I'd like to be able to make some SMT Leds light up through the use of some sort of rf controlled switching. I was looking at a flashing cellular antenna and noticed there is no power connection. It seems to actually be powered by the RF signals coming from the phones antenna. Any idea how I can accomplish this?

I'm trying to make a little setup similar to that of the flashing antenna so I can see when my phone is ringing while it's on silent.

I'm also wondering if anyone knows of a rather inexpensive source for smt leds. I haven't been able to find much. I'm more specifically looking for purple and aqua.

 

I've seen call-indicator for cell-phones without power,but it contains a small neon-lamp(glimm). If you need LED-flashing,this can't work without power. ( new GSM-phones have very small RF-power)

 

I figured the same thing but this antenna isn't wired to any + or - . There's what looks like a transistor on the board. From that a wire goes down to the antenna base on the phone, so long as that wire is touching the antenna base the LEDs will light up, if that wire is pulled away from the antenna base the LEDs turn off.

I'd even be interested in putting together my own sort of flashing keypad if I could, hard wired to any + or - source. Any info you could give me on either one would be great.

 

The small component must be a microwawe semiconductor. It rectified the RF when the phone transmit. If this DC voltage enough for LED, it can work.

 

I've been told there's some sort of IC chip under this white porcelin looking stuff to control which lights flash and when. Would this just be some sort of a programmed timer IC? If so how do I find one that is so small? This is probably 1/2 the size of a 12c508 if not smaller.

 

Here's exactly what I'd like the LEDs to do..

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