Week 5 Activity

Part 1: Finish integrator and amplifier circuit

We found that the theoretical voltage of the coil calculated last week was wrong. The radius should not be the radius of the copper wire, it should be the radius of the coils. We measured the diameter of the coil was 2.4mm, using the same calculation steps as last week and the theoretical voltage should be 3.75*10^(-6).

First we finished building the integrator circuit and got the expected output waveform. We changed the circuit diagram we used before. The final circuit of integrator was:


The input signal was a 120mV, 50kHz square wave and the output signal was a -1.3V, 1.667 MHz triangle wave. The output signal was amplified by about 10.83 times. 


 
(Integrator circuit)

Then we built the amplifier circuit. We designed the voltage gain of the amplifier circuit is 1000. According to: G=1+50k/Rg, we calculated Rg=505.05 ohm. However, the output signal was opposite with what we expected. The output voltage was smaller than the input, which was not amplified. We tried to figure out the problem but had no progress.


(Amplifier circuit)
Part 2: Combine power amplifier and current transducer 

Then we finished building power amplifier and current transducer circuit. The frequency response of power amplifier was 5-50kHz. The current transducer was connected with 395ohm resistance (We used 330ohm and 65 ohm resistor connected in series ) The power amplifier circuit court work but the noise had big influence on the output waveform.




Finally we combined each part together to get a whole rogowski coil circuit even though the amplifier circuit has not finished completely.

This is the poster we designed.





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Week 1 Activities

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Part 1: Preparations before the lab After getting all of the experiemnt components, the first step we did was to check the modle type of every components and search their properties and usage in the global circuit. We set a primary image of the rogowski coil circuit by looking up online materials and the circuit we decided to use is like: We dicided to wind the coil but we did not find a suitable material to wind it. Then we dicided to build the integrator circuit first. The integrator will be used to integrate the voltage generated by the coil in the global circuit. Part 2: Build the integrator circuit The following is our disigned circuit diagram and we built the integrator circuit according to the diagram. We chose several 10k ohm resistors and a 330k ohm resistor. The capacitor we used was 10nF, 100nF. The input AC voltage was 50kHz, 3V square waveform and DC input is 5V.  This is the circuit we built. We changed the resistance, capacitance and...
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Week 4 Activity

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Part 1: Power Amplifier Circuit First we built power amplifier circuit. According to the instruction book, we knew we need to used two 1000 μF capacitors connected with power amplifier. Then we inserted a resistor to measure the output signal. According to the instruction book of power amplifier, it requires a symmetric DC power supply with an output range of 30 to 35V. In the experiment we provided a 30V DC power supply.  After testing the power amplifier circuit, we put current transducer into the circuit but the result was incorrect. We decided to finish this part in next week. Part 2: Theoretical voltage of coil We estimated the ratio of number of turns to length 1cm. The estimated result is 21 turns per centimeter, so N/L=2100 (turns per meter). Then we measured the coil diameter by electronic digital caliper is 2.4mm so r=1.2mm. In the experiment, the signal frequency we used was 50kHz. The calculation of coil theoretical voltage is following: ...
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