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H: Thevenin equivalent and op amp
I have some problems obtaining the thevenin equivalent with op amp. The next example is in Fundamentals of electric circuits of Sadiku. Can you help me get thevenin equivalent from the example?
AI: First deal with the op amp. It has a gain = -Rf/R1 so that the voltage feeding into R2 ... |
H: Power source select for Raspberry Pi
I'm creating a board which takes an external power source to drive motors which are controlled by a ULN2003A connected to the Raspberry Pi GPIO.
It would be nice if when the external power source is connected it could provide power to the Raspberry Pi itself through the 5V GPIO ... |
H: What is Atmel's 2x5 ICSP connector called?
I'm looking for a male connector that fits in the left female connector shown in the image. My goal is to break each lead out to holes on a breadboard. What is that kind of 2x5 connector called?
Searching for ICSP connectors doesn't help me.
AI: Those are 0.100", or 2.54m... |
H: Using Bessel function graph to finde out side bands
If I am not wrong, using Bessel function we can estimate the side bands of a carrier? Is this correct? If so, what are the steps to find these values from the graph?
For example if modulation index is 2 and amplitude of the signal is 2volt what are the first few s... |
H: 12v to 300v Boost Converter - Ideal Inductor for 9kOhm load
I'm currently working with a MAX1771 chip, the design can maintain a stable voltage up to around 15kOhm and is as follows: 12V to 300V DC-DC Boost : Disregard NMOS and DIDODE Value
The inductor currently being used is a SRN1060-151M, unfourtanately it has... |
H: Low Pass Filter that can quickly turn on or off?
I may be pushing physics here so please tell me if I am. I have a signal I'm trying to anti-alias at 50Hz (sampling at 100Hz). The problem is my input signal is essentially an Amplitude Modified square wave that matches the sampling frequency with a very short duty c... |
H: Some doubts about PCB USB connectors
I'm trying to make a PCB where I have USB connectors, but I'm really new into this and I'm trying to solve a few questions online about the theme, if you could guide me online through the theme that would be great. For this purpose, this systems is a USB sensor with 2 USB connec... |
H: Is voltage a delta? Can it always be treated as a potential difference from a reference point?
I've always considered voltage to be absolute, i.e. something that is there or is not there. However, the more I think about it, it seems to be more like a delta.
For example, let's say we have a supply that lists its pin... |
H: Intentionally mis-use the USB port on an Arduino?
I want to take an Arduino and after programming it on the PC like normal via USB, push a button or something and change its mode so that the behaves differently. Is this possible? I'd like to interface with this:
Pins are +1.5V, clock, data, ground. Blue box on top... |
H: What are these symbols?
Well I have these schematic of a vaccum tube amplifier, and I'm having some problems to understand some symbols.
What are these symbols in red?
What does exactly CW mean? It should be a logarithmic potentiometer but have that strange down arrow.
AI: RT1 is probably a negative tempco resistor... |
H: How to choose between Mealy and Moore state machine
I know the basic differences between Mealy and Moore FSM (Finite state machine). What I want to understand is the following:
Pros and cons of using Mealy over Moore and vice versa
In which situation Moore is more suitable than Mealy and vice versa
The figures of... |
H: Identity of TI mystery chip: CM060B
I am having trouble identifying one of the two ICs on my dog's ultrasonic collar tag. The lettering on the 16-pin SOIC package was obscured by some sealant which I had to scrape away, leaving the markings quite faint, so it's possible I'm misreading them (and thus far I have foun... |
H: Attempting to Understand Transistor Specs and Pick One
I'm trying to find a transistor that will power on with very low input. The entire circuit is running on 3.3 V, DC and needs to use little current (Max 50 mA). The resistance between the power supply and the "base" of the transistor will vary between 50kΩ to 12... |
H: How do receivers know what to output to radio speaker or TV screen?
I understand that receivers are often used with mixers which take the sum and difference of two signals to make an output signal. How does a radio signal of say 102.5 MHz know to tell the speakers to output a person singing, a guitar with distorti... |
H: Measuring the mic signal of a computer headset
my colleague and me have hit a brick wall - and are hoping somebody can help us out here :)
Following scenario: We record some data using a computer with an NI card and some signal transducers. We need to record audio from a mic of an headset synchronously. First thou... |
H: What is the purpose of parallel RC network in the bridge rectifier output?
Can anybody explain the necessity of the RC network shown in the figure. I found this in circuit for a logic power supply using Fly-Back converter?
AI: With capacitors in series they theoretically share half the supply voltage between node1 ... |
H: Leading Power Factor effects on electrical System
If power factor comes in leading & showing -0.95, is there any effect on electrical system? If yes, then please tell me what would be the effects and how long we keep power factor in leading??
Keeping power factor in leading shows more KW & less KVA? Is it correct o... |
H: 5V 1A from 24VAC transformer with grounded secondary
I built a power supply for a micro-controller board that requires 5VDC and peak of 1A (typically sits at 500mA). The power supply has an input of 24VAC. I used a bridge rectifier and an LM2575-5 switching regulator to get 5V 1A. All good, worked well.
Problem is ... |
H: Using LDO with Outboard Pass Tranistor
I need a power supply capable of supplying 7.5V at 6A using linear devices. To minimize power dissipation at this current level I have decided that using a LDO would allow me to lessen the power I need to dissipate by allowing me to have a lower input to output voltage.
I hav... |
H: Difference between If-else and Case statement in VHDL
I want to understand how different constructs in VHDL code are synthesized in RTL.
Can anyone tell me the difference between If-Else construct and
Case statement constructs of a process in VHDL in terms of how the code is inferenced into RTL circuit by the syn... |
H: Is there an instrument that can measure the capacity of lead acid batteries
Background
I have an electrical scooter with 6 x 12Volt lead acid batteries (72 Volts total), which are now in such a condition that they can barely get me to my work and back. I got a bunch of used UPS batteries from a friend, and want to ... |
H: eagle cad - defining orientation of footprints of components
I prepared a PCB layout on Eagle Cad 6.4
Here below is the end version of the PCB
As you can see the the layout is printed as the MCU will be placed from the bottom layer. However, I would like to place the MCU on the top layer and solder the legs on th... |
H: High voltages Transmission lines?
I am having a doubt in why are the transmission lines are sent at a very high voltages? I also went through quite a few sources which said that it is to decrease the losses in the lines. BUt I am not quite satisfied with the solutions, can somebody please let me the answer for thi... |
H: How to sense when a plant needs to be watered?
Im trying to design an embedded system that detects when a plant needs more water (mostly the kind of plants you have in at home in a pot)
What kind of sensors would you recommend?
AI: If you use two probes, made of different material, and they're in the moist environm... |
H: What concerns are there with running high frequency traces?
I am working on a project where i will be laying out some traces that will be handling Gigabit Ethernet traffic. I know that putting these traces on the outside layers (Top or Bottom) is a bad idea, with noise and other EMI issues, but what other issues sh... |
H: Most compact high voltage source for making long arcs
Out of curiosity, I have a question about high voltage electricity sources. Hypothetically, the requirements are that the source must be no larger than a water bottle (although smaller is better), and that the source is capable of producing an arc at least 1 met... |
H: Can one use PiFace for A/D conversion?
the PiFace is advertised as the shield "connecting the Raspberry Pi to the real world" and they claim that this includes things like temperature sensors. I know how to read the temperature using an AVR microcontroller and the A/D converter, but I cannot see that such a convert... |
H: Using an NPN vs a PNP transistor
Is the following circuit electrically sound? My recollection is that the right way to do it is to use a PNP transistor on the high side and an NPN transistor on the low side. Will it work if they are both NPNs? What differences in performance are there?
simulate this circuit – Sche... |
H: matching input and output impedance in an audio circuit
I have searched many places but have failed to get a clear and convincing explanation about why we match input and output impedance in audio circuits. For example: lets consider a simple audio circuit where microphone is connected to amplifier and then to a sp... |
H: the . hex file we burn goes to flash memory or RAM or EEPROM of Atmega8?
The flash memory of atmega8 is 8Kb.
Is this the maximum size for the .hex file, or it the max memory which i can allocate to variables in my code?
If none of the above is true, than what is memory allocation structure of Atmega8? To which memo... |
H: Memory modelling and Memory module in Verilog synthesis
I am using a synthesis tool and when I am synthesizing a verilog file
module test();
reg reg1;
reg [1:0] reg2;
reg reg3 [1:0];
reg [1:0] reg4 [0:4];
endmodule
It's giving an error to "use memory module" with the help of a option.
So what I need is to make a ... |
H: Is it possible to convert radio waves to some small DC power?
Is it possible to generate a small DC power from Radio waves?If yes then how?
AI: Yes, it is possible. In fact, crystal radios work on this basis. With a reasonable antenna and a powerful enough AM station, they can drive a high impedance headphone to ... |
H: How to isolate a soil moisture sensor
When using a soil moisture sensor in a plant to measure water indoor, how can we avoid dangerous water and electrical interaction.
In general, when there's water in the plant
When watering the plant, and accidentally dropping water on the wire connection
This is the sensor of... |
H: How can I integrate microphone and speaker into my microcontroller project?
Having never worked with mic and speakers in the past, I am experimenting with these. I already made a simple circuit with a mic (electret condenser microphone) and speaker. I used the above mic with simple amplifier stage and then computer... |
H: Can I convert a toggle switch to momentary switch using a transistor and capacitor?
After searching online for an answer to how to convert a toggle switch to a momentary switch I found the circuit below. I've simulated it and it works in CircuitLab.
simulate this circuit – Schematic created using CircuitLab
I'd li... |
H: What's the importance of source impedance termination?
Given a circuit like this:
simulate this circuit – Schematic created using CircuitLab
What's the importance of R1? One can guess that it's to make the output impedance of BUF1 equal to the impedance of the transmission line, but why is this important? What hap... |
H: What is input and output impedance of an opamp?
I have never understood input and output impedances of an op-amp. If anyone can explain what these two terms mean in an op-amp I'd highly appreciate it. Thank you!
http://www.eecs.tufts.edu/~dsculley/tutorial/opamps/opamps5.html
AI: The short answer: input impedance i... |
H: What is the reason for adding a buffer stage?
I was following this microphone and speaker circuit and I could follow mostly but got confused when the author introduces a DAC buffer.
http://www.instructables.com/id/Arduino-Audio-Output/?ALLSTEPS
This isn't the first place I have seen engineers putting a buffer stag... |
H: Meaning of negative voltage
When solving for circuit consists of ideal voltages and conventional resistors I get that one of the resistor's voltage is negative- does it mean the resistor delivers power, or the polarity of the resistor need to be changed?
AI: Voltage is measured relative to something.
Say you measu... |
H: How can current-limiting supplies be possible?
Knowing Ohm's law, the current drawn is directly proportional to the resistance. In some power supplies, you can limit the current. Let's say the voltage is 12 volts, it supplies 1 amp, and the resistance is 8 ohms. The current going through should be 1.5 amps, but the... |
H: What is a maintenance free battery?
I have searched on Google but can't find anything. Could anyone please tell me what a maintenance free battery is? Perhaps some examples of maintenance free batteries and any good sites for further research could be provided.
AI: The term "Maintenance Free Battery" is typically a... |
H: how to make frequency divider?
Can anybody show me how to make divider by 3 frequency using flip flop and logic gate ?
Does anyone here have any good suggestions ?
AI: Start with a basic divide by 4 circuit.
when it gets to the 4th count (A = '1' AND B = '1') reset it and it starts again at zero |
H: What is the purpose of the thin wire at the top of power transmission lines?
I know a power transmission line carries usually two sets of 3 phase conductors. But I have noticed a relatively thin wire at the center-top of the power transmission line. What is the purpose of this thin wire?
AI: Wikipedia says they are... |
H: Programmable differential amplifier
I would like to measure signals up to 5Mhz, between different ranges -2,2 and -36,36, I could use a differential amplifier with level shifting like here.
What is the best way to change the gain of the amplifier? Is it a good idea to use a mux/switch controlled by the ucontroller... |
H: Altium: reuse schematic AND pcb layout
I want to build a circuit with many repeating pieces of schematic/pcb layout, and I want to reuse both schematic & pcb layout. Altium offers to reuse schematic, or reuse pcb separately - via snippets and circuit sheets.
But is it possible to reuse both? I.e. when I place anoth... |
H: Use of current division
"Calculate V (across the current source) and the current flowing down through R1."
simulate this circuit – Schematic created using CircuitLab
Does the voltage source also produce current, so that the current flowing to the parallel resistors is the sum of 40mA and the current produced by t... |
H: transmit data wirelessly under water?
I am looking into constructing a small submarine with a Raspberry Pi. This is just for a hobby project but my idea is to have it communicate with the surface wirelessly. I know that normal radio waves will not work very well so I was thinking of using some type of Ultrasound de... |
H: 16X2 character LCD changes contract intermittently and doesn't work with raspberry pi
I've been following adafruits RPi tutorials (and bought their starter kit)
I had an Sparkfun LCD Kit lying around. (It has an HD44780 controller LCD, a 10K trimpot and a 16 pin male header)
I soldered the header to the LCD, not al... |
H: a good way to detect disconnections on the PCB traces
I make home-made cheap PCBs (I use toner transfer, then acid etching method now, but I might use UV etching someday). I wonder what is the best (and cheap) way to control if there is no problem on connectivity of the traces?
I control the connections by a multi... |
H: How do I connect non-I2C devices to an I2C bus?
I'm quite new to electronics and just trying to do my first Raspberry Pi based system: one diode, one pressure sensor and LCD 1602 with keypad shield (the one for an Arduino board). The way I'd like to connect all the devices is using I2C (the Raspberry Pi doesn't hav... |
H: Any sequence asynchronous counter
While I can understand the logic behind synchronous counters that can implement 'any-sequence',I'm not sure how I would go about doing that with an asynchronous counter.
For example one that produces a 2->3->5->8->13->2->3->... sequence.
Any tips?
AI: Asynchronous means you don't h... |
H: PCB drilling - drill bit material selection
I am planning to buy a bench drill (something like that one) to make small hole, 0.5-1.0 mm.
I recently used a Bosh drill and 1mm steel drill bit to make a hole on a FP4 fiberglass board, but the drill bit broke on the second hole drilling process.
Now, I will buy 0.6 m... |
H: Two signals alternately on the left and right of a frequency
I was listening to the WebSDR of Twente University, just outside the amateur band, and saw these signals. The x axis is frequency in kilohertz, the y axis is time, where the whole axis shown is about 15s.
It occurred to me that the two signals are altern... |
H: Do the logic gate inputs of 74HCXX integrated circuits exhibit a high impedance?
Do the inputs of the 74HC374-SMD D-type flip flop have high impedance inputs? In datasheet is stated that it has buffered inputs, I assume that means high impedance, right?
In other words, do I have to put resistors in the input pins?
... |
H: LC filter sizing 50Hz AC to good DC (RMS to DC)
I'm using a LTC1966 for a RMS to DC converter. My capacitor is a 10 µF. When measuring with an oscilloscope, I have a small ripple which I want to remove.
My result from ADC to the program shows a ripple of ~8-9bits, and it is to much.
Input to the circuit is a 230V 5... |
H: Detect car +12V using Arduino
I am looking to detect 12+V from a car wire using an Arduino.
I have found the following schematic:
I know how crazy automotive voltage can get so I just want to make sure the schematic I found above will accommodate the crazy random currents that the car could produce.
Also, wouldn't... |
H: Sensing 12v inputs in 3.3v system
Sorry if this has been asked before, but I searched for a while and didn't find anything that exactly answered my question.
I would like to sense the "dummy lights"(oil, neutral, etc.) in my motorcycle with my mBed. The bike runs of a 12v battery and the mBed senses at 3.3v. Now I ... |
H: Current carrying conductor axially through a copper ring
What effect would a copper ring around a current carrying conductor have on the current in the conductor? How can I go about mathematically modelling the current in the conductor?
Details : The conductor in question is a electrode roughly 2 meters in diameter... |
H: PCB boards: Epoxy resin vs Epoxy glass
I see these PCB material types often: FR4 epoxy resin, FR4 epoxy glass. I see epoxy resin is cheaper than epoxy glass (at least the price that I see from couple suppliers).
I wonder if there is a major difference between epoxy resin and epoxy glass, e.g. the way they are etch... |
H: Clean 12v car power
I am looking to get a constant, clean 12V from my cars 12V line. I am wondering if all I am in need of to pull this off would be a simple 12V fixed regulator?
The 12V would be hooked up to a pico motherboard (19v max input), 7" LCD monitor and an Arduino.
I did find this schematic here:
So wou... |
H: N MOSFET Issue in Battery Charging Circuit
My project uses a USB connection to charge a LiPo battery. The LiPo has built-in circuit protection. Everything works fine when hooking the +5V line straight from the USB hub to the battery's positive terminal, and connecting the grounds.
I want to use an LED to indicate ... |
H: Noise problem with buck/boost switching regulator
I am designing a electrical device for a research project (I'm a PhD student, but unfortunately not EE!). More info on the device can be found at http://iridia.ulb.ac.be/supp/IridiaSupp2012-002/
The last prototype had a problem with the power supply, and thus I trie... |
H: Why is speech malformed when listening to a USB signal with an LSB receiver?
When you listen to an LSB (Lower Side Band) signal with your radio set to USB (Upper Side Band) or vice versa, the speech you hear is malformed. What causes this behaviour?
AI: The spectrum is reversed. Nice images at Wikipedia
LSB is sh... |
H: Selecting dsPIC33FJ programming pins
I'm getting ready to print up a board for a project using a dsPIC33FJ256GP710A. I've currently got it running on a EasyPic Fusion devboard.
I see that there are a bunch of pairs of PGED's and PGEC's available to choose from for layout convenience. I also see that there are c... |
H: Reasons of more than one ground pin in L293
Why in L390 they provide four pins for the ground and the heat sink? For heat sink,is only one pin is not sufficient? Here is the datasheet
http://www.ti.com/lit/ds/symlink/l293d.pdf
AI: Increasing the number of pins in such IC designs serves at least two purposes:
Great... |
H: Why ceramic IC packaging?
As someone with no background in electronics whatsoever, I wonder:
why are ICs packed inside ceramic or plastic? I thought we wanted the heat to go out as fast as possible, and ceramic is a good thermal insulator.
AI: In IC packages it certainly is desirable to dissipate heat with the low... |
H: understanding how a motor is controlled with an L293D and raspberry pi
See update, picture of robot below.
So today I hooked up a motor and made it spin with my raspberry pi and an L293D by reading this tutorial.
This is what the circuit looks like (larger pictures):
It work's and I'm pretty happy. My end goal is ... |
H: Why are microcontroller WiFi modules expensive compared to USB WiFi adapters?
I recently bought a WiFi adapter for my Raspberry Pi for about 8 USD. At the same time, WiFi modules for Arduino and similar microcontroller boards cost several times as much.
What is fundamentally different between a USB WiFi module and ... |
H: Bit error rate calculations for a photodiode receiver driven from a laser
I'm having problems understanding how the following specification for a photo-diode (with built-in amplifier) rationalizes the bit error rate: -
Circled in red are two important figures. One is NEP (noise equivalent power) and the other is m... |
H: Detecting button press over computer network
I would like to make a networked device (along the lines of hotel room service call) that has multiple input lines that may be uniquely identified on a computer on the network.
I found a product with similar functionality.
I assume the device will require a microcontro... |
H: Why do we need an isolation transformer to connect an oscilloscope?
My professor always insists that I provide power to an oscilloscope thorough an isolation transformer. What is the necessity of this? What is the risk if I don't connect it?
AI: You should never float a scope with an isolation transformer! This is ... |
H: Why is a railway's third line or overhead line DC and not AC?
As the title states, in the rail industry, why are the majority of railway's third line or overhead line in DC volts and not AC volts? My initial guess would be that it is in AC since it is easier to distribute AC over long distances. I do know there a... |
H: What is the point of the transistor to drive the relay coil
In the circuit the relay is controlled from a manual switch on a 12v bus. I can't understand why you would want to add the extra components of the transistor and diodes to the circuit? ie why are D4, R1, T1, D1 needed? Thinking about cost and component cou... |
H: How does an antenna radiate (how do currents flow through the wire)
I don't understand how antennas radiate a signal.
I understand the basics of antennas (wavelength, electron E field, etc.), but I simply don't understand how a current can go through a wire that doesn't have negative pole.
Can you please explain th... |
H: Run out of electrons
If electricity is a flow of electrons in a wire then eventually all electrons will leave the beginning of the wire and reach the end of the wire. Is that possible? Why if not? What will happen then if yes?
AI: A battery is a device which has a bunch of electrons on one side of it and a lack of ... |
H: Why are circuits drawn like this(see picture) and not closed?
And how do you analyze them if they have a voltage source in the middle of the circuit? What is the Vin supposed to mean if there is a battery source? Thank you in advance!
AI: It's a simplification and Vin and Vout are simply references. Basically they'... |
H: Which layer does UART belong to?
I am a little confused by UART protocol. Can we map it to any layer in OSI model?
Certainly, it's not physical layer because it doesn't talk about voltage levels. Is it datalink layer?
AI: Most interfaces that are integrated on microcontrollers only cover the
data link layer, with... |
H: Electrical Code issues with light switches and Arduinos
Are there any electrical code issues with placing an electronic circuit inside the light switch box of a house?
I am planning on adding a WIFI (8266) and relay control to a light switch.
Does anyone know if there are any code issues with placing electronic cir... |
H: Cyclone V external memory group pins DQ/DQS
I'm trying to understand the functions of external memory pins in Cyclone V (5csema5af31c6n)
I do understand that colums HMC Pin Assignment for DDR3/DDR2/LPDDR2 shows pin functions for external memory implementation (using hard memory controller). But for what DQS x8 an... |
H: Are chicken bits left in space-qualified ICs?
A chicken bit "is a bit on a chip that can be used by the designer to disable one of the features of the chip if it proves faulty or negatively impacts performance."
Would space-qualified logic components leave this feature in, or would the final design "best practice" ... |
H: Trouble reading analog input
I have connected a photo-resistors terminal to atmega320'S ADC0 (PC0) PIN, the other to 5V and the third to ground via resistor
I'm powering my atmega with 3.7v. My goal is to output the value of ADC0 on DC6 pin using PWM. I have the following code:
#define F_CPU 8000000UL
#include <a... |
H: Using a lower pot value for motor bidirectional controller
I'm looking to make a bidirectional motor controller. I would like to use the following diagram. What values should the resistors be in order to use pot(S) of smaller value than 100k and the circuit still work?
Can someone please explain the formula when u... |
H: How is NTSC analog video written to a Video8 tape, or analog tape in general for that matter?
I am trying to recover some videos on a Video8 tape and was wondering how in general how analog video was written to tapes. I've been researching the NTSC specification and it seems like there are these vertical and horizo... |
H: Why aren't smartphone batteries parallel?
So I'm thinking, imagine a phone with a 3000mah battery. Then if we divide that battery in two, we get the same capacity but those batteries can now be charged twice as fast. What's the mistake with this thinking?
AI: It depends where you think the limitation of the chargin... |
H: 12v low power, high brightness solution - urgent
I need to quickly come up with a way of lighting a trade show booth from a 12v marine battery for 8 hours. My original idea to light the booth was to use a power inverter hooked up to an 80Ah battery and use 120v AC LED bulbs totaling ~45w.
The math on paper looked g... |
H: Calculate 12v Battery Runtime When Using Only 3.6v
What is the best way to calculate the runtime of a 12v battery if I am using 12 - 1 watt LEDs using 320mA @ 3.6v? Can someone post the formula?
AI: Ok, we have:
12 LEDS with Vf=3.6V and Iftot=320mA when in parallel (If=24mA per LED).
12V battery with let's say 100... |
H: What is the magnetic field due to an electromagnet at a point that is not along its axis?
For e.g. at a point below(or perpendicular) to a cuboidal/cylindrical core electromagnet?
I am confused whether the magnetic field for an iron-core electromagnet is limited to the axis passing through it because if that is the... |
H: What is the difference between DCM and PLL in e.g. Xilinx FPGA?
Some FPGAs have both DCM (Digital Clock Manager) and PLL (Phase Lock Loop) for use in internal clock generation.
Xilinx Spartan-6 FPGA Clocking Resources UG382 (v1.10) documentation describes a number of features for DCM:
Eliminate clock skew
Phase sh... |
H: Difference between wire wound and ceramic chip inductors
I have two boxes of SMD r.f. inductors. One lot are wire wound, and the others are ceramic chip. What is the difference in construction? From peering at them with a microscope I see that the wire wound ones are, umm, wound with wire. But how are the ceramic c... |
H: Why does the current intensity decrease when I connect two voltage sources in series?
I actually connected lemons with batteries and I found that the voltage of lemon and the battery (i.e. the bottom left circuit) is 3.8V while the current intensity in the top left circuit is 0.1mA!
The question is why the current ... |
H: Charge on plates of two capacitors in series are not equal
I have a simple circuit below with two capacitors are initially charged to Vo1 and Vo2 respectively. The two capacitors are in series however the charge on plates are not equal.
Could anyone tell me what is wrong here?
PS:
It seems that no one understands m... |
H: FIltering ADC input
I would like to filter signal on ADC input. My question is if I can add before input ordinary RC filter. I suppose that this is not good idea. I have to limit number of operational amplifiers on the board so it can't be isolated by buffer amplifier.
If resistance is too big the internal (S&H) ca... |
H: Can I safely toggle the CS pin without sending any data?
Update: I've tried the solution I proposed in comments in practice (utilizing E pin on the 138 IC during changing target device) and it did indeed work. Read the whole thing if you want more details.
simulate this circuit – Schematic created using CircuitLa... |
H: Low amps high volts vs high amps low volts?
What is the difference between the two?
Why would you use say, 5 volts and 2 amps, over higher voltage and lower amps?
AI: Going off of your post content rather than the title, I think you are asking why use higher voltage and lower current vs lower voltage and higher cur... |
H: Does AC OR DC flow?
I'm reading about transducers and have a related question.
Is the audio signal flowing through the voice coil of a loud speaker AC or DC?
AI: WE try to never put DC through a speaker coil. The design intent is for only AC to flow through a speaker and never DC. See: Why are DC signals bad for l... |
H: Two resistors in series
I know the summation equation for two or more resistors in parallel or series, and I know two parallel resistors will give more power.
But sometimes I saw some circuits that used two resistors in series, and I am wondering why that method was used and why they didn't use one resistor with a ... |
H: Period for this astable multivibrator (nor gates with limiting diodes)
I was able to find the period without the diodes which was T=2RCln(3)
But I am unable to find the expression when we connect the two diodes. (Our course says it is :
T= RCln( (VDD+Vd) /vt).
I am unable to find out how we obtained this expressi... |
H: How to solve current source prb W/O using Nodal Analysis?
I have the full solution to this problem, but it is using nodal analysis.
I am not a fan of Nodal Analysis. Is there a different approach to this problem?
AI: Yes there is an alternative to this problem. First, note that you have three resistors in paralle... |
H: LTspice unlogical DC offset
I have a Problem with an LTspice simulation. Specifically, I am designing an 12V bridge amplifier. The Problem in my simulation is that there is an DC offset which partially defies logic as far as I can tell. I attached a screenshot of the schematic for reference. Please Note that this i... |
H: Reflow soldering issues
I've been using a halogen oven with a home made controller as a simple reflow oven. The controller uses a thermocouple to measure and control the temperature profile.
The problem I have is that I'm getting inconsistent results depending on the component. As a test I made a simple board with ... |
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