I had a catastrophic failure of my electric blanket, and the autopsy of the damage leaves more questions than answers. I lost bedding and my mattress, while there were no open flames, it scared the living crap outta me. I woke up to amazing heat in my bed, in a very localized area very close to my body. All the damage was from melted synthetic bedding and mattress materials. The house was filled with smoke and fortunately I woke up quickly enough to escape without injury. I was able to remove the cable from the blanket, and it looks like it failed only in one location. The wire in the area of the failure was black and melted. In the area where the damage was the worst, there were 2 of the conductors melted together with almost no insulation left on the wires-it had apparently caught fire and burned totally away. I can only guess that the blanket wasn't laying flat and that the wires crossed, which created more heat in a small area. So, the insulation began to melt, eventually failing, which allowed the conductors to short together as the wires insulation became molten. I've used this brand of electric blanket for years, this is the third catastrophic failure I've had in the last 20 years. Although none of the previous failures were nearly as damaging as the latest one. The electric blankets are high end Biddeford brand products, were all the same model, the TC12BO controller, see: https://biddefordblankets.com/products/controller-digital-tc12bo All of the previous failures were quickly and briefly autopsied, but I'm feeling compelled to dig deeper after this last failure. All the blankets used heavy duty 600 volt rating on each of the 4 pins on the connector that runs from the controller into the blanket, a photo of the connector is here: https://duckduckgo.com/?q=3Dbiddeford+elecrtric+blanket+failures&t=3Dbrave&= iax=3Dimages&ia=3Dimages&iai=3Dhttps%3A%2F%2Fimages.bonanzastatic.com%2Fafu= %2Fimages%2F7714%2F7783%2FBiddeford__76PA_1.jpg Inside the controller is a PIC chip, triac switching and a mylar cap based line voltage to low voltage power supply. There is a thermistor mounted on the PCB, which is used to compensate for the ambient temperature change in the room. There are 2 output wires and the heating element is a single conductor (actually 2 parallel conductors) within the blanket itself. Although there are 4 terminals on the controller connector, only 2 of them are used. There are no connections to the other remaining pins on the blanket. Here's where it gets interesting............ The heating element wire is actually made up of 2 conductors, each very very small. One is copper (or it appears to be). The other is some sort of silver color, likely tungsten or nichrome, or a combination of both. The silver colored wire, which I assume is the heating element is at the center of the heating cable, it is spiral wrapped with some sort of very small diameter multi stranded synthetic cord, with fibers so fine, I can't see the individual fiber strands. Around the core is a layer of what appears to be insulation. On the outside of that, the copper wire is spiral wound around the insulation, at about 6 turns per inch. Over that, is the outer sheath of the wire. The company has a PR type version of the controllers function, which sounds like crap to me....claiming that the insulation and the copper conductor signal the controller to shut down if a fault occurs. However, there is no signal path to the controller, even if the plastic insulating material was indeed some sort of temperature sensitive sensor. THE COPPER AND THE SILVER COLORED WIRES RUN IN PARALLEL WITH EACH OTHER, THERE IS NO SENSOR OR FEEDBACK METHOD FOR A SENSOR. In other words, there is no possible way for the controller to know that the 'sensor' is detecting a hot spot, there are only 2 active terminals in the blanket and in the controller output. The company's explanation is here: https://biddefordblankets.com/pages/our-technology The verbiage of the company makes it sound like there is an active sensor, but the heating element is 2 parallel conductors. There is no way to for the controller to know there is a hot spot in the blanket. At best, I think they can only detect a change in current flowing through the heating element, which can only occur after the electrical failure and is not reusable....a one shot deal. I know it's possible to make temperature sensitive self regulating heating elements, but the company strongly implies there is an actual 'sensor'. By the way, my smoke detector never went off!!!! I discovered that every single smoke detector in my house, including some pricey AC powered units is the ionization type, which are nearly worthless. I count myself as lucky to have learned this lesson without getting seriously injured or worse. I have 2 temporary smoke detectors (photoelectric) bought at the local hardware store and will do a more proper photoelectric detector buy and install soon. I urge all to weed out the ionization smoke detectors and to replace them with more proper photoelectric types. Any search engine, or youtube search will yield info regarding why the ionization detectors are being outlawed lately-to many people have died needlessly. Regards, Art --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .