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bilalinamdar
03-30-2010, 06:06 PM
How to keep charging Mobile 24/7 with timer ?


Hi i am hobbyist in electronic but i don't know electronics much.
In my application i will have to leave the Mobile / cellphone charger ON for 24/7 in the motorcycle. My bike contain 12v battery. so i would like to know

The cellphone (Nokia 3310 LI ION battery 3.6v)will be connected with a car charger and applied a 7805 which will keep the voltage 5v (because the car charger was outputting 8v dc while i tested it on home ac adaptor) and will go to 12v Battery of the bike..

1) I want the mobile to get charging of 30min / from 24hours (should i increase or decrease this time ?).
2) It should not overcharge (Exception)
3) Where should i place the circuit on Position A or B ? (refer to he image plz)
4) How to reduce the 5V further for a Good 3.8v Dc (for good battery life). If resistor than which value and on which node (positive or negative)
5) Will i have to use PICAXE ic ? is the right way ? if yes than how because i never used PICAXE before...


I thought putting a alarm clock but it will be bulky better would be using a circuit design which will do the same as the alarm clock.


Even if the circuit is not possible atleast tell me how to charge the mobile if the circuit is triped because of alaram clock for atleast 30min...



I thought of using 555 timer or other options but never used that....Please do guide...

vikas
03-30-2010, 06:46 PM
This page has all the details you need -

http://shdesigns.org/lionchg.html

Or is want something better look into Microchip IC's like MCP73841 .

You have to learn Lithion/Lithpolym charging charectistics , And use a charger designed around ur battery ... Lith ion are bombs if handled incorrectly.

bilalinamdar
03-30-2010, 07:44 PM
This page has all the details you need -

http://shdesigns.org/lionchg.html

Or is want something better look into Microchip IC's like MCP73841 .

You have to learn Lithion/Lithpolym charging charectistics , And use a charger designed around ur battery ... Lith ion are bombs if handled incorrectly.



But i just want to charge the mobile for 30min daily what could go wrong with that...
It will be like kept untouch for long duration.. I know the li-ion battery get exploded because of overcharge and stuff that is why i need a simple solution to charge the mobile with a Timer..

I have something in my mind but i don't know will it work or not..
How About using a Digital Alarm Clock and using it Buzzer/Speaker as an trigger for timer 555 and will start 30min timer which will charge the mobile.
Will it be okay if yes than should i have to Mod the aftermarket alarm clock (the small ones) or should i build a circuit ...?
If circuit than how to build one i tried google but it shows very complicated design for Digital alarm clock !...
Is micro controller will be good solution ?

regarding MCP73841 i never used one and don't have any idea on using it so completely lost on that...

I programmed atmega8 & attiny2323 but never used the above mcp ic and dont know how to proceed with it...

akshay66
03-31-2010, 09:19 AM
Hi,
PIXACE ic is not available in INDIA so forget about it.Try & make the circuit given by Vikas.I have personally tested it.

I actually could not understand what do you want to do with timer.You want the charger to automatically get off after 30 min or there should be alarm & you manually turn it off??
Use ic555 & set the values RC such that it gives a 30 min delay.It would be better if you use circuit suggested by vikas & not your 7805.

bilalinamdar
03-31-2010, 10:56 AM
My application demands that the mobile should be kept unattended for long period of time (months) so i need a solution where in i do not need to charge the mobile again and again... It must be done automatically that is why i need to build a SMART AUTO CHARGER for Cell Phone (Li-Ion battery).
Yeah if i build the above circuit i think there will be no need for CAR CHARGER and the Voltage regulator (7805). AM i right ?

But i am still confused as to build which circuit because there are 3 pdf and which one would be okay for my need

My battery specification is (Nokia 3310)
Lithium Ion Voltage 3.6V 950mAh


Kindly suggest me which Circuit to build from the page http://shdesigns.org/lionchg.html
and also will it be okay i keep the circuit unattended for long period ?

Ulhas
03-31-2010, 03:38 PM
How to keep charging Mobile 24/7 with timer ?


Hi i am hobbyist in electronic but i don't know electronics much.
In my application i will have to leave the Mobile / cellphone charger ON for 24/7 in the motorcycle. My bike contain 12v battery. so i would like to know

The cellphone (Nokia 3310 LI ION battery 3.6v)will be connected with a car charger and applied a 7805 which will keep the voltage 5v (because the car charger was outputting 8v dc while i tested it on home ac adaptor) and will go to 12v Battery of the bike..

1) I want the mobile to get charging of 30min / from 24hours (should i increase or decrease this time ?).
2) It should not overcharge (Exception)
3) Where should i place the circuit on Position A or B ? (refer to he image plz)
4) How to reduce the 5V further for a Good 3.8v Dc (for good battery life). If resistor than which value and on which node (positive or negative)
5) Will i have to use PICAXE ic ? is the right way ? if yes than how because i never used PICAXE before...


I thought putting a alarm clock but it will be bulky better would be using a circuit design which will do the same as the alarm clock.


Even if the circuit is not possible atleast tell me how to charge the mobile if the circuit is triped because of alaram clock for atleast 30min...



I thought of using 555 timer or other options but never used that....Please do guide...


Take Car cell battery charger, i dont know whether you have cell phone with battery or you are using battery alone.
But still making circuit to realise that battery charged or not is a money consuming thing, also making alarm or uC based system to disconnect the charger is difficult task.

Still if can't be avoided then i will recomment to use mobile with battery which has inbuilt overchage prevention, use car charger switch off mobile , apply charger output to mobile, take taps from battery and then use it
But still its a energy conversion you because of efficiency of conversion it will not be required

What the best you can do is take electronics regulator convert 12VDC from battery to the one you want, Use SMPS Ics so that you will get max efficiency.

But still i dont understand means do you want to charge the battery or you want to make charger,
Your apllication is not still clear

bilalinamdar
03-31-2010, 05:56 PM
Okay i will make the application as clear as possible...

I want to add security for my motorcycle. If some one touches it (vibration activate switch) i he will get warning if he touches again under a specific time it will buzzer and dial a number of mien...
For this purpose everything is ready but only i have to manually charge the Mobile Everytime (Nokia 3310) at my home.. Which is not a good option for security devices.
I have 12v battery in the bike which can be used to charge the Mobile But again it should not overcharge so i purchased Car Mobile Phone charger (http://bestcellbuy.com/bestcellbuy/images/Nokia/Car_charger/Nokia_6101_car_charger.jpg) the image is used as reference i purchased a local market charger. It is a MULTI CELLPHONE CHARGER with lots of Pins.
I don't know if this charger have the Overcharge Protection system....
I tried to read the output of the car charger by applying a 12v ac-dc adaptor current on the car charger and i got 8v on the Multimeter. which is high... I didn't tried connecting to the battery(12v motorcycle)..and i didn't check while charging the phone...but it charges the phone..I think 8v will definitely harm the mobile. so i am trying to build a smart charger....
i think i made it clear and please refer to the Image i posted in my First Post it will also provide u a brief info abt my need...

I will be charging the MOBILE PHONE not the Battery....will the cellphone inner circuit protect my battery from overcharge or something like that ? will it cutoff ? because many people say it would...
If the cellphone (Nokia 3310) is smart enough to cutoff and have the protection from overvoltage than i don't need to build anything... Also it should be compatible with the 8v car charger..

Ulhas
04-01-2010, 08:54 AM
Yes, many phone offers overrun protection.
Just connect charger to mobile and wait for message for batteryy full or obsereve there is no progress in battery charging although you have charger ON,
If you find this on your mobile then your mobile have inbuilt battery overcharge preventor.

All chargers works on PWM cycle in which they monitor current status of battery, Of course you will get output voltage 8v on the Multimeter or greator which is unloaded voltage, Don,t bother about it but Do remember it may nmot be DC, to check it up connect charger output to mobile and Connect output to Osciloscope to see the waveform.

However you can think to Remove the battery from cell and directly power mobile from bike battery with some regulator chip.
vibration activate switch is new to me, will you please ellaborate on same for our info ?

bilalinamdar
04-01-2010, 09:50 AM
http://www.instructables.com/id/Motorbike-Phone-Alarm/

the above will tell u many things about the project. The person added charger to the ignition plug so when he will ride the bike the phone will charge but i will not use bike daily (that is why i want this system)..

I know there are aftermarket security (Chinese) system available but there is none like mobile alert...So i will build it..
And ulas as i see u are from mumbai exactly from where? also from where u buy the resistor, capacitor and other stuff.. because mainly i live in pune so i buy from rajiv electronics...In mumbai i know we can get it from lamington road but can u tell me perfect addres of the shop ?
Also is there any one who can do my project (this is my hobby projects not college of school projects) like if i provide the circuit to build it or if i provide the idea to implement it and are they reasonable.. because i will want to sell this product.