Welcome to electrical and electronics engineering discussion website, Please login or register to continue.

Welcome to electrical and electronics engineering Q&A site...

Join our WhatsApp group

in Power Electronics by
How is Power electronics distinct from linear electronics?
Join me on Google Pay, a secure app for money transfers, bills and recharges. Enter my code 908dq to earn ₹51 back on your first payment!

Please log in or register to answer this question.

1 Answer

0 votes

It is not primarily in their power handling capacities.

While power management IC's in mobile sets working on Power Electronic principles are

meant to handle only a few milliwatts, large linear audio amplifiers are rated at a few thousand


 The utilisation of the Bipolar junction transistor, Fig. 1.2 in the two types of amplifiers best

symbolises the difference. In Power Electronics all devices are operated in the switching mode -

either 'FULLY-ON' or 'FULLY-OFF' states. The linear amplifier concentrates on fidelity in

signal amplification, requiring transistors to operate strictly in the linear (active) zone, Fig 1.3.

Saturation and cutoff zones in the VCE - IC plane are avoided. In a Power electronic switching

amplifier, only those areas in the VCE - IC plane which have been skirted above, are suitable. Onstate

dissipation is minimum if the device is in saturation (or quasi-saturation for optimising

other losses). In the off-state also, losses are minimum if the BJT is reverse biased. A BJT switch

will try to traverse the active zone as fast as possible to minimise switching losses. 




An example illustrating the linear and switching solutions to a power supply specification will

emphasise the difference. 

The linear solution, Fig. 1.4 (a), to this quite common specification would first step down the
supply voltage to 12-0-12 V through a power frequency transformer. The output would be
rectified using Power frequency diodes, electrolytic capacitor filter and then series regulated
using a chip or a audio power transistor. The tantalum capacitor filter would follow. The balance
of the voltage between the output of the rectifier and the output drops across the regulator device
which also carries the full load current. The power loss is therefore considerable. Also, the stepdown
iron-core transformer is both heavy, and lossy. However, only twice-line-frequency ripples
appear at the output and material cost and technical know-how required is low.
In the switching solution Fig. 1.4 (b) using a MOSFET driven flyback converter, first the line
voltage is rectified and then isolated, stepped-down and regulated. A ferrite-core high-frequency
(HF) transformer is used. Losses are negligible compared to the first solution and the converter is
extremely light. However significant high frequency (related to the switching frequency) noise
appear at the output which can only be minimised through the use of costly 'grass' capacitors. 

Version 2 EE IIT, Kharagpur 

Distributed under Creative Commons Attribution-ShareAlike - CC BY-SA.

Amazon Shopping

Welcome to Q&A site for electrical and electronics engineering discussion for diploma, B.E./B.Tech, M.E./M.Tech, & PhD study.
If you have a new question please ask in English.
If you want to help this community answer these questions.


Most popular tags

power motor dc circuit transformer voltage current used system phase factor resistance load synchronous ac energy induction generator electric frequency series use speed between capacitor meter line electrical type mosfet control transmission difference magnetic plant high single instrument bjt source advantages function diode machine unit winding torque amplifier define supply thyristor motors arduino field shunt relay armature electricity maximum time parallel transformers types problem coil diagram state flow value material three starting on direction method emf operating theorem digital microprocessor test instruments efficiency ratio loss measure operation connected low applications wave effect and single-phase working losses different network wattmeter measuring constant signal controlled breaker device full temperature compare drive wire materials machines inductance switch flux resistivity disadvantages logic converter transistor gain protection scr angle force core measurement number free principle rc generators law negative bridge friction open pole conductor conservation steam iron loop resistors hysteresis short computer lines secondary station battery rectifier inverter linear relays nuclear regulation design using analog work rotor electronics gate forces diesel damping rlc connection factors capacitors minimum insulation basic moving running reactance systems circuits air fault range direct main stability quality starter igbt eddy ideal ammeter rl 3-phase plants arc induced thermal error fuzzy biasing dielectric pressure balanced errors rotation characteristics feedback measured electronic start alternator off back curve over solar three-phase tariff locomotive peak bias zener capacitance commutator surge rating universal potentiometer superposition permanent mechanical copper self transducer capacity electrons memory adc excitation inductive explain fuse pure harmonics application internal pmmc average reaction welding resonance traction breakers designed electromagnetic si generation brushes density switching shaded rate impedance distribution transfer methods star oscillator reluctance semiconductor inductor 8085 weston dynamometer insulating strength installation permeability definition fuel heating earth units neutral rms rated engineering conductors controller usually reverse excited change body components form made response terminals two