Recent content by his_tonyness

Thanks for your help, you have filled a valuable gap in my knowledge too!

Close indeed! 1111 1111 1111 1000 or FFF8

Ok thanks this is the gap knowledge I needed to fill here goes; The data output 0 of the '138 is connected to the buffers, so according to the truth table we need ABC to be low in order to connect to the buffers. A3 needs to be high to establish the data enable. So the 16 bit binary I have...

The 138 works as a 3 to 8 bit decoder where 3 inputs can deliver (23) 8 outputs For a NAND gate if MEMRQ is low the A15 to A4 have to be high. A3 is part of the data enable along with RD and the NAND output. A0 to A2 are address lines, part of the ABC logic table where all inputs except one...

Thanks for your reply For (a) I am not entirely sure how to interpret the hex address of the "address bits" i.e A0, A15 etc. I think if I understand correctly it is to do with memory maps. It could be something really simple but I don't understand the circuit diagram well enough.

Homework Statement 4. FIGURE 1 shows how a 3 to 8 line decoder (74138) can be used in conjunction with NAND gate (74133) to connect a set of switches to the data bus of a microprocessor system via buffers (74367). Answer the following questions relating to the diagram: a) What address, in HEX...

Re- Uploaded the file showing the actual An and Bn values. You forgot to multiply An by 2 and Bn by - 2.

Correct. I looked at "H2" and assumed the rest was all "IMDIV'ed", my mistake. Unfortunately I don't know how to perform IMDIV on multiple cells and I am not doing it one by one for 1024 cells! Multiplying the real and imaginary parts separately is a pain too to extract sine and cosine coefficients.

Ok, If i produce a simulation over 57ms or 1/T with the 3 principals at their orignal not square values that would be a more accurate synthesis?

Thats the darndest thing, the sample interval does not state the time units. "The supply current was sampled 1024 times over a very short time interval" that's all it gives me with regards to time, I assume we can use any sensible small time period. If you hover the mouse cursor over cell I3, it...

Here it is. Also features An and Bn Fourier co efficients.

I performed FFT on the sample data in excel file I was given, which the spreadsheet automatically calculated the frequency and I2 magnitude columns and the spectrum diagram in post 5. I can't figure out how to use Fourier synthesis to replicate the original waveform.

I simulated on LT spice roughly to reconstruct the original waveform by adding the 3 harmonics on the same time axis (50ms) http://forum.allaboutcircuits.com/attachments/213-gif.85824/

Do you know a good step by step method for sketching the original waveform from the 3 principal harmonics?

Recalculating I come up 96.89%. I thought the question identified In as the rms of those harmonics that's all.