dialog listlengths 4 30 | title stringlengths 15 150 | category stringclasses 14 values | dialog_time stringdate 2016-01-21 01:59:30 2018-07-01 01:34:46 |
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[
{
"message": "I connected a phase shifter to a VNA and measured S11 and S21. Upon setting the angle (phase) to a 100 degrees and measuring the phase of S11 I obtained the following graph, whereas theoretically S11=S22=0. I am having difficulties explaining this result and would appreciate some help.As can be se... | Scattering parameters of a phase shifter | electronics | 2017-11-23T07:06:18.273 |
[
{
"message": "I'm using an instrumentation amplifier (INA118) to measure the signal from a full bridge strain gauge (tension only, all 4 resistive elements are strain gauges, slow changing (DC) signal). I'm using a single +3.3 V supply (V+ = 3.3V, V- = 0V). The common mode voltage has been set to 2.35 V based o... | Compensating for offset voltage in bridge measurement before instrumentation amplifier | electronics | 2017-11-23T08:26:36.507 |
[
{
"message": "Can someone help me work out total amp draw for LEDs with an in-series resistor?I am getting conflicting answers depending on where I look.One way tells me the amp draw is the total amp draw of all LEDs combined, same as supply voltage.Another way seems to indicate that the total amp draw is singu... | Amp draw of multiple chains of LEDs | electronics | 2017-11-23T12:02:58.560 |
[
{
"message": "<a href=\"https://electronics.stackexchange.com/questions/311021/alternate-design-for-an-astable-555-circuit/311045\">Similar, but is using a 555 differently, as opposed to not using one at all.So, for a circuit I am in the process of building, I need an astable, and am attempting to avoid using a... | Ways of making an astable without a 555? | electronics | 2017-11-23T13:50:45.983 |
[
{
"message": "I hope this is the correct forum for this question, I don't have a background as a electrical engineer, just a hobby.I have a problem that I can't figure out. I have two audio sources, one default and one 3.5mm mono audio jack. The plan is to use the default source as long as a cable isn't connect... | Two audio sources, one default and one 3.5mm audio jack, one output | electronics | 2017-11-23T21:00:56.613 |
[
{
"message": "Note: the key question is now in bold at the bottom, for the people who have had trouble figuring out what I'm trying to ask. Sorry about the meandering explanation.I've been experimenting with resistive droppers lately, and designed the following very simple circuit:<a href=\"https://i.stack.imgu... | LEDs seem to automatically self-regulate to achieve ideal voltage across terminals | electronics | 2017-11-23T22:16:32.273 |
[
{
"message": "I have a CD-ROM that I would like to use the stepper motor from. I specifically would like to use the existing driver for it. The circuit diagram for this driver, the <a href=\"http://www.alldatasheet.com/datasheet-pdf/pdf/86528/ROHM/BD7907FS.html\" rel=\"nofollow noreferrer\">BD7907FS, is below. ... | I need help controlling the 'sled' motor of a CD-ROM, based off of a datasheet | electronics | 2017-11-24T00:59:38.823 |
[
{
"message": "<a href=\"/plugins/schematics?image=http%3a%2f%2fi.stack.imgur.com%2fQ0Lbx.png\">simulate this circuit – Schematic created using <a href=\"https://www.circuitlab.com/\" rel=\"nofollow\">CircuitLabI have built a circuit, which consists of a 9V AC transformer, feeding a bridge rectifier and th... | MOSFET produces excessive spikes from transformer | electronics | 2017-11-24T05:27:59.730 |
[
{
"message": "I am having a voltage stabilizer which is connected to AC and the output of voltage stabilizer is connected as input to a pwm for controlling a 12V, 10A dc motor.The doubt i was having is that the output of pwm is showing 17 V when i am not connecting the motor to it and using the potentiometer i ... | output of pwm/ speed controller with input from voltage stabilizer | electronics | 2017-11-24T05:32:28.853 |
[
{
"message": "As a disclaimer I know very little about this so I'm probably describing this in a very imprecise way. Say you generated a sine wave on your computer at 800Hz and played it through a speaker. Would the speaker also vibrate at 800Hz?",
"role": "user"
},
{
"message": "An ideal speaker wi... | Does a voice coil vibrate at the same frequency as the source sound file? | electronics | 2017-11-24T11:52:26.207 |
[
{
"message": "Can anyone assist me with correcting this circuit? I'm trying to build a 12 V lead acid battery charger that would have a green LED indicator when charging and a red LED indicator when fully charged. I feel the collector should send enough voltage only to allow a flow of current through the emitte... | Battery charging circuit | electronics | 2017-11-24T19:33:41.993 |
[
{
"message": "I came across this rather strange looking thermometer. It seems to have two scales and some kind of wires inside it. There are two terminals at the top. Is it a thermostat? But it seems to be too long for one. Should be at least an arm length.It seems to be very old to as I was unable to find anyt... | What could be this particular thermometer used for? | electronics | 2017-11-24T19:57:37.417 |
[
{
"message": "I'm doing a power controller for an electric grill, where through PWM I allow to pass x number of cycles from the 124V @ 60 Hz source of my lab.Here you have the diagram:<a href=\"/plugins/schematics?image=http%3a%2f%2fi.stack.imgur.com%2f1cRai.png\">simulate this circuit – Schematic created... | Problem with using SCR to control power for an electric grill | electronics | 2017-11-24T22:33:29.243 |
[
{
"message": "<a href=\"https://i.stack.imgur.com/ORKse.png\" rel=\"nofollow noreferrer\">Problem: Explain why this circuit does not work for Fan-In=1 and Fan-Out=3 for all logic gates(including the complex logic gate).Firstly, I would say the Inverter Gate is fine because it does not violate the Fan-Out=3.But ... | Fan-In/Fan-Out - Circuit - Explain why this circuit does not work | electronics | 2017-11-25T21:15:14.957 |
[
{
"message": "I highlighted below, something that was connected to the serial clock and serial data. I am not quite sure what this connections means and what exactly its doing. it seems to me that there is another sla and sda connecting to the main microcontroller. if anyone could please explain i would appreci... | msp430 schematic serial data and serial clock | electronics | 2017-11-26T00:09:36.560 |
[
{
"message": "I have a small space heater that each has a pair of quartz radiant heating elements. Each element is 400 Watts with individual latching button switches. This allows the heater to operate at 400W or 800W (either of one button pressed or both buttons pressed).I find that the heater is often too ho... | Simplify switch network for dual-element heater | electronics | 2017-11-26T01:39:01.330 |
[
{
"message": "I have a small space heater that each has a pair of quartz radiant heating elements. Each element is 400 Watts with individual latching button switches. This allows the heater to operate at 400W or 800W (either of one button pressed or both buttons pressed).I find that the heater is often too ho... | Simplify switch network for dual-element heater | electronics | 2017-11-26T01:39:01.330 |
[
{
"message": "There was once a phone in my bathroom, so now there is an LV box with a Cat5 cable in it at the end of a 30ft run.Can I hack something together to power a Google Home Mini with that cable?",
"role": "user"
},
{
"message": "You don't need any expensive and fancy PoE injectors or like. A... | Powering a 2amp micro-usb device over cat5 | electronics | 2017-11-26T03:43:17.890 |
[
{
"message": "My understanding of the audio domain is very bad and I apologize for that.In <a href=\"https://en.wikipedia.org/wiki/Headphones\" rel=\"nofollow noreferrer\">a Wikipedia article, they say in the \"History\" section that \"Those headphones used with early wireless radio had to be more sensitive and... | sensitivity vs impedance of headphone | electronics | 2017-11-26T07:20:19.557 |
[
{
"message": "I am having trouble understanding how this relaxation oscillator works. <a href=\"https://i.stack.imgur.com/Cyldk.png\" rel=\"nofollow noreferrer\">Can someone explain, why it produces a square wave form, how do the currents flow in this circuit and what is the op amp output each time?",
"role... | Relaxation oscillator explanation | electronics | 2017-11-26T15:16:40.323 |
[
{
"message": "Below the RLC circuit on the left side by the help of a periodic impulse generator V1 generates periodic damped oscillations with a certain frequency, and the resulting oscillating current couples to the circuit on the right side via the magnetic field. The circuit on the right side is exactly the... | Some questions about a magnetically coupled circuit | electronics | 2017-11-26T20:12:49.363 |
[
{
"message": "<a href=\"https://i.stack.imgur.com/vw4aB.jpg\" rel=\"nofollow noreferrer\"><a href=\"https://i.stack.imgur.com/TQfUa.jpg\" rel=\"nofollow noreferrer\">I am restoring an old ROTEL turntable and have come across a \"NEC MPC1003C\" chip, acting (I think) as voltage regulator. I can not find any info... | NEC "MPC 1003C" chip | electronics | 2017-11-26T23:56:46.777 |
[
{
"message": "Okay, so I have no experience in EE (I do SE), so I don't know where to start. I apologize in advance this isn't the right place for this kind of question.I bought a vaporizer with a small battery a while back, and the specs online say 3.7v 190mAh. Recently the battery died, but I have a much larg... | Help with calculating voltage using watts/ohms (batteries/coils) | electronics | 2017-11-27T06:08:16.487 |
[
{
"message": "<a href=\"https://i.stack.imgur.com/XJYpJ.jpg\" rel=\"nofollow noreferrer\">In the schematic above, the diode should not light, but why? (Ignore the pencil drawings on the schematic).",
"role": "user"
},
{
"message": "<a href=\"https://i.stack.imgur.com/cLVEM.gif\" rel=\"nofollow noref... | Why wouldn't the diode in this transistor scheme turn on? | electronics | 2017-11-27T12:06:50.497 |
[
{
"message": "I'm trying to figure out a good LED + resitor pairing for my circuit. However, I'm provided with a challenge and limited knowledge.Here's the situation:I'm creating a minimized version of <a href=\"https://www.adafruit.com/product/1334\" rel=\"nofollow noreferrer\">THIS sensor board. The board bre... | 3.6V Circuit and 2.8V LED | electronics | 2017-11-27T16:39:35.827 |
[
{
"message": "I want to use the Raspberry Pi's 3.3v GPIO pins to control whether a 5v LCD screen is on or off. The Raspberry Pi has a 5v pin but it cannot be turned on or off using Python or similar. Only the 3.3v GPIO pins can.Therefore, to do this I want to use a CD40109BE level shifter (<a href=\"http://www.... | How to use CD40109BE to level shift one input from 3v to 5v? | electronics | 2017-11-27T17:54:07.147 |
[
{
"message": "I've created the following simulation on LTSpice and I'm running a DC sweep for V1, I1: .dc V1 0 5 5m I1 0 100u 10u.After the simulation is finished, I get those two graphs for \\$ V_c=f(V_b)\\$ and \\$I_c=f(I_{b})\\$.<a href=\"https://i.stack.imgur.com/3vLFf.jpg\" rel=\"nofollow noreferrer\"><a h... | CE transistor curves | electronics | 2017-11-27T18:10:55.333 |
[
{
"message": "An article I have read regarding switching power supplies (<a href=\"http://sound.whsites.net/articles/smps-primer.html\" rel=\"nofollow noreferrer\">http://sound.whsites.net/articles/smps-primer.html) says that push-pull, half-bridge, and full-bridge switching supplies don't use an air gap in the... | Air gap in switching power supply transformer | electronics | 2017-11-27T21:20:51.013 |
[
{
"message": "I have acquired an Elliott Progress No.1 pillar drill with a Crompton Parkinson motor. It must date from the 1960s.The motor worked fine when I first acquired it. The rest of the drill was in a bad state, so I stripped and restored it and gave the motor a good clean. It's single phase with two win... | Wiring a Crompton Parkinson single phase motor | electronics | 2017-11-27T21:54:47.293 |
[
{
"message": "I want to calculate the integral of a voltage pulse. I have designed this circuit to do the integration. I am using a non inverting integrator:<a href=\"https://i.stack.imgur.com/HwvGk.png\" rel=\"nofollow noreferrer\">The op_amp_2 is the voltage pulse. Comp_1 is used to discharge the cap once the... | Integration Output Doesn't make sense | electronics | 2017-11-27T23:19:10.663 |
[
{
"message": "I want to build a sensor that can see changes in the magnetic field, like a hall sensor but larger, I want to be able to see the changes in the magnet field around high power tension lines and around cell towers, If there is a magnetic disturbance I want to see it.I need to know how to build a Hal... | Build a magnet field sensor like a Hall sensor large scale | electronics | 2017-11-28T02:53:31.587 |
[
{
"message": "I need to create a clock divider which has 2 inputs: n(12 bit) , clock.For every even N it needs to divide the clock frequency by that number. (2,4,6,8 etc). However I have run into some problems. First of all I created the following divider.<a href=\"https://i.stack.imgur.com/FuN5o.png\" rel=\"no... | Divide by N clock/frequency | electronics | 2017-11-28T03:32:43.477 |
[
{
"message": "I am trying to design a brushless DC generator system for portable use of charging batteries and if suitable possible hybrid power system of an aircraft.The \"BLDC\" motor/generator will be connected to a 1.5KW, 2.011HP and 10,000RPM Max water cooled engine. The reason for a brusheless motor is du... | Designing a BLDC generator | electronics | 2017-11-28T14:58:48.023 |
[
{
"message": "I have the basic series RLC circuit in simulation below.As one can see in SPICE simulation, the output voltage at resonance frequency goes upto 1KV:<a href=\"https://i.stack.imgur.com/k0FIU.png\" rel=\"nofollow noreferrer\">Can I really obtain that much voltage as in the simulation in practice by ... | How possible is producing very high voltage and electric arc by a using this simple setup | electronics | 2017-11-28T15:18:27.030 |
[
{
"message": "I have modeled an ideal diode rectifier fed from a 230V/50Hz grid with a slim DC link capacitor and a constant power load (1kW) coupled with a small resistive load. For Cdc=14uF i get a phase input current that oscillates between 0A and 8A while it is dampened. However for Cdc=15uF (or 16uF, 19uF,... | LTspice diode commutation | electronics | 2017-11-28T16:05:36.110 |
[
{
"message": "I recently had my eyes on the the tear-down of onboard charger from Tesla, and saw that they have placed the control circuitry under the major magnetic components (PFC boost inductor (toroidal), phase-shifted full-bridge transformer). The control circuitry were placed on the other side of the PCB,... | Effect of placing components under a magnetic component (transformer, inductor) | electronics | 2017-11-28T16:47:14.827 |
[
{
"message": "Disclaimer: I am a geophysicist with limited electrical engineering background. I am not sure if this problem is incredibly easy, incredibly complex, or completely nonsensical.My goal: Determine the bulk resistivity of a rock sample using resistor networks. The rock sample is to be modelled using ... | How do you determine the effective resistance of a finite grid of resistors? | electronics | 2017-11-28T20:06:23.823 |
[
{
"message": "if the load of an inverter(using a battery) is a pure reactive load, will the battery be drained ( neglect the efficiency of DC/AC conversion)?",
"role": "user"
},
{
"message": "If you neglect efficiency, there will be no drain on the battery with an inductive reactive load. An inverte... | reactive power and battery drain(in inverter) | electronics | 2017-11-28T20:30:05.980 |
[
{
"message": "I'm looking to build a nixie clock. I have looked online, I found some guides but many used expensive nixie clock kits or custom pcbs. I came across some threads about driving a single nixie tube with an arduino. Later I found this thread here on this site called \"How to drive nixie tubes from Ar... | How to drive four nixie tubes with arduino?(in-14/clock) | electronics | 2017-11-28T22:27:38.843 |
[
{
"message": "I'm looking to build a nixie clock. I have looked online, I found some guides but many used expensive nixie clock kits or custom pcbs. I came across some threads about driving a single nixie tube with an arduino. Later I found this thread here on this site called \"How to drive nixie tubes from Ar... | How to drive four nixie tubes with arduino?(in-14/clock) | electronics | 2017-11-28T22:27:38.843 |
[
{
"message": "I'm trying to drive this <a href=\"https://rads.stackoverflow.com/amzn/click/B00KTEN3TM\" rel=\"nofollow noreferrer\">JBtek 4 Channel DC 5V Relay with a signal originating from a <a href=\"https://www.pjrc.com/teensy/techspecs.html\" rel=\"nofollow noreferrer\">teensy 3.6. This means I somehow nee... | 3.3V @ 10mA to 5V @ 50-60mA | electronics | 2017-11-29T02:25:40.813 |
[
{
"message": "I am working on a project with two inputs and an output as shown. IN2/OUT are external connections, and IN1 is internal. Based on input from this forum and research I have come up with the following common-mode filter for placement between IN2 and OUT. (L1&L2 are actually the same CM choke, ju... | RF Common-Mode Filter Topology | electronics | 2017-11-30T04:48:19.290 |
[
{
"message": "I have a circuit like on this image.I want to reduce 10V signal to (-)1V.<br>But my op. amp. is powered from 3.3V and absolute maximum Vcc is 6V.Is it save to connect like that?<a href=\"https://i.stack.imgur.com/vLgj4.png\" rel=\"nofollow noreferrer\">",
"role": "user"
},
{
"message":... | Connect higher voltage than power supply to an amplifier | electronics | 2017-11-30T09:05:22.683 |
[
{
"message": "I plan to build 2 high-side switch, following this circuit :<a href=\"https://i.stack.imgur.com/45St7.jpg\" rel=\"nofollow noreferrer\">The two switchs will be controlled by a ESP32 output : 3.3V, 40mA max.The first one should power on/off a device with 5V / 500mA maxThe second one should power on... | Part selection for high-side switch | electronics | 2017-11-30T14:51:16.873 |
[
{
"message": "I have stm32l100 and stm32l152 disco boards and am using stm32cubemx and sw4stm32 IDE.After creating default project for them in cubemx - I mean I go through board chooser and then leave everything as is except changing library from HAL to LL in project -> settings -> advanced settings for both RC... | STM32L100RC and STM32L152RC disco boards fail on LL_FLASH_GetLatency() != LL_FLASH_LATENCY_1 | electronics | 2017-11-30T16:19:45.723 |
[
{
"message": "Why and how does this active band pass filter change a triangle form to a sine form? I know that the band pass filter consists of a low pass and a high pass , so it cancels out some frequencies , but I don't understand graphically how this could happen.<a href=\"https://i.stack.imgur.com/zFDFT.png... | triangle wave form to sine form through band pass filter | electronics | 2017-11-30T16:40:44.927 |
[
{
"message": "<a href=\"https://i.stack.imgur.com/MQNnB.png\" rel=\"nofollow noreferrer\">I have this circuit and I need to find \\$u_{o}(u_{i})\\$ if \\$ZD_{2}\\$ and \\$ZD_{1}\\$ are ideal zener diodes with \\$U_{z}\\$ zener voltage and the op-amp is also ideal. My problem is that I have no values, I just nee... | Expressing output voltage in a circuit with zener diodes without any value given | electronics | 2017-12-01T15:26:43.993 |
[
{
"message": "In Sedra/Smith the following image may be founded that is used for output resistance equation derivation of common-base BJT amplifier. The question is why the gm*v and v/re currents are directed up? Why they are not displayed in down direction?The equation of output resistance with image current i... | BJT common-base output resistance derivation | electronics | 2017-12-01T19:26:53.153 |
[
{
"message": "I need a circuit to go from 48V down to 12V-9V less than 30mA, it doesn't need to be a buck converter. I don't want to use transformers as simplicity is good (and adding components to the library is bad) and I probably already have inductors that I could use on my shelf. Most of the stuff out ther... | Need a buck circuit to go from 48V down to 12V-9V less than 30mA | electronics | 2017-12-01T20:00:52.663 |
[
{
"message": "Please be kind. I have a thorny and important question from a different field of engineering whose answer may be fairly well-known in electrical engineering. I asked a similar question on <a href=\"https://stackoverflow.com/questions/47537580/truth-table-reduction-to-ternary-logic-operations-vpter... | How to map a truth table to ternary logical functions? | electronics | 2017-12-02T00:10:49.843 |
[
{
"message": "I've been trying to make an LED blink. My first approaches were without the 555 timer, and they were unsuccessful. I decided to make an Astable multivibrator circuit. I'm using an NE555, and I'm using the circuit on <a href=\"https://www.youtube.com/watch?v=stN-ZzHfiO4\" rel=\"nofollow noreferrer\... | Very Basic 555 Timer oscillator not working | electronics | 2017-12-02T00:19:30.560 |
[
{
"message": "I have this board with three DIP ICs already mounted in their sockets.<a href=\"https://i.stack.imgur.com/i2W90.jpg\" rel=\"nofollow noreferrer\">The decoupling schematic is this:<a href=\"https://i.stack.imgur.com/ln0mn.png\" rel=\"nofollow noreferrer\">So we have a sum of 8 ceramic caps and 2 el... | How to add decoupling capacitors to already mounted ICs | electronics | 2017-12-02T14:06:12.500 |
[
{
"message": "It may be some kind of stupid question and i'm sorry if it is. Let's say that we have ideal non-inverting op-amp and we use virtual ground to solve the Vo value. But what if we change inputs? Does it really matter in ideal case?<a href=\"https://i.stack.imgur.com/tbJY1.png\" rel=\"nofollow norefer... | Can we change op-amp inputs when using virtual ground? | electronics | 2017-12-02T14:08:35.880 |
[
{
"message": "<a href=\"https://i.stack.imgur.com/ZmLN2.jpg\" rel=\"nofollow noreferrer\">I have created a circuit with an Arduino Uno with a joystick, controlling two standard servos. I have connected these servos to a 5V power supply. The problem is that often when I turn on the power supply, both servos turn... | Why do my servos jump to one side when i turn on the power supply? | electronics | 2017-12-02T16:01:24.037 |
[
{
"message": "I'm a noob. Please correct my mistakes.I'm making a circuit where I'd like to protect my Li-ion battery (3.7V, 3500mAh) from discharging too much. The batteries have a protection inbuilt which shuts of at 2.5V. I'd like to stop the discharging at 3V.The battery connects to the PCB with a JST conne... | Low voltage disconnect with no quiescent current | electronics | 2017-12-02T16:09:54.620 |
[
{
"message": "Why there are several curves on next image (datasheet for 2SK170)? What condition changes to use one or another curve?<a href=\"https://i.stack.imgur.com/NQnXl.png\" rel=\"nofollow noreferrer\">",
"role": "user"
},
{
"message": "Idss is what is different. Idss is a characteristic of th... | JFET I drain vs V gate to source curves | electronics | 2017-12-02T18:19:01.277 |
[
{
"message": "My question is about time varying nonlinear equations in simulating of them in simulink. in nonlinear time independent equations x,Dx,D^2(x) are made with multiple integral block like the picture in below:<a href=\"https://i.stack.imgur.com/UO4T1.jpg\" rel=\"nofollow noreferrer\">For nonlinear tim... | Nonlinear time dependent equation in simulink | electronics | 2017-12-02T19:54:48.243 |
[
{
"message": "I'm trying to make a simple microphone circuit using this microphone:<a href=\"http://www.cui.com/product/resource/cma-4544pf-w.pdf\" rel=\"nofollow noreferrer\">http://www.cui.com/product/resource/cma-4544pf-w.pdfI am connecting a 3V supply to a 2.2k Ohm resistor which then leads to terminal 1 of... | Wiring an electret condenser microphone? | electronics | 2017-12-02T22:23:14.123 |
[
{
"message": "I've got power supply (transformer based) 9V powering modelling guitar effect processor. That noise gets amplified and it hurts.Humming noise is 100Hz rectified mains. Processor takes 300mA 9V (500mA rated). Unfortunately I cannot tell ripple voltage (don't have an oscilloscope).Is there any equat... | How to determine what capacitance is required for eliminating humming noise? | electronics | 2017-12-02T23:32:16.527 |
[
{
"message": "I know about inverters is as follows (correct me if I am wrong)DC source such as battery fed current into transformer by controlled switches such as mosfet or IGBT. This controlled current fed into primary side of step up transformer. While the control circuit modulate the high frequency carrier w... | How sinewave pwm inverter filter output? | electronics | 2017-12-03T05:20:46.817 |
[
{
"message": "EDIT: Original post was phrased as XY problem. What I need to do: Determine if power at \"Switched power\" is being turned on by SW1/FET combination or other power sources not pictured in the diagram below (there are multiple sources). My first thought was to sample the voltage on the switch line... | How to get ADC input with high resistance? | electronics | 2017-12-03T20:11:39.737 |
[
{
"message": "The project I am working on specifies a 12v 0 12v centre tapped transformer. I have a 12v twin secondary left over from a previous project. My plan is to wire the two secondaries in series in order to form a centre tap, as per this thread:<a href=\"https://electronics.stackexchange.com/questions/2... | Using a twin secondary in place of centre tapped transformer | electronics | 2017-12-04T10:27:33.857 |
[
{
"message": "Original situationI live in an apartment with a 12VAC intercom/open button for the street door.Current situationI've wired a normally-open relay, linked to a NodeMCU, across the terminals for the open button. This works fine and I can now remotely open the street door. The NodeMCU is currently pow... | How can I power a NodeMCU from a 12VAC building intercom? | electronics | 2017-12-04T12:56:26.033 |
[
{
"message": "<a href=\"/plugins/schematics?image=http%3a%2f%2fi.stack.imgur.com%2f5mR8b.png\">simulate this circuit – Schematic created using <a href=\"https://www.circuitlab.com/\" rel=\"nofollow\">CircuitLabI have looked at several questions/answers regarding this topic on EE.SE and other forums I foun... | Calculate Base Resistor for LED Switch | electronics | 2017-12-04T17:14:18.530 |
[
{
"message": "I'm designing my first PCB in Eagle. This PCB is for surface mount LEDs (Epistar 1-3W) and has 5 independent channels. There is an input from my driver circuit and an output for daisy-chaining more LED PCBs. I'll use this to provide different light treatments to plant cell cultures growing in bior... | Check my first PCB design for errors (simple high power LED circuit) | electronics | 2017-12-04T19:38:01.593 |
[
{
"message": "I bought a bipolar stepper motor (Mercury SM-42BYG011, 12V, 0.33A) and an LN293 H-bridge. I drive the motor with a 9V alkaline battery. Unfortunately the stepper motor empties the battery very quickly. I don't need a lot of torque, and I don't need high accuracy (the motor turns 1/10 of a turn eve... | Drive stepper motor with a battery efficiently | electronics | 2017-12-04T22:57:19.233 |
[
{
"message": "I want to store a variable every time a breakpoints is hit, while i am running a test. Any idea how can i automate the task??Or How can we monitor keil via python or any other script language ?",
"role": "user"
},
{
"message": "You can use the <a href=\"http://www.keil.com/support/man/... | Send a command in keil as soon as Breakpint is hit | electronics | 2017-12-05T04:56:45.037 |
[
{
"message": "Will it work if I place hall sensors facing the magnets like in the picture below? I cannot put it in between the teeth because the hall sensor is bigger than the gap.<a href=\"https://i.stack.imgur.com/80aWD.jpg\" rel=\"nofollow noreferrer\">",
"role": "user"
},
{
"message": "No that ... | Will it work if I place hall sensor heads facing magnets in outrunner brushless motor | electronics | 2017-12-05T07:38:46.730 |
[
{
"message": "I currently have a 36vbdc 800w motor connected to a 36v 800w motor speed controller (similar to what they use to control ebikes) just like this one: <a href=\"https://aws.robu.in/wp-content/uploads/2016/02/919811586_739.jpg\" rel=\"nofollow noreferrer\">https://aws.robu.in/wp-content/uploads/2016/... | How to connect a 2.4ghz 4ch RC receiver to a brushed dc motor controller? | electronics | 2017-12-05T14:22:36.267 |
[
{
"message": "I have a circuit that is essentially just a 1kV DC source connected to a very high resistance (<a href=\"http://www.falstad.com/circuit/circuitjs.html?cct=$%201%200.000005%2010.20027730826997%2050%205%2050%0Av%20560%20368%20560%20304%200%200%2040%201000%200%200%200.5%0Aw%20560%20304%20560%20176%20... | Amplifying High Voltage nA Current | electronics | 2017-12-05T15:18:13.657 |
[
{
"message": "I know what I want but not sure how to achieve it! I have car dash cam supplied by 5 volts. I've set up a 5volt power bank to run the dash cam when parked and wired up a relay operated by an Accessory circuit to switch from car battery power (via a 5v usb adapter) to power bank battery when the ca... | Need to maintain 5v to load during supply switch over | electronics | 2017-12-05T19:34:57.580 |
[
{
"message": "When designing a boost converter to take a low input voltage to a high output voltage, there are many knowns that you control, such as the choice of inductor and the duty cycle of the switching that is at the heart of the boosting voltage. The below circuit is a demonstration of what I'm talking a... | How do you calculate the output voltage of a discontinuous inductor boost converter? | electronics | 2017-12-05T20:30:26.297 |
[
{
"message": "On the GPIOs of some ARM-based microcontrollers, you are given a register <code>BSRR</code> which you can write to to perform atomic changes in a ports output register. For example, to set <code>Port A Bit 5</code> to a <code>1</code> you simply do <code>GPIOA->BSRR = (1<<5)</code>This al... | How does the BSRR register work? | electronics | 2017-12-05T21:48:46.060 |
[
{
"message": "In my application I need to measure the power consumption of the Raspberry Pi 2 model B board under different conditions: taking pictures, compressing images, encrypting data etc.As I don't have precision multi-meters with data logging, I thought of using an ADS1115 16bit ADC, hooking up a 0.1ohm ... | Measuring the Raspberry Pi power consumption | electronics | 2017-12-06T15:24:44.077 |
[
{
"message": "I need a -140V reg which doesn't exist, so I'm trying to learn how to build simple discrete regulators (starting with positive regs). As I only need a few tens of milliamps with a fairly constant load, I feel this shouldn't be too onerous a task. I've spent some time reading and simulating, but as... | Help analysing a discrete voltage regulator circuit | electronics | 2017-12-06T16:25:40.083 |
[
{
"message": "Is it possible to use the NX3DV42 pins designated for USB Data + for Data - ? And use the pins designated for Data - for Data + ? <a href=\"https://i.stack.imgur.com/4K80C.jpg\" rel=\"nofollow noreferrer\">It is my understanding that because the NX3DV42 is essentially just a switch, either routing... | NX3DV42 Routing | electronics | 2017-12-06T16:45:40.643 |
[
{
"message": "Many books talk about the capacitances between terminals of the transistors, specially the capacitances \\$C_\\mu\\$ and \\$C_\\pi\\$ which are the base to emmiter and collector to base capacitances. There are some methods to determine the high frequency behavior of transistors which rely on the f... | Transistor capacitances | electronics | 2017-12-07T04:40:10.533 |
[
{
"message": "I am really confused with the difference between steady state error and actuating error. My teacher gave the following notes on this topic and explained using 1 example. He said that there will be 2 types of problems Case of non measuring and E(s) not specified in the problemCase of measuring or w... | Control System Basics | electronics | 2017-12-07T05:10:52.937 |
[
{
"message": "I know this is \"noob-ish\",but where do you actually put in the thevenin calculation.Particularly i have <a href=\"https://imgur.com/a/xvK6c\" rel=\"nofollow noreferrer\">this circuit and i know the Thevenin will be like <a href=\"https://imgur.com/a/RkTGB\" rel=\"nofollow noreferrer\">this , my ... | Thevenin calculation | electronics | 2017-12-07T16:38:13.173 |
[
{
"message": "I'm second year Electrical-Electronical Engineering student (It's Electrical Engineering basically but naming issues I guess) and my knowledge about circuits is limited to capacitors, inductors, resistors, basic diodes element-wise and simple circuit analysis using KVL-KCL and Terminal Relations. ... | Desing Problem with Single Axis Solar Tracking System | electronics | 2017-12-07T16:49:21.687 |
[
{
"message": "This is the circuit that I built: (desired voltage levels are described next to the circuit)<a href=\"/plugins/schematics?image=http%3a%2f%2fi.stack.imgur.com%2fZJAya.png\">simulate this circuit – Schematic created using <a href=\"https://www.circuitlab.com/\" rel=\"nofollow\">CircuitLabI tr... | Differential Amplifier Biasing Problems | electronics | 2017-12-07T17:10:55.973 |
[
{
"message": "<a href=\"https://i.imgur.com/2mJEomb.jpg\" rel=\"nofollow noreferrer\">Here's problem (Lathi):<a href=\"https://i.stack.imgur.com/CUtHb.jpg\" rel=\"nofollow noreferrer\">a. \\$ x(t) = 5 sinc^2 (5 \\pi t) + cos (20 \\pi t) \\$Bandwidth = \\$ 20 \\pi \\$\\$ f_s = 10 Hz, w_s = 20 \\pi \\$Signal can ... | Signal processing, signal recovering with lowpass filter | electronics | 2017-12-07T20:35:46.520 |
[
{
"message": "<a href=\"https://i.stack.imgur.com/0j4bx.jpg\" rel=\"nofollow noreferrer\">It’s given in the book Dr. J. S. Chitode that u(n) repeats after every sample but as we have searched on google quora answers are saying that u(t) is not periodic. So, now I’m confusedIn my perception u(n) isn’t periodic s... | Is u(n) a periodic signal? | electronics | 2017-12-08T08:43:29.487 |
[
{
"message": "In the following circuit, my understanding is that when there is a spike or rise in the data line higher than Vcc, the top diode conducts and the voltage flows into the path to protect the downstream IC/circuitry. But how does that voltage flow into the top Vcc, which is a probably a power supply?... | ESD protection diode circuit confusion | electronics | 2017-12-08T14:12:22.213 |
[
{
"message": "I have been tasked with creating a logic probe that reads High/Low/High Impedance, but what works in simulations, isn't working in practice.This was my idea:<a href=\"https://i.stack.imgur.com/03Y3F.png\" rel=\"nofollow noreferrer\">I made a symmetrical power source using two resistors and a virtu... | How to make a symmetrical DC power source? | electronics | 2017-12-08T19:50:43.563 |
[
{
"message": "Lots of questions have been asked about mixing analog and digital on the same board and protect analog from digital noise. I have different situation: my analog current is so high that it cause instability in digital part! I try to control really big BLDC motor using MCU and I try to fit it all on... | Mixing high-current and digital logic on same PCB causes interference | electronics | 2017-12-09T01:52:30.350 |
[
{
"message": "I am building an amplifier with multiple op-amps, and it seems that some are overheating. Here is the schematic:U62 heats up the most (too hot to touch), U63 also heats up but a little less, U64 heats up the least but still significantly. U65/66 don't heat up at all. DAC0_OUT1/2 are current output... | Op Amp Overheating | electronics | 2017-12-09T05:00:01.720 |
[
{
"message": "I'm trying to understand an exercise reported in Microelectronic Circuit Design by R. C. Jaeger & T. N. Blalock (4th ed, p.237). $$\\beta_F = 50, \\beta_R = 1$$.<a href=\"https://i.stack.imgur.com/6D3wC.png\" rel=\"nofollow noreferrer\">I don't agree with the discussion they make.<a href=\"htt... | NPN Circuit simulation doesn't agree with book | electronics | 2017-12-09T10:25:18.423 |
[
{
"message": "I'm trying to make a impedance meter using STM32 and I want to ask that question to make sure it work ( at least the theory).So, Can opamps work with signal that may go higher or lower than supply voltage(single positive supply) as long as it's output remains in Vsupply region ?Sorry for my bad En... | Can opamps work with signal that may go higher or lower than supply voltage? | electronics | 2017-12-09T15:10:16.780 |
[
{
"message": "I feel that this is a stupid question but I have really no idea how to answer it.Looking at <a href=\"https://electronics.stackexchange.com/a/39147/162522\">this answer first part and of course the other answer it's <a href=\"https://electronics.stackexchange.com/a/15143/4512\">pointing to, I unde... | What/How many devices to put in one local ground net? | electronics | 2017-12-09T21:25:15.740 |
[
{
"message": "I'm using a step-up converter (MT3608) to convert 3.3V to 5V Output. However, because I don't need the 5V all the time and my device is battery powered, I want to turn off the MT3608 IC through its EN pin (LOW = Off, HIGH = On).Two questions:Do I need a pull-down resistor from EN to GND to ensure ... | Pull-Down / Pull-Up Resistor value for minimum current leakage | electronics | 2017-12-09T22:18:34.723 |
[
{
"message": "If I want to create a device that produces high static electricity fields, such as negative ion generators, what kind of transformer specs I should look for?I want super huge static electricity, and input voltage of 12-24V (1152/2304W).Note that I cannot translate \"flyback transformer\" into a me... | What transformer I should use for negative ion ionizers | electronics | 2017-12-10T03:24:16.267 |
[
{
"message": "Okay so this is extremely specific and I've searched around but I might be using the wrong terminology. I have two automotive foot pedals that I can attach microswitches (or anything I guess) to, either when depressed or not to know its state. I've drawn it out many ways but can't wrap my mind aro... | Wiring a circuit with 2 microswitches for 2 pedals where circuit is off under only one condition | electronics | 2017-12-10T06:44:39.713 |
[
{
"message": "I am trying to create an SR Latch with two NOR logic gates that lights an LED. I am implementing the gates using 2 transistors and 2 resistors each.Here is the schematic:<a href=\"/plugins/schematics?image=http%3a%2f%2fi.stack.imgur.com%2fYKK5e.png\">simulate this circuit – Schematic create... | How to find current of different parallel components in SR Latch | electronics | 2017-12-10T21:37:24.480 |
[
{
"message": "I tested for charging a mobile using SMPS, it charges the battery 10% percent in an hour. But when I connect the same mobile to the mobile charger it charges the battery 40% in an hour. The SMPS input and output ratings areIN 100 - 240V AC 0.23A, 50-60HzOUT 5V DC /2000mA.Charger input and out... | Can SMPS works as cellphone charger? | electronics | 2017-12-11T12:25:23.770 |
[
{
"message": "I have a Problem turning a MOSFET On/Off with my Arduino. I try to controll multiple mosfets to supply a high power Device with current. Now my issue is that the mosfet does not turn on.Here is a basic sketch of the circuit for one MOSFET.<a href=\"https://i.stack.imgur.com/AN57d.png\" rel=\"nofol... | Problem switching a MOSFET with arduino | electronics | 2017-12-11T13:01:29.270 |
[
{
"message": "I am part of a research group that is developing a concept for a PCB for an external piece of equipment. This piece of equipment can be controlled with a microcontroller. It communicates to my microcontroller through I2C, using SDA and SCL pins. However, it uses another pin; they call it an \"inte... | Is my reasoning about an ATMega328p connected to equipment requiring an open-drain pin correct? | electronics | 2017-12-11T14:18:40.490 |
[
{
"message": "<a href=\"https://i.stack.imgur.com/CUnSG.jpg\" rel=\"nofollow noreferrer\">According to my analysis, none of the options are correct. But the answer mentioned in my workbook is option B. <a href=\"https://i.stack.imgur.com/evnkb.png\" rel=\"nofollow noreferrer\">In positive half cycle, I'm gettin... | Diode Circuit Analysis Problem 2 | electronics | 2017-12-11T21:39:15.450 |
[
{
"message": "I'm playing around with high-power LEDs (the \"high\" part is relative - 3W). I need 3 channels - 1 per RGB. Because I need independent control of the system, I would need either a multi-channel constant-current driver, or 3 separate single channel drivers. My question is - can I get away with a s... | Can I round-robbin high power LEDs to minimize driver channel requirements? | electronics | 2017-12-11T22:44:34.240 |
[
{
"message": "In the thread below, there are different opinions whether output voltage of a boost converter operating in continuous conduction mode (CCM) depends on load current or not. <a href=\"https://electronics.stackexchange.com/questions/90157/boost-converter-output-voltage-dependence\">Boost Converter Ou... | Does output voltage of a boost converter depend on load current in CCM? | electronics | 2017-12-11T23:04:01.593 |
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