the sensors are fed to the microcontroller 8051. Microcontroller checks in which order the sensors are illuminated. And gives output to the 7 segments accroding to the programm. This one is very easy to practice and get some experience of microcontroller 8051 programming.

Microcontroller 8051 programmer kit

Most of the electrcial and electronics projects include controlling part i.e. brain, which is a microcontroller. If we talk about microcontroller 8051, then you need to program it time and again for testing purposes and then integretaing the microcontroller 8051 with the ciruit.
            So we want to fuse a programming facility in our programming tool with your programmed code i.e microcontroller 8051. Now the programmer we are going to design, supports the devices in the 8031 family of Atmel, AT89SXX, and its AVR microcontroller AT90SXXXX series controllers. Here is the circuit diagram of a standalone spi programmer.
                    Here interfacing of the power is provided by PC USb port as it is very easy to provide the power using the system you are using for programming purposes. A USB port can supply a max of 100mA current. You have to get a cheap USB cable, cut the cable at one end and attatch the two power lines i.e. black indicates ground and red indicates 5V.
                PC parallel port is used to provide the parallel lines to the microcontroller. To isolate the programming device , microcontroller 8051 and PC parallel port we use 74HCT541 ic. This acts as buffer for the parallel port signals. It is necessary to ensure that the programmer works with typical 3V type parallel port. A 40-pin zip socket is used for 8051 microcontroller.
                In the diagram below DB25 connector shown denotes the PC parallel port. BE, CK, D0 and RS are the output lines of parallel port while DI is the input line. Sip resisstors are used to pull the lines high. I would recommend to use the resistors for all the output lines on the kit as well to provide ease in testing purposes.

circuit diagram

 

software

The ISP-30a.zip files consisits of the main programm and the driver used for i/0. Copy all the files in the same folder. For the auto hardware deection it is necessary to short pin2 and 12 of DB 25 connector otherwise software uses the default parallel port i.e. LPT1
You can download the software here
ISP-30a

Dilemma of Project selection for Electrical Engineers explained

Helo friends! Today, the most common problem for the electrical engineers and engineering students are the selection of their final year project and thesis to shine their ways throughout their careers because this is a gateway to get better oppertunities in the vast horizons of field work.
         This is quite a common observation now a days that the electrical engineers who get themselves right on selecting the project also get better of the chances to make their way to their career objectives. So this is surely the area of concentration for the electrical engineers and students to get along the right ways and get beter insight of the on-field projetcs and hand on experience on these new technologies before getting to the real practical life on the field.
            One of the fact is that many of the electrical engineers wanted to get more practical involvment in their student life but usually are not able to get inside the stretches of electrical and electronics engineering. What is the reason? A big question mark !!!  Is it some mistakes on their part or they are not able to do that!
        Some people can point to ambiguous reasons for that but some of them might get it right as it may be apparent if those students themselves are asked the question. y?
This is most realistical view of getting the answer. I have asked these question to many of them. And from most of them i have got the answers that the data on internet is not easily understandable for an on going electrical engineering student or its not clearly demonstrated on some websites or some of the parts are missing and so on. And some of them put a huge question marks on the abilities of their teachers to guide them through the selection headache of these projects. So out of all the problematic scenario i thought of providing the data base to those electrical engineering students who are not able to get well on their track by using my blog. I hope you people appreciate my effort.