Hello Friends,

we can only grow by sharing ideals. That the purpose of this room. To share ideals on electronics designs. Good for elec/elect students and circuit developers. Just post your problems or offer solutions to problems (if you know them). Thats what its all about! Its a free community

I am curently engaging in a serious research design of controlling a car from anywhere in the world using any phone but i have a minor problem.

The GSM module i used as a modem requires 8V, 650mA to keep it running from a 12V DC supply. Anyone who can provide me with a circuit diagram solution. You can test with nokia 1100. if it charges it, it will charge my module.

Hit me on midje@ieee.org if you have a solution. Cheers

If you talk like this, then i can tell you that I am currently working on a wireless 10kva generator. The generator will transmit power to its reciever unit in your house and you can do away with cables. it should work up to 100m range.

Really, Pls share the ideal. Lets hear your design

I think a simple fixed or variable voltage regulator should do the job for you. Try the 7808 series if you are sure you need 8v or a 7805 with a resistor set on pin 2 to give you 8v. If your modem doesnt pull more than what it needs you should be fine.

I think 78XX regulators can not source the current i really need. Once u can get a circuit that can charge a Nokia 1100 phone very well from a 12V Dc supply, then it should be able to work well with my modem. My modem needs aboout 500 - 800mA.

Also check out the circuit in the attachment and tell me what u think about it pls

Thanks brother but am still expecting more support from u

78xx series regulators are simple to use, they require little or no additional compos and can handle up to 1A current. the s8050 transistor supports up to 700mA only. I have a bit of concern on your 1kohm resistor and the 9.1V zener diode application in your diagram. Is this a circuit you ahve tested already? If you want more power you may want to build a power cct however that may not fit into a standard car charger enclosure.

@Iukpe,

I have not tested the circuit o. Can u pls attach to me the circuit for the 78xx and the power cct. I am not really concerned about size but efficiency. Am not putting it into a charger case but adding it to my design (modem).

IF u could, test the circuit with a Nokia 1100 because the modem am creating is of same power. If it cld charge the nokia 1100 without error, it will work perfectly for mine. But with a DC (12V) power supply

Once more, thanks a lot for your support. U are one in a thousand

this thread is funny, I'm also a grad of comp & electronics but

@midje: why don't u just use a Nokia 1100 car charger and save yourself all the hassle

@Iukpe: transmitting 10KVA electricity wirelessly na Nobel prize be that oo!

check this out, you'll like it http://www.thinkgeek.com/stuff/41/wec.shtml, i came across it a while back

wow its so cool, thank for information