Monday, 11 October 2010
The piezo used was a standard 85mm square Motorola Horn, Maplin part number WF09K or WF55K. These are rated +/-3dB to 28kHz
The circuit is based on IC1, which is a 555 timer IC in astable mode. IC1's current output is amplified by TR1, and the voltage at the collector is stepped up by T1, a mains to 6-0-6 V transformer. Heat-sinks are advised for TR1 and T1.
Before applying power, VR1 should be advanced to a full 5 K. While power consumption is monitored with a multimeter, VR1 should be turned back slowly until power consumption rises to 300 mA maximum. The fluorescent tube should now shine brightly. Power consumption should not exceed 300 mA, or the circuit may be destroyed.
Should a universal AC/DC adapter be used at a later stage, constructors are advised to repeat the setup procedure with VR1, since the voltage of such adapters is unstable and may destroy the circuit. Constructors should be aware that a high voltage is present at the transformer primary, which could deliver a nasty shock.
Please note that if the temperature then falls, the relay will de-energize. If the environment temperatures changes rapidly, then the relay may chatter, as there is no hysteresis in this circuit.
Hysteresis, allows a small amount of "backlash" to be tolerated. With a circuit employing hysteresis, there will be no relay chatter and the circuit will trigger at a defined temperature and require a different temperature to return to the normal state. Hysteresis can be applied to the circuit using feedback, try a 1Meg resistor between op-amp output, pin 6 and the non-inverting input pin 2 to give the circuit hysteresis.
Without offset null adjustment, the output of the 741 IC will be around 2 Volts (quiescent) swinging to nearly full supply when triggered. The 4.7k and 1k resistor form a potential divder so that under quiescent conditions the transistor will be off. Quiescent or steady state means no signal, or in this case (when the temperature does not cause the output to swing to full voltage).
when the switch is thrown the opposite way (to the blue dot) both transistors are wired as an astable square wave generator. This provides enough harmonics from audio up to several hundred kilohertz and is useful for testing AM radio Receivers.
The fast switch on time of the transistors produces the switching spike which is rich in harmonics.
These two circuits are multi-range timers offering periods of up to 24 hours and beyond. Both are essentially the same. The main difference is that when the time runs out, Version 1 energizes the relay and Version 2 de-energizes it. The first uses less power while the timer is running; and the second uses less power after the timer stops. Pick the one that best suits your application.
The Cmos 4060 is a 14 bit binary counter with a built in oscillator. The oscillator consists of the two inverters connected to Pins 9, 10 & 11; and its frequency is set by R3, R4 & C3.The green Led flashes while the oscillator is running: and the IC counts the number of oscillations. Although it's a 14 bit counter, not all of the bits are accessible. Those that can be reached are shown on the drawing.
By adjusting the frequency of the oscillator you can set the length of time it takes for any given output to go high. This output then switches the transistor; which in turn operates the relay. At the same time, D1 stops the count by disabling the oscillator. Ideally C3 should be non-polarized; but a regular electrolytic will work, provided it doesn't leak too badly in the reverse direction. Alternatively, you can simulate a non-polarized 10uF capacitor by connecting two 22uF capacitors back to back (as shown).
Using "Trial and Error" to set a long time period would be very tedious. A better solution is to use the Setup tables provided; and calculate the time required for Pin 7 to go high. The Setup tables on both schematics are interchangeable. They're just two different ways of expressing the same equation.
For example, if you want a period of 9 Hours, the Range table shows that you can use the output at Pin 2. You need Pin 2 to go high after 9 x 60 x 60 = 32 400 seconds. The Setup table tells you to divide this by 512; giving about 63 seconds. Adjust R4 so that the Yellow LED lights 63 seconds after power is applied. This will give an output at Pin 2 after about 9 Hours.
The Support Material for the timers includes a detailed circuit description - parts lists - a step-by-step guide to construction - and more. A suitable Veroboard layout for each version is shown below:
The timer was designed for a 12-volt supply. However, provided a suitable relay is used, the circuit will work at anything from 5 to 15-volts. Applying power starts the timer. It can be reset at any time by a brief interruption of the power supply. The reset button is optional; but it should NOT be used during setup. The time it takes for the Yellow LED to light MUST be measured from the moment power is applied. Although R1, R2 and the two LEDs help with the setup, they are not necessary to the operation of the timer. If you want to reduce the power consumption, disconnect them once you've completed the setup. If you need a longer period than 24-hours, increase the value of C3.
- Pushover analysis – cyclic loading, deterioration effect in RC Moment Frames in pushover analysis
- Rehabilitation – Evaluation of drift distribution
- Analysis of large dynamic structure in environment industry
- Theoretical study on High frequency fatigue behavior of concrete
- Seismic analysis of interlocking blocks in walls
- Estimation of marine salts behavior around the bridge structures
- A comparative study on durability of concrete tunnels undertaken in AP irrigation projects
- Prefabricated multistory structure, exposure to engineering seismicity
- Shape optimization of Reinforced underground tunnels
- Properties of Fiber Cement Boards for building partitions
- Behavior of RC Structures subjected to blasting
- The use of green materials in the construction of buildings
- Finite element model for double composite beam
- A new composite element for FRP Reinforced Concrete Slab
- Effect of shear lag on anchor bolt tension in a base plate
- Elastic plastic bending, load carrying capacity of steel members
- FE Analysis of lateral buckling of a plate curved in nature
- Green energy and indoor technologies for smart buildings
- Building environmental assessment methodology
- Numerical study on strengthening of composite bridges
- Strengthening effect for RC member under negative bending
- Effect of negative Poisson’s ratio on bending of RC member
- Macroeconomic cause within the life cycle of bridges
- Long term deflections of long span bridges
- Structural damage detection in plates using wavelet theories (transforms)
Information has become a commodity in today's world, and protecting that information has become mission critical. The Internet has helped push this information age forward. Popular websites process so much information, that any type of slowdown or downtime can mean the loss of millions of dollars. Clearly, just a bunch of hard disks won't be able to cut it anymore. So Redundant Array of Independent (or Inexpensive) Disks (RAID) was developed to increase the performance and reliability of data storage by spreading data across multiple drives. RAID technology has grown and evolved throughout the years to meet these ever-growing demands for speed and data security.
A technique was developed to provide speed, reliability, and increased storage capacity using multiple disks, rather than single disk solutions. RAID takes multiple hard drives and allows them to be used as one large hard drive with benefits depending on the scheme or level of RAID being used. The better the RAID implementation, the more expensive it is. There is no one best RAID implementation. Some implementations are better than others depending upon the actual application. It used to be that RAID was only available in expensive server systems. However, with the advent of inexpensive RAID controllers, it seems it has pretty much reached the mainstream market.
The Array And Raid Controller Concept:
A drive array is a collection of hard disk drives that are grouped together. When we talk about RAID, there is often a distinction between physical drives and arrays and logical drives and arrays. Physical arrays can be divided or grouped together to form one or more logical arrays. These logical arrays can be divided into logical drives that the operating system sees. The logical drives are treated as single hard drives and can be partitioned and formatted accordingly.
The RAID controller is what manages how the data is stored and accessed across the physical and logical arrays. It ensures that the operating system sees the logical drives only and need not worry about managing the underlying schema. As far as the system is concerned, it is dealing with regular hard drives. A RAID controller's functions can be implemented in hardware or software. Hardware implementations are better for RAID levels that require large amounts of calculations. With today's incredibly fast processors, software RAID implementations are more feasible, but the CPU still gets bogged-down with large amounts of I/O.
The basic concepts made use of in RAID are:
Mirroring involves having two copies of the same data on separate hard drives or drive arrays. So the data is effectively mirrored on another drive. The system writes data simultaneously to both hard drives. This is one of the two data redundancy methods used in RAID to protect from data loss. The benefit is that when one hard drive or array fails, the system can still continue to operate since there are two copies of data. Downtime is minimal and data recovery is relatively simple. All you need to do is rebuild the data from good copy.
A raid controller writes the same data blocks to each mirrored drive. This means that each drive or array has the same information in it. We can add another level of complexity by introducing yet another technique called striping. If we have one striped array we can mirror the array at the same time on the second striped array. To set up mirroring the number of drives will have to be in the power of two.
Digital audio broadcasting, DAB, is the most fundamental advancement in radio technology since that introduction of FM stereo radio. It gives listeners interference - free reception of CD quality sound, easy to use radios, and the potential for wider listening choice through many additional stations and services.
DAB is a reliable multi service digital broadcasting system for reception by mobile, portable and fixed receivers with a simple, non-directional antenna. It can be operated at any frequency from 30 MHz to 36Hz for mobile reception (higher for fixed reception) and may be used on terrestrial, satellite, hybrid (satellite with complementary terrestrial) and cable broadcast networks.
DAB system is a rugged, high spectrum and power efficient sound and data broadcasting system. It uses advanced digital audio compression techniques (MPEG 1 Audio layer II and MPEG 2 Audio Layer II) to achieve a spectrum efficiency equivalent to or higher than that of conventional FM radio.
The efficiency of use of spectrum is increased by a special feature called Single. Frequency Network (SFN). A broadcast network can be extended virtually without limit a operating all transmitters on the same radio frequency.
EVOLUTION OF DAB
DAB has been under development since 1981 of the Institute Fur Rundfunktechnik (IRT) and since 1987 as part of a European Research Project (EUREKA-147).
" In 1987 the Eureka-147 consoritium was founded. It's aim was to develop and define the digital broadcast system, which later became known as DAB.
" In 1988 the first equipment was assembled for mobile demonstration at the Geneva WARC conference.
" By 1990, a small number of test receivers was manufactured. They has a size of 120 dm3
" In 1992, the frequencies of the L and S - band were allocated to DAB on a world wide basis.
" From mid 1993 the third generation receivers, widely used for test purposes had a size of about 25 dm3, were developed.
" The fourth generation JESSI DAB based test receivers had a size of about 3 dm3.
1995 the first consumer - type DAB receivers, developed for use in pilot projects, were presented at the IFA in Berlin.
2. MODBUS protocol implementation on RS485.
3. Home automation (AC/DC) using RF module.
4. HARMONIC DISTORTION meter.
5. SOLAR ENERGY meter.
6. Robot control using TV remote.
7. Robotic Arm manipulator.
8. Access Control system using i-Botton.(1-WIRE PROTOCOL)
9. Electronic Eye with Security Dial up(Digital IC Based).
10. Microcontroller Based Fire Monitoring System in Petrochemical industries
11. SPI based voice recording system.
12. MMC card interface.
13. EEPROM/FLASH Programmer.
14. Digital IC tester.
15. Moving message Display.
16. Automation of Car Parking.
17. BATTERY CHARGER using microcontroller.
18. PC AT-Keyboard interface with microcontroller.
19. Auto BAUDRATE detection for microcontroller.
20. Interfacing GRAPHIC LCD with microcontroller.
21. Automation of Toll Gate.
22. Automation of Rail Gate.
23. Automatic Water Gardening system.
24. Wireless DATA Communication through IR.
25. Design of LOCK-IN-AMPLIFIER.
26. USB-UART Bridge.
27. Microcontroller based Digital POWER ENERGY METER.
28. Maximum Power point tracking using SOLAR PV Panels.
29. PREPAID ELECTRICITY billing system.
30. Interfacing COLOR SENSOR with microcontroller.
31. Handheld SPECTROPHOTOMETER.
32. Designing pH meter using microcontroller.
33. SMS keypad interfacing with microcontroller.
34. Digital Power Supply with microcontroller.
35. Home automation (AC/DC) using TV remote.
36. Frequency meter.
37. Digital Thermometer.
38. Interfacing RTC with microcontroller.
39. Serial data transmission & Reception between two controllers.
40. Data Entry system with password security.
41. Remotely monitoring Parameters through GSM module.
42. Digital fare meter for transport vehicles.
43. Robot control using RF module.
44. Data Acquisition system.
45. Data Logger system.
46. SMS transmitting using RF modules.
47. Data Communication using RF modules.
48. Real Time Clock Control application.
49. Temperature monitoring and control.
51. Home automation (AC/DC) using GSM module.
52. DC motor RPM measurement.
53. DC motor Speed measurement using tachometer.
54. Bi directional DC motor speed control.
55. Stepper motor control using microcontroller.
56. Robot control using PC interface.
58. Intruder Alarm System.
59. Water level monitoring system.
60. Design of INVERTER using microcontroller.
61. Sharp IR Range Finder.
62. Traffic Light System.
63. Voltage, Current & Resistance measurement.
64. Remote Valve Operation using GSM module.
65. Remote Valve Operation using RF Modules.
66. Digital Clock with snooze facility.
67. Auto Timer using microcontroller.
68. BABY WARMER system with microcontroller.
69. BCD UP DOWN Counters using Controller.
70. Interfacing GSM module with microcontroller.
71. Anti-theft Alarm system.
72. Watch Dog Timer.
73. Solar Panel interface.
74. Light Sensing Robot.
75. Dallas 1-wire Temperature sensor interface.
76. Smoke detection using microcontroller.
77. Intelligent object counting system.
78. SPI protocol based seven segment led display interface.
79. Home automation (AC/DC) using PC interface.
80. Season based automatic Streetlights switching.
81. Viscosity of liquid Measurement.
82. Clap sensing Robot.
83. Touch sensing application.
84. Automatic Water tank filling.
85. DO measurement and control using microcontroller.
86. Interfacing GPS Receiver with microcontroller.
87. PC based message-scrolling display.
88. Voice IC APR9600 interface with microcontroller.
89. FUNCTION GENERTAOR using microcontroller.
90. STROBOSCOPE effect based RPM measurement.
91. VEHICLE TRACKING system with GPS & GSM.
92. Digital Capacitance meter.
93 Industrial fault indication systems with over voltage, over current, over temperature using analog to digital (ADC) converters.
94 Data Acquisition system using RF.
95. Speed control of DC motor using Pulse width Modulation technique (Speed sensor).
96. Speed control of DC motor with pulse
98. Temperature dependent dc fan speed control using thermistor
99. Password operated industrial machinery control (wireless, more than 8 machineries)
100. Six channel Petrochemical Fire Monitoring & Control Station.
101. PC Based data acquisition system using (MAX232).
102. Robot direction controlling using RF Communication .Remote monitoring Any Alarm on PC Using Radio Communication.
103. Home Automation through PC.
104. Autonomous Robot.
105. Design A.M.F.A.T.S (Auto main failure & automatic transfer switch).
106. Automatic Control of rail Gate.
107. PT-100 Temperature Controller
108. LCD display driver with demo board Software.
109. Highly Flexible Keypad Alarm.
110. DC motor Speed control.
111. Automatic dish antenna position controller.
112. Liquid level control.
113. Light intensity control system
114. Automatic flow control system.
115. Level measurement using load cell.
116. DC circuit breaker.
117. Voltage monitor and control.
118. Current monitor and control.
119 Seven segment display driver with demo Board & Software.
120. Stepper motor driver with demo Board & Software.
121. Digital Lock.
122 Electronic Eye (8051 Based)
123. Electronic Eye 8051 Based With Event Logging On PC.
124. Micro controller based energy meter.
125.8051 General Purpose Project Board.
125. Eight channel ADC Board (0809) with Software.
126. Single supply Temperature monitoring using thermistor.
127. Single supply Temperature monitoring using thermocouple.
128. Automatic Bottle filling System.
129. Temperature analyzing system for industrial control.
130. Industrial Protection system using Temperature, Smoke sensors and
Light Dependent Resistor.
131. Super intelligent robot using smoke sensors and light dependent resistor.
132. PC based Synchronizing and speed controlling of dc motor (Wireless).
133. Electrical apparatus control system in a plant using R
167. Automatic room light controller with visitor counter (IR sensor).
168. Channel IR based remote control.
169. Communicating single master with many slaves by using SPI protocol.
170. Inter integrate communication protocol(I2C).
171. PC to PC communication with IR.
172. Automatic meter reading system using RF.
173. Industrial Automation system using RF.
174. Dimmer lights automation system.
175. GSM based Building Automation.
176. Implementation of Mobile Based HI-Tech door Locking System.
177. Design a Factory alarm system.
178. Stepper Motor Controller.
179. Temperature control and monitoring.
180. Solar Tracking.
181. Voltage logger.
182. 8-Channel data acquisition system.
183. DC Motor Control.
184. Speed Detection.
185. D.C power Supply.
186.8051 Based Code Lock with Security Telephone Dialer.
187. Mobile or landline Telephone based industrial protection.
188. GSM based parameter monitoring system using MAX 232 Serial Communication and analog to digital converters (ADC).
189. Hi-Tech Wireless Equipment controlling System.
190. Microcontroller based Vehicle speed acquisition system.
191. Wireless digital code lock with a status display.
192. Wireless chatting System using RF Communication.
193. Wireless power System distribution and controlling.
194. Wireless data Encryption and Decryption using RF communication.
195. Parking Information System.
196. Electronic Gardener using SOIL Moisture Sensor.
197. PC based home automation.
198. Wireless communication using IR led and detector.
199. Interfacing Microcontroller to GSM modem and application implementation SMS based M2M communication.
200. GPS based road traffic monitoring system.
The ROBOTIC ARM WIRED CONTROL teaches the basic robotic sensing and locomotion principles, testing your motor skills, as you build and control the Arm. You can command this unit with it's five-switch, wired controller with corresponding lights to grab, release, lift, lower, rotate wrist and pilot sideways 350 degrees. After assembly, observe the dynamics of gear mechanisms through the transperent Arm. Five motors and five joints allow flexibility and fun!Recommended Accessories: For educators and home schoolers. You will find the Personal Computer Interface (optional) very useful tools.