Wired remote extender for Tivo?

Also found these on Silicon Cip Magazine's site (who designed Jaycar's kit):-

===

Remote Control Extender Questions

I’ve recently purchased a Remote Control Extender kit (SILICON CHIP, July 1996) and was wondering if the following is possible. I would like to hook up two or three separate rooms to be able to receive remote control signals and have the transmitted signal sent back to a single destination using the one kit (if possible).

I’ve searched your site and noticed people asking for multiple IR transmitters (IR LED1) but not multiple IR receivers (IC1).

I was thinking I could house the PC board main unit near the receiving devices (VCR/DVD and A/V receiver) and use a single 9V DC power supply to drive the multiple IR receivers (IC1) rather than having to plug in up to three separate power supplies with three separate kits.

I was thinking I could do this by running three wires (using Cat 5e) in series to each of the IR receiver positions in the rooms but have no idea about the resistors, etc needed. Alternatively, if I used four wires, I could possibly accompany each of the IR receivers with its own acknowledge LED.

Please let me know if this is possible and how I could achieve it. (P. R., via email).

There is no reason why three IR receivers (IC1) cannot be paralleled, with the outputs connected together. The outputs are essentially open-collectors requiring a pull-up resistor.

In the circuit, they use a 1kΩ resistor in series with a LED. So use the one IR extender and add in two more IR receivers by paralleling the positive supply, 0V and outputs.

Note that each external IR detector would need a 10μF electrolytic capacitor across its power supply.

=====

More IRLEDs for remote control extender

Could you let me know if it is possible to run more than one IRLED on the remote control extender featured in the July 1996 issue. If so, what do I have to do so it still works. I need to do this because I have two units in different places.(R. S., via email).

You can run another IRLED via a separate 220Ω resistor connected to transistor Q1.

=====

Extending the IR extender

Some time ago I purchased a Remote Control Extender kit, as described in the July 1996 issue of SILICON CHIP. While the unit works fine, I find that the operational range of the IR transmitting diode is only around 1.2m. I have played around with VR1 but this is the best range I can achieve. I have an application where I would like to mount the IR transmitter around 3.5m away from my stereo and was wandering whether it is possible to extend the range to a similar range of my stereo's remote control.

I do not have access to an oscilloscope but have used a multimeter to test the voltage and current of the IR diode while operating. The diode is drawing around 3-5mA during transmission. The Dick Smith Electronics reference material suggests that normal operation should be around 20mA with a maximum of 50mA. Is it possible to increase the output of this diode by reducing the resistance of the 220W resistor at the collector of Q1?

(P. B., via email).

The current through the LED is 40mA and so increasing the current could damage the IRLED. Further range could be achieved by paralleling more IRLEDs, each with their own 220W resistor in series. Also you could try adding a torch reflector behind the LEDs to give a more concentrated beam of IR light.

=====

Cheers,

Tony

(in Yoda voice) TinyURL you seek, yes.

Hi Tony & Shane,

Yes, the Jaycar / Silicon Chip kit is the one Shane and I are using. But I don't know why his one works with the TiVo and my two extenders do not.

Both are without modification from the standard design, although the connection to the LED goes through a significant length of Cat5 cable (about 20m all up) with a join by the network hub. Still, they work for the other devices, so I think it must be something to do with the fidelity of replicating the TiVo IR codes.

Shane - have you done anything different in constructing or setting up yours? Where have you placed the LED in relation to the TiVo?

Colin

I too used to have one of those Jaycar extender kits that worked resonably well for most devices but didn't want to work with the TiVo. The cable run isn't excessive and there is no other "joins" or extras in the circuit. After getting frustrated with it all I decided to explore other options. I ended up buying the Xantech setup that Waynez had mentioned earlier and it works perfectly. The sender and receiver are also a lot more discreet as opposed to looking like something you slapped together in electronics class :D and it works perfectly with all my remote controlled devices. It cost me around $400 in total but has saved on the swearing and cursing when trying to use the TiVo in other rooms.

I have not done anything different with mine, i use to use it with a sky remote now it works with the tivo one. I have the LED taped onto the piece between the two leds on the front of the Tivo. There is an adjustment pot on the circuit from memory so perhaps you could try adjusting that.


Shane