COMMUNITY

I am trying to make a heating element that would only turn on once the element itself reaches a certain temperature. This element, possibly ceramic, would be dormant until it reached an internal temperature from an external source (liquid) of 100 deg F. Once it is triggered, it would produce heat to maintain the liquid at 100 deg F. Ive been trying to figure out the best way to do this and how much power would be required. Say the liquid, well go with water, was 12 fl oz. how would I build a circuit that can be sensing temperature without using power, and once it reaches the desired temp, turns on the heater until the temperature either goes too high or drops too low so that it is not trying to work too hard. Open to suggestions on heating element types or anything that could help with my project. Thanks in advance!

I need your help with a very very short code ?i have this code#include "Keyboard.h"#include "HID.h"void setup() { Keyboard.begin(); }void loop() {delay (1000); Keyboard.write(KEY_F1);delay (3000); Keyboard.write(KEY_F2);}this code works fine for me... but the problem isthis code give me only one "F1" and one "F2" in 4 seconds. i need "F1" appears every second (1000ms) and "F2" every 3 seconds (3000ms) in a infinyte loop

I've seen a few ideas online but so far no clear instructions. I want to mount a fan outside, probably on a spinning head to face the wind, then run that current through smoothing capacitors and a step down convertor to give a stable 5v output (through a usb port). The problems I anticipate are 1. keeping the electrics of the fan dry (I was thinking of mounting it in a hood / tunnel to keep the rain off) 2. the spinning head and not having cables twisting and breaking (maybe i could use the oscilating head of the fan to do this?) 3. too much power coming in and damaging the capacitors / step down convertor. Has anyone attempted a similar project and / or have any advice on this please?

I have a " series " of 27 5mm straw hat LED lights that require much more than 12 volts. I understand that LED's are amp driven, but the voltage requirement must still met. The battery requirement for this amount of voltage is prohibitive. I'm hoping someone can tell me how to light the LED's with only 12 volts getting sufficient illumination that they really shine -so to speak.