App note: Hot-surface warning light with no external power

This design harvests heat energy to make electricity, and uses it to flash a warning light. Flashing LED hot-surface detector:

Using a thermoelectric generator (TEG) to sense the temperature of a surface and a step-up switching regulator to boost the TEG output to a useful level, this warning circuit flashes a high-brightness LED when the surface temperature exceeds a threshold.

We’ve slowed the app notes a bit to accommodate the haters, but we thought this one is really cool. Thanks rsdio!

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9 Comments

  1. I like the app notes. It is a unique feature that got me to add dangerous prototypes to my daily blog list. I don’t have the copious free time or professional access to updates. I would like to see at least one app note every day. It is a short headline that “app notes haters” can skip over. I can not make app notes appear once they are gone.

  2. I appreciate the app notes. If it’s easier to complain about them then just scrolling past them then your looking for an excuse to complain.

  3. Sounds like there’s a lot of fans too. We have a two-page backlog of app notes in wordpress. We’ll let them flow. Thanks to MichaelZ and rsdio who are constantly on the lookout for interesting tidbits. We’ll come up with a new “exciting standardized format” for posting them, and let them go from now on. M-F or 7 days a week, it sounds like you want your app notes ;) We enjoy them too, it’s always interesting seeing someone’s (great, or horrifying) take on a design problem.

  4. Awesome! I don’t really favor Maxim as much as it might seem, but they have a newsletter with chip announcements and app notes, so I don’t have to work as hard to find them. But I’ll pass along anything that seems relevant to a project here at Dangerous Prototypes, whether it’s in production or just being discussed. I also have a couple of months of backlog, so I’ll keep feeding my picks to Ian, who will then select the cream of the cream of the crop.

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