With a recent order from a Chinese seller on eBay, this little gadget was included in the package as a freebie:
I’ve not smoked for a long time, so I’m not too sure what use I’m going to find for this device, but it’s an electronic lighter!
Pushing the slider forward reveals a red-hot heater, mounted in the plastic (!) frame.
Pushing the other way reveals a USB port to charge the internal battery.
A couple of screws releases the end cap from the cover & the entire core unit slides out. Like all Chinese toys it’s made of the cheapest plastic imaginable, not such a good thing when heat is involved.
The element itself is a simple coil of Nichrome wire, crimped to a pair of brass terminals. The base the heater & it’s terminals are mounted to is actually ceramic – the surround though that this ceramic pill clips into is just the same cheap plastic. Luckily, the element only remains on for a few seconds on each button push, there’s no way to keep it on & start an in-pocket fire, as far as I can see.
The main PCB clips out of the back of the core frame, the large pair of tinned pads on the left connect to the heater, the control IC has no numbering of any kind, but considering the behaviour of the device it’s most likely a standard eCig control IC.
The other side of the board has the USB port on the right, the Lithium Polymer cell in the centre, and the power button on the left. The cell itself also has no marking, but I’m guessing a couple hundred mAh from the physical size.
Here are the internals of a cheap Microwave/Convection Oven combo. Electronics bay is pretty much the same as a standard microwave, with the magnetron, transformer & diode/capacitor voltage doubler, with the addition of an extra fan & a pair of nichrome elements to provide the convection oven function.
Convection blower which keeps the cooking vapours & smoke away from the elements, & circulates the hot air around the cooking chamber. This is a 12v DC centrifugal type blower.
The elements are inside this steel shield, air duct extends from the centre.
This oven has a pair of thermal switches on the magnetron.
The usual capacitor/diode voltage doubler in the magnetron power supply. The transformer is visible to the left.
Electronic controller PCB. This has a pair of relays that switch the elements & the magnetron transformer.
This is a 1500W hairdryer, death caused by thermal switch failure.
This is the switch unit. Attached are two suppression capacitors & a blocking diode. Cold switch is on right.
Heating element unit removed from housing. Coils of Nichrome wire heat the air passing through the dryer. Fan unit is on right.
Other side of the heating element unit, here can be seen the thermal switch behind the element winding. (Black square object).
The fan motor in this dryer is a low voltage DC unit, powered through a resistor formed by part of the heating element to drop the voltage to around 12-24v. Mounted on the back of the motor here is a rectifier assembly. Guide vanes are visible around the motor, to straighten the airflow from the fan blades.
5-blade fan forces air through the element at high speed. Designed to rotate at around 13,000RPM.