Mobile phone flasher

[cardoso115]

Does anyone knows how to build a mobile phone flasher?
I guess it has some sort of coil which transforms the waves in power, but I haven't found out how.

Thanx in advance, Carlos Cardoso

 

[MacGyverS2000]

I doubt it is simply a coil... there is probably a bit of active electronics there (active in the sense that it's more than a coil, but not active in the sense of being provided power by the battery... power is provided by way of the RF energy). The chip merely looks for a strong signal from the phone back to the local cell caying "I'm active"... once it senses that pulse of energy, it goes off.

 

[VEBill]

If the light source is an LED or light bulb, then it is almost certainly powered by a battery - otherwise it would have to extract about 10% of the total RF power output to fire up the LED (that's unlikely).

If the light source is neon or similar, then it might be using the RF itself to fire up the light. Last evening I was unpacking a new neon novelty light ("BAR") and every time that it rubbed against the styrofoam packing material it flashed. It doesn't take much energy to fire a neon, but it does require at least about 70 volts (a cell phone would require some sort of step-up transformer).

 

[melone]

What do you mean "flasher"? Are you trying to make a few LED's blink in some useless fashion, or are you trying to reprogram the application code?

 

[MacGyverS2000]

VE,

I've never paid close attention, but aren't those novelty antennas used on cell phones non-battery powered? From what I could see in the packaging, you simply replaced the stock antenna with that one, no wiring necessary, which to me means no battery connection and all power comes from the RF.

 

[VEBill]

Possible, but seems like a waste of perfectly good RF...

 

[MacGyverS2000]

<chuckle> Do you honestly think the people who put flashing lights in the antenna of their cell phone really care about wasting a bit of RF energy?

I can think of a few people who would carry cell phones around even if they didn't actually make a call... just because they look cool doing it. There were the days (late 80'of fake cell phone antennas for cars

 

[cardoso115]

Hello,

It's like this, My new office will be a bit noisy, so I'm planning on working with some sort of headphones on my hears. Since the headphones will most likely damp the noise from the cell phones ringing, I thougt on doing a gadget that will flash a light every time the cell phone rings.

I've seen some gadgets of this kind and I'm almost sure that it doesn't have any sort of battery.

Thanx and merry christmas!

 

[VEBill]

There are those replacement keyboards (or similar) that are infested with dozens of tiny LEDs. I assume that they connect into the phones wiring by means of a hidden connection provided by the phone manufacturer. The entire phone lights up like a blinking Xmas tree (how appropriate...) when there is an incoming call.

Seems like you need to visit your local shopping mall and drop by the booth that sells such cell phone gadgets.

 

[MacGyverS2000]

Yeah, the lighted keypads will set you back about $30-$50... worthwhile for this sort of situation.

 

[skiier]

cardoso115

When my phone rings in the car it "screws up" the sound coming out my stereo. I discovered this quite by accident and it has been very useful when the volume is way up on my stereo. I simply leave the phone near the radio on my dash and I always know when it is ringing.
Try setting your phone on top of your computer tower or near your laptop and hear what happens when it rings, maybe this is a simple solution for you and it doesn't cost a cent.

skiier

 

[cardoso115]

My laptop doesn't flinch when my cell phone rings... I know this for sure. However my pc monitor in the work place will. :\

It's not the flashiest solution, but... It's a solution
Thanx

 

[Andy6]

I bought one for £1 from a news agents, its about an inch long and half an inch wide. It has a sticky backing and you just attach it to the side or any convenient place on your phone. It has several little lights which all flash when the phone is in use.

 

[VEBill]

Are the lights LEDs, or something else?
Any sign (or not) of a small battery?

 

[WorkedVYSV8]

Sit your phone as close to your sound card/amplifer as you can and you will hear it, or, ontop of your monitor if its a CRT, close to the Yoke and it will distort the image, put it on vibrate and put it in your pocket, spend a couple of dollars and buy a flasher...

I would be interested in exactly how those flashers do work though...

 

[Rich2001]

http://www.mutr.co.uk/prodDetail.aspx?prodID=12

 

[VEBill]

...that device uses LEDs and (although it doesn't clearly state it) it must relay on external battery power (since it can be triggered by the EMI from a small motor).

 

[shammer]

I have not tried it, but it may be worth a shot:

http://www.electronics-lab.com/projects/misc/010/index.html

 

[maged541946]

Hi, I had a broken one, it is not more than a wire and LED of the high brightness small LED. It is powered from the RF and I noticed a reduction in power on some cell phones when one is installed...
If you have an old non electronic phone, place a cell 1- feet away from it, while you are talking in the phone, let tthe cell rings, (like calling the cell number from other phone) , you will be surprised of what you will hear on the regular non electronic phone, picked only by the wired driving an old ear piece no amplifiers no power source of any kind. I was shocked when I heard the picked noise are greated that the sound received from the other end