Power saving using time operated programmed industrial load controlling system is a reliable circuit that takes over the manual task of a switch on/off the electrical devices with respect to time. It uses real-time clock (RTC) which tracks the Real Time. When this time equals to the programmed ‘ON’ time, then the corresponding Relay for the device is switched ON and then OFF as per the ‘OFF’ time that finally switches the load ON or OFF. Multiple ON/OFF times the entry is the biggest advantage of this project. Matrix keypad helps to enter the time while relays used with relay drivers for the loads.The complete circuit has its onboard power supply.
Multiple ON and OFF Time Programmed Industrial Load System
The hardware and software requirements of this project include power supply block, voltage regulator (lm 7805), microcontroller (at89s52/at89c51), DS1307 RTC, matrix keypad, relay, seven segment, BC547, resistors, capacitors.
Keil is an ARMS Company makes C compilers, macro assemblers, real-time kernels, debuggers, simulators, integrated environments, evaluation boards, and emulators for ARM7/ARM9/Cortex-M3, XC16x/C16x/ST10, 251, and 8051 MCU families.Compilers are programs used to convert a High-Level Language to object code. Desktop compilers produce an output object code for the underlying microprocessor, but not for other microprocessors. i.e the programs written in one of the HLL like ‘C’ will compile the code to run on the system for a particular processor like x86 (underlying microprocessor in the computer).
For example compilers for Dos platform is different from the Compilers for Unix platform So if one wants to define a compiler then the compiler is a program that translates source code into object code.
- It is a smaller computer, it as on-chip RAM, ROM, I/O ports…
- Features of AT89S51/52
- Compatible with MCS®-51 Products
- 8K Bytes of In-System Programmable (ISP) Flash Memory
- Endurance: 10,000 Write/Erase Cycles
- 4.0V to 5.5V Operating Range
- Fully Static Operation: 0 Hz to 33 MHz
- 256 x 8-bit Internal RAM
- 32 Programmable I/O Lines
- Three 16-bit Timer/Counters
- Eight Interrupt Sources
- Full Duplex UART Serial Channel
- Interrupt Recovery from Power-down Mode
- Watchdog Timer
- Dual Data Pointer
- It is an electromagnetic switch, used to control the electrical devices. Copper core magnetic flux plays the main role here
- The relay’s switch connections are usually labeled COM, NC, and NO:
- COM = Common, always connect to this; it is the moving part of the itch.
- NC = Normally Closed, COM is connected to this when the relay coil is off.
- NO = Normally Open, COM is connected to this when the relay coil is on.
Relay Driver (ULN 2003)
- ULN2003 is a high voltage and high current Darlington transistor array
- It consists of seven NPN Darlington pairs that feature high-voltage outputs with common-cathode Clamp diode for switching inductive loads.
- The ULN2003 has a 2.7kW series base resistor for each Darlington pair for operation directly with TTL or 5V CMOS devices.
- Current, Output Max:500mA
- Voltage, Input Max:5V
- Voltage, Output Max:50V
A keypad is a set of buttons arranged in a block or “pad” which usually bear digits, symbols and usually a complete set of alphabetical letters. If it mostly contains numbers then it can also be called a numeric keypad.
In order to detect which key is pressed from the matrix, the row lines are to be made low one by one and read the columns. Assume that if Row1 is made low, then read the columns.
If any of the keys in row1 is pressed then correspondingly the column 1will give low that is if the second key is pressed in Row1, then column2 will give low.
- The RTC chip is a specialized chip that just keeps track of time
- It runs on a battery and keeps time for you even when there is a power outage!
- Using an RTC, you can keep track of long timelines, even if you reprogram your microcontroller or disconnect it from USB or a power plug.
The RTC we’ll be using is the DS1307. It’s low cost, easy to solder, and can run for years on a very small coin cell.
Features of DS1307
- Real-time clock counts seconds, minutes, hours, date of month, month, day of week and year with leap year compensation valid up to 2100
- 56 byte nonvolatile RAM for general data storage
- 2-wire interface (I2C)
- Automatic power fail to detect
- Consumes less than 500 nA for battery back-up at 25’C
BC547 (NPN –Transistor)
- The BC547 transistor is an NPN Epitaxial Silicon Transistor.
- It is used in general-purpose switching and amplification BC847/BC547 series 45 V, 100 mA NPN general-purpose transistors.
- The ratio of two currents (Ic/Ib) is called the DC Current Gain of the device and is given the symbol of hfe or nowadays Beta, (β).
Liquid Crystal Display (LCD)
- Most common LCDs connected to the microcontrollers are 16×2 and 20×2 displays.
- This means 16 characters per line by 2 lines and 20 characters per line by 2 lines, respectively.
- The standard is referred to as HD44780U, which refers to the controller chip which receives data from an external source (and communicates directly with the LCD.
The project is intended to work an electrical load several numbers of times as per the program. It overcomes the troubles of controlling the load ON/OFF physically. This system has an integral real-time clock (RTC) to continue tracking the time and therefore to switch ON/OFF the load accordingly.
Load shedding is what electric utilities do when there is an enormous demand for electricity that surpasses the supply. Thus in a delivery system, it needs to be accurately controlled for an exact period of time.
The proposed system is a reliable system that takes over the physical task of switch ON/OFF the loads with respect to time. It employs a real-time clock (RTC) interfaced to an 8051 family microcontroller. While the set time equals to the real-time, then microcontroller gives the signal to the equivalent relay to turn ON the load and then one more command to switch OFF according to the program. Numerous ON/OFF time access is the biggest benefit of this project. A matrix keypad assists entering the time. A seven segment display is interfaced to the microcontroller to exhibit time.
Further the project can be improved by interfacing a GSM modem to the accessible project so that the entire control of the load can be done by sending an SMS to the control unit. Furthermore, any queries regarding this concept or to implement any electrical projects please give your valuable suggestions by commenting in the comment section below. Here is a question for you, what are the applications of time operated programmed industrial load controlling system?