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| university:courses:electronics:electronics-lab-9 [25 Aug 2017 10:31] – add breadboard circuits + xy plots Antoniu Miclaus | university:courses:electronics:electronics-lab-9 [03 Jan 2021 22:21] – fix links Robin Getz |
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| ====== Activity 9. Regulated Voltage Reference ====== | ====== Activity: Regulated Voltage Reference ====== |
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| ====== Version 1 ====== | ====== Version 1 ====== |
| ===== Objective: ===== | ===== Objective: ===== |
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| The zero gain amplifier (Q<sub>1</sub>, R<sub>2</sub>) and stabilized current source (Q<sub>2</sub>, R<sub>3</sub>) from activities 7 and 8 can be used in conjunction with a PNP current mirror stage (Q<sub>3</sub>,Q<sub>4</sub>) in negative feedback to build a circuit which provides a constant or regulated output voltage over a range of input voltages. | The zero gain amplifier (Q<sub>1</sub>, R<sub>2</sub>) and stabilized current source (Q<sub>2</sub>, R<sub>3</sub>) from activities 10 and 11 can be used in conjunction with a PNP current mirror stage (Q<sub>3</sub>,Q<sub>4</sub>) in negative feedback to build a circuit which provides a constant or regulated output voltage over a range of input voltages. |
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| ===== Materials: ===== | ===== Materials: ===== |
| <WRAP centeralign> Figure 2 Regulator Version 1 Breadboard Circuit </WRAP> | <WRAP centeralign> Figure 2 Regulator Version 1 Breadboard Circuit </WRAP> |
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| Waveform generator 1 should be configured for a 1 KHz triangle wave with 4 volt amplitude and 2V offset. The Single ended input of scope channel 2 (2+) is used to measure the stabilized output voltage at the collector of Q<sub>4</sub> ( negative inputs 1= and 2- should be connected to ground). | Waveform generator 1 should be configured for a 1 KHz triangle wave with 4 volt amplitude peak-to-peak and 2V offset. The Single ended input of scope channel 2 (2+) is used to measure the stabilized output voltage at the collector of Q<sub>4</sub> ( negative inputs 1= and 2- should be connected to ground). |
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| ===== Procedure: ===== | ===== Procedure: ===== |
| <WRAP centeralign> Figure 5 Regulator Version 2 Breadboard Circuit</WRAP> | <WRAP centeralign> Figure 5 Regulator Version 2 Breadboard Circuit</WRAP> |
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| Waveform generator W1 should be configured for a 1 KHz triangle wave with 4 volt amplitude and 2V offset. Scope channel 2 (2+) is used to measure the stabilized output voltage at the emitter of Q<sub>4</sub>. | Waveform generator W1 should be configured for a 1 KHz triangle wave with 4 volt amplitude peak-to-peak and 2V offset. Scope channel 2 (2+) is used to measure the stabilized output voltage at the emitter of Q<sub>4</sub>. |
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| ===== Procedure: ===== | ===== Procedure: ===== |
| ==== For Further Study: ==== | ==== For Further Study: ==== |
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| ADI Mini Tutorial on [[http://www.analog.com/static/imported-files/tutorials/MT-087.pdf|Voltage references]] | ADI Mini Tutorial on [[adi>static/imported-files/tutorials/MT-087.pdf|Voltage references]] |
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| ====== Using an NPN transistor array: ====== | ====== Using an NPN transistor array: ====== |
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| All the emitters can be tired to ground ( pins 3,7,10,13 ). Devices Q<sub>1</sub>, Q<sub>2</sub> and Q<sub>3</sub> can be connected in parallel and serve as Q<sub>2</sub> in figure 2. Q<sub>4</sub> and Q<sub>5</sub>can be used for Q<sub>1</sub> and Q<sub>3</sub>in figure 2. An individual device such as a 2N3904 etc. can be used for Q<sub>4</sub> in figure 2. The 3 to 1 emitter area ratio will result in an output voltage very nearly 1.2 volts if R<sub>1</sub> and R<sub>3</sub> are both equal to 2KΩ (when R<sub>2</sub> is 100Ω). | All the emitters can be tired to ground ( pins 3,7,10,13 ). Devices Q<sub>1</sub>, Q<sub>2</sub> and Q<sub>3</sub> can be connected in parallel and serve as Q<sub>2</sub> in figure 2. Q<sub>4</sub> and Q<sub>5</sub>can be used for Q<sub>1</sub> and Q<sub>3</sub>in figure 2. An individual device such as a 2N3904 etc. can be used for Q<sub>4</sub> in figure 2. The 3 to 1 emitter area ratio will result in an output voltage very nearly 1.2 volts if R<sub>1</sub> and R<sub>3</sub> are both equal to 2KΩ (when R<sub>2</sub> is 100Ω). |
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| | <WRAP round download> |
| | **Resources:** |
| | * Fritzing files: [[downgit>education_tools/tree/master/m2k/fritzing/regulated_voltage_reference_bb | regulated_voltage_reference_bb]] |
| | * LTspice files: [[downgit>education_tools/tree/master/m2k/ltspice/regulated_voltage_reference_ltspice | regulated_voltage_reference_ltspice]] |
| | </WRAP> |
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| **Return to Lab Activity [[university:courses:electronics:labs|Table of Contents]]** | **Return to Lab Activity [[university:courses:electronics:labs|Table of Contents]]** |
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