All Questions

7
votes
0answers
347 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, ...
7
votes
0answers
125 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, ...
6
votes
0answers
240 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). ...
4
votes
0answers
99 views

How can I get this circuit to “make noise”

I designed this noise generator circuit that uses a 1N514 Schottky diode with a VDB transistor amplifier(note: the upper VDB resistor is actually 15kOhm). Looking at the oscilloscope trace it seems to ...
4
votes
0answers
83 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 ...
4
votes
0answers
147 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 ...
4
votes
0answers
307 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 ...
4
votes
0answers
434 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
179 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 ...
3
votes
0answers
41 views

RF Differential and Single Ended Microstrip Impedance in PCB Design

In pcb design (using 4 layer osh park stack up) if the rf trace is single ended than i simply calculate microstrip impedance and draw copper trace with calculated width. For example for 50 ohm ...
3
votes
0answers
46 views

Power use question for a trail camera

I am trying to calculate how long that a trail camera can be deployed before the batteries run out. The trail camera in question is a Reconyx HyperFire 2. Here is a useful review of the trail camera ...
3
votes
0answers
41 views

Microphonic SAW transmitter?

I built this very simple SAW transmitter, with a simple "spring" antenna for the right frequency. To test it, I tuned a portable receiver to around 433.92Mhz and fine tuned it until I heard silence. ...
3
votes
0answers
77 views

How do USB to serial adapters work?

I'd like to know how a USB to serial adapter (such as the FTDI FT232RL chip) works. The way I think it does is the following: Picture a system composed of a MCU, a USB to serial adapter and the PC ...
3
votes
0answers
68 views

How to distribuite high current in multilayer PCBs

I'm designing a 150Amp controlled rectifier and I'd like to know how to distribute the current using a multilayer design. Currently, I have a 4 layer design containing: Top Layer: 6oz, Vdc+ and Vdc-...
3
votes
0answers
27 views

Altium testpoints auto-placement

Is there a way to use Altium to automatically generate testpoints on an already routed board? When there is no usable via, I'd like to place a pad on the net. When reviewing altium API reference ...
3
votes
0answers
35 views

What's the circuit diagram symbol for a variable reluctance sensor transducer?

I know I've seen the symbol before, it's something like a circle with an open triangle facing in the direction of current flow with a line through the middle. I'm specifically thinking of the ...
3
votes
0answers
41 views

Alternate uses for Gate Driver - Driving a Load without External IGBT or FET

What issues would one encounter by using a gate driver IC to directly drive a load instead of using it to drive transistors? For consideration would be the very affordable Infineon 2EDN752x series ...
3
votes
0answers
50 views

Can I extrapolate battery power by a brief observation?

Part of the research we are conducting requires us to estimate how detrimental our proposed algorithm to the battery life of the wearables. To do so, I opted to simply charge the wearable to 100% and ...
3
votes
0answers
68 views

Modeling scalar control of PMSM

I have met with a scalar control algorithm for a permanent magnet synchronous motor. I haven´t heard about it before so I decided to develop a dynamic model to further analyze this control algorithm. ...
3
votes
0answers
126 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
106 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
77 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
384 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
46 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
189 views

SPI comunication - Only receive 0xFF (Linux)

I've been stuck in setting up the SPI communication in Linux and can't figure out any solution. I working with a beagle bone black, which runs Linux. I have a piece of code that send data through the ...
3
votes
0answers
154 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
76 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
72 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
157 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
330 views

Interfacing with MIPI CSI-2 camera sensors like the Omnivision OV2732?

CSI-2 is used in pretty much every smartphone however I'm struggling to find much information on how most companies receive and control CSI-2 sensors. I understand there are NDAs. This is not for a ...
3
votes
0answers
157 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
454 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
412 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
99 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
145 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
245 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
148 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
273 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
32 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
78 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
145 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
254 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
82 views

Running Application on SIM808 GNSS module beside it's internal firmware

I'm trying to load my written program to SIM808 and the module will responsible to run my program beside it's internal firmware,does any one here with such experiences? SIMCOM has a document about ...
3
votes
0answers
241 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
236 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
348 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
107 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
173 views

What is the 3D radiation pattern of this chip antenna?

I know that the 3D radiation pattern of an antenna could be found by knowing the xy, xz and yz plane cuts and vice-versa. This process is pretty straight forward for a dipole antenna which has a 3D ...
3
votes
0answers
264 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. ...

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