The Cellar - What are you good at?

The Cellar (http://cellar.org/index.php)

- Home Base (http://cellar.org/forumdisplay.php?f=2)

- - What are you good at? (http://cellar.org/showthread.php?t=17361)

Yeah, well, Tinks gonna kick your ass anyway.:haha:

I like the zip tie. Nice touch. 15 minutes huh? Milking the clock? ;)

I really good at being tall.

Quote:

Originally Posted by xoxoxoBruce (Post 460190)

Yeah, well, Tinks gonna kick your ass anyway.:haha:

Right, as usual.

Quote:

Originally Posted by footfootfoot (Post 460547)

I like the zip tie. Nice touch. 15 minutes huh? Milking the clock? ;)

timeline-ish
00-01 -- cuss
01-07 -- clean sink (scoop, carry, drop in can. no disposal to eat the glass)
07-10 -- *find* thin plywood
10-13 -- measure, *find* fine saw, cut wood
13-14 -- assemble shelf, leaving room for undershelf drawer
14-15 -- reload food

give or take...

-----------

I'm also good at fixing stuff. This time my improvisational skillz were inadequate. Disassembly, diagnosis, locating and acquiring new parts, installation and reassembly, those skills were adequate.

Could be crossposted in What is this?

A clothes drier. Natural gas variety.

Edit: Looks like you replaced the thermostat after a failed attempt to improvise it by just shorting the wires! :eek:

Yes, our clothes dryer, natural gas variety.

Your hypothesis is (uncharacteristically) wrong, this time.

I am indeed shorting one of the circuits, but not the thermostat circuit. That sensor is on the back of the cabinet where the hot air from this burner assembly enters the drum. If you look closely at the second picture, you can see the blue and white wires in place. They're connected to a different sensor, right at the burner, the flame sensor. I had laboriously troubleshot all the other aspects of the non-working dryer, and this was the only one that was not working. I tested it by bypassing it, as you see in the first photo. Then I shut down the dryer, went and got another flame sensor ($40), installed it and Voila!

pic01 -- 3, 2, 1, Ignition!

pic02 -- "Flame On!"

Aw crap. And I was so sure of myself.

But in my defense, I've never taken a gas clothes drier apart before, so I don't know what all the parts do.

What does a flame sensor do? Clearly it senses that there is a flame, but couldn't a thermostat do the same thing? Is it a safety device to keep unburnt natural gas from entering the house if there is no ignition?

I am good at making things work :D

Quote:

Originally Posted by glatt (Post 460804)

The flame might go out during a prolonged burn leaving the surrounding area hot, until that cools the gas will spew forth. A flame sensor will shut the gas off as soon as ignition stops.

Do you know how a flame sensor works? What does it sense? Heat? I suppose I could Google it...

Quote:

Originally Posted by glatt (Post 461351)

Do you know how a flame sensor works? What does it sense? Heat? I suppose I could Google it...

I'll race you.

I did google it and there are two varieties, radiant detection and flame rectification. I cribbed the following from the internet. I understand the purpose of the flame sensor is to verify that when the gas is flowing that it is also burning. Your question of *how* it verifies that a flame is present is described below, somewhat beyond the depth of my understanding.

Quote:

There are infra red flame sensors that only need to get a "look" at the flame, but I think you are referring to the flame sensors commonly in gas furnaces and equipment.

These types of flame sensor use a process of flame rectification to sense that the flame is lit, and they must be actually engulfed in the burner flame to function.

Flame rectification uses the fact that a flame will rectify an AC voltage to DC and allow that DC current to flow through a flame to detect a flame.

Commonly, an AC voltage is applied to the flame sensor with a wire coming from the ignition module. When the flame sensor is engulfed by a flame, The AC voltage is rectified and a DC current, commonly 4-12 microamps, flows from the ignition module through the wire to the flame sensor, through the flame to ground on the furnace chasis.

The ignition control module has a circuit to detect that DC current, and commonly closes a relay when the DC current is detected that verifies that the burner is properly lit. If the burner fails to light or is extinguished for any reason, that DC current disappears and the control module takes suitable action to turn the burner off.

****
Flame rods or ionization probes work on the principle that when an AC voltage is applied between the rod and ground a suitable flame and correct placement will cause the AC to be superimposed with a DC component (ie shift the zero axis positive or negative) The flame sensor amplifier responds to this DC component. The magnitude of the DC and hence reliability of the flame operation is determined by a number of things including 1) the rod must be placed in an area where good combustion is taking place 2) The flame must be firmly "anchored" to the burner diffuser which is ground 3)the surface area of the efficient ground compared to the flame rod itself must be in the ratio of 4:1 or better (ie thin rods work best usually made from kanthal.

Quote:

Originally Posted by BigV (Post 461432)

*how* it verifies that a flame is present is described below, somewhat beyond the depth of my understanding.

I read it twice and I still don't understand it. In both cases, it sounds like the flame itself is a conductor and carries current. Amazing.

What I want to know is if there's untapped potential here for an AC power adapter that you light with a match.