BME 372 Electronics I. Quiz #2

Transcription

1 BME 37 Electronics I Quiz #

2 BME 37 Electronics I Quiz # Do problems,, 3,, and 5 for your basic grade Do problem 6 for guaranteed extra credit SHOW ALL WOK

3 Electronics I Quiz #. Calculate the value of the gain A of in the amplifier as a function of to produce an output signal within the ± volt. Assume V IN is ±0.5volts. Amplifier V IN / / i i v o A i i 3

4 Electronics I Quiz #. Calculate and plot the voltage gain of the following circuit as function of frequency, ω. Use words to justify your answer. v s v i 3 L v o

5 Electronics I Quiz # 3. Find the current and voltages for each of the circuit elements in the following circuit. Submit this page with your test book. 50k i D μamps.5v i D v D v D volts 5

6 Electronics I Quiz #. Calculate the voltage gain of the following circuit. What kind of amplifier is? 3 V in (s) _ v o L _ 6

7 5. Diode Circuit Electronics I Quiz # a) Show all possible states as shown in the table for this diode circuit and the voltage V and current I. Show which state works. 5V I b) Find the states of the diodes. The Diodes are ideal. Find the voltages V and currents I as applicable. 5V k D D k I k k k V V 5V 5 V State D D OFF OFF ON OFF 3 OFF ON ON ON D D D3 D 7

8 Electronics I Quiz # 6. Calculate the value of the gain A in the amplifier to produce a signal within the ± volt range for =±0% and =±5%. Assume V IN =5 volts. Also, what sort of amplifier is needed in this circuit? Hint: Simplify the Wheatstone bridge using Thevenin s equivalent circuit. Amplifier V IN b a v i Av i v o Wheatstone Bridge 8

9 Electronics I Quiz #. Calculate the value of the gain A of in the amplifier as a function of to produce an output signal within the ± volt. Assume V IN is ±0.5volts. Amplifier V IN / / i i A i i A vo Aii ii VIN VIN 6 VIN iin / / / /3 5 / / where: / / 3 / 3/ 6VIN VIN ii iin iin / A A VIN A vo ii VIN 5 5 v o A v o A A VIN

10 Electronics I Quiz #. Calculate the voltage gain of the following circuit as function of frequency, ω. At DC capacitor is open; gain 3/ At high frequencies caps are shorts, gain > Z v Z Z v v v ; Z Z o f o s Z Z vs Z ( ) j C j C j C j C Z Z j C j C 5 j Av.5 j 6 Z j C ( ) ( C ) tan C( ) () (3 ) tan 3 5 j C Av ; A 0 v C j 5 Av 5 j C 6 5 v s v i 3 0 L v o Magnitude Phase

11 Electronics I Quiz # 3. Find the current and voltages for each of the circuit elements in the following circuit. Submit this page with your test book..5v 50k i D v D i i D μamps v D =0.6v i D =8μa V =.5.6=0.90 or 8μ x 50k=0.90 Intercepts: v D =.5v, i D =.5/50k=30μa v D volts

12 Electronics I Quiz #. Calculate the gain of the following circuit. i in s V in (s) v f v L o v o _ i o v i v v 0 0 v v iin 0; vi 0 v v' v' in in i f f f f o o 3 6 v v v (3 ) 6 ' 5 o o o (3 6 ) where (3 ) vf vin vo vo 3 vo Noninverting amplifier v in

13 5. Diode Circuit a) Electronics I Quiz # Find the states of the diodes for both circuits. The Diodes are ideal. Find the voltages V and currents I as applicable. I D V 5V D 5V State : D OFF D OFF No current flows and I=0 & V =0 but D has 5 volts across it in the FB direction and therefore D is has to be ON. D has 0 volts across and has to be ON. 5V D I V D 5V 3

14 5. Diode Circuit a) Electronics I Quiz # Find the states of the diodes for both circuits. The Diodes are ideal. Find the voltages V and currents I as applicable. State : D ON D OFF Current flows and I=5/=.5a which is proper direction to keep D ON. V=0 but D has 0 volts across it in the FB direction and therefore D is has to be ON. I 5V D State 3: D OFF D ON Current flows and I=0/8=5/=.5a which is in the right direction to keep D ON and V=*5/=5v but D 55 = 0 volts across it in the FB direction and therefore D is has to be ON. D 5V D V I V D 5V 5V

15 5. Diode Circuit a) Electronics I Quiz # Find the states of the diodes for both circuits. The Diodes are ideal. Find the voltages V and currents I as applicable. State : D on D ON Current flows through D 5/=3.5 to keep D ON and therefore, V=5. Current flows and I=5/=.5a. Both I and the current flowing in D flow through D in the FB direction and so D is ON. THIS WOKS. I D V 5V D 5V 5

16 Electronics I Quiz # 5. Diode Circuit b) Find the states of the diodes for both circuits. The Diodes are ideal. Find the voltages V and currents I as applicable. 5V k 0 V k 5V k 5V k 0 V k I=9ma V D D OFF OFF D 3 D OFF OFF 5 V Make a assumption of the diode states, calculate the currents and voltage to make sure the diode states are in agreement with the assumption. If there is no agreement, make another assumption.. Assume all diodes are OFF. Then the resistor chain is isolated from ground and the current through is (55)/6k=5mA. This will make the voltage at the cathode of D 55=0Volts to ground. This will cause D to be B. The voltage at the anode of D=5volts to ground which make D FB. 6

17 5. Diode Circuit b) Electronics I Quiz # Find the states of the diodes for both circuits. The Diodes are ideal. Find the voltages V and currents I as applicable. 5V k D OFF 7.5V k 0 V k 7.5V k.75vk I=7.5ma D ON D 3 OFF V D OFF 5 V Make a assumption of the diode states, calculate the currents and voltage to make sure the diode states are in agreement with the assumption. If there is no agreement, make another assumption.. Therefore, let s assume D is ON and the remainder of the diodes are OFF. Thus, the first resistors on the left have 7.5 volts across it since D goes to ground. Thus D has 7.5 volts to ground and is still B. There is now 5 volts across the 3 resistors on the right side of the chain. The total resistance is k and the current will be 5/k=3.5ma. Thus D3 will have 7.5 volts at its cathode and D will have.75 v at its cathode. Therefore 0(7.5)=7.5v across it and D3 will be FB. 7

18 5. Diode Circuit b) Electronics I Quiz # Find the states of the diodes for both circuits. The Diodes are ideal. Find the voltages V and currents I as applicable. 5V k D OFF 7.5V k 0 V k 0 V k 7.5V k I=7.5ma D ON D 3 ON V D OFF 5 V Make a assumption of the diode states, calculate the currents and voltage to make sure the diode states are in agreement with the assumption. If there is no agreement, make another assumption. 3. Therefore, the next assumptions is that D and D3 are ON and D and D are OFF. With D3 ON, the left side of the second resistor to the right is grounded by D3. Therefore, there is 5 volts across the two resistors on the right of the chain. This makes the voltage (to ground) at the anode of D equal to 7.5 making it B. This agrees with the current assumption. Therefore, V=7.5 and I=7.5ma. 8

19 Electronics I Quiz # 6. Calculate the value of the gain A in the amplifier to produce a signal within the ± volt range for =±0% and =±5%. Assume V IN =5 volts. Also, what sort of amplifier is needed in this circuit? V IN b a r b r V V V ( ) V T brigdeopencicuit ab IN Let r where r is the variation of ( ) VIN r r ( ) VIN ( ) VIN r r r ( ) VIN r ( r) T ab r ( r) r ( r) ( r) ( 3 r) a r r b a r 9

20 Electronics I Quiz # 6. Calculate the value of the gain A in the amplifier to produce a signal within the ± volt range for =±0% and =±5%. Assume V IN =5 volts. Also, what sort of amplifier is needed in this circuit? Vo Avi v i T T v ab A v ab A A ( r) vab v ( 3 r) ( 3 r) ( r) r A( r) v ab (8 5) r r vab ( ) VIN r A( r) r A r V ( ) V V (8 5) r r (8 5) r o IN IN ab V ab T v i Av i i o v o % t Vab Vi Vo/A A A r r VIN V (8 5 r) (8 5 r) IN Use a Differential Amplifier 0