What Does the PASSIVE Device Mean

AE1M13VES first name:

16th. January 2014 surname:

1. What does the “PASSIVE” device mean?

·  it can be just resistor, capacitor or inductor, no other devices,

·  device, where output power (Pout) is lower (or equal) than the input power (Pin),

·  device, where input power (Pin) is lower (or equal) than the output power (Pout),

·  all the semiconductor devices, e.g. LED, thyristors etc.

2. What does the “LINEAR” device mean?

·  device, that can be described by means of simple linear formulas and their combinations,

·  device, that can generate harmonic signals and their combinations (intermodulation),

·  device, which behavior is determined by differential equations with both time and coordinate variables,

·  device that exhibits linear dependence between temperature and its resistivity.

3. Which elements (and their combinations) are not often used for common resistors:

·  Gold (Au),

·  Carbon (C),

·  oxides of Pt + Ni,

·  oxides of Fe + Cr + Ni.

4. In which units is given the temperature coefficient of resistivity (TCR)?

·  W-1

·  K-1

·  K/W

·  J/kg

5. How can we define the dissipation factor (D)?

·  it is an angle between current I flowing trough the capacitor and applied voltage V,

·  it is an angle between voltage V on the capacitor and voltage on the parasitic inductance L of the outlets,

·  it is an parameter responsible for total power losses in the capacitor,

·  it is a self resonance frequency; above this limit capacitor starts to be “more inductance” than the capacitor.

6. Which important materials are used for electrolyte capacitors?

·  Aluminum (Al) or Tantalum (Ta), solution of KOH or H2SO4,

·  Stainless steel (Fe), other ferromagnetic metals (Ni, Cr, Etc.),

·  Carbon (C),

·  Silicon-carbide (SiC).

7. Electrolyte capacitors are typically used:

·  for high voltage and high frequency applications (low power losses needed),

·  as charge accumulators thanks to big specific capacity,

·  as variable capacitors for tuned RF applications,

·  for filtering in AC/DC converters, in power sources.

8. Variable capacitors are typically made and designed as:

·  rotating parts with an air (dielectric) gap,

·  foil capacitors based on plastic dielectric (PE, PA, PVC, etc.),

·  rolled capacitors with metallization on both electrodes,

·  ceramic capacitors made from ferroelectric (FexOy) or similar dielectric with large permittivity.

9. Inductors, coils and transformers can be made:

·  as a simple air-winding - without any magnetic circuit,

·  only from ferromagnetic cores (Fe, Ni, Cr),

·  only from dia/paramagnetic cores (Al, Mn, Cu),

·  from a copper winding wounded on some ferromagnetic core.

10. Quality factor (Q) of inductor can be defined as:

·  ratio between imaginary and real part of the inductor’s impedance,

·  an angle between flowing current in inductor and voltage on the inductor’s outlets,

·  an product of absolute and relative permeability of used ferrite material,

·  maximum magnetic flux in the middle of the magnetic core.