>50mA 1-wire devices?

[Rob_in]

Hi all,

As discussed here...

https://groups.google.com/d/topic/loxone-english/ai7KA4ZlbJc/discussion

... I'm going to have a go at getting one of these CO2 sensors working.

Slight issue though - the Loxone 1-Wire 5v supply is only good for 50mA and the author of that project says the MQ135 needs at least 200mA.

Solutions?

1. Try it anyway and hope the Loxone extension can actually supply the necessary current. Probably not a great idea, does anyone know if the quoted 5v 50mA current is accurate?

2. Get an external 5v supply and use that to power the 1-Wire bus.

#2 sounds the right thing to do, In which case, the question becomes, how should this be wired? I assume it is as simple as: 

- Disconnect the +5v wire of your bus from the Loxone 1-Wire extension and connect it to the +5v output of the new PSU.

- Connect the GND output of the new PSU to the GND of the 1-Wire extension (which is still connected to the bus of course).

- DO NOT connect the +5v of the new PSU to the +5v of the Loxone 1-Wire extension as they aren't designed to work in parallel assume that would be a bad idea???

Job done?

Any feedback much appreciated.

Cheers,

Robin

[Duncan]

your 2nd option is correct as you suggest all 3 bullet points are correct

[Rob_in]

Finally got round to setting this up today. Extra PSU wired as discussed works like a charm.