The transformer used in mobile is pulse transformer which operates at very high frequency pulsating DC in order to make charger energy efficient and light weight.
THe mbile charger takes a.c (alternating current) from power source and convers it to d.c(direct current) and feds it to mobile battery. The charger also steps down the voltage from the power line voltage 110v etc to very small voltages e.g3 v etc.
Those are special type transformer used for both step down and step up in a single transformer ,they are specially designed . their wire thickness in both winding is thicker than ordinary step up or down transformer.and they are costly too.
If the bed lamps use a low voltage bulb then the type of transformer will be a step down transformer.
A true voltage transformer is not designed for power applications; it will only supply so many VA to your charger. I would suggest you purchase a power transformer for this application. You'll need to rectify the AC voltage, and minimize the ripple. Rectifiers are used for the first part, capacitors, varistors, and power transistors can be used to minimize the ripple.
Yes, a diode can be used in a battery charger to prevent reverse current flow from the battery to the charger when it's disconnected. This protects the charger from potential damage.
A resistance furnace runs on electricity so it will be some type of electrical transformer.
the auto transformer is the one winding transformer. it ismaily used in practical purpose.
Mineral oil
The device used to increase or decrease the voltage of an electric circuit is a step up transformer or a step down transformer respectively. A Variable Resistor
The Linear Variable Differential Transformer is a type of electrical transformer used for measuring linear displacement. A counterpart to this device that is used for measuring rotary displacement is called a Rotary Variable Differential Transformer.
Shielded transformer
The linear variable differential transformer (LVDT) is a type of electrical transformer used for measuring linear displacement.