A Tesla coil is a radio frequency oscillator that drives an air-core double-tuned resonant transformer to produce high voltages at low currents. Tesla's original circuits as well as most modern coils use a simple spark gap to excite oscillations in the tuned transformer.
Proton-exchange membrane fuel cells, also known as polymer electrolyte membrane fuel cells, are a type of fuel cell being developed mainly for transport applications, as well as for stationary fuel-cell applications and portable fuel-cell applications. Their distinguishing features include lower temperature/pressure ranges and a special proton-conducting polymer electrolyte membrane. PEMFCs generate electricity and operate on the opposite principle to PEM electrolysis, which consumes electricity
At its most complex, a BoM is a multi-level document that provides build data for multiple sub-assemblies (products within products) and includes for each item: part number, approved manufacturers list (AML), mechanical characteristics and a whole range of component descriptors.