13-02-2013, 02:20 PM
PRE PAID ENERGY METER
PRE PAID ENERGY .docx (Size: 702.5 KB / Downloads: 20)
INTRODUCTION
By using this technique we show that how we convert all meter with the prepaid logic. B y using this type of technology it is possible to stop he misuse of electricity. Normally in every postpaid connection bill is much higher then the prepaid. When there is postpaid, no body want to take care of the wastage, but at the end of month when bill is present then bill is paid by the house inch rage, small workers in the office, employees in the school, in all the private and Govt office no body want to take care of the wastage. So we add some innovative idea to avoid and save this valuable energy for every one.
In this project we use one LCD screen. LCD screen display the balance amount every time, LCD screen not only show the balance amount but at the same time LCd display the unit consumption. When the balance is zero then output is off.
Now for continue the electricity we must need to recharge the unit from the mobile phone. Now we go to any energy shop and tell the shopkeeper to transfer the amount of 100 or any add amount to my this energy meter. Shop keeper transfer the amount with the help of easy recharge. For this purpose first of all he dial the particular gsm number and when phone is automatic on then he transfer the amount in digit code. This data is decoded by the circuit and value is to be added in the unit. This added value is to be shown in the lcd screen automatically. When we want to go any palace then first of all we press the off switch, then unit the stop reading and no energy is consume. When balance is below 5 R/s then alarm is on. This alarm is a indication that you must recharge the unit. By chance if the supply is off then electronics circuit is also off and there is no supply . In normal electronics circuit is also off, but in this project we provide a memory feedback option. With the help of this memory feedback it is possible to record all the detail of the LCD screen. When supply is again on then first of all memory is on and recall the last detail by auto feedback logic
5 VOLT REGULATED POWER SUPPLY CIRCUIT.
In this project firstly we use one step down transformer. Step down transformer step down the voltage from 220 volt Ac to 12 volt Ac. This Ac voltage is further converted into DC with the help of rectifier circuit. In rectifier circuit we use four diode. All the diodes are arranges as a bridge rectifier circuit. Output of this rectifier is pulsating Dc. To convert this pulsating DC into smooth dc we use one capacitor as a filter components. Capacitor converts the pulsating Dc into smooth DC with the help of its charging and discharging effect.
Output of the rectifier is now regulated with the help of IC regulator circuit. In this project we use positive voltage regulator circuit. Here we use three pin regulator. Output of this regulator is regulated voltage. If we use 7805 regulator then its means its is 5 volt regulator and if we use 7808 regulator then its means that it is 8 volt regulator circuit. In this project we use 5 volt dc regulated power supply for the complete circuit. Separate 9 volt dc power supply is used for the relay coil
Guard Time Adjustment
In situations which do not require independent selection of receive and pause, the simple steering circuit of Figure 4 is applicable. Component values are chosen according to the following formula:
tREC = tDP + Tgtp tGTP = 0.67 RC The value of tDP is a parameter of the device and tREC is the minimum signal duration to be recognized by the receiver. A value for C of 0.1µF is recommended for
most applications, leaving R to be selected by the designer. For example, a suitable value of R for a tREC of 40ms would be 300K. A typical circuit using this steering configuration is shown in Figure 1. The timing requirements for most telecommunication applications are satisfied with this circuit. Different steering arrangements may be used to select independently the guard-times for tone-present (tGTP) and tone absent (tGTA). This may be necessary to meet system specifications which place both accept and reject limits on both tone duration and interdigit pause. Guard time adjustment also allows the designer to tailor system parameters such as talk-off and noise immunity. Increasing tREC improves talk-off performance, since it reduces the probability that tones simulated by speech will maintain signal condition for long enough to be registered. On the other hand, a relatively short tREC with a long tDO would be appropriate for extremely noisy environments where fast acquisition time and immunity
Input Configuration
The input arrangement of the CM8870/70C provides a differential input operational amplifier as well as a bias source (VREF) which is used to bias the inputs at mid-rail. Provision is made for connection of a feedback resistor to the op-amp output (GS) for adjustment of gain. In a single-ended configuration, the input pins are connected as shown in Figure 1, with the op-amp connected for unity gain and VREF biasing the input at ½ VDD. Figure 6 shows the differential configuration, which permits the adjustment of gain with the feedback resistor R5.
Clock Circuit
The internal clock circuit is completed with the addition of a standard television color burst crystal or ceramic resonator having a resonant frequency of 3.579545MHz. The CM8870C in a PLCC package has a buffered oscillator output (OSC3) that can be used to drive clock inputs of other devices such as a microprocessor or other CM887X’s as shown in Figure 7. Multiple CM8870/70Cs can be connected as shown in figure 8 such that only one crystal or resonator is required.