Where would YOU tap in for 3v?

[eobard]

I've got a couple of temp probes that run off of 3v batteries. I'm wanting to run them off the PSU but can't decide if I want to tap the 3.3v line from the PSU, go off the mobo somewhere or take the 5v line off a molex and drop it down with diodes. What would you do? (and why is that the best way to go?)

[wannaoc]

I have used the 5v line in a molex with no problems. No idea if its the best but it worked fine powering LEDs so I would imagine it would work fine for the probes as well.

[Xtreme Barton]

what kind of probes, if i may ?

i would stick to a soltion that comes straight from your psu. no need to draw anything out of your mobo you dont have to.

[four4875]

the 3.3 v rail should do ya fine, im sure batteries can range in actual voltage present from a lil over 3 down to however low it gets before stopping working. if you're really concerned, measure the current draw with a fresh battery in and vary temps on the probe, see if its affected. then use a resistor calculator and stick a resistor in to drop that little .3 Vs. or find a diode with a forward voltage drop of .3vs and put inline. but i would stick 'em straight on the 3.3.

[Zulu-1]

when you get a new battery, its usually .2V or so over spec.. (a AA battery is usually 1.7V when brand new)... so id say the 3.3V line.. as long as it isnt overvolted...

[Xtreme Barton]

and congrats on your engagement !! :D

[eobard]

The probes are from a Thermaltake Hardcano II (http://www.thermaltake.com/accessories/hardcano/a1278.htm), and for some reason they made them to run off batteries, which need to be replaced every month! My case has 3 sensors for CPU, HDD and internal air temp, (although I could use them for anything really) I want to use the Thermaltake sensors to monitor GPU temps without taking away one of the sensors I'm already using.

I'm just scouting ideas on the best place to tap in for power, you never know who's got a novel idea sitting in their mind just waiting to be heard by the masses.

Thanks for the congrats btw.

[apu318]

How much sap could a sap tap tap if a sap tap could tap sap?


Seriously though.. how much?


Even more seriously,

5v line w/ resistors. On the occasion a fan header. Not a good idea for that one.

[four4875]

how i occasionally tap lines from the atx connector and keep it removable.... ( i use it for 17 and 24Ving fans) is... take an 18 guage or so wire, strip it and tin it. then bend it in half so its double wide, and stick it in the bckside of the atx plug on the wire you want. then it jams beween the contact thingy inside and the plasric, getting a nice connection. as long as you dont tug too hard, you wont have any problems with it falling out, but it still comes out nice and easy when needed. play around with it and you'll get it down (hopes thats what is meant when where to tap into it at...)