All Questions

6
votes
0answers
173 views

What is causing this long tail in the transient reponse?

I have a fifth order transfer function for which I designed a controller using pole-zero cancellation technique on a root locus. I am after <5% overshoot and <2s settling time. Currently, ...
4
votes
0answers
62 views

Switch from JTAG to SWD with bitbang sequence on STM32F103VB

I am trying to switch from JTAG to SWD without any external devices. Why? Because I would like to use the SWO pin to send a stream of logging information to another device. To do accomplish this, ...
4
votes
0answers
374 views

Interfacing FPGA to an external chip and timing constraints

I have designed a system using Artix-7 FPGA on a custom board. The goal is to transfer 32 bit data to an external on-board chip whose data bus is an inout port. ...
4
votes
0answers
3k views

How to write optimal power flow constraints in MATLAB?

I am writing an optimal power flow (OPF) program. OPF is an optimization problem in which some decision variables like Generation, Load dispatch are adjusted in power flow program so as to minimize ...
4
votes
0answers
216 views

Compensating for unbalanced via count in DDR3 routing

I'm working on a DDR3 layout at 533Mhz clock speed in a balanced T configuration. I am currently unable to route the address/ctrl lines with an equal amount of vias (+1 on a limited number of lines). ...
3
votes
0answers
66 views

Ultra Low Consumption White LED Flasher

simulate this circuit – Schematic created using CircuitLab I need an LED flasher circuit to operate inside small model lighthouses. Ideally the flash needs to be white and the battery needs to ...
3
votes
0answers
44 views

Microstrip transmission line impedance calculation

I'm attempting to calculate the necessary trace width of a PCB transmission line in order to have a characteristic impedance of 50ohm. However, different online calculators are giving me slightly ...
3
votes
0answers
48 views

High-Level Synthesis (HLS) vs RTL for ASIC flow

I'd like to know when it's a good idea to use HLS over RTL (Verilog/VHDL) design if I'm targetting ASIC implementation? Can synthesis tools like Design Compiler convert HLS C/C++ into gate-level ...
3
votes
0answers
105 views

STM32F103C8T6 fake?

I have a curious problem: Prequel: I "designed" a clone of the Black Magic Probe v2.1, which I like a lot but has IMHO some shortcomings (e.g. the 1.27mm-pitch connector to name just one). I got a ...
3
votes
0answers
74 views

Enhancing the bass response of an audio isolation transformer

Below is a simple buffer circuit using an isolation transformer : The green trace is the output of the transformer and the blue trace is the input signal (20hz to 20Khz sine wave). As you can see the ...
3
votes
0answers
64 views

JTAG trace length affecting programming ability

I've recently had a design made that requires a programming port to be located quite far from the device I'm trying to program. This has meant that my cJTAG traces are around 13cm long. I think as a ...
3
votes
0answers
106 views

What is the purpose of this transformer winding in the following SMPS schematic?

I am trying to understand how the following PC switched mode power supply works : The way it works in general is OK. What is not clear to me is what is the purpose of the following part in red : ...
3
votes
0answers
85 views

Parallel connection of old and new gel batteries

I have a battery system shown in the picture, 6 parallel branches of 4 batteries connected in series. The first 3 consist of old batteries which are 2 years old, the fourth branch consists of 1.5 ...
3
votes
0answers
72 views

Contact a very small area (impedance matched)

In my current project, I want to apply a voltage to a capacitor (top electrode on a thin film heterostructure) very rapidly. Since capacitors have their own charging rate \$(\tau = R \cdot t = R \cdot ...
3
votes
0answers
54 views

Inductor for a GPS active antenna

I have been testing the GPS / GPRS development module A9G, Aithinker which uses an active GPS antenna, according to the schematic reference diagram, the value of the inductance is 82nH: The question ...
3
votes
0answers
86 views

Safety Capacitor Selection

When selecting an X2 safety capacitor what must be taken into consideration. There are only a few types of capacitance ranges and seem to be chosen based on voltage rather than capacitance. Take ...
3
votes
0answers
179 views

How to analyze/decode a Manchester encoding?

I have a barcode scanner working on 433Mhz (FSK). Since this is relatively old product and the PC software is not working with Windows 10's and I can't use the SDK anymore. I therefore have decided to ...
3
votes
0answers
45 views

System of multiple conductors: image method

The problem statement, all variables and given/known data The following figure represent the traversal cut of a system with two cylindrical equal conductors of radius r0 length l at a distance d ...
3
votes
0answers
99 views

Mazzilli flyback driver mosfets keep failing

I've been trying to build a high voltage generator consisting of a high-voltage transformer and a Crockoft-Walton multiplier. I have actually tried several different drivers to drive a high-voltage ...
3
votes
0answers
134 views

Gate of a transistor and mosfet damaged

In my schematic, I found that the base of transistor Q7 (2n2222) was damaged. I tried to replace it with a BS170 MOSFET, and the same thing happened where the gate was damaged. The microcontroller ...
3
votes
0answers
63 views

Low entropy transfer function, output impedance

I am trying to understand and apply the concept of low entropy transfer functions as outlined by C.Basso and equally stated by a couple of people here. As an example I wanted to work through an L-C ...
3
votes
0answers
69 views

Frequency locking for averaging resampling

Background I've done a long one-shot measurement of a periodic signal by an oscilloscope. Thus, I've captured around 250 periods of a signal. The signal itself is a pseudo-random binary sequence at ...
3
votes
0answers
138 views

0.5 tesla solenoid

Alright, I am supposed to make a solenoid (water cooled) having 0.5 T field at the center. The solenoid should be ideal so we are supposed to make the length of solenoid quite large as compared to ...
3
votes
0answers
147 views

Is this stackable low RPM generator design viable?

I'm trying to invent viable handcrank energy generator for charging phones and similar low-power appliances. I want to avoid gears altogether in the design, because they are hard to manufacture at ...
3
votes
0answers
341 views

P-Channel MOSFET gate protection

I'm controlling a P-Ch MOSFET on a circuit, VIN is 8-30V TTL_IN is a 0-5V signal generated by a MCU, which can source/sink currents up to 15mA Zener Izt 5mA (BZT52C15) MOSFET Vgs limit 25V I'm ...
3
votes
0answers
380 views

My First Circuit Diagram - How to improve it

I started taking more of an interest in micro-controllers and electronics last year, I started to design a circuit (which I hoped to have created as a custom PCB - Though I don't know how to go about ...
3
votes
0answers
92 views

Can this example be used for explaining the effect of lamination on power loss in a power transformer?

I'm trying to demonstrate to a group of people how a lamination of the transformer core reduces the power loss due to Eddy currents by not using any complex math. I start with a non-laminated core as ...
3
votes
0answers
134 views

Load Sharing/Isolation Circuit with ADP5063

I'm designing the battery power/charging circuit for the Reform DIY laptop which uses a (big) LiFePo4 cell. For the charger IC I've now settled on ADP5063 as it seems simple and can charge with 1.5A ...
3
votes
0answers
276 views

LM386 guitar practice amp circuit not working, need help finding mistake

Im very new to electronics and I built this guitar amp circuit on a breadboard: and it was working really nicely. Now Ive decided to put the circuit on a universal pcb which i'll use in the actual ...
3
votes
0answers
231 views

How to develop for the NRF24LE1?

I found about the nRF24LE1 chips a while ago and they seem perfect for really small applications that require RF, since they are the same as the well known nRF 24L01, but include a 8051 MCU and memory....
3
votes
0answers
130 views

Why accessing the SRAM is slower with AVR XMega load instructions?

The AVR XMega has 16 GPIO registers in I/O space in addition to its internal SRAM. Interestingly the timing of LD instructions differ to these locations: Accessing the (rather large) I/O space is ...
3
votes
0answers
236 views

STM32F429ZIT6 with SDRAM IS42S16320F Read/Write Issue

I designed a board which is containing two SDRAM (IS42S16320F) and STM32F476ZIT6 MCU (and other components also). I can access the SDRAM but the data is changing independently from the code. My board ...
3
votes
0answers
31 views

Successor of VTI's SCP1000 Family of Absolute Pressure Sensors

VTI's SCP1000 product family is a range of ceramic capacitive pressure sensors that have reached the end of their lifespan. It has been suggested that certain sensors designed by others (like Bosch ...
3
votes
0answers
75 views

“Performance Density” for a CNN Implementation on FPGA

In the paper "Improving the Performance of OpenCL-based FPGA Accelerator for Convolutional Neural Network" at table 6 there is a metric called Performance Density. ...
3
votes
0answers
126 views

RF switch for multiple antennas

I'd like to design an rfid reader with 4 output antenna's ports. My rfid reader module maximum output power is 30 dBm. My target is for the maximum output power in the antenna ports, to be 30 dBm. If ...
3
votes
0answers
239 views

Gimbal motor periodically shaking back and forth instead of spinning

I am using the BGMC2 (http://www.rovertec.com/products-bgmc2.html) to control a gimbal motor (http://www.iflight-rc.com/ipower-motor-gbm5208h-200t-brushless-gimbal-motor-with-as5048a-encoder.html). I ...
3
votes
0answers
213 views

Understanding EGSM-900 (LTE 8 band) electromagnetic spectrum

I am trying to fully understand the physical layer of the GSM standard. For doing that I am looking at the E-GSM-900 band (mostly used in Europe). In my country these frequencies has been assigned to ...
3
votes
0answers
212 views

Using a “noise eating” active low-pass filter

I'm trying to use a MAX281 low-pass IC to filter a DC signal I'm producing on-board. I'm yet to find other chips with the same features so, if you haven't come across them, they're designed to work by ...
3
votes
0answers
315 views

4 switch Buck-Boost, boost not reaching designed current

I am working on a power supply that regulates the voltage coming out of a 3S LiPo battery. The buck portion of the circuit works fine and outputs 5+A with acceptable ripple. The Boost portion instead ...
3
votes
0answers
91 views

Incrementing net name for group

I am wanting to make 50 copies of the block below, but I need incrementing numbers on each of the net labels (these will go to a connector). I do not want each block connected to the other blocks. It ...
3
votes
0answers
3k views

Stability factors of a voltage divider bias circuit

I am trying to derive the stability factors of a voltage divider bias circuit. I could derive S,S', however I'm facing some problem with derivation of S''. Please help me in this regard. How to find \...
3
votes
0answers
252 views

Wait make the STM32L073RZ freeze in stopmode

With my STM32 I'm trying to configure a deepSleep mode and use RTC to generate interruption (actually each 30 seconds). When my STM start, this one configure the RTC and directly go in Stop mode. ...
3
votes
0answers
136 views

bearing ambiguity resolve (direction finding) for multiple sources

I am working on wideband direction finding algorithms for passive sensors. I started with Music algorithm. For practical reasons, the spacing can not be maintained lambda/2. For greater antenna ...
3
votes
0answers
236 views

STM8 nested interrupt bug, not described in current errata sheet ES019

If main process execute WFI with AL bit set in CFG_GCR, changing I1/I0 priority bits in the ISR cause CPU stalled when nested IRQ occured. Preconditions: all ITC_SPR1 registers has default value 0xFF....
3
votes
0answers
778 views

Why is the line-to-ground voltage half of what it should be?

Our electric power provider delivers 240 V, 60 Hz split-phase power to residential buildings. I've been checking our three-prong receptacles and I normally get the following measurements: line-to-...
3
votes
0answers
671 views

Master-slave timing on ARM Cortex-M0

I have set up a slave timer that starts counting when the master timer is enabled. I want to know if the slave starts counting when the master timer receives a valid edge (my configuration is count ...
3
votes
0answers
731 views

How to disable USB mass-storage in STLink on Nucleo?

Is it possible to disable the USB Mass Storage option on the STLink hardware of the Nucleo board? I want to prevent mounting the device when I plug it into computers (while keeping the virtual com ...
3
votes
0answers
775 views

LVDS_25 voltage range

I understand that thee voltage level for LVDS standard has a typical offset voltage of 1.25V and voltage swing of 350mV. However, when I am doing some pin mapping on Xilinx FPGA, I encountered some ...
3
votes
0answers
1k views

STM32F0 USB device - unexpected Device_Qualifier descriptor request

Edit I may not have asked the correct questions here. Please do not attempt to answer before I edit again to remove this message. Summary I'm developing firmware for a USB device, and I can't get ...
3
votes
0answers
5k views

Determining suitable wire gauge for LED-strips (voltage drop)

I am software engineer by trade and a novice in this field, please point out any mistakes in my assumptions and vocabulary regarding this topic. I am designing a lighting plan based around commonly ...

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