Unanswered Questions

11
votes
0answers
706 views

Signal Flow Graph for electrical circuits

I am a student and my question is about finding the signal flow graph for a simple circuit. I found the above formula for a \$k\$ node having \$U_k\$ potential. In the book it is said that this is ...
5
votes
0answers
126 views

Typical zero sequence data for 80MVA transformer

I need to model a 80MVA transformer 132/33kV built in 1973. There is very little information on this transformer but I need to populate certain values in the model. Where can I find typical zero ...
5
votes
1answer
216 views

Implementation of AES algorithm using Systolic architecture

I need to generate a VLSI Systolic array to implement the AES encryption algorithm with key length of 128 bits. Following are the possible ways : Systolic for Key expansion Systolic in MixColumn ...
4
votes
2answers
240 views

How to implement critical sections on ARM Cortex A9

I am porting some legacy code from an ARM926 core to CortexA9. This code is baremetal and does not include an OS or standard libraries, all custom. I am having a failure that appears to be related ...
4
votes
0answers
116 views

Things to be aware of when using voronoi shaped traces

I was thinking of giving voronoi shaped traces (e.g. http://publications.csail.mit.edu/abstracts/abstracts05/rus/rus.html for those who need an example, or just google image search it) a try. In ...
4
votes
1answer
187 views

RTOS for Cortex M4 with 802.15.4/6LoWPAN stack

I'm evaluating operating systems to use in an Internet of Things Project and I don't know what's the best way to proceed. I'm using a TM4C123GH6PM MCU with 32k RAM and a CC2520 802.15.4 transceiver, ...
4
votes
5answers
273 views

Calculating current draw from a battery using voltage and time information

Is it possible to work out the current or power a device is drawing/using, based on the following information: Maximum capacity of a battery (48 Ah) A table of voltage readings over time (starting ...
4
votes
2answers
312 views

Does a 40 MHz radio frequency have any interference to Bluetooth signal?

From my understanding, the Bluetooth signal is using a 2.4 GHz frequency. However, when someone is playing with a 40 MHz RC vehicle, the Bluetooth signal keep on getting interrupted or disconnected. ...
4
votes
2answers
226 views

Explanation of performance graph of FPGA design

After implementing a mathematical function on a FPGA chip. The following graph shows for ~40 inputs the time response, i.e. how long it took to get the output calculated. This data is part of the ...
4
votes
1answer
224 views

Unable to read file greater than 2K in FatFS

I am reading a file from the SPI Flash with FATFS file system, on STM32F103 platform running FreeRTOS. I can successfully read File of size less the 2048, but if read a file file of size greater than ...
4
votes
0answers
379 views

Trifilar Transformer Common-Mode Rejection Circuit (Signal Recovery, Hybrid Combiner, RF)

I'm trying to develop a circuit that allows me to effectively subtract two different sources of RF noise from a single signal at the same time. I am planning to use something called a "trifilar" ...
4
votes
5answers
2k views

DIY NFC boosting antenna for a mobile device

I am very new to this. I'm a dentist trying to improve client flow in a busy office. I would like to develop a cheap proof of concept for an NFC enabled client tracking system using a hacked mobile ...
4
votes
5answers
282 views

Determining Capacitor Discharge Rate

First time poster, apologize if I accidentally missed any rules. I've built a circuit that keeps a relay closed that is attached to battery power for a specific amount of time so my Raspberry Pi has ...
4
votes
2answers
245 views

Is it good to ground the polygon plane on the routing layer?

For my final project I have to measure multiple signals up to 10MHz with a TMS320F2809 processor which is clocked at 100MHz. I have the following layer stackup: Top Signal Ground Signal Signal ...
4
votes
2answers
698 views

Charge Model vs Voltage Model for Piezo Electric Sensor

The following document describes signal conditioning circuits for Piezeoelectric sensors. I was interested in knowing which model should I use when designing signal conditioning circuit for ...

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