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H: QUCS simulation of simple capacitor/resistor circuit - strange results.
Hi I have just started to learn electronics. In order to understand the RC constant I have built the following very simple circuit in QUCS simulator.
According to the formula
RC time constant = R x C = 2,000,000 ohms x 0.000015 farads = 30 s... |
H: Engineering a voltage signal with an asymmetric power spectral density
My question is as follows. I know that classically speaking, if you have some time varying signal X(t) its power spectral density S_X(f) will be symmetric around f=0 as the signal is real. This is why your spectrum analyzer only shows the positi... |
H: Changing terminal leads on a live battery
So somewhere along the line I made an idiots mistake that I'd like to avoid making again. I have a large 51.2V battery that's wrapped in shrink wrap and has wire leads soldered into a charging circuit that is soldered onto the terminals. The connections recently got crushed... |
H: VHDL define range as previously defined range + offset
Is there some way in VHDL to define a range as a previously defined range plus some offset? Below is an example of what I would like to do but I can't figure out the correct way of going about it. In this example the FIFO's din/dout are 47 downto 0.
constant X_... |
H: What is the (most likely) technical reason behind temperature specifications?
Im talking about electronic devices, which may be handheld or similar, so nothing exposed to "artificial" temperature (welding, soldering, cooling with liquid gas). Devices designed to be operated by ("unprotected") humans, indoors or out... |
H: LT1528 adjustable operation
Below is a schematic for adjustable voltage of the LT1528. The documentation did not mention whether there should be a small valued capacitor on input, nor did it mention what approximate value the output capacitor should be. Does anyone have any recommendations?
AI: Input capacitor:
Th... |
H: Why can you not combine resistors in series when there is a voltage or current source between them?
Combining resistors in series with a voltage source in between
The answer says no, but I don't understand how it alters the circuit at all. If there is a current source between two circuits, the end result is current... |
H: How to model PCB Trace with RLC?
I have a PCB board with the stackup shown below. I want to calculate what would be the impedance (and capacitance too?) of a 5" PCB trace on the L1 layer.
How to calculate it?
For example, I am trying to use this calculator (https://www.eeweb.com/toolbox/microstrip-impedance/), w... |
H: Is solder mask expansion overlap legal?
I used the component wizard in Altium to automatically create a footprint but it decided to overlap the solder mask expansion with neighboring pads. Is this ok or should I change it such that there is a gap between each pad.
AI: The overlap is not a problem as far as having t... |
H: Page table - I don't understand how this table has been made
CPU has generated this sequence of logic addresses (in decimal):
777, 2047, 1199, 1100, 546, 129, 3201
page size is 512 Byte, CPU generates logic addresses, 12 Bit length, main memory has 4 pages.
I understand the following table: We just converted the d... |
H: Replace one Voltage Regulator by two coexisting regulators (NOT in "parallel")
First of all, I know that I cannot simply parallel two voltage regulators to double my output power. At least not without actions to keep the two regulators "balanced" as was discussed here:
2 Voltage regulator wired together to produce ... |
H: How to compute acceleration from accelerometer raw data
I'm working on a project based on NXP accelerometer MMA8653.
This is a I2C, 3-axial accelerometer with 10-bit resolution.
Actually I can read the accelerometer registers and I'm able to configure it.
I configured the accelerometer with full scale equal to 2G a... |
H: Reduce using Boolean Algebra
How to reduce \$(\bar B.C + B)\$ to \$(B + C)\$?
Idempotent Law
A * A = A
A + A = A
Associative Law
(A * B) * C = A * (B * C)
(A + B) + C = A + (B + C)
Commutative Law
A * B = B * A
A + B = B + A
Distributive Law
A * (B + C) = A * B + A * C
A + (B * C) = (A + B) * (A + C)
Identity Law
A... |
H: Differential input voltage necessary for maximum slew rate in operational amplifiers
Today I ran into a problem with op-amp slew rate when playing with a design where an op-amp spends a lot of time in saturation, only to occasionally "come down" and regulate the output.
(I'm simulating this using LTspice, and the o... |
H: Can a 240V 3 phase input battery charger be somehow used with only 240V single phase?
I was wondering if a battery charger rated at 240V 60 Hz 3 phase input can be somehow made to work properly if I only have 240V 60 Hz single phase available. I know there are expensive phase converters available on the market but... |
H: Arduino: Reliable and practical way to connect an I²C device (1 m away)
This is a combined mechanical/electrical question. It is mainly about getting the I²C connection reliable; this question does not concern itself with the software side (i.e., how to handle an I²C fault on the microcontroller).
I have an Arduino... |
H: How does IF remain constant in a heterodyne receiver after mixing?
Below is an illustration about heterodyne principle:
I can see the motivation behind heterodyning. I read that it is basically done to obtain a "fixed" frequency for the amplifiers at different incoming tuned RF carriers. But look at for instance t... |
H: Need help with circuit task
I just began digital technology in my school and im struggling with one task my teacher gave me. Since I have holidays right now I cant ask my teacher (living in Germany). So I hope I'm at the right spot here!
This is the task he gave me:
Create a circuit (functional block diagram) wh... |
H: how the capacitor equation can be modified?
I have a 500 mF capacitor with a charge of 1 V and connect an 1 ohm resistor in series.
What will be the maximum current flowing through the resistor? It may be 1A, right?
But the max capacity of this capacitor at 1 V is 500 mC, so how can we say that in our circuit the ... |
H: What's this yellowish stuff on this PCB?
I took this op-amp IC out of an electronics kit. It's on a PCB and soldered to some longer leads. There's some yellow/brown goo on the back of the board, and I'm not sure what it is.
You can see it in a stripe through the middle, and partially covering some solder joints:
I... |
H: Missing Code - Different DNL definitions
According to IEEE Standard 1241-2010 for Terminology and
Test Methods for Analog-to-Digital Converters you have a missing code if the following inequation is true (page 44):
\$ DNL[k] \leq -0.9 \$
But according to the book: Analog-to-Digital Conversion by Pelgrom(Second Edit... |
H: Testing changing sheet resistance with impurities
I have a chemical film, and I'm trying to detect the presence of impurities on the film. They should change the resistance. Assuming it does, how do I measure it? I believe the four point probe method might be right, but as far as I can tell that method is for unifo... |
H: Which voltage source to use in PSpice?
I'm relatively new to using PSpice. I'm trying to copy over a circuit from an example I have in order to figure out the values across the resistors. I cannot figure out how to place a voltage point(without ground) on top of the circuit, with the ground on the bottom of the cir... |
H: How to calculate the values of \$R\$ and \$C\$?
Greetings, it is asked given the next circuit
so that it can be calculated the values of the components \$R_1\$, \$R_2\$ and \$C\$.
Ok, Im given the next data and question (besides the values !):
\$iR_1(0^+)=20mA\$ ;
\$V_C(\infty)=76.73V\$ ;
\$PR_2(\infty)=588.8... |
H: Relays to control both directions on tubular motor using Raspberry
I'm using a Raspberry to control a tubular motor for a window blind and I have an issue whent testing it, the relays used to operate the motor got "stuck" and stopped working after a few direction changes.
The motor has 4 cables. 1 neutral, 1 ground... |
H: How can i make a circuit such that output voltage is reduced by golden ratio, using feedback
I want output voltage to equal input voltage divided by phi. Is there a way to use feedback such that i get an exact result? I don't want use numerical convergence with resisters but rather use feedback so as to create the ... |
H: Programmatically verifying EEPROM pins connected
I can't find really much about it online, but am curious if there is any bit-fiddling like tricks to verify all pins on a EEPROM are properly soldered/connected (particularly address pins on a parallel chip). I don't believe writing to a specific address and reading... |
H: Latching Relay Driver
I've selected a potential latching relay for use in a project (switching mains power), but - having been away from electronics for a while - I'm still trying to wrap my head around a couple things. Here's the relay in question:
http://www.digikey.com/product-detail/en/te-connectivity-potter-b... |
H: PCB with no analog and ac current and capacitor question
I'm a beginner in EE. Lastly I read a lot about this field and I want to jump in.
I think of a toy PCB design, to experiment essentially.
I picked the different hardware so that all the components have digital outputs, which is what I want to stick with (less... |
H: Questions about modelling a typical crystal radio and simulating in LTspice
This might look like an awkward question but I'm trying to model and simulate an early typical simple crystal radio in LTspice. The first reason doing this was to add a variable resistor in series to the typical crystal circuit to adjust th... |
H: Need to create -5.5/+5.5 and 25.5VDC from 12VDC wall wart
I'm looking for a cost efficient way to create +/- 5.5v and 25.6v from a 12VDC wall wart supply. The product I'm working on will probably use a DC wall wart so I need a solution that will work with that.
I need these voltages to drive the GWTS80MNFG1E by So... |
H: How do I use Circuit Lab to show me Voltage and current information on this circuit?
I have a bunch of red LEDs, I don't have their data sheet and I am trying to figure out a safe resistor to use to lower the current across them safely.
My current setup is as follows:
simulate this circuit – Schematic created usin... |
H: Filter design for piezoelectric transducer
I'd like to use a piezoelectric transducer at one of its resonant frequency (4500 Hz). In order to get a clearer signal, I would like to use a band-pass filter.
First of all I calculated the impedance of the piezoelectric transducer. To achieve that, I put a variable resis... |
H: Is this transistor switch circuit designed correctly?
I am making a little home made electronics project.
The plan is to turn on a Red LED when a SCART input is sending an RGB signal. Pin 16 on a SCART cable is 1-3V when the input is carrying an RGB signal (according to wikipedia - in my case it actually sends 4.5... |
H: Amplifier impedance compatibility
Amplifier ICs always list the maximum load the amplifier is stable with. For example, a class AB amplifier is listed as 8 ohm capable.
Is that amplifier suitable to drive a 32 ohm load?
Are there any attributes that make an amplifier better suited to drive a lighter load vs a heav... |
H: H Bridge not working with two DC motors on paralell -- Arduino
I've done a simple H Bridge with 5V relays and 2N2222A transistors using Arduino Nano, just like this one:
A 6V 4A battery supplies the Arduino (on Vin). Relays are supplied with 5V of the Arduino, but the Normally Open Contacts are connected to 6V.
Wh... |
H: Is it noticeable if audio is inverted?
I'm looking at the LM4881 headphone amplifier. The amplifier uses an inverting OpAmp style set up.
What is the effect when audio gets inverted?
Will a difference be noticed or do we hear inverted audio all the time and never notice?
Should there be a second inverting stage t... |
H: Fuse link system for LED bulbs?
I recently learned how incandescent Christmas bulbs can be modified to continue conducting electricity after burning out thanks to a fuse link that bridges the two leads at the base of the bulb.
When the filament burns out and stops conducting, the entire circuit voltage is briefl... |
H: Half bridge galvonic gate drive with deadtime
I'm a Tesla enthusiast and build Tesla coils now and then. One thing I have always wondered, a lot of designs (some very popular) utilize a transformer to drive a N-MOS half bridge (see image below). My concern with this, and simulations have shown it to be true, should... |
H: What is symmetrical output voltage swing?
what does it mean by symmetrical output voltage swing (Amplifier)? Vcc = 10V.
It is a basic, but i can't find any reasonable answer for this question. I am almost a beginner in electronics.
AI: The voltage swing is a term that describes how much the output of an OpAmp can s... |
H: What is the difference between power inductors and decoupling inductors?
I am trying to pick an inductor for use with switching regulator with switching frequency of 500KHz.
I looked at single inductor manufacturer which has two line up. One saying "Inductors for Decoupling Circuits", and the other saying "Inductor... |
H: Why does a longer fiber optic cable result in lower attenuation?
I just carried out an experiment in my college to study the attenuation of fibre optic cable versus length and type of cable.
This experiment was carried out with an LED light source and a power meter connected at the other end.
The wavelength is set ... |
H: Measurement of a signal at microcontroller's output pin
I have a control board with a microcontroller in BGA package.
I need now to measure a signal on some microcprocessor's
output pin. The problem is that there is no test point around
the microcontroller on the PCB. Does it exist any possibility
how to get to th... |
H: Switch off on overvoltage
How is it possible to modify this reverse polarity protection circuit, to switch off when more than 5.5V will be applied.
I was thinking about voltage divider, and zener diodes, or voltage comparator linked to gate of MOSFET, but I'm not sure which way is better one.
I have DDS generator w... |
H: thyristor equation
I know how does an I-V curve of a thyristor look like, but is there any thyristor equation that can represent the curve?
AI: Each straight line can be characterised by an equation based on 2 transistors.
The breakover or trigger voltage is the same as any power transistor, Vbe and current gain... |
H: LM741 not amplifying
I used LM386 to amplify but its minimum 20x gain is to much for me use because my signal is maximum +-0.5v ac , riding 1V dc .
this is my circuit.
I am seeing a signal on scope but I cant hear anything when I connect the speaker [I am measuring without it].
Moreover the scope image is the same... |
H: AVR Pointer Atomicity
On the AVR XMEGA, or any AVR, is it safe to do pointer operations, like passing by reference and accessing pointers while interrupts are on? I keep feeling like I need to wrap each pointer operation into an ATOMIC_BLOCK() macro. Is this necessary? Also, I need to copy a structure with like 30 ... |
H: Why is the signal sawtooth shaped?
I am currently working with interfacing a stepper motor (4-pin bipolar), and providing it the propper input signal, such that it accelelrate and decellerate correctly.
In recently also across an application note by atmel (link), which adresses this issue, and also provides the co... |
H: Do high-temperature rated coin cells exist?
I'm currently working on a project that will implement a coin cell as its primary power source. My PCB will likely be exposed to high temperatures ranging from 100C upwards. Now I realize that I will likely need a proper enclosure along with other cooling capabilities, ho... |
H: Getting more volts out of 3.7v battery
I have a 3.7v 12A rechargable battery I'm using in my electric cigarette. I noticed that the cigarette can go up to 75W. I want to turn 3.7 into 9v to give more voltage to my motor, what component can I use to do this? Thanks!
AI: Not a single component, but a boost converter ... |
H: How does shift register works as I/O multiplexer
I was checking on eBay for a CNC controller. I came across this unit, which provides 64 buttons. The micro is a 28pin PIC chip but there are 8x LS165A IC's on it. I am guessing there is some sort of multiplexing is going on, since the 28 pin PIC can not provide that ... |
H: Difference between reading data from fifo and the register
I am currently working on a hardware design as a part of my project in verilog.
I am fully aware that we usually use the registers to break the datapath which in turn helps us achieve timing closure. However I am not really sure if reading data from the fif... |
H: Determining state-of-charge of a lead acid battery under load
I am trying to implement an extremely simple lead acid battery state-of-charge (SOC) estimation calculation. The following values are known:
\$V_F\$ for SOC=100%: Open circuit voltage of the battery when full
\$V_E\$ for SOC=0%: Open circuit voltage of... |
H: Some questions on optimizing a Schmitt trigger to eliminate possible glitches
Above is a Schmitt trigger circuit using a LM2903 open collector comparator. On the left side the incoming pulses are mixed with noise. Before the noise the desired clean 5Hz incoming pulse train looks like:
After adding up to the incom... |
H: I need some help with finding out how to power LED's (And how "power" works in circuits in general)
Ok, I am new to electronics, but I am getting a general idea. I need some questions answered to secure my knowledge:
If I have a device that consumes 5V and 600mA, will a source with more than 600mA work? If it does... |
H: What is the purpose of this solder jumper?
I've been studying the schematic of an audio modem, which takes/sends data as audio signal over an audio jack via FSK encoding:
Does anyone know what the solder jumper SJ1 is supposed to do? My reading is that it's a 3-way jumper, but shorting all 3 pads would effectively... |
H: Signal that changes (depending on different key presses) is not working
I am writing a code for my FPGA that sends a signal 10 us wide every 2 ms. The code is working great, and now I am trying to implement some new code that will allow me to change the pulse width and delay using 4 different buttons on the FPGA. W... |
H: Is this the correct connector to receive and split out an S-Video cable
I am looking for the correct connector to receive and give me access to each of the 4 signals on an S-Video cable. I have found this:
http://uk.farnell.com/pro-signal/psg01568/socket-mini-din-4pole/dp/1280741
and also this :
http://uk.farnell.c... |
H: STM32F042 failed hardware reset?
Background
I am working on a school project where I have designed a prototype PCB with the core being a STM32F042K6T6 microcontroller. I am using the ST-Link from a Nucleo STM32F401RE card to program it.
Problem
When programming the device with some simple code to light an LED, the... |
H: What instruction on the STM32 consumes the least amount of power?
The ADC module of the STM32 is used in my application which is very sensitive to power consumption.
In this application, the ADC is required to work only at 20 samples per second. Using the DMA uses more power than I expected. I decided to make it wo... |
H: Gain of an Operational Amplifier
This is a question I found in one of the textbooks I have. The textbook didnt explain thoroughly about the concept or theory of the op-amp, and that left me confused. So please correct me if I'm wrong. I was just wondering if the voltage of the noninverting pin of the op-amp is zero... |
H: SD cards electrical specification
I designed a -very simple- circuit powered by a 12V battery.
I would like to add a sd card connector (its type is of no importance right now) on that circuit.
But I am concerned by the datasheets I find on the net:
first. No operation voltage?
second. How could I possibly feed a h... |
H: Stacking high voltage and low voltage PCBs
I am working on a project which involves micro-controller and switches (triacs and EM relays). Due to size constraint, I need to stack one over the other. Here is unfinished relay and triac board which will go on top of micro-controller board of the same size:
PCB descrip... |
H: Power supply ground connection
Which is the right way to do it?
or
AI: The top is probably better, although depending on circumstances, you might want to use the bottom. If the 5 V supply is isolated, then the top scheme is required.
The reason I prefer the top scheme (assuming non-isolated supply) is due to regu... |
H: Reading from EEPROM problem
I write a structure into EEPRM as follows
typedef struct
{
fract32 AmpF; // amplitude fundamental
fract32 AmpH; // amplitude harmonic
UINT32 b;
UINT16 d;
UINT16 crc;
}CoilBoardAmp_T;
// mechanic angles and salt water angles of coil stored in coil-eeprom
typedef struct
{... |
H: What is this electronic symbol?
I am trying to repurpose a scavenged motor, however the wiring diagram that's on it has a schematic symbol I have never seen and could not find on the Internet.
Anyone know what this is and what it means?
For more context, here's a reproduction of the entire schematic:
Update:
The ... |
H: npn switching an pnp with dual led
im trying to use a 0-7V control signal to switch an NPN controlling a LED but then using collector of the NPN to switch a PNP. So when control V is low NPN LED is on and PNP LED is off and when control V is High NPN LED is off and PNP LED is on. Is the below circuit a good way of ... |
H: multiple MCP4131 potentionmeters with common Slave Select line
I fiddle with a digital potentiometer MCP4131 which communicates via the SPI protocol. I've seen several tutorials in which multiple SPI devices are connected to a common Slave Select line and the bits of information overflow from the first Slave device... |
H: IR emitter LED with jack 3.5
Currently I'm using an IR LED connected directly to a PCB where an Arduino UNO is connected. When I send a command with the Arduino, the LED sends what I want to an IR receiver.
Now I'm thinking to change a bit this solution, because I want to extend the IR emitter, but not with some l... |
H: Common mode choke vs individual inductors for offline flyback smps
I am working on Viper22a based offline switcher and I was going through similar app notes by ON semi and ST. I found two different implementations of noise filtering on incoming mains.
This one uses individual inductors (each of value 1 mH):
And th... |
H: Does the separation of the differential pair shielding of a SATA cable matter?
Basically I want to replace a consumer grade SATA cable with something a bit more tolerant to high temps and other environmental stresses.
The general cross section of a SATA cable looks like this:
And the cable I want to use looks lik... |
H: 50Hz hum on oscilloscope probe only when using clip
Background:
I was just trying to track down some noise in a gadget I built.
There's a DC signal that represents the level of ambient RF, and I am interested in very small changes in that level. These work out to changes of less than 100µVolts in the DC signal.
... |
H: Standard way for novice to prevent small round plug from rolling away while soldering wires to it
This very trivial task is to solder wires to the terminals of a small round 3.5 mm audio plug.
I can do this myself, but I need to show to others and this is one of the first times they're trying any kind of soldering... |
H: Calculating Resistance of Unknown resistor, total current and voltage across each resistor
simulate this circuit – Schematic created using CircuitLab
The circuit above has total power dissipation of 60 watts. I need to calculate:
- Resistance of R2
Since it is given that total power is 60 watts, and the series ci... |
H: How can I plot the voltage across any component by Matlab?
I want to ask how can I plot the voltage across any component by Matlab?
I have a simple RLC circuit and I want to plot the voltage across the 3 components and I didn't use Matlab before. I found the transfer function here in the site but still can't plot t... |
H: What is the ADP option on a digital multimeter used for?
What is the ADP option/range on a digital multimeter used for?
I've tried to find the answer by searching the net, but I couldn't find any explanation.
AI: Figure 1. A multimeter manual with an ADP setting.
It's to allow use of an ADaPtor. In the example it's... |
H: Is the main purpose of cascoding is to increase gain in FETs?
In my recent studies, I have come across the concept of cascoded amplifier using Common Source and Common Gate Configuration. What exactly is the reason of cascoding?
AI: It is mainly done to increase the output resistance and or reduce the Miller effect... |
H: Is there a professional field/classification for people who do test-engineering?
Through my career so far, I have always done work involving developing software to test electronics. This has involved writing diagnostics in embedded C/C++ for ARM controller, and even such high level stuff as writing C# code to test ... |
H: how to use interrupt service routine without interrupt.h file in avr?
In avr microcontroller, when using interrupt service routine ,you write the function :
ISR(Int_Vect){
}
To use this function you must include < avr/interrupt.h>. so now , i don't want to use the interrupt.h file because i am trying to write my ... |
H: How do gamepad buttons interact with the PCB?
How do the buttons (like A, B, X, Y, and D-Pad) on game pads (such as the Xbox controller) interact with the PCB? If my question sounds vague, refer to the pictures below:
Are A/B the same as C/D? In game, the D-Pad (left) shows up as "Axis", while the buttons (right) ... |
H: why biasing an emitter follower with a transistor will cause the following transistor falling into active region?
My textbook says Q2 is not in the saturation region. I just think the Q2 transistor can be in the saturation region as long as R3 is small enough to provide the saturation current.
The author explained... |
H: Pebbles in potted electronics
I was recently taking a look at a failed power supply for 12V halogen lighting and noticed an unusual texture in the potting compound. I tried chipping some of it away with a screwdriver and got a nice surprise:
Yes, pebbles. But why? Are they special pebbles or just normal ones?
AI: ... |
H: Is this a safe way to create a single OFF switch for multiple loads?
Here is an example of a scenario that describe the question using a car electrical wiring harnest as the complete and complex system unit overall. The tail lights, brake lights and reverse lights are each seperately wired using different fuse rati... |
H: Simple way to determine I/Q phase difference (positive or negative) without using FFT
I have a Doppler sensor with I/Q channels for detecting moving object. I need to also detect the moving direction of the object. Due to the limited power and flash memory of my MCU, I cannot afford FFT() or atan() or sqrt() functi... |
H: What's the relationship between capacitor and resistance in a fading LED circuit with a 555 timer?
I followed the instructions in this video to make a fading LED circuit with a 555 timer:
https://www.youtube.com/watch?v=qLAi7hkDuYw
...apparently loosely following the schematics here:
Note that the guy in the video... |
H: Analog Stick Wiring
I am making an accessible computer interface device with an arduino at the core. For mouse control, I am using an analog stick, and ordered the Omter OM200B (http://www.omter-tyxn.com/2-axis-potentiometer-joystick-OM200B-M3.html). It has 3 leads on each on 2 sides (6 total), and I assume that ... |
H: What is reducing the NOISE when probes are connected to a circuit?
When the oscilloscope probes aren't connected to anything, the following waveform is observed:
The oscillations are more then 1.5mV.
When the probes are connected to measure the voltage on a 27Ohm resistor with 30uA current flowing:
the big oscill... |
H: How large current is needed to get a voltage change over a capacitor?
First off, this is question from my homework.
I'm not sure I understand the question, wouldn't the needed current be > 0?
AI: Two equations to consider with Capacitors
Q = CV
\$I = C\frac{\Delta V}{\Delta t}\$
Likewise
Q = It
For there to be... |
H: USB powered IR emitter for night vision webcam
I had a spare webcam which i turned it into a night vision camera. I have to use IR emitters to be able to see with it ( http://www.instructables.com/id/Night-Vision-Webcam/?ALLSTEPS ) and i don't want to use a tv remote for that. I was wondering if i could power the e... |
H: Problem with arduino controlled constant current supply with MOSFET/NPN
I am building a lamp using 5 1-Watt LEDs, an 18V DC power supply and an Arduino for dimming/controlling it. Im using a simple design (below) for the constant current driver (as was used here for example). The MOSFET I have is not logic level (i... |
H: What is the 'continuous standard load' of a battery?
I'm currently integrating a coin cell power design into an electronics project. I am trying to verify my understanding of the 'continuous standard load' rating given for a battery (datasheet)
When looking through coin cell data sheets, I am typically looking at t... |
H: Why there is welding on some iron transformers' core?
(This photo isn't mine!)
Why there is welding on some iron transformers' core?
is it only for holding the laminations together?
edit
can we repair or rewind this kind of transformers?
AI: This is done on all MOT's (Microwave Oven Tfmr )to keep the kitchen quiet... |
H: Ways to lay this cyrstal out without increasing the PCB footprint?
I am trying to follow the best practises in laying out a crystal.
Namely:
1. Keep traces short and direct
2. Keep it as close to the pins
3. Keep-out region under the crystal
4. No vias
5. Isolate the crystal
However I cannot fit my bypass caps near... |
H: Night light, schematic and functioning
I recently bought an el-cheapo night light for $1 just to see how they manage to get the costs so low. I expected to meet an el-cheapo voltage regulator at best or even a bridge rectifier but alas! None exist here. I just can't figure out how or why the circuit here works with... |
H: STM32: avoiding DMA & CPU collisions
Section 13.4 of the STM32 Reference Manual (for my STM32F303RE board) states:
The DMA controller performs direct memory transfer by sharing the system bus with the
Cortex-M4 ® F core. The DMA request may stop the CPU access to the system bus for some
bus cycles, when the CP... |
H: Difference between Power System Contingency analysis and Power Network Loading study
I was reading through some research papers on Power system contingency analysis but it seems like the researcher is talking more about network loading. I searched on the internet about the difference but I just couldn't get somethi... |
H: Which Ampere range and precision does my amperometer need to monitor a current of 220V between 50W and 300W
I need to measure the evolution of the electric power at the level of the electric plug of a computer in function of its CPU usage percentage.
The voltage is 220V and the wattage between 50W and 300W.
For thi... |
H: How do computers calculate sin values?
How does a computer calculate a sin value? Logically, when I think about it the only apparent way is to put many sin values into memory, and when a sin value needs to be "calculated" it would just pull data from a specific memory address.(ex. sin(x) would pull data from the me... |
H: Op Amp CMRR problem
I'm studying on my own for an exam. I bumped into this problem that really got me. My answer just doesn't match.
Find the CMRR of the operational amplifier above, consider Ad = 1000000 (Answer CMRR= 100000)
From the theory I know that CMRR = 20*log(Ad/Acm) where Ad is the gain in differential ... |
H: Will 802.3af device work on 24v passive poe?
I have seen a lot of questions and answers all over SE about using a passive POE device on an 802.3af network. But can you use an 802.3af device on a passive POE network?
In particular, I have this POE injector that outputs 24V @ 0.5A (12 W?), and a Mitel 5320e IP phone ... |
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