Tea Kettle teardown - Page 1
Forum section: electronics / general

author: reagle
author_rank: Unknown
timestamp: May 30, 2016, 04:23:41 pm
content: Not the typical fare for my blog, but this thing was in need of some debugginghttp://kuzyatech.com/and-now-for-something-differentAny comments and insights are welcomed- I am not very up-to date on mains connected thing.

author: SeanB
author_rank: Super Contributor
timestamp: May 30, 2016, 05:51:30 pm
content: Funny enough I just did the same to a similar kettle. Fault like yours was a crispy collection of switches, and as the centre power connection had a large amount of deposited copper vapour on it, along with a few broken pieces of the handle clips rattling inside i did a Dave on it, though i did not bother with the security screws, just ripped them out with the plastic bosses they were in.Unlike yours the blue illumination is from 10 blue LEDs on 3 small PCB units at the base, and they are driven with a resistive dropper, giving a 5mA current through each LED. Interestingly the led's all have a 330R resistor across them, so a failed Led does not cut off the whole string of 5 in series, just the rest are slightly dimmer and, as the 2 strings alternate down the board, the dim ones are not noticed too much.

author: reagle
author_rank: Unknown
timestamp: May 30, 2016, 06:16:19 pm
content: Yours at least had some actual electronics componentsI do wonder what they do with thermal cutoffs. One is has actuator driven by temperature sensitive disk, but the other is just pressed in by the bracket?!

author: GEuser
author_rank: Frequent Contributor
timestamp: June 02, 2016, 04:41:56 am
content: QuoteThat's what you get for chucking all that Tea in the ocean .andI gather one for instant Coffee is different .(They be Nice looking though)

author: SeanB
author_rank: Super Contributor
timestamp: June 02, 2016, 04:52:31 am
content: Second one is the safety cutout, which activates on boil dry when the whole base is heating up and there is no steam to trip the main thermostat.

author: Brutte
author_rank: Frequent Contributor
timestamp: June 02, 2016, 07:54:41 am
content: Quote from: SeanB on June 02, 2016, 04:52:31 amSo there are two independent switches.Theupperone:is closed by (the user pressing on a lever),is opened when (steam condenses on its bimetallic surface) or (the lever is pressed back).Thebottomone opens when the bottom plate temperature raises above boiling temperature to prevent melt-down.How does it close and return to its normal state? Does this happen when the bottom plate cools down so it ticks on/off/on/off when the user forgets to pour water? Or is it a latching type and requires some manual intervention? I can see these two switches are not mechanically connected so clearly one cannot reset bottom switch with pressing back the lever.

author: reagle
author_rank: Unknown
timestamp: June 02, 2016, 12:09:20 pm
content: I actually counted three switches:top power switch with steam cutoff,bottom thermal cutoff that resets when the kettle cools down,and one more in the bottom with an actuator just pressed against the bottom. Not sure how that one gets set/reset

author: Brutte
author_rank: Frequent Contributor
timestamp: June 03, 2016, 11:30:54 am
content: Quote from: reagle on June 02, 2016, 12:09:20 pmPerhaps if overheated it latches up open and is reset only by picking a kettle up from its base and not only by cooling down..