Universal Multiphone charger
Transcription
Universal Multiphone charger
Universal Multiphone charger Charging your cell phones with novelty Almost every electronic device needs to be recharged. This charger serves the purpose. Not only charging your 5 batteries simultaneously but also charging your motorcycle battery 5/21/2012 Universal Multiphone charger Group memebers Usama mehboob 143 Muhammaad hamad akram 76 Majid mushtaq 55 Yasir qureshi 151 Class ………………………………….BEE-2B Submitted to: MR saleem iftikhar 2 Universal Multiphone charger ABSTRACT “Universal pin charger” as the name suggest is used to charge more than one device at a time. it is capable of charging not only single type but also multipurpose devices. The project was designed for the ease of human life to meet the ever increasing demands of luxurious lifestyles of humans. There are always more than one electronic device in each home and charging them is seems to be a big problem for every individual. These chargers not only make your life easier and comfortable but also ensure the safety of device. Circuit is fabricated in compact form and providing the alternative path for various devices. No other charger in the market is designed in this way. All the chargers being designed in the market are capable of charging only one device at a time or at most two devices.but this universal multiphone charger is capable of charging five devices at a time.we are quite sure that this charger is going to change the lifestyle of every human being who will make it as a part of his life. This charger is going to define a new road map in the era of rechargeable electronic devices. 3 Universal Multiphone charger Table of Contents 1. introduction .......................................................................................................................................... 6 2. Background research ............................................................................................................................ 7 2.1 MOTIVATIONS .................................................................................................................................... 7 2.2 Research and Development ............................................................................................................... 7 2.2.1 regulation ........................................................................................................................................... 8 2.2.2 preserving the current of battery .................................................................................................... 9 3 4 5 6 7 componenet analysis .......................................................................................................................... 10 3.1 transformer ................................................................................................................................. 10 3.2 Diodes as a rectifier .................................................................................................................... 10 3.3 Filter ............................................................................................................................................ 11 3.4 Regulator circuit .......................................................................................................................... 12 3.5 Heat sink ..................................................................................................................................... 12 cost analysis ........................................................................................................................................ 14 4.1 Transformer ................................................................................................................................ 14 4.2 Rectifier circuit ............................................................................................................................ 14 4.3 Filter circuit ................................................................................................................................. 14 4.4 Heat sink ..................................................................................................................................... 14 4.5 Regulator IC (7805) ..................................................................................................................... 15 4.6 Additional costs........................................................................................................................... 15 4.7 Total cost ..................................................................................................................................... 15 circuit simulations on PSpice .............................................................................................................. 16 5.1 Rectifier circuit simulation .......................................................................................................... 16 5.2 Filter circuit working ................................................................................................................... 17 5.3 Regulator circuit working ............................................................................................................ 18 implementation problem and their solutions..................................................................................... 19 6.1 Swollen of capacitor.................................................................................................................... 19 6.2 Heating up of IC(7805) ................................................................................................................ 19 6.3 Backward flow of current............................................................................................................ 19 6.4 PCB fabrication problems ........................................................................................................... 20 limitations & improvements ............................................................................................................... 22 4 Universal Multiphone charger 8 7.1 Max number of batteries ............................................................................................................ 22 7.2 Supporting devices ..................................................................................................................... 22 7.3 Motorcycle battery charger ........................................................................................................ 22 7.4 Size .............................................................................................................................................. 23 conclusions .......................................................................................................................................... 24 TABLE OF FIGURES Figure 1 transformer(component) .............................................................................................................. 10 Figure 2 bridge rectifier circuit.................................................................................................................... 11 Figure 3 filter capacitor ........................................................................................................................ 11 Figure 4 regulator IC 7805........................................................................................................................... 12 Figure 5 Heat sink....................................................................................................................................... 13 Figure 6 rectifier circuit designed to convert AC to DC............................................................................... 16 Figure 7 simulation results for rectifier circuit............................................................................................ 16 Figure 8 filter circuit simulated ................................................................................................................... 17 Figure 9 regulator IC circuit with different batteries in paralle ....................................................... 18 5 Universal Multiphone charger 1. INTRODUCTION Universal multiphone charger as the name suggests is operated under 230 V rms.in case of load shedding which is legitimate problem in Pakistan it can also be operated under 12 volt battery. This charger is capable of charging 5 phones at a time , whether it is being operated in 230V AC or 12V Dc power supply from a battery. It delivers its output in 5 different PINS. Each pin is able to charge one mobile at a time. it does not matter of which company your mobile is whether is a cheap mobile of nokia or a smart phone android(capable of being charged from a usb port).all mobile can be inserted simultaneously this charger also includes of charging a 6 volts motorcycle battery.2 crocodile clippers are provided at its outputs which are two be connected to positive and negative terminals of a battery to be charged. this charger has an upper hand on other chargers available at market in this regard that it ensures the safety of human life where other charger fails. An extra fuse is added in series in the circuit which does not allow the current to exceeds the required safe amount.in short this multiphone charger can surely be regarded as the jack of all trades. 6 Universal Multiphone charger 2. BACKGROUND RESEARCH 2.1 MOTIVATIONS Motivation for this project came because we care for your needs. A bundle of chargers are available in the market. But all has a common problem where they fail to be called as a universal charger. The name only cannot ensure the functionality of the device especially when your product is capable of charging only one device at a time. As actions speak more than words so keeping these words in mind we hit upon an idea that there must be charger that surely would be called as a universal charger. Motivation for this project came to bridge this gap of universal chargers in some way. So atlas we came up with our glorious product in the market as multipurpose phone charger. This charger not only charges your cell phones but also 6 volt your motorcycle battery. So we used the basic concept to charge a single phone but we tapped it and expanded it in very intelligent and ingenious way to introduce our product in the market. 2.2 Research and Development Research was done only to expand the concept of charging a single mobile at a time to make it able to be applied on multiple mobiles simultaneously. So we took the simple concept of charging the batteries & what we found was mere to regulate the voltage after converting it into DC,but one extra thing we added to preserve the battery charging is to stop the current of battery from flowing in backward direction 7 Universal Multiphone charger 2.2.1 regulation So in order to increase the current we had to make a trade off of giving of various resistances for regulation of voltage. So in order to compensate this we used a regulator IC 7805 so that it would regulate the voltage to required level without alternating the current in circuit. input from 230V AC transformer(230V/10V) Rectifier(AC to DC) Filter(high capacitance) Regulator 8 Universal Multiphone charger 2.2.2 preserving the current of battery In order to stop the backward flow of current from the battery we adopted a new scheme that we employed diode before each battery although we had to give the sacrifice of 0.7 volts to diode yet it did good job in preventing the backward flow from the battery. So this is how we came up with our circuit In last we just added 5 pins including USB female port in parallel across the 5 volts from the regulator IC. Diode + Battery to be charged --- As indicated a diode is placed in series with the each battery so when battery is being charged current is flowing in the battery so diode is forward biased so no hindrance for the current toward the battery but as soon as the external supply is disconnected ,if the battery current tends to flow in backward direction diode will become reverse biased so battery current is preserved. This is how we made a tradeoff between 0.7 voltage drop and battery current storage. 9 Universal Multiphone charger 3 COMPONENET ANALYSIS Our circuit consisted of following components: Transformer Capacitor 4700uF 7805 regulator IC Heat sink Diodes as a rectifier 3.1 transformer A transformer is employed to convert from 230V rms to 10V rms with 2 A current. As transformer is step-down so current at the output may increase. this current serves the basic of our charger to make it available to different batteries. Figure 1 transformer(component) Before transformer we employed a fuse for the safety of transformer so that current may not increase above the required limit 3.2 Diodes as a rectifier Four diodes are employed to make a bridge rectifier. This is a full wave rectifier having peak inverse voltage 10 Universal Multiphone charger Peak inverse voltage=Vs- Vd So this less peak inverse voltage enables the diode to withstand the high inverse voltage to prevent from going into breakdown region Figure 2 bridge rectifier circuit 3.3 Filter filter circuit is used to remove the ripple coming from rectifier. It consist of large capacitor (to have greater time constant) and first capacitor is charged as long as voltage is increasing and as soon as voltage drops it start discharging slowly & steadily and tries its best to maintain the voltage. Figure 3 11 filter capacitor Universal Multiphone charger In this way we get a DC supply with small ripple so that we may be able to use it as input to the regulator circuit. 3.4 Regulator circuit +10V DC supply obtained from filter circuit is employed and fed to a 7850 regulator IC. Figure 4 regulator IC 7805 Regulator IC output is taken between terminal 2 & 3.terminal 2 serves as a ground and terminal 3 serves as an output. And give 5 volts regulated supply which is fed to the batteries. Batteries draw current and charges.. 3.5 Heat sink Heat sink is thick aluminum sheet that is employed along with regulator IC.this thick sheet is used to prevent the IC from being overheated. As aluminum has very low heat of coefficient so it does not overheat .and absorbs the all the mess and keep the IC cool to make it able to function fully and steadily. 12 Universal Multiphone charger Figure 5 Heat sink 13 Universal Multiphone charger 4 COST ANALYSIS In this sections cost analysis of different component is being discussed.that how much each electronic component costs.moreover fabrication details are also given: 4.1 Transformer Transformers we purchased was of 100 rupees.transformer didn’t cost too much as rating is low.we required low rating transformer as battery does not draw more than 200mA current.so our transformer rating was 230V input and give 10V/2A current max So transformer cost=100 rupees 4.2 Rectifier circuit Rectifier circuit consisted of 4 diodes connected in a way so as to form a bridge.we bought 12 diodes.4 were destroyed because of mishandling of voltage supply .each diode cost 5 rupees so.we also employed diodes at the end before the output so as to prevent the backward flow of current from the batteries Diodes cost for rectifier=40 rupees Diode cost for backward current protection=20 rupeees 4.3 Filter circuit Filter circuit contains a 4700uF capacitor.one is employed in circuit.we bought 2 capacitors.one was destroyed as over current was flown into &it was swallowed Each capacitor cost 25 rupees so cost of filter circuit was Filter cost=50 rupees 4.4 Heat sink Heat sink serves the big purpose as it ensure the life of regulator IC.we bought 2 heat sinks,one for each IC,none of heat sink became useless as there is nothing in heat sink to be destroyed.each heat sink cost about 15 rupees 14 Universal Multiphone charger Heat sink cost =30 rupees 4.5 Regulator IC (7805) Regulator IC is the main component of our circuit.as it regulated the voltage from 10V to 5volts.there were 3 regulator IC we bought from the market.2 were destroyed as we shorted the output terminals mistakenly and a large amount of current 7A flew throught that destroyed the IC.each IC cost 25 rupees Regulator IC(7805) cost=75 rupees 4.6 Additional costs Some additional cost were done on the following components: LEDS=3*6=18 rupees PCB board=1*50=50 rupees FECL3 (for etching)=20 rupees Wires=10 rupees 4.7 Total cost Grand total of whole package was: Total cost=313 rupees 15 Universal Multiphone charger 5 CIRCUIT SIMULATIONS ON PSPICE Before implementing the circuit simulations is always done to expect about results:so circuit that is simulated on PSPICE is: 5.1 Rectifier circuit simulation in V6 VOFF = 0 VAMPL = 11 FREQ = 60 D21 D23 D1N4002 D1N4002 R3 V+ 1k V- D22 D20 D1N4002 D1N4002 V 0 0 Figure 6 rectifier circuit designed to convert AC to DC Simulations results are obtained as: 20V 10V 0V -10V -20V 0s 10ms 20ms V(IN,V6:-) V(D23:2) 30ms 40ms 50ms Time 60ms Figure 7 simulation results for rectifier circuit 16 70ms 80ms 90ms 100ms Universal Multiphone charger Here the green waveform is input and red is output.it is clear that it bridge rectifier is working properly so we proceeds to next step: 5.2 Filter circuit working Filter circuit result is given below : 20V 10V 0V -1 0 V -2 0 V 0s 1 0 m s 2 0 m s 3 0 m s 4 0 m s 5 0 m s 6 0 m s 7 0 m s 8 0 m s 9 0 m s1 0 0 m s V (IN ,V V (D 6 :-) 2 3 :2 ) T im e Figure 8 filter circuit simulated Herhh Here we have introduced a capacitor across the load resistor which in our case is batteries so as the diagram suggests, capacitor is doing the reasonable job, by comparing figure 8 and figure 7 we come to know that large value of capacitance (4700uF) was chosen very correct as Time constant=RC Greater the time constant greater will be the time required by the capacitor to discharge that’s why we are getting the straight and steady line(RED) on the input AC(green).in this way we are getting a smooth DC voltage without any ripple so this encouraging results suggest us that this voltage about(9.3V) can surely be fed to the regulator IC.so next we get just 5 VOLTS and different batteries are connected each draws its current according to its requirement. 17 Universal Multiphone charger 5.3 Regulator circuit working Our next step is toward regulator IC So instead of drawing regulator IC on PSPICE.5V dc supply is given and different resistors in parallel indicate different batteries with different resistances so every battery would draw its require current from the +5 volt IC. 5.000V V10 5.000mA R4 5 7.143A R5 0.7 1k 17.15A 0V Figure 9 10.00A R6 0.5 0 regulator IC circuit with different batteries in paralle this current would continue to flow in the battery until the battery is fully charged then current stops flowing .As multiple batteries can be charged because there is no limit on current because transformer is capable of giving 2 ampere current which is more than enough for charging four or five batteries. 18 Universal Multiphone charger 6 IMPLEMENTATION PROBLEM AND THEIR SOLUTIONS Of course we faced a number of problems during patching our circuit.all these difficulties are honestly discussed here: 6.1 Swollen of capacitor Problem 1: First problem we faced was the swollen of Capacitor. We were using 1000 uF capacitor. It worked well when only one battery was connected but when 3 or 4 batteries were connected at a time it got swollen and also got extremely hot. Solution: We overcome the problem by installing a large capacitor like 4700uF in our case. The new capacitor has greater time constant in other words charging and discharging time and works well for more than 4 batteries as well. 6.2 Heating up of IC(7805) Problem 2: The second problem we faced was heating up of Regulator IC 7805. As more batteries were connected it gets more hotter and hotter. Solution: The problem was overcome by using heat sink. Heat sink solved the problem to much extent. 6.3 Backward flow of current Problem 3: The 3rd problem faced by us was backward flow of current that is discharging of batteries when no input is applied. It was observed that in the absence of any source if the charger is connected to the battery the battery gets discharged and the backward flow of 19 Universal Multiphone charger current takes place. This was very serious problems as most of the times people forget to unplug the charger and in case of downfall of electricity the battery will start getting discharged. Solution: The solution to this problem we decided was to put a diode in way of each pin such that current may flow in forward direction but it opposes the current to flow in backward direction. Battery. Although we had to give the sacrifice of 0.7 volts to diode yet it did good job in preventing the backward flow from the battery. So this is how we came up with our circuit. As indicated a diode is placed in series with the each battery so when battery is being charged current is flowing in the battery so diode is forward biased so no hindrance for the current toward the battery but as soon as the external supply is disconnected if the battery current tends to flow in backward direction diode will become reverse biased so battery current is preserved. This is how we made a trade off between 0.7 voltage drop and battery current storage. 6.4 PCB fabrication problems Problem 4: The last problem we had to face was after patching our circuit on PCB. We patched the circuit almost right way but it wasn’t working . We tested each equipment and even replaced the equipments but still were in vain. The problem was anonymous. We were getting the outputs at the transformer 20 Universal Multiphone charger secondary and getting the rectified waveform after the bridge rectifier but were not getting the regulated output after the 7805 IC. Solution: After 2 hours of discussion we came up to point of again simulating the circuit at PSpice. So we simulated the circuit and by the grace of Almighty got the solution. We were actually giving the rectified +ive output to the negative terminal of the IC. 21 Universal Multiphone charger 7 LIMITATIONS & IMPROVEMENTS Of course every device being manufactured has some limitations and some improvements has to be done in order to bring the device to the commercial level.our device is manufactured on personal level so it has some limitations: 7.1 Max number of batteries First limitation is that our charger is capable of charging 5 batteries at a time.but not more than 5.because charging them needs a lot of current which exceeds beyond the rating of our transformer So in order to charge more number of batteries a bigger transformer has to be employed but using a bigger transformer would increase the cost.this is the trade off u have to take care of 7.2 Supporting devices According to our survey all the mobile in the market uses 5 volts for their charging.our charger supports Nokia Samsung Sony ericsson Androids But we found some exceptions that some china mobiles uses 9 volts for their charging.so on order to charge them we have to use an inproved regulator circuit instead of using a single regulator IC. 7.3 Motorcycle battery charger Charger is capable of charging the motor cycle battery which is +6V.but if u wana charge motorcycle battery u have to disconnect other batteries as motor cycle 22 Universal Multiphone charger battery draw a lot of current so all the current given by transformer is utilized in charging this.again if u want to charge other batteries or 12 volts batteries u have to employ the bigger transformer and bigger capacitor. 7.4 Size Size of multipurpose charger is big enough because of capacitor and transformer.but if u want to make a smaller and portable size.this is also possible but that would increase the cost of charger.our company is offering compact charger according to the demands of customer.but mostly customers are happy even in its bigger size as it become ergonomic. 23 Universal Multiphone charger 8 CONCLUSIONS Multipurpose charger designed ,served a lot as its design is simple & ergonomic. Moreover its user-friendly operation and low cost make it efficient charger available uptill in the market. More over its capability of charging the mobile batteries with both AC and DC supplies make it priceless. Out of all other aspects the major one is that its capability to charge five batteries simultaneously and also additional motorcycle battery make it the basic need of common man. But like all other devices it also has some limitations for china mobiles. As there is no check & balance on china mobiles so it is very difficult to make it charger for all china mobiles available in the market. But it does good job indeed for any other company in the market. In order to bring it to the commercial level some improvement has to be done. But indeed it is worth saying that this multipurpose charger is superb and ingenious effort of electronic engineers. After all we care. 24