mini remote (ninja and others)

[berlusconi]

I know it is not "politically correct" posting here, but has anyone developed any modification for the ninja remote, or those similar from ebay?
I own one and would like to increase the range, maybe replacing the two small leds, or adding more leds. It works with a single 3Volt button battery.
thx

[richms]

You could look at the tv-b-gone schematic for the LED and transistors and stuff, and put that onto the LED output of the universal remote, probably best to just get the tv-b-gone kit, and instead of putting the 8 pin AVR in, just put wires to the LED of the keychain remote. Should be enough to get it working.

My keychain remote went thru the wash and died, and with how much of a pain in the ass it was to get working on any given TV I decided not to replace it.

A project I have been putting off for ages it to try a CCTV camera IR board and a TIP122 driving it. Limor made the bedazzler which is also some grunty LEDs with transistors controlling them you could copy the schemtic of and replace the LEDs with IR ones. I thought that is what she was doing when she put the pic of the board up

Depends how far you want it to go and how much $ and time you have to throw at it, but the stock led on those remotes and the pathetic power supply they have makes the stock range virtually useless.

You could try a decent 3v supply to the keychain remote and see if that helps pretty cheaply.

[berlusconi]

thanks for the reply richms! You are quite right! I do not recommend to anyone those little remotes, like ninjas, because they are useless without a strong hacking! LEDs are ridiculous.

[berlusconi]

Strange behavior: I opened the mini keychain remote and noticed that although the two LEDs were connected in parallel, only one was fed! Then I soldered a wire to feed the other led. Now they both work, I can see them blinking with my phone cam, but I can not control my plasma TV anymore, sometimes i can mute it, sometimes not! On a old TV it still works.

[richms]

Possibly taking too much current and resetting before the code is totally sent.

Wouldnt suprise me if only connecting one led was the manufacturers way of "fixing" it

Give it a decent source of 3v, not a cheap banned coin cell and see how it goes. Even a branded 2032 will be a massive improvement over the bulk junk ones, but 2 AA's would be even better.

[berlusconi]

Even a branded 2032 will be a massive improvement over the bulk junk ones, but 2 AA's would be even better.

Very interesting! Actually the keychain comes with a 2025 that is a 170 milliamp hour battery . The 2032 is 240.
I'm trying with 2AA, will post results as soon as possible!

[richms]

Its more the current that they supply that matters - a 2032 can light an LED directly at 20-30mA because of its high internal resistance. With a IR LED you want lots more than that to get good range.

The cornfield tv-b-gone has 2 2032's in it in parallel and a single LED and barely gets the range of a standard TV remote. As the remotes are so cheap they are IMO disposable, try 3 cells as well 3.6 to 4.5v and see what that does for range of it.

[oPossum]

The Cornfield TV-B-Gone uses one battery for the microcontroller and the other for the IR LED.

The Vf of an IR LED is much lower than a visible LED, so the current is quite a bit higher (if not limited by a resistor). If only one battery was used, then the voltage would drop below what the microcontroller needs to operate. So two batteries are used to allow maximum IR LED current and reliable operation of the microcontoller. Remotes that use a single battery limit the IR LED current with a resistor so the battery voltage does not drop too much.

Lithium coin cells should not be connected in parallel. The weaker battery will discharge the stronger battery and life will be greatly reduced.

TV-B-Gone Generation 1,2,3 Schematic

[oPossum]

IR Booster for keychain remotes
PCB
Higher power version

[richms]

Wow, That one totally slipped by when I was hacking with the thing, was a while ago anyway since its dead now after my botched hookup of a transistor sent 12v into it. That was an oops moment if ever there was one.

Vf on them is a little lower but still you dont get anywhere near enough current out of a coincell into them to get decent range. Thankfully the Vf isnt too high or all those lame stereo remotes with only 2 cells wouldnt work at all on NiMh, rather than the just dont work as well that they do.

[berlusconi]

Mate, you were absolutely right! I connected two AA batteries, not just the range is significantly increased, 8 / 10 m =30 ft (before it was 4 m), but also the speed of scanning! Now it takes a few seconds to find the right code. And the voltage is 2,8 volt only, so current is the crux! Thank you very much for the advice!
I will try also with a 2032 battery, when i find one.