All Questions
15
votes
0answers
925 views
+100
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
66 views
Yields in DRAM and other Massively Redundant Processes
I'm right now combing the electrical engineering literature on the sorts of strategies employed to reliably produce highly complex but also extremely fragile systems such as DRAM, where you have an ...
5
votes
0answers
404 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
0answers
159 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 ...
3
votes
0answers
50 views
converting induction motor winding to reluctance motor winding
I want to build simple reluctance motor for education purpose. I have couple of small 3 Phase AC Induction motor with 24 slot stator lap winded for 4 pole design.
I want to convert it to reluctance ...
3
votes
0answers
209 views
USB termination on STM32F437xx
I'm about to layout the USB connection on our boards and wondering whether the termination resistors and pull-up on D+ are necessary when using the STM32F437xx. The datasheet tells:
...
3
votes
0answers
138 views
HSPLL mode freezes 18F46K20 micro controller
COMPILER: XC8 v 1.30
micro: PIC18F46K20
I use this in CONFIG1H register to get 64MHz Fosc (and use PLL):
...
3
votes
0answers
754 views
Connect microphone to RN-52 Bluetooth module
My goal is to build a bluetooth hands free device, basically a speaker phone, to pair with a mobile phone. I am using the Roving Networks RN-52 Bluetooth Audio module mounted on a breakout board from ...
3
votes
0answers
374 views
FPGA link to external memory
I am trying to use the cellular ram on the Nexys 4 FPGA development board. I am using Xilinx Vivado and would like a Microblaze soft core processor to be able to perform reads and writes. So far I ...
3
votes
0answers
437 views
Analyzing the Protocol
I am trying to understand a protocol (shown in figure 1) . For now this I have understood that data is transferred at high to low clock. as shown in figure. and the sync is for every 8-bit.
But then ...
3
votes
0answers
2k views
Msp430g2553 i2c communication library with itg3200 gyroscope
I've been creating an I2C library for communicating with ITG3200 gyroscope for MSP430g2553 experimental launchpad. I still have slight problems with sequential reading and the signed values but I'm ...
3
votes
0answers
185 views
SPI transaction timeout linux device driver
I am stuck for last 3 days at a point.
I am working on eink device driver with msm8960 qualcomm chipset.
Scenario:
In file: ...
3
votes
0answers
459 views
How to route Gigabit Ethernet, remote PHY or remote RJ45 connector?
I need to design a 10/100/1000 BASE-T “backplane” board that contains multiple PHY outputs from Ethernet controller chips. On the board ,the LAN specifications are very strict in regard to how the ...
3
votes
0answers
190 views
Xbee module , using X-CTU reset
I got this question and it might be really easy but its just something I have been wondering about I can't seem to be able to find the answer.
When my baud rate in X-CTU isn't the same baudrate as my ...
3
votes
0answers
2k views
USB CDC-ACM Class Driver on STM32F4
Simply my project is to connect a Huawi USB modem to my STM32F407 Discovery board, and start using AT commands to send text SMS.
so here is what I've and what I want :)
I've OTG USB capability on ...
3
votes
0answers
207 views
Substitute for permalloy core for power transformer
I want to build an 220AC/22AC transformer to use in PSU for 90W amplifier. The problem is ...
2
votes
0answers
21 views
Make a simple sim card reader circuit
I'm trying to implement a sim-card reader for my own. I followed step by step the guide on www.ladyada.net site but it does not work as it would be. My PC and softwares i used to read/write data ...
2
votes
0answers
54 views
PIC EEPROM after re-programming
I was trying to get my EEPROM read/write working on my PIC.
I first programmed a write cycle, and then reprogrammed it to read it out. (To avoid writing every time I start the program/pic)
But I ...
2
votes
0answers
30 views
BLDC speed/torque control with L6229 or L6235
I'm trying to control 12V 12,000 rpm BLDC motor with 3x120° Hall sensors
using ST evaluation board based on L6229 IC.
I tried to control motor's speed by feeding PWM to FWD/REV pin as suggested in ...
2
votes
0answers
42 views
Wire for harsh environment
One of the jobs I often have to perform is repairing the infra-red sensing headsets for BattleSports equipment.
Basically the headset consists of a pair of IR detectors and red LEDs for indication. ...
2
votes
0answers
79 views
Switch between power supplies with a mofset
i'm new here and my knowledge in electronics is basic, so what i'm trying to do is to switch between two power sources, one at 5V an other at 12V, i already made a circuit that kinda works, but i have ...
2
votes
0answers
36 views
Weather Balloon Wireless Mesh Networking
I am trying to get real-time data feed from a homemade weather balloon radiosonde with the objective of sending HD video during the flight; this could be relevant for GoPro-ers who want to send their ...
2
votes
0answers
58 views
Under water distance measurement
For a laboratory / field test, I'm looking for an easy solution to measure the soil surface elevation. The test runs a flow on a bed. When the erosion takes place the sediment concentration goes high ...
2
votes
0answers
52 views
Can't seem to write to spi flash
Well I've been stuck on this for a while, maybe 2-3 weeks at this point. I'm just not sure what I'm doing wrong. I'm trying to write to this spi flash part, and now I'm just running routines to ...
2
votes
0answers
47 views
How are Operating Temperature Bands Determined?
Manufacturers like Maxim, Altera, and many more seem to adhere to a commonly defined range of temperatures for applications. For instance,
Full military (-55°C to +125°C)
Automotive (-40°C to ...
2
votes
0answers
25 views
How to set the offset for the componets name in Eagle Schematic?
I am using Eagle 7.1.0. In the eagle schematic the componet name is started by default by 1, 2, 3..... How can I create an offset so that it starts from diffent value. for eg offset of 100, should ...
2
votes
0answers
49 views
psIsolation Transformer DC 12 volts
I want to use 12 volts DC and step it up to 400 volts AC or higher at 100khz. I am buiding a signal generator that outputs a sine wave or square wave with an adjustable frequency of up to 100 kHz. I ...
2
votes
0answers
67 views
What is the charge-discharge (Wh) efficiency for lead acid batteries at different SoC and charge current 10-35A/100Ah C10?
There is a 1996 Sandia study with the title "A study of lead-acid battery efficiency near top-of-charge and the impact on PV system design" for charge and discharge lead-acid battery efficiency at ...
2
votes
0answers
68 views
LED module design considerations for an aluminium board
I need to design a LED module something similar to below.
Could anyone who is experience tell me if there is any SW (or tools) to determine how to place the LEDs to have a good and evenly ...
2
votes
0answers
23 views
imx6q sabre board microphone
i have been trying to record audio using the circuit below. It is different from the normal microphone circuit in that the MIC_IN and MICBIAS are separate paths. I tried to connect an electret ...
2
votes
0answers
23 views
802.11 Channel Use Regs
With a 5.8Ghz WLAN device, operating in the upper UNIII band, 5745mhz-5825mhz...
...is it required that if the device is using a standard 20mhz wide 802.11 channel, that you can ONLY be centered on ...
2
votes
0answers
30 views
Linux enc28j60 driver always times out on transmit
I've wired up an ENC28J60 module with an SPI interface to a Beaglebone Black development board running Linux 3.8, but I cannot get the device to TX (or RX) anything. Every attempt to TX times out and ...
2
votes
0answers
66 views
Reducing noise for a TDA8947J amplifier
I have an PC audio amplifier using TDA8947. One 30W subwoofer and two satellites.
It produces a lot of background noise and I would like to cut it down a bit. The noise is all in the subwoofer. It ...
2
votes
0answers
63 views
Direct cable to board compact assembly?
I am looking to attach a cable to board in the most compact (yet manufacturable) way possible. This does not need to be disassembled ever, it can be a permanent connection.
Is there a standard way ...
2
votes
0answers
128 views
How can I log information from code in IAR Embedded Workbench to a log file?
I'm trying to develop an application for the NXP LPC1788 microcontroller and I would like to be able to log formatted strings at arbitrary points within the source code to a log file in a way that has ...
2
votes
0answers
79 views
LTSpice showing negative transistor power
I'm using LTSpice to model a LC oscillator, driven by a NPN transistor. When I used the power calculating function on the transistor, LTSpice indicated that during part of the cycle the power ...
2
votes
0answers
118 views
how to parallel mosfet
i want to build induction furnace
i parallel 16 power mosfet(irfp460) 8 fet for high side and 8 fet for low side for half bridge
i use ir2104s and bd139 and bd140 totem pole for drive mosfet.
like ...
2
votes
0answers
51 views
Combine Bluetooth Buttons (Volume up / Next, Volume Down / Previous)
I have a question regarding the control of a bluetooth device, which I would like to connect to some old headphones.
Bluetooth SMD Module - BC127
There are some pins on which I can connect the ...
2
votes
0answers
53 views
CMRR test methodology and effect of open loop gain
I am trying to test the CMRR of opamp and so measuring offset variation across Common mode range in unity gain mode. I have gone through many articles on CMRR measurement. All those are suggesting a ...
2
votes
0answers
73 views
DC-circuit with N-JFET transistor
My task is to decide RD and RS in this circuit:
The properties of the N-JFET are Up = -3.5V and IDSS = 10mA. The criteria here is that the operating point should give UDS = 7V and ID = 5 mA.
With ...
2
votes
0answers
123 views
How to quickly fill up the entire DDR memory using Xilinx tools?
I have a board with a DDR3 memory and a Virtex 7 FPGA. I have used Xilinx MIG to create a memory controller and I am able to succesfully read/write to the memory using Microblaze registers. I would ...
2
votes
0answers
113 views
How to tell CCS debugger where to start?
I am just starting with MSP430 and Code Composer Studio (CCS).
I want to make a pure-assembly project. At the moment, I have a "hello world" program that does nothing but light an LED on the ...
2
votes
0answers
92 views
Discrepency with experimental vs. simulation of AC-DC circuit
I'm analysing a PIR Circuit's power supply, but I'm having a large (almost double) discrepancy between simulation/theoretical current values and experimental values (experimental is almost half ...
2
votes
0answers
91 views
Memristor equations
I was working with memristors and wondering about their equations. If the memristor resistance(or memristance) is based on the amount of charge, the memristance should equal:
$$M(t)=\int(C(t))dt$$ or ...
2
votes
0answers
61 views
Home made passive tablet pen
I have an old wacom tablet at home, its really big and I'd like to use it but I've lost the pen for it. It uses pens with passive LC circuitry. The board creats an EM-field (I can see it on my ...
2
votes
0answers
51 views
will two plls wander with shared reference clock
I'm trying to learn about pll wander or drift. My reading leads me to believe one of the reasons plls were developed was to fight wander so maybe it does not effect plls? Although I've seen some ...
2
votes
0answers
64 views
Connecting home elliptical trainer to TV power
I'm attempting to use a TV addiction to help motivate an exercise routine. To do this, I am going to connect an elliptical trainer to the power of a television set (flatscreen). Here is my plan:
I ...
2
votes
0answers
726 views
STM32F4 NAND flash via FSMC, difference between bytes written and read back
I have a Waveshare Open407V-D development board, basically a "motherboard" in which an STM32F4DISCOVERY kit is fitted (this kit, for those not familiar with it, is made by ST itself and based on the ...
2
votes
0answers
68 views
IEC 60079 Explosive Atmospheres Compliance
I'm wondering whether anyone has some experience with designing electronics for compliance to IEC 60079 Explosive Atmospheres. I have designed a device to be installed in silos facilities which are ...
2
votes
0answers
94 views
simple GSM SIM modem
I'd like to build a prototype of simplest possible GSM device - a simple modem with SIM holder, capable of logging on to the SIM's provider network and nothing else. It's meant to be used as a GSM ...
