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university:courses:electronics:electronics-lab-heartbeat [23 Aug 2019 15:09] – Antoniu Miclaus | university:courses:electronics:electronics-lab-heartbeat [08 Sep 2020 04:45] – fixing resistor naming Alexanadre Robichaud |
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The input signal from the heartbeat measurement setup is fed into a Differentiator Amplifier Circuit(([[http://www.electronics-tutorials.ws/opamp/opamp_7.html|Differentiator Amplifier]])) (C<sub>1</sub>, A<sub>1</sub>, R<sub>3</sub>). The capacitor blocks any DC content, C<sub>1</sub> and R<sub>3</sub> behaving as a high pass filter with the cut-off frequency F<sub>c1</sub> being determined by the following formula: | The input signal from the heartbeat measurement setup is fed into a Differentiator Amplifier Circuit(([[http://www.electronics-tutorials.ws/opamp/opamp_7.html|Differentiator Amplifier]])) (C<sub>1</sub>, A<sub>1</sub>, R<sub>3</sub>). The capacitor blocks any DC content, C<sub>1</sub> and R<sub>3</sub> behaving as a high pass filter with the cut-off frequency F<sub>c1</sub> being determined by the following formula: |
<WRAP centeralign><m>F_c1=1/{2 pi R_3C_1}</m></WRAP> | <WRAP centeralign><m>F_c1=1/{2 pi R_1C_1}</m></WRAP> |
Besides filtering, this stage serves also as an amplifier taking as input the current (I<sub>A1</sub>), and generating at the output an inverted voltage (V<sub>A1</sub>) based on the negative feedback resistance (R<sub>3</sub>): | Besides filtering, this stage serves also as an amplifier taking as input the current (I<sub>A1</sub>), and generating at the output an inverted voltage (V<sub>A1</sub>) based on the negative feedback resistance (R<sub>3</sub>): |
<WRAP centeralign><m>V_A1=-I_A1*R_3</m></WRAP> | <WRAP centeralign><m>V_A1=-I_A1*R_1</m></WRAP> |
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====Active Low-Pass Filter=== | ====Active Low-Pass Filter=== |
<WRAP round download> | <WRAP round download> |
** Lab Resources:** | ** Lab Resources:** |
* LTSpice files: [[ https://minhaskamal.github.io/DownGit/#/home?url=https://github.com/analogdevicesinc/education_tools/tree/master/m2k/ltspice/heartbeat_ltspice | heartbeat_ltspice]] | * LTSpice files: [[downgit>education_tools/tree/master/m2k/ltspice/heartbeat_ltspice | heartbeat_ltspice]] |
* ADIsimPE files: [[ https://minhaskamal.github.io/DownGit/#/home?url=https://github.com/analogdevicesinc/education_tools/tree/master/m2k/adisimpe/heartbeat_adisimpe | heartbeat_adisimpe]] | * ADIsimPE files: [[downgit>education_tools/tree/master/m2k/adisimpe/heartbeat_adisimpe | heartbeat_adisimpe]] |
* Fritzing files: [[ https://minhaskamal.github.io/DownGit/#/home?url=https://github.com/analogdevicesinc/education_tools/tree/master/m2k/fritzing/heartbeat_bb | heartbeat_bb]] | * Fritzing files: [[downgit>education_tools/tree/master/m2k/fritzing/heartbeat_bb | heartbeat_bb]] |
</WRAP> | </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]].** |