#mq-3

[shimemaru]

MQ-3

ガスセンサーの実験を始めています。数値に関してはほど安定しているのではないだろうか？ただし、ここで言う数値は、センサーからの電圧であり、ppmなどのわかりやすい単位に変換する必要があるのだが・・・・。計算式を探している最中。簡単に変換できるといいのですがね~

[shimemaru]

gas sensorのキャリブレーション中

４８時間のプレヒート＆キャリブレーション中です。まだ、３時間。しばらくこのまま放置です。

[tymkrs]

Drink Me Breathalyzer Take 3!

Hopefully this is the last iteration.  But there are a few things that we needed to add.  

1) A switch so that power wouldn't constantly be drained from the batteries.  So to run it, you'd have to push the switch down, wait a little, and then blow. 

2) We needed to change the load resistor from 200k to 10k.  Wasn't sure if I showed that on the last schematic.

2) It was suggested that I make the LEDs less bright so that we wouldn't be drawing so much current. This too will help with saving battery life.

So!  With a few tweaks here and there:

You can see the added switch, and the changed resistor values.  Now I know I did a whole thing on how between pins 7 and 8 there was this ref + 1.25v thing going on.  @wireengineer says it's just a nominal 1.25V no matter what any of the other refs are.  I'm just going to accept this :p.

So! With V=IR and V = 1.25V.....the leds are getting 10.4mA with 1.2k resistors which seems to still be quite bright.  So I'm going to get a few other value resistors and see how that goes!

Circuit design, never a dull moment!

@atdiy/@tymkrs

[settorezero]