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H: Current through each resistor
I'm solving this high-school level problem, where I have to find the current through each resistor.
simulate this circuit – Schematic created using CircuitLab
There aren't any resistors in parallel or series, which could be combined, so I tried using Kirchoff's law for junctions and l... |
H: Why do we assign our outputs to signals first in VHDL?
I saw in many VHDL codes that data/control outputs are first assigned to signals and then to output ports, and not instantly to the output ports.
I'll give an example:
entity ex is
port (clk, rst : in std_logic;
....
data_out : out std_logic);
end e... |
H: Sallen-Key low pass filter cutoff frequency
How do I calculate the cutoff frequency and the gain of a second order sallen key low pass filter? For example if I want to have a cutoff 35KHz what would be the values of the two resistances and the two capacitors
Using R1=R2=4700 as it was suggested
As you can see w... |
H: ECG circuit Pre amplifier
I am in the process of designing an ECG circuit to detect heartbeat abnormalities. I have two question regarding the AD8220 datasheet:
What is the function of the 2.2pF, 10pF capacitor, 10k, 15k resistors, and the diodes prior to the AD8220?
What is the function of the capacitor on the OP... |
H: Implementation of Analog Matched Filter
I have been reading about communication theory and I was wondering if matched filters can be implemented with analog parts and what they would look like?
If they can't be it seems like the matched filter construct is of only theoretical interest without any practical implemen... |
H: Use MOSFET as switch enabled by Arduino output
I have an input from a source at 5V with a maximum current of I believe 2A. I want to drive an output also at 5V but only at certain times. The output should be capable of supplying up to 1A at 5V. The arduino has other sensors and when certain values on these sensors ... |
H: Why fake harmonics appear when using weighting windows?
As far as my understanding goes, windows in the FFT can be used to reduce the leakage error.
Suppose that I need to sample a continuous time sinusoidal signal s(t) with frequency \$F = 10 Hz\$. Suppose the sampling frequency \$Fs = 100 Hz\$.
Suppose that the s... |
H: "etching" transparent conductor on transparent plastic film or glass?
I've put the word etching in quotations as the method to get conductive tracks on a glass or plastic film might not involve a subtractive approach as with traditional PCBs of applying a conductive layer (such as ITO in this case) and then removin... |
H: MPSA42 3.3v switch
Hello I am wondering if I am understanding this correctly,
I have an ESP8266 and I want to drive a 5V relay, I have an MPSA42 Transistor (datasheet) and I am wondering if the base will accept 3.3v. I see in the datasheet it says Base-Emitter saturation Voltage (highlighted in yellow under the On ... |
H: How does MPPT algorithm and 2-stage battery charging go together?
I understand that for finding the MPP of a solar panel, the PWM of a switching converter needs to be regulated based on an algorithm. And that if a battery is connected to the converter the output voltage will be constant (that of the battery).
How i... |
H: Saturation Points for Mosfets; driving gate with 3.3V output
I'm still new to this so please go easy on me :)
I'm looking at using N channel Mosfets to act as a switch between my microcontroller (ESP8266 breakout board) and LED Strip. Here's the schematic:
When I was reading about how mosfets and transistors work,... |
H: Understanding a simple crystal oscillator transmitter
I try to understand the AM transmitter on the figure below, but I cannot figure out two essential things. The carrier frequency is created by the crystal oscillator chip.
Why does it suffice to put the audio input in parallel to the battery, in order to add th... |
H: Solving Difference Equation Using Z-Transform
I was trying to solve a problem given in my textbook. I have attached the solution given in the book.
I thought some modifications where needed to it and tried to solve in a different way. I ended up getting absurd results. Where's the mistake in my approach ?
AI: Y... |
H: ESP8266, GPIO0 or GPIO2 as input
I have a ESP8266-01 and I want to use it to check if my door is open or not using GPIO0 or GPIO2 as input.
As GPIO0 and GPIO2 both needs to be high or floating at boot, I cannot directly connect my switch to either of it. The solution is that I connect the switch between GPIO0 and G... |
H: Another question about LEDs in series
I have been doing a lot of reading on trying to match constant current drivers to series of LEDs but either my calculations are incorrect or the demands of what I am proposing are way off the charts. This is part of a project to make a strobe light.
I would like to run 5 LEDs i... |
H: ESD protection: clamp to 12V or derived 5V?
I have an input connector which provides 12V power, and a few 5V logic lines. The 5V Vcc is derived from a local regulator:
simulate this circuit – Schematic created using CircuitLab
What's best practice for ESD protection on this input connector? I'm thinking clamping d... |
H: Can somebody explain why normal diode(1N4001 or 1N4007) is used in rectifier bridge insteed of schottky diode
I have 9v AC(1A, 50Hz) as input to 5v DC(500mA) as output rectifier circuit to power up the development board. But I had a doubt if I use Schottky diode instead of normal diode what happens to the circuit. ... |
H: Acceptable conformal coating expansion ratio for PCB with delicate SMT parts?
I have heard that conformal coatings can put stress on SMD parts because of expansion/shrinking while curing or because of temperature differences. How much of a problem is this?
The only value relating to this which I found in the datash... |
H: LTC3525 Shutdown feature reacts to wrong thresholds
I've be thankful if somebody can help me with my energy harvesting board problem.
I've created an energy harvesting board based on the step-ups Linear Technology LTC3105 and LTC3525-3.3.
Below please find the schematic and board design.
A small 3V solar panel ch... |
H: OP Amp outputting 0 volts
I'm trying to use a non-inverting operational amplifier to amplify a voltage by a gain of 2 (using 2 10 ohm resistors). I'm using a 12 volt battery (made by combining 8 1.5v batteries) to power the op amp, and I'm using the 3.3v pin on a Raspberry Pi to connect to the non-inverting input o... |
H: resistor on npn transistor, led works, fan doesn't
I'm trying to control a dc fan with a Raspberry Pi 3 and I'm using a NPN transistor (BC547) to switch the fan on and off.
The schematics I found called for a PNP transistor with a 1k resistor on the base. I left the resistor but used a NPN transistor instead becaus... |
H: Disposable camera EMP coil not producing any field
I recently took on this project: https://www.youtube.com/watch?v=WIMhraVcdTg
Trying to use a disposable camera as an EMP generator.
I wrapped my wire around a bottle, but it still won't do anything, except I do hear a little spark in the push button. It goes throu... |
H: Troubleshooting 4066 as a button hack
I have an Arduino project which needs to simulate a human button press on a third-party board, an 883LM garage door opener controller. The other board has its own power supply which is separate from my project. My multimeter shows 3.3V DC across open the button. I don't have an... |
H: Tube amps on voltage regulator
I have one basic question, because I don't know much about tube amps. I live in a country where during winter, voltage can be from time to time low (around 160V-180V). I decided to keep my amp safe using an automatic voltage regulator, which keeps it around 220V-230V, which is good. C... |
H: What can i use an oscilloscope for in terms of networking
as someone who is just getting their feet wet in networking (going for a+ cert currently and would like to go further,) ive noticed that oscilloscopes can be used to monitor... seemingly any wavelength. as someone who may possibly buy one in the future, once... |
H: Name of this switch?
Can some one tell me what this type of switch is? It seems kind of like a trigger in action.
AI: It's usually called a "detector switch". Digikey has them listed under "snap action, limit switches". There are many kinds, one similar type shown below. |
H: How is the code written in ARM7 compatible with ARM9?
I'm studying ARM families,
In the above image, it is written that the code by supported ARM7 can be migrated to ARM9 and others.
ARM7 uses the Von-Neumann architecture (single bus for data and instructions) and 3-stage pipeline (i.e., fetch, decode and execute)... |
H: Transformer Basics
According to my thinking, the answer should be 400-200+200=400V, but the answer given in my workbook is 0V. Can you please point out my mistake ?
AI: The two 200v windings have their 'finish' (not dotted) terminals connected together. This means that there is 0v between the two start (dotted) t... |
H: Setup and hold time output when violated
Consider a positive edge triggered D flip flop with input signal X with a setup time of 20 ns and a hold time of 0 ns. What will be the output?
C is clock signal with a period of 40 ns.
During the 6th positive edge, we see that the data (or X) is not stable for 20 ns (setup... |
H: Why is "trimming" a carbon compositon resistor not possible?
I read that carbon composition resistor can't be trimmed and thats a big reason why the tolerances for them are so high. What I don't understand is why I can't just carefully cut some of the resistive material out to increase the resistance value.
AI: You... |
H: Can anybody explain the heat produced in the circuit during operating and non-operating state
I have designed motor monitoring circuit(Agricultural Purpose) with Stepdown transformer, Rectifier, Relay Module, and processor.I planned to run the module to run 24*7 but I afride that heat will affect the circuit.My cir... |
H: Any possibility of dead short in trim pot
I want to add one trimpot of 1K in my ADC board to test several analog channels. I thought of connecting two ends to VCC and GND and middle pin (wiper) to analog input. But I am not sure if I need to add any additional resistor on one of the sides to protect any possible sh... |
H: Is an exhausted PSU safe to use for an FPGA?
For a project I will have 4 stepper motors,a laser module and few modules attached to the FPGA.
I need around 10 amps.
Clearly the FPGA can't provide enough power for all the modules.
I think to use and old 300W PSU to provide power to all the modules.
From 2 connectors... |
H: Is the rise time of the output of a logic IC or optocoupler independent of the rise time of the input?
Is the rise time of the output of a logic IC (e.g. flip-flop or inverter) or optocoupler independent or dependent on the rise time of the input? If the answer is dependent, are there any other devices where the r... |
H: Why are "ice cube" PCB mount power relays pinned out so that the COM pin is between the coil pins?
If you have used "ice cube" type PCB mount power relays before, you're probably familiar with the de facto standard pinout for them:
Why is this such a standard pinout though? It's clearly not an optimal pinout -- p... |
H: How to properly pull up a single-relay module
I've previously discussed in this post how to drive the relay with an ESP8266, and eventually came up with this circuit:
Problem is, the particular type of relay module used has an "active low" input: it is OFF at ~vcc in its input pin, and ON on ~GND.
The circuit actua... |
H: Distortion Elimination with Differential Transistor Pair
Most of you know that incorporation of negative feedback within amplifier is one of major considerations when designing a hi-fi amplifier. Till now, I have only dealt with differential transistor pair as input stage of amplifier and "eliminator" of distortion... |
H: Two Crystals & Two PIC18F Microcontrollers on same PCB
I am planning to have two PIC18F microcontrollers with 20 MHz crystal and 22pF capacitors on the same board. So, there will be two PIC18F microcontrollers, two 20 MHz crystals (one for each PIC18F) and 22 pF capacitors (two for each PIC18F) on the same board. B... |
H: How to lift the Flip Flop D equations of an ASM-Chart?
For example, I have the following ASM-Chart already done,which represents an automatic door
:
With moving sensors...
It has 4 state blocks, there are 3 Inputs:
P - Presence Sensor, A - door is completly open , F - door completly closed;
And 2 outputs: SF-The di... |
H: DIY Oven heater
I was not exactly the best studier in my class, when everything was explained, but I suddenly got interest in electrical engineering and now - how heaters are made.
I may not attempt to make one, before I educate myself a little. But it is just puzzling me and I cannot rest without knowing the answe... |
H: Replacement Triac
I have a simple dimmer module with a busted Triac MAC97A6. I want to replace that component so that the module will work again but stores near my area don't have that specific component. One store keeper suggested I replace it with a BT169D which he had.
Will this work out? I had a quick look at ... |
H: Higher Order Filters
I am designing a signal conditioning circuit to remove all frequency under 20Hz for some EMG measurement. I have several questions about the circuit design:
For the instrumentation amplifier, should I go with higher gain (i.e. around X100) or lower gain (i.e. around x10)? I read several papers... |
H: piezo stereo preamp
I have found several projects on piezo preamps but I cant find anything that can run 2 piezo inputs to make it stereo and uses potentiometer to control volume gain etc.
What I found is "Collin’s Lab: DIY Contact Mic" from make magazine website that uses an MPF102.
1. Can I just make 2 of them... |
H: BOOT0 circuit design in STM32f446
I'm designing STM32f446 chip in PCB in a project. It will be programmed through SWD.
but I'm stuck with (BOOT0) pin. I want it to be (0) as recommended.
The thing is that there is no enough info. about it.
I've looked at the data sheets to find the rating (voltage and current), I j... |
H: On PIC MCU, a pin assigned an IO function the neighboring pin is also affected
I have been chasing the 'read modify write' problem for two days. This is a problem that when you write to one pin a neighboring in is affected. It suddenly started happening - different chips - different computers - different breadboar... |
H: Thevenin equivalent voltage calculation
Hi please see diagram attached. I can calculate the Rth but I am confused about the equivalent Vth. The part that makes this difficult for me to understand is the 2A current source. Could you please help and explain how Vth is calculated and it's of value 6V.
Thanks
AI: The E... |
H: Oscilloscope AC coupling and PWM signal
I made a traditional PWM signal generator using a 555 timer IC.
However, when I connect the output (pin 3 of the 555) to my oscilloscope and set it to AC coupling, the signal shown on the display is around -5V and 4V.
I know that I should set my oscilloscope to DC coupling b... |
H: Common source amplifier using mosfet: Why is my Id dependent on my Rd?
Since I'm (trying to work) in the saturation mode, the following formula should be valid:
Since Vto is a static parameter it shouldn't change, same for K. And Vgs is 2 as determined by the voltage divider circuit. My DC operating point simulat... |
H: 3 phase AC circuit problem
I am confused with problem 12.3. I have attached the solution and my attempt. I am confused why we are getting factor of 2, can anyone please help me ?
AI: Two things:
You calculated the average transferred power. You have calculated it right. You use RMS value phasors, the book uses ... |
H: How can microinverters be as efficient, or more, than power optimizers of solar arrays?
According to Wikipedia:
solar panels produce voltages around 30 V. This is too low to be effectively converted into AC to feed to the power grid. To address this, panels are strung together in series to increase the voltage to ... |
H: Using two filters in series
I know my question is a bit broad, but I haven't found the answer to this question. As a work for university , i am asked to use an oscillator that produces a triangle wave and after that use two active filters (one band-pass and one second order low pass) so that the triangle waves beco... |
H: Why are most IR phototransistors slow?
Most NPN silicon phototransistors that I see (Everlight, Kingbright, etc.) have fairly poor rise and fall times, on the order of 10us.
The best one I've seen so far is the QT Brightek QSD8T120B with rise and fall times of 7 us. Manufacturers always specify these times given ce... |
H: can leds take varying voltage > listed voltage, with constant current?
My confusion stems from a an led that shows: Input(DC): 600mA-700mA / 3V-3.4V.
the product suggests a constant current led driver (same brand as LED) that shows: Output: Current 600mA (Constant) ; Voltage 18-34V
In researching I have read that ... |
H: Reading a huge number of analog sensors in real time
I'm trying to build a MIDI-like controller that has a neck like a guitar. On that neck, there is a huge matrix of pressure sensors. The controller will emulate 3 strings.
The way this works is:
There are 3 long strips of double sided copper tape (0.5 cm in wid... |
H: CGR 17360 negative voltage
I have disassembled a battery pack for an old (2007-ish) Panasonic camcorder. The battery pack would not charge, so in the interest of pyromania science, I decided to try to learn what's up.
The two batteries from the pack are labelled CGR17360 Li-ion MH12210. I have found http://www.data... |
H: Design a combinational circuit that has an output of 1 if the binary value is even?
There are three variables x,y,z respectively.
\begin{array}{|c|c|c|c|}
\hline
x & y & z & F\\ \hline
0 & 0 & 0 & 1 \\ \hline
0 & 0 & 1 & 0 \\ \hline
0 & 1 & 0 & 1 \\ \hline
0 & 1 & 1 & 0 \\ \hline
1 & 0 & 0 & 1 \\ \hline
1 & 0 & 1 ... |
H: Help with my H-bridge circuit using MOSFET
I had a problem with making H-bridge to drive 32V 6A Motor
voltage control is 12V
input: IN1/IN2
whenever i tried to test it the Amp goes up in the 32V motor power "it becomes short circuit"
if you need more information let me know thanks.
AI: That's really very simple. ... |
H: Grounding considerations for 2018, and DVdd/Avdd connections
So, here we go again with the typical "what's the best ground layout?" question.
Seems this question has different answers depending on the application, manufacturer, and decade.
From what I've read, the trend nowadays is to use a single ground plane for... |
H: LED Control with current sinking
I've been looking into the schematics for some Arduinos in detail to increase my understand of them. Take in particular the Arduino Zero schematic, we can see the RX/TX LEDs are connected as:
simulate this circuit – Schematic created using CircuitLab
As per my understanding, the MC... |
H: Switch on ESP8266
I'm not that good in electronics, so maybe what I'll write bellow might sound awkward to you. If so, please correct me where needed, or ask me for any other more details.
I'm trying to add a standard wall switch to an ESP8266 module. I've set as input for the switch 3v from the ESP module, and for... |
H: How does ASK account for attenuation?
I'm reading about amplitude shift keying, where 2^n assigned amplitudes of a carrier map to n bits per symbol. Unfortunately, most of the introductory material only covers OOK, where n=1 and decoding is trivial.
For an ASK system where n > 1, i.e. a system where the amplitude c... |
H: Estimating Battery Life
I am working on a design that needs to operate outside on two AA batteries for at least a year.
I have optimized the design to reduce power and using a spreadsheet analysis I now have an average current consumption. I should be able to verify that is right by monitoring a prototype for a whi... |
H: When will electromagnetic waves reflect? What are the criteria for reflections?
When an EM Wave comes to a boundary of two different media (i.e different electrical permitivity and magnetic permeability media), the things below could be seen:
Reflections
Refractions (Transmitted wave)
Absorpiton
Scattering (I am ... |
H: What component is this? Royal 283
I have no idea what this is and found nothing on google
AI: It is an "axial-lead cement wirewound resistor" rated at 3W. Resistance is 0.22\$\Omega\$ +/-5%. Here is a datasheet.
I've been in their factory. ;-) |
H: LDO with tantalums and circuit with ceramic bypass capacitors
I'm going to use MIC5205 voltage regulator.
According to the datasheet and many sites and discussions I must use tantalum capacitors for the output. This LDO is unstable with ceramic capacitors (low-ESR caps in general). So I'm pretty aware of that.
But ... |
H: 1N5062 is getting hot at only half of its rated current
I have a rectifier bridge with 4x (GP)1N5062 diodes (body made of black plastic tube - like 1N4007). I have seen that they are getting hot, even if the current passing through the rectifier is 0.95 A.
I can only keep my finger on its terminal for 3-4 seconds, ... |
H: female 6 pin pcie power plug?
i am looking for a datasheet, or ideally an eagle library, that has a female 6 pin pcie power plug, like this:
as easy as it seems, i cannot seem to find ANYTHING online.
AI: This is a Molex 45718-0002 connector -- refer to their mechanical drawings for the dimensions and recommended f... |
H: Voltage regulator position
Hello if unregulated power supply (transformer, bridge and main caps) is 30 cm away from the circuit to feed, is it better to put the voltage regulator close to the circuit (long input and short output) or close to the power supply (short input and long output)?
AI: If your DC currents ar... |
H: Check of my first Eagle boards
I am attaching two boards I have just designed in Eagle and would appreciate if any expert around here willing to take a quick look would flag any obvious errors in the design.
There is one board that would serve as a light switch PCB, sending a CAN message over the CAN bus. There w... |
H: Eagle create library remove "direction" in symbol
I am making a library in eagle, and I am currently working on the symbol. I made pins, but they all show a small "direction":
which shows up in little green lettering next to the pin, like this:
I cant figure out how to remove it. Does anybody know? Thanks.
AI: Tho... |
H: Switching Between Two Power Supplies Without Reverse Current
I'm new to electronics, so I'm bound to have gotten something wrong.
I'm designing a basic sensor and want it to be powered by USB by default, but use a lithium polymer battery when not connected via USB.
I designed a very basic circuit which uses two enh... |
H: Reading values on continuity test but there is no beep
When checking traces of my PCB I realized that checking continuity between one of the output trace and GND some values appear on multimeter screen but the buzzer does not beep.
On the Vcc trace there are two different capacitors. Does that depend on these capa... |
H: Unknown port in videocassette recorder JVC HS-D320S
I have an old videocassette recorder JVC HS-D320S, I want to ultimately try to digitalise some videocassettes, but I'm having troubling identifying the ports on the back.
PS: I'll clarify the question a bit more if you could tell me what those little grooves in ... |
H: Floorplanning vs Placement in VLSI
The major steps of physical design that I learnt from a VLSI lecture are: 1)Partitioning 2)Floorplanning 3)Placement 4)Routing. The question of mine is about the steps 2 and 3.
It seems like the steps floorplanning and placement are somehow overlapping. We decide the places of th... |
H: Inductive Coil - detecting open coil
We are using an inductive coil transformer for a sensor. We excite the signal with a low frequency (1kHz-3kHz), and what we measure on the secondary indicates the proximity of a part.
Generating the signal and receiving the secondary signal has been completed, but one important... |
H: Anyone recognise this capacitor and its symbol (circle with dot)?
Trying to repair an old Hameg CRT oscilloscope and looking at the schematics for the HV Z board I see the following capacitor symbol (in red box):
The capacitor itself looks (vaguely) like this:
I'm not suggesting it is a vacuum dielectric cap, it ... |
H: Pinout for board to board ribbon cable
Update/significant change:
The question below is based on a false premise: taking into account that an IDC with keys pointing out from the cable on both ends swaps the front and back rows, simply rotating one of the connectors gives a 1 -> 1 mapping (thanks @DiBosco for pointi... |
H: Can I use a 20V or 24V to power up a piano that needs 21V?
The power adapter of the piano should be AC/DC 21V, 1.5A.
But I can't find in a short time to buy something exactly like that, but I found this options:
20V, 3A or
24V, 3A
Can I use one of this to power the piano or it's not ok?
AI: The difference of 1.5... |
H: LED + resistor in parallel with equivalent resistor, all in series with a larger resistor, LED not lighting up
I don't know whether I'm missing something obvious here, but I'm pretty confused. Here are a few diagrams (the ✔ or ❌ indicating the status of the LEDs when I tested it):
Sorry for the lack of labels; c... |
H: BLDC Commutation and output states of half bridges
I am trying to run a BLDC motor using TI DRV832.
In the datasheet, there is the following truth-table, where I do not know what are GLx, GHx and SHx. Also, what does Hi-Z do?
I want to control the bridge directly, so I assume the bridge is something like this:
I ... |
H: How to trigger a "Relay Module With OPTO Isolation Support High or Low Level Trigger" with a momentary switch
I am a complete novice with anything beyond simple wiring of guitar effects and kits. I have a unit, a Roland GR-55, that has a momentary switch built-in. I want to trigger this switch with a separate unit ... |
H: Proving equivalence between circuits
On page E-3, example E.3
In the example the author has asked us to prove that the two circuits are equivalent. On searching I found that circuits are considered to be equivalent if they have the same I-V characteristics. But how do I prove that they have the same I-V characteri... |
H: When talking about input and output impedances, what are we comparing them to?
Let's consider a theoretical highpass filter:
simulate this circuit – Schematic created using CircuitLab
I'm trying to show that the worst-case input and output impedance is R but the whole concept of input / output impedance isn't real... |
H: Switch for turning off MSP430
A MSP430F1232 is connected to a PL2303, i.e. URXD0/UTXD0 are connected to the PL2303 TX and RX. VCC and VSS also come from the PL2303 (over USB). In addition, a switch with a pull-up resistor and a LED with a resistor to ground are connected to P1.0 and P1.1.
The circuit and program ar... |
H: how to determine the pinouts of a 6 pin optical slot sensor/encoder?
i have a 6 pin optical slot sensor/optical encoder, which does not have a part # on it. I need a way to determine what each pin is. I will award the answer to the first answer that accurately explains the process of determining the function of eac... |
H: Simplest way to create regulated 400VDC from 12VDC
I would like to create a regulated 400VDC supply with relatively low ripple (less than +-1VDC ideally). Required current is very low (< 1mA). V_IN is 12VDC. Currently I have a boost converter that is able to create well above 400VDC based off a NE555 in astable con... |
H: How does a cable insulator prevent energy loss?
So I was watching a recent video for TED-ED titled "How to practice effectively...for just about anything - Annie Bosler and Don Greene," and at one point the speaker said the following:
Myelin is similar to insulation on electrical cables. It prevents energy loss fr... |
H: Question regarding dimension when creating an EAGLE Footprint
Hi so i was trying to create a footprint based on this dimension. But i'm not quite sure what these two numbers mean exactly? Are they MAX/MIN? Which one should i use? Thank you!
AI: The two dimension means the Maximum and Minimum size. You need to use ... |
H: Why is this switch sparking?
I have a Vega 650 power supply which does not have a power switch. So I wired a switch into the power cord. When I flip the switch, there is about a 1 second delay, then the power supply fan turns on and the switch audibly clicks and sometimes visibly sparks. I get about 1 - 3 audibl... |
H: Help me out with DC - AC inverts!
so ive got quite a bit of questions about these DC - AC converters, so ive got an inverter wich converts 9V DC alcaline battery to around 240V AC output, my questions are, is this circuit realy useable, because i see videos on youtube a 9v battery can power 120v or 240v light boulb... |
H: Is it probable that a 15VDC device be damaged by a 14-16VDC battery?
I have a KBD101 (a brushless motor controller from Thorlabs) that, in the manual, specifies a regulated 15V/2A supply. I need to power it from a 14.4V/10A Li-ion battery. The other electronics are rated at 12V and are protected by LDO regulators... |
H: Small SMD components: are they really capable of withstanding high voltages?
You can easy find some SMD components which are pretty small for such a high voltage (500V @ 0805 package for example - crazy?!). 0805 case would have 1.3 mm distance between the contacts, so I doubt that this voltage would be normal under... |
H: is this li-ion battery still safe to use?
While replacing my phone's screen I seem to have scratched and maybe damaged the battery. I don't know much about li-ion batteries so I'm wondering if it's still safe to use, or if I should look for a replacement.
AI: No. That could be dangerous. Dispose of it properly, a... |
H: Parallel resistors, why? (Basic electronics)
I'm curious as to why R1+R3 is parallel to R4 and not R2? could someone please explain this to me.
What rules are R2 violating that makes it non-parallel (and what makes R4 parallel)?
Thanks.
What i was thinking: (R1+R3)//(R4+R2)
Correct expression: (R1+R3)//R4 + R2
AI:... |
H: DC and AC coupling peak-peak difference
I have been measuring signals in an oscilloscope and I have stumbled upon a practical exercise of calculating the DC offset of a signal. Basically what I did was turn on the DC coupling, take the maximum voltage (eg. 2.36 volts) then turn on the AC coupling , take the maximum... |
H: Paralleling MOSFETs: Can I use a common gate resistor, or do I have to use a separate one for each MOSFET?
When calculating gate resistor for a single mosfet, first I model the circuit as a series RLC circuit. Where, R is the gate resistor to be calculated. L is the trace inductance between the MOSFET gate and the ... |
H: How to set up Keil Logic Analyzer to read specific pin?
How can I set the Keil uVision 5 Logic Analyzer so that I can read the status of a specific pin, example high or low?
I have read the official docs here, however it does not say anything of the sort. I know it can be done as I had seen a demonstration which us... |
H: How to explain why equivalent resistance between two points in this network is dependent on specific resistance?
The original network is an square network with two diagonals as you can see here there is no intersection between the diagonals.:
The question is what is the equivalent resistance between points A and C... |
H: beginner h bridge questions
i have some questions regarding the L298 h bridge.
what are the current sensing pins, and how do i use them?
why is there a supply voltage and a logic supply voltage?
what do the 2 inputs do? what will happen if they are both high?
AI: 1) The sense pin allows you have a sense resistor ... |
H: Are Coaxial DC Power Plugs with Grounding available?
I have a LCD Monitor that has a 2.1mm Right Angle DC Power Plug which has gotten loose over time. It frequently comes off and I needed to tap it in, but now even that does not seem to work. I'm wondering if I can replace just the plug at the end. I'm looking at v... |
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