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Topic: TV-B-GONE (Read 12963 times) previous topic - next topic

TV-B-GONE

Finished the tv b gone that use the european version that i wrote.
it is an eating cr2032...

Re: TV-B-GONE

Reply #1
To use less battery you could SLEEP() the PIC between LED changes, then only the timer is running. I'm not 100% sure how to do this, but I have done it in the past and it wokred well.
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Re: TV-B-GONE

Reply #2
If i sleep the pic how then i wake up it?

Re: TV-B-GONE

Reply #3
Depending on the PIC, you set a sleep level that will wake up on an interrupt, and then the PIC wakes up when the timer interrupt fires. I forget how the TV B Gone firmware works, but if there is a timer I think the timer interrupt can wake it up.
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Re: TV-B-GONE

Reply #4
i really need to find a solution because with new battery there is no problem but after 20/25 times of using the range drop a lot, from more than 10 meter to 2 m

Re: TV-B-GONE

Reply #5
It sounds like the voltage is sagging and your resistors are giving less current than designed for.

I think a better method is use a constant current driver, then the current is the same no matter what the battery is doing. It only takes two extra diodes on the base of the transistor to make it work. Check out the IR Toy v2 design, it uses this driver with good results.
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Re: TV-B-GONE

Reply #6
i'm working on a version with two AA as power supply and 4 leds

Re: TV-B-GONE

Reply #7
The constant current driver is super simple and works great. I'd highly recommend it even with 2 AA batteries.
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Re: TV-B-GONE

Reply #8
i am building the second version with the cr2032 but this time i want use only one led.
I'm writing this because i need help for calculate the costant current driver.
I don't know if, for this configuration , is better a transitor or a mosfet.
I already have a couple of 2n2222 and this mosfet http://docs-europe.electrocomponents.co ... e5615d.pdf . What should i use?
This is the led http://docs-europe.electrocomponents.co ... e1b0e6.pdf .
I also find this document and it use a different way to power the led http://www.ti.com/lit/an/slla175/slla175.pdf .
Thanks for the help.

Re: TV-B-GONE

Reply #9
The "geek zone' section describes how to calculate the constant current driver:
http://dangerousprototypes.com/docs/USB ... ransmitter
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Re: TV-B-GONE

Reply #10
i build a prototype using the schematic of the pdf and it works great.
It has a range of more than 20m and it doesn't lose power with the time, the capacitor is a 200uf 4v that i desolder from an old remote, the led is a tsal6100.
I still need to put a smooth capacitor on the line but it works fine also without it.
Now i'm designing the board in eagle.

Re: TV-B-GONE

Reply #11
I was trying to find a really nifty led driver I found a few months ago, but it seems I can't find it right now. :( The chip package was only like 4 pins, really simple, and easy to solder, with current adjustment through a resistor. If I find it I will post it in here!
Led drivers are really nifty in these situations, some have a buck/boost converter functionality right inside the chip so your led gets the exact same amount of current regardless of battery voltage.

Re: TV-B-GONE

Reply #12
Let me now if you find it.

Re: TV-B-GONE

Reply #13
After few devices i finally build one that i completely love.
I found an old nokia around the house and use the case for the tv b gone.
The circuit is similar to the adafruit kit's one, i use the phone battery that is a 1000 mAh Li-on.
The switch is under the number 7.
I made a usb charger with a max1555 on a piece o perfboard (pain to solder both the max and the smd usb socket).
The range is incredible bigger than anything i build before, it passes glass, and in a store is super funny.
In the future i will add a switch so i can choose wich code to send, european or american.

Re: TV-B-GONE

Reply #14
Very nice casing work. Happy TV turn-offing :)
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