Download presentation

Presentation is loading. Please wait.

1
Transformer Coupling

2
Introduction Figure shown the transformer coupling to a load resistance such as a Loudspeaker in a radio. With a transformer – the small load resistance can be stepped up to a higher impedance level This improve the voltage gain – also since no signal power is wasted in a collector resistor, all the ac power is delivered to the final load resistor Very popular at audio frequencies (20 Hz kHz)

3
**AMPLIFIER AMPLIFIER OBJECTIVE**

CC RB1 Vout VCC Vin(ac) Rgen RB2 RC RL RE AMPLIFIER OBJECTIVE PROVIDE V, I , POWER to the LOAD most efficiently

4
AMPLIFIER POWER LOSS CC RB1 Vout VCC Vin(ac) Rgen RB2 RC RL RE

5
**TRANSFORMERS V & I transformation**

Nprim : Nsec Vprim Vsec Iprim Isec I & V ONLY ac

6
**TRANSFORMERS Z & R transformation**

Nprim : Nsec Vprim Vsec Iprim Isec Zsec Zprim I & V ONLY ac

7
**TRANSFORMER COUPLED AMPLIFIER**

Vout VCC n :1 Vin(ac) RL CC RB1 Vout VCC n :1 Vin(ac) Rgen RB2 RL

8
**TRANSFORMER COUPLED AMPLIFIER**

CC RB1 Vout VCC n :1 Vin(ac) Rgen RB2 RL VCC RB2 RB1 RprimDC DC EQUIVALENT CIRCUIT IDEALLY Rprim,DC = 0

9
**TRANSFORMER COUPLED AMPLIFIER**

CC RB1 Vout VCC n :1 Vin(ac) Rgen RB2 RL CC RB1 VCC Vin(ac) Rgen RB2 Rsec,ac ac EQUIVALENT CIRCUIT Rprim,ac = n2 RL

10
**TRANSFORMER COUPLED AMPLIFIER DC LOAD LINE**

‘ideal’ DC load line ‘Q’ point determined by BIAS CIRCUIT VCEQ = VCC Q

11
**TRANSFORMER COUPLED AMPLIFIER ac LOAD LINE**

OPERATION maximum output voltage ‘ideal’ DC load line Q ac load line ‘Q’ point determined by BIAS CIRCUIT VCEQ = VCC 2VCC

12
**TRANSFORMER COUPLED AMPLIFIERS**

Advantages: electrical isolation: SAFETY NO XC voltage drop : input higher efficiency : no RC power loss zero or 180 degree phase shift : DOT NOTATION impedance matching : better power transfer voltage / current transformation : can be used as a ‘gain’ stage Disadvantages: COST WEIGHT frequency response SIZE : reduces as frequency increases

13
**EXAMPLE: Determine the amplifier Q-point**

CC RE RB2 RB1 Vout VCC 20 V RL k :1 Vin(ac) Rgen Determine the amplifier Q-point Operating Q-point for the max. o/p i/p impedance, o/p load power

14
SOLUTION: Q-point ii) Operating Q-point for the max. o/p

15
iii) i/p impedance, CC RE RB2 RB1 k :1 Vin(ac) Rgen Rin Vout RL Rinb

16
iii) o/p load power,

Similar presentations

Presentation is loading. Please wait....

OK

EET426 Power Electronics II

EET426 Power Electronics II

© 2018 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on laws of liquid pressure Ppt on cleanliness in schools Ppt on 360 degree performance appraisal Ppt on addition and subtraction of like fractions Ppt on arabinose operon Ppt on case study of company Ppt on historical significance of taj mahal Resource based view ppt online Ppt on ordinal numbers for grade 1 Download ppt on abdul kalam