text stringlengths 83 79.5k |
|---|
H: Can I parallel multiple resettable fuses to achieve a higher current rating?
I have an application wherein I spec'd a fuse, rated for 80VDC 500A. The customer is concerned about what happens if they have to replace the fuse, it being rather difficult to access. They suggested resettable fuses as an option.
I'm not ... |
H: 555 timer accident
I accidently applied around 5V to the output pin of the 555 timer.The output is zero when I ground the trigger, and an LED connected between 5V and pin 7 will not respond when 5V is applied to the threshold. Pin 8 is also connected to 5V. Is it damaged? Could it be something else?
AI: Sounds dead... |
H: Inductor for Switched regulator
I'm implementing a Step-Down Switching Voltage Regulator with Vin = 12V, Vout = 5 V 300mA and I followed the application which is in the page 13.
I have no doubts in choosing all the components around the regulator but how do I choose the right inductor for this application?
I have s... |
H: FSK combined with either ASK or PSK?
Why is it that we are able to combine Amplitude and Phase modulation (Resulting in QAM) but are not able to do so with frequency? Why not combine all three degrees of freedom (Amplitude, Frequency, Phase) for modulation?
AI: Quadrature amplitude modulation could be viewed as a c... |
H: What is the current source for in the Schmitt trigger?
What is the current source for in the schmitt trigger? I can't understand this. Can't see any resistor either.
AI: This appears to be a misuse of the symbol for a current source. Obviously, it should be a voltage source (which sets the comparison threshold), b... |
H: Recommended Mosfets for switching purposes
I'm looking for common MOSFETs to do some experimenting with. They should be able to switch at least 3A at 15V, have a low on resistance for power efficiency and also be quite cheap.
I require all four types, that is P & N channel, both depletion and enhancement mode.
So f... |
H: IC pins too small for my breadboard
I recently bought some IC's with 8 and 16 pins.
I was used to work with bigger ones, so now I cant test them in the breadboard without soldering an individual wire to each pin (which would probably destroy the IC).
I thought about sockets, but it doesn't make the distance betwe... |
H: Power switchers copper fill / region
When is it considered that too much is too much when it comes to copper fills on DC-DC switchers. I am currently laying out a Buck, 3 Amp max output. Every literature that I have scanned before advises me to pour and fill solid regions on the input node, the switch node(where th... |
H: Understanding PCB layer stack-up shorthand notation [2:(1(2+345*67)*16):7]
I was given a PCB layer stackup specification like this:
[2:(1(2+345*67)*16):7]
For an 8 layer blind via setup.
Could someone provide a reference to decode this shorthand notation?
What is the proper name of this shorthand notation?
How wid... |
H: Have some queries about Fourier Transform?
I am fond of Fourier Transform. I have some queries about Fourier Transform
In most of the cases,the Fourier transform of a signal is symmetric about positive and negative axis.I think the computational complexity increases because only half part of symmetric spectrum (i... |
H: Saving the state of the LED on illuminated momentary button
I have three illuminated momentary buttons with a separate anode and cathode for the led.
(source of image)
I want a circuit that illuminates the LED of the button that was most recently pushed.
My initial idea has been to use three SR Latches created... |
H: Can a power MOSFET for switching application be used as a linear amplifier?
Power MOSFETs nowadays are ubiquitous and fairly cheap also at retail. In most datasheet I saw power MOSFETs are rated for switching, without mentioning any kind of linear applications.
I'd like to know whether these kinds of MOSFETs can b... |
H: Saturation when using differential amplifier with op amp
I built an amplifier following this schematic:
And the gain is approximately 1000. When I use 10mV sine wave from a function generator, it works perfectly (it also work with other signals: triangle, pulse, square etc). However, when I get the input from elec... |
H: How does the RC time constant affect behavior of a passive integrator/differentiator?
I'm reading the first chapter of the AoE. I've come across this section on differentiator/integrator circuits and couldn't understand the math behind it.
For the first picture, it says small RC means dV/dt being much lower than ... |
H: Calculating charging current
I have following situation:
Solarpanel with 20 W, 2 12V lead-acid batteries, the solar panel is charing the batteries. I measure the current coming from the panel with a ACS712 in a 3 minute interval.
The output then looks as following:
Amp;Date
1.08699;"2015-05-07 12:42:33"
1.09222;"20... |
H: Estimate minimum discharge voltage in a laptop battery
The objective is to determine the best 18650 cells to replace the ones in my laptop battery.
To do that, I need to know the minimum voltage the battery controller accepts before ordering the OS to shutdown the laptop. So, I have discharged my battery until the ... |
H: is it possible to mix chipsets
I'm designing a home made game console motherboard, and want to integrate the ATI Mobility Radeon 9000 GPU in it. The problem is, the Northbridge I picked only supports PCI Express, and the GPU uses AGP x4. So I found a second Northbridge chip designed for AGP, but as far as I know, i... |
H: Add exposed copper to eagle board?
I am new to using eagle. I want to put some exposed copper pads that I can solder to on my board. The catch is that they cannot have through holes. I tried just making polygons in the top layer, but I am unsure if I will be able to solder to that. Any advice?
AI: You'll want to ma... |
H: Measuring the dampening sinusoidal wave of a simple LC Tank circuit?
I've been trying to do the simplest of things...measure the decaying sinusoidal wave of a LC Tank circuit on a breadboard.
I've created an "inductor" out of a coil of copper wire I wrapped around a pen. I have a 1uF capacitor connected in paralle... |
H: Switching bjt transistor with photodiode
Initially I thought this would be a pretty simple problem, but I'm just getting started learning electronics so I would love some assistance.
This is my circuit:
I calculated the values based off this calculator: http://www.daycounter.com/Calculators/Transistor-Switch-Satur... |
H: Is it possible to decrease the speed of a standard servo motor?
I have TowerPro SG-5010 and its speed is 0.17 sec/60° at 4.8V and 0.14 sec/60° at 6V.
Just to be sure, is it possible to further decrease the rotation speed?
AI: Yes, the given speed would be "maximum" speed.
To decrease the speed of a regular motor yo... |
H: Calculating different rated power from the rated parameters for a delta AC motor
A delta connected motor in the following link:
http://www.vanbodegraven.nl/en/products/ac-motors/asea-mbg-200-m-60-6/
has rated current 47A, voltage 380V
Here is the rated values. Cos(fi) = 0.8 on the label.
So the power I calculate is... |
H: PORTB and PINB in avr studio while programming for Atmega8?
what is the difference between PORTB and PINB in avr studio while programming for Atmega8 using " Atmel Studio.6 " software ??
AI: There is a massive amount of difference. Those differences are most noticeable when the pin is in input mode (DDRxn = 0).
Wh... |
H: Why does I²C only have pull-up resistors (interview question)?
The interviewer wanted to know why pull-up resistors are used on SDA and SCL when the opposite logic can also be implemented. Is there an explanation for why pull-up resistor usage is the chosen design?
AI: To expand on Jon's answer a little:
Yes, it is... |
H: what to do with JTAG pins when idle?
So I have this design here where I talk via JTAG from a microprocessor to a CPLD.
The JTAG protocol is done via bit-banging of four GPIO pins.
This connection is just very infrequently. It's just for the initial programming of the CPLD and may be used if a bitstream update is n... |
H: VHDL - Can't see why these two architectures produce a different RTL
I have the following examples:
architecture two of andex is
begin
process(abus)
variable y: bit :='1';
begin
for i in 7 downto 0 loop
y:=abus(i) and y;
end loop;
x<=y;
end process;
end;
architecture three of andex is
begin
pro... |
H: Periodic Steady State voltage Buck Converter
What does Periodic Steady state mean with regard to a Buck Converter ? Does it mean the normal operation ?
Also, From what I read, the net change in the capacitor voltage in the buck converter is 0. Why is it so ? Is it because it becomes constant ?
AI: Periodic steady... |
H: Where i can select and buy ferrite toroid core for SMPS?
I made push-pull smps working on 50 khz. It has up to 90-120w power (input voltage 12v and output 24v). For transformer i am using two ferrite toroids on top of each other, it's a old USSR toroids with initial permeability 2000
(there is a link, for more inf... |
H: Measuring change in inductance
I have a coil whose inductance will be changing continuously. I would like build a circuit to monitor the change in inductance continuously. Can I just use a RCL circuit and give it a sine wave of f Hz, and measure the voltage across the coil?
AI: It might be easier to build the induc... |
H: Impedance matching for a guitar pedal
So it's me working on a pedal again. I would like to add some equalizer effects on the pedal and found a fascinating circuit "Smash Drive":
As far as I know, maximum power with lowest effect is attained with high impedance input and low impedance output. However, I see in the ... |
H: Low Output from MIC5205 LDO Reg
I have a PCB that's designed to output 3.3V from a 5V source. The 5V source I'm currently using sources several amps (3A), though I only need about 100mA. I based the schematic on "Ultra-Low-Noise Fixed Voltage Application" circuit in the datasheet for MIC2505. For some reason when I... |
H: Why does the Tx pin of an USB to TTL adapter provide current?
I'm currently making a little electronic board on my own. On it, a microcontroller: an ATmega328p running with 5V. To communicate with a computer, I've planned to use an XBee, but for now I'm using simply an adapter TTL <-> USB based on an FTDI FT232RL c... |
H: AC-DC Adapter - Output lower than rating and what's this 'cont' output for?
I have a Canon AC adapter, Model K30321, that I'd like to use in a project. I'm attempting to test the adapter for correct voltage output.
Adapter specs:
Input Voltage: 100 - 240VAC ~ 50/60Hz 60VA 0.65A
Output: 24V === 1A
Connector: 3 pin r... |
H: Operating system on an ARM9 MCU
I have an ARM926EJ MCU (datasheet) that I am learning how to program for a research project. I have been researching, as well as reading a textbook on Professional Embedded ARM Development in order to learn how to program, and I have learned much about bare metal programming for my ... |
H: Solar battery charger with load sharing
I'm looking to design a circuit around the CN3065 that will be solar powered with a li-ion backup battery. I've seen circuits that can achieve this by using a charge controller with a dedicated load output, but CN3065 doesn't have one (and unfortunately I'm restricted to this... |
H: Sonar single transducer element SNR vs array SNR
Background:
I'm taking a flexible learning unit on radar and sonar systems in a vocational college for an assoc. degree level course. The teacher has given us a reading assignment: "Chapter 15 Underwater Acoustics", source unknown, and we are to answer the end-of-ch... |
H: How to measure input/output impedance of amplifiers in a simulation?
What is the most effective way of measuring the input/output impedance of an amplifier in a simulation?
When I know the impedance I want to measure is purely resistive, I usually set up an input signal Vin and a test resistor as a resistive divide... |
H: How does an AM radio filter out only the desired frequency?
I understand that electromagnetic waves in the air induce an alternating current in the antenna. I also understand how, once you filter the signal to obtain the desired frequency, you can get the envelope of the signal and drive a speaker.
What I don't un... |
H: Why do fiber-optic interfaces have much higher bandwidth than optocouplers?
I've noticed that optocouplers typically have a bandwidth in the kHz range (i.e 200 kHz). Fiber-optic interfaces can reach speeds of 100 gigabits / sec. What's so different about these two technologies that gives fiber-optics such a high ba... |
H: What use is a pull-up/pull-down with a push-pull output?
For at least some STM32F4 MCUs, push-pull + pull-up/pull-down is a valid GPIO configuration, but what would you ever use it for, and why? I assume there's some saner reason than "I just really felt I needed that juicy extra 100µA of wasted current per pin"...... |
H: How does a diode valve work based on this sentence?
In a diode valve, the anode would not emit electrons when heated so when the polarity of the voltage across the tube was reversed, no current flowed. Notice how the solid state transistor works in a similar way.
Why does the anode not emit electrons?
Why does ... |
H: How do you solve Thevenin equivalent for circuits with variable resistors?
I have this circuit and I have to solve the Thevenin equivalent across the terminals A and B. How do I solve for RTh in terms of the variables present in the circuit?
AI: The problem is not to have one (or two) variable resistors, because yo... |
H: Which way are heat sinks supposed to be mounted?
Which way are heat sinks supposed to be mounted? With the fins around the component, or facing outside?
AI: For a non-forced-air cooling regime, the fins are best positioned so that they are vertical. The air can then naturally rise and these convection currents flow... |
H: How can I relay 120VAC with a raspberry pi?
I have five 75W 120V AC LED lamps on a dimmer switch. They draw 13 watts each (375W total). I also have a 600W Lutron dimmer switch hooked up but the thing buzzes when the lights are dimmed. I also tried a Leviton dimmer with the same results. I've heard about debuzzing c... |
H: LED organ input problem
I'd made this LED organ (schematic below and here):
And one of the filters are not working. On the opamp's inverting input, there's a small sin signal, and I don't know where it comes from.
I measured these with my scope on the filter. This is the (audio) input signal from the function gen... |
H: Understanding this LPF in opamp feedback loop
I'm using a basic opamp driven mosfet to implement a precision low current sink for an LED:
This seems to work just fine within the range that I want it (10mA or so). I've seen other circuits that put an lpf in the feedback loop (R3 was 1K in the one I saw):
I'm tryin... |
H: LED can't stop blinking (AVR-C)
So here is the basis of my code, I have an array of different instructions for the prescribed LEDs to follow.
The led will blink for the prescribed number of times in an interrupt before they stop and increment the array value, which will lead to the second set of instructions in th... |
H: Are op-amps always assumed to be ideal?
Given a circuit with resistors, op-amps, independent voltage and current sources, how do I solve the node voltages? Do I always assume that op-amps are ideal?
AI: No, depending on what you are trying to do you might have to use a more complex op-amp model with finite gain, in... |
H: Perpendicular tracks in 2 different layers (PCB)
Many times ago I heard it's not good to have 2 perpendicular track in 2 different layers of 2 layers PCBs(I mean one track in one side become perpendicular to another track in other side of the pcb) . I can't remember what was the type of tracks (digital signals or v... |
H: DALI: Handling multiple responses from DALI system
I designed my own DALI devices and now trying to build-up a DALI system. Since my DALI gears are based on MSP430G2553, I took advantage of code being already done for TI's DALI demonstration board.
Source code
Application note
Right now I'm working only with one DA... |
H: How to drive 3 1/2 digit static TN LCD with ATmega328 in low power mode?
I've built this clock with a 3 1/2 digit static TN LCD (GYTN-0587). I drive the 28 LCD segments with an ATmega328 and four 74HC595N shift registers chained together.
Here are the (simplified) schematics (link to larger image):
And here's a pi... |
H: How does this timed fan controller work?
My bathroom fan controller recently started misbehaving, so I pulled its PCB out. This is what I found.
simulate this circuit – Schematic created using CircuitLab
LIVE/NETURAL are the 230 AC mains. I think I have a fairly good grip on what's happening here: the upper part o... |
H: My For loop isn't exiting and I don't know why
I'm programming an ATMEGA328p on a breadboard and using an arduino board to do the USB to Serial conversion. Part of some code I'm writing involves a for loop that is being used to take the 8 bit output from the SPI MOSI line (connected to an SD card) and stick it int... |
H: Multimeter battery test
I have a multimeter with a battery test setting in addition to voltage measurement. This is marked 1.5-6V 50 ohm. I have some questions:
is the only difference between the voltage and battery tester increased decreased resistance?
why is the top voltage rating only 6V? should larger batteri... |
H: Transistor help
I've read some info on transistor about how it works. So let's say I savaged a receiver from a remote control car which generates 1.2v output from the receiver when signal is transmitted from the controller, would my circuit works? Still a beginner in electronics, forgive me for my bad circuit drawi... |
H: Output clock of the LPC1768?
I am using NXP's LPC1768 development board and I came across the User Manual for this part and page 67/849 section 4.10 descusses the External Clock Output. I couldn't figure out which pin out of the 40 pinouts on the board is this clock out sitting on. By Googling around, I found this ... |
H: Fuse rating and safety
Under what conditions would a faster, higher rupture capacity, higher voltage-rated fuse be less safe than the equivalently current-rated fuse which was slower, lower rupture capacity or lower voltage-rated? My intuition is that a faster fuse is not always good because it may trigger too easi... |
H: Why does my mainboard power the cathode to turn the Power-LED off?
Close to all desktop motherboards have a pin header that is supposed to power an LED on the front of an enclosure with to indicate that the computer is on.
In the documentation for my board, these pins are described as "Power LED Signal anode (+)" a... |
H: Average alternating power
"For each of the values calculate P and Q" (average)
V = 250 \$\cos (\omega t +45)\$
I = 4 \$\cos (\omega t -30)\$
The way I would try solving this would be by converting to phasors, taking the product and multiplying by a half. I will then be left with a phasor with phase shift of \$15\$ ... |
H: How to Find value of Early voltage of output characteristic curve of BJT?
I have this graph from data that I have. This is the output characteristic curve of BJT.
I want to find the value of early voltage VA?
AI: Early voltage: -
It should be fairly easy to plot back the curves and see if they intercept as Mr. Ear... |
H: Does DC DC switching converter needs pot readjusting on input voltage change?
I have adjusted my LM2596 regulator to 5V output with 16V input. I'm about to change the input to 25V. Will my 5v output stay the same or do I need to adjust the pot again ?
I can't easily test myself because my circuit would need unsolde... |
H: Binary calculation (11 +01010101 )
Kindly help me with this Binary calculation
Add the following 2's complement numbers
11 +01010101 = ?
How i solve it :
0000 0011 + 01010101 = 01011000 but the book say its 84???
Please help!
AI: The two values have differing bit widths which you aren't taking into account.
... |
H: How to request “GET” from an ASP.NET website using ESP8266?
AT+CIPSTART="TCP","zgrdataserver.com.azhar.arvixe.com",80
OK, works.
AT+CIPSEND=92
The response is ">". Works fine, but
GET /androidserver.aspx?param=esp8266 Http/1.1\r\nHost: zgrdataserver.com.azhar.arvixe.com\r\n\r\n
This code, no matter what, always ... |
H: How do residential analog and smart meters measure power?
I'm building my own digital meter in order to upload the data to a SQL database; up until now I know that there are several parameters being measured into a digital watt-meter:
volts, current, apparent power, instantaneous power, actual power, power factor
... |
H: Is it OK to use switching regulators to charge mobile phones (and such)?
I had several issues with car usb adapters (dc-dc step-down regulators), and I'd like to make one myself.
Issues:
Nokia cell phone refusing to charge
Motorola phone power supply circuitry fried
Insufficient current
The first thing I'd like ... |
H: can i use a 20V, 2.0A for my laptop that needs 19V, 4.74 A?
i have a laptop that needs 19V and 4.74A
my laptop's charger broke and i replaced it with a 20V and 2.0 A
the laptop seems fine but i noticed that the charging goes on and off for like an interval or 1-2 minutes if i use it heavily. but if i just place it ... |
H: How is speed torque curve of an induction motor plotted experimentally?
I'm wondering how is obtained a 3-phase induction motor's speed-torque curve obtained. I couldnt find any procedure.
Are they first applying fixed voltages with fixed freq. to stators. and then gradually increasing the torque or they speed up t... |
H: Two power sources connected with one device, from where will get its power
Hello and thanks for your time reading my post.
I've my router connected with its adapter and a battery for backup.
Details:
The adapter output 15V and 0.4A
The battery output 12V and 12A
The router needs: 9V and 0.6A (I've a regulater to mi... |
H: what happens to SPI clock in loop-back
I want to use SPI module in loop-back mode. so I wire MOSI to MISO.
but how about the clock??. is it wired somewhere?? and how the clock works loop-back mode
AI: Usually you don't have to wire the clock as the sending device, which transmits also the clock, always samples the... |
H: Xilinx bitgen warning
I am getting a warning in bitgen like:
This design is using one or more 9k block RAMs(RAMB8BWER). 9k block RAM data, both user defined and default requires a special bit format.
Is it a critical warning or can I proceed with dumping the bitfile onto the FPGA?
AI: The warning you are seeing ... |
H: Flash memory read and write
I'm always disabling interrupts while writing to some sectors on Flash, but does Flash memory requires disabled interrupts even when you just want to read from it? Why yes and why not? Thanks for the answer
AI: No, you don't need to disable interrupts to read from Flash. Reading Flash is... |
H: Why does an induction motor not have the maximum torque when it is locked?
In theory the maximum current induced at rotor must be when the rotor is locked hence the force is B.I.L it must produce the max torque.
But why torque is not maximum when it is locked but it is maximum at a point called breakdown torque?
A... |
H: Rotor current paths and lamination in an induction motor
As far as I understood, the rotor currents circulate through the aluminium bars embedded inside steel laminations. But why do they use steel for laminations instead of an insulator if the the idea is to loop the current only through the bars?
AI: Steel/Iron/F... |
H: Can rated stator voltage frequency be exceeded safely in an induction motor?
The following induction motor at the link has rated 50Hz stator freq. on namespace label:
http://www.vanbodegraven.nl/en/products/ac-motors/asea-mbg-200-m-60-6/
It seems it is 6 pole since it has 970 rated rpm and therefore sync. freq. is ... |
H: variable or field ' ...' declared void
I'm working on an ADC ATSAM3x8e arduino due board. I'm trying to write new .h and .cpp files.
How do I create a datatype like same as instance name of the processor?
Example: In ADC of the processor the datatype name like as ADC* p_Adc, In EMAC the datatype like as Emac* p_em... |
H: Calculating rechargeable battery charging rate curve
I am trying to understand the rate of charge of a rechargeable battery - let's say, a Li-ion one. What I'm interested in, is to understand whether the charge (the "percentage" of the Ampere-hours the battery can hold) in the battery is accumulated homogeneously o... |
H: Poor clock output from Spartan6 FPGA
I am using the LX9 Microboard from AVNET with the Spartan 6 PFPGA. I implement SPI to read from an ADC (ADS7822). I was getting wrong sampled values. When I ched the signals with an oscilloscope, it was not as I expected.
FPGA Clock (system): 100 MHz
Divider: 32
SPI Clock (outpu... |
H: What does it mean for reactive power to be delivered / consumed?
Real power makes sense since there is actual consumption, but regarding reactive power; what is consumed / delivered? And how does the circuit change once this happens?
AI: To answer the question: Real power is consumed by a circuit. Reactive power i... |
H: Switching a resistor by software
I want to communicate with a microcontroller over a CAN bus which needs (ideally) 120 ohm terminal resistors at the end of each bus. I want to integrate this resistor into the circuit and activate it only if it is needed (depending on which software is being flashed on the controlle... |
H: How can I power a cellular phone for a week with a car battery or other type of battery?
I am about to start construction of a new house, and unfortunately the property is not near where I live. I wanted to keep an eye on the construction site (No electricity) to make sure workers are showing up. To do so I want t... |
H: Does the STOP condition have any meaning on a single master I2C system?
I'm currently working on rewriting some of the code on my I2C driver, and I'm trying to figure out the exact purpose of the STOP condition.
I believe that on a multi-master system, once a START condition has happened, the other masters can't/sh... |
H: How to find the direction of current of the circuit?
Okay this is the circuit
The magnet given is moved up and down continuously at a high rate through the coil and generates a peak voltage of 4V.
I eagerly use the right hand rule in order to find the direction of the current . But what I have found is very-much ... |
H: TLV1117 Regulator Thermal Issue
I'm using this Regulator namely TLV1117-50IDCYR for a project that I'm working on. Aparently everything is working fine with this chip but sometimes I feel it's heating too much and I'm not putting all the load there.
I'm making a regulation from 12V to 5V for a 300mA output current ... |
H: PIC18 GPIO switch from input to output(dual mode)
I have always wondered if it is possible to switch the port direction of the PIC GPIO during the course of the program execution. So, for instance I start with a particular port set as an input(digital level). I monitor that pin, and if the level changes, I change t... |
H: Changing potentiometer from a gaming steering wheel
I have Logitech's vibration feedback wheel which has a rotation of 270 degrees. I am considering changing its potentiometer so it can rotate more (900 degrees or 1000 degrees maybe).
What potentiometer should I choose for this task? Apart from its Ohm resistance ... |
H: Detect NeoPixel status
I am powering a 1m strip of these with a Spark Core (which is like a small web-enabled Arduino if you're not familiar with it). Right now everything is working swimmingly on my workbench, but I'm looking forward to when it is in the field, and I want to know if there's any way for the control... |
H: Difference between dichroic, LED and halogenated lamps
I think that this isn't the best place to ask this, but I couldn't find my answer to this and I couldn't find any other stack exchange site related to this.
I wanted to know the differences between dichroic lamps, LED lamps and halogenated lamps. I don't want t... |
H: What determines BLDC rotation direction when using trapezoidal commutation with BiPolar Switching?
Block commutation seems simple enough, the rotation is determined by the order in which the 6 step sequence is executed (ex. cw 1->6 or ccw 6->1)
What's confusing is how bipolar switching changes this. If you drive th... |
H: Self Contained Temperature Display in Very High Temp Environment
I want to build a temperature sensor + display that will operate in a high temperature environment (routinely 120C, but periodically spiking to 175C, and might be exposed to 350C where it would be required to survive for very long--ie it could fail af... |
H: Physical significance of singular matrix in two port network
In class we've been introduced to two port networks, and I was wondering: Is there a physical significance to a singular matrix in a two port network, or is it simply where the mathematical model breaks down?
AI: It doesn't mean that the model breaks down... |
H: SMD package sizes in Altium
I'm a little confused about the standard SMD package sizes. Say I have picked some capacitors, and their package is 1005 (0402). Would this have the exact same footprint as a resistor or inducor with the same listed package size? I ask because I'm using Altium, and the generic PCB footpr... |
H: 1N4148 Diode for 3V-5V PWM
I have 2 PWM ports, one generates 5V PWM and another at 3V. But only 1 will be generating at a time. However, their output is going to a same wire or pin. So, to avoid the current to pass into each other, I want to put diodes on each port as protection. For this, I would need fast switchi... |
H: How to select power (between USB and battery)?
I'm hoping to power my device with a 3.7V (2x 18650) rechargeable battery which can be recharged within the device using USB (like in a phone, laptop, etc.). I believe some kind of power selector is needed if the device is to be operational during charging. Is there a ... |
H: Solar panel strings: when does current flow via bypass diodes where each panel has a different maximum power point?
When having strings of 5 till 6 a-Si/µ-Si thin film PV panels and each panel its junction box is containing a BY255 by-pass diode, to make sure that current will flow in less optimal situations, like ... |
H: A doubt on potential difference
This is a schematic diagram of the circuit.
Is it possible to take the voltage difference between AB as E? I have learned that the potential difference in parallel circuits are the same, Therefore I did assume the potential difference across AB as E. But I want to know whether ... |
H: Is it possible to transfrom a transfer function into voltage?
So I have a control system which I'd like to control externally. I have the error signal from the system and I use an ADC to convert the signal to number. I have the transfer function of the system (calculated with CHR method). I want to use a PI (Propor... |
H: Voltage drop through a resistor using Ohm's Law?
I'm having a very hard time comprehending basic Ohm's Law.
I was recently watching a video on the operation and use of Operational Amplifiers, and was completely lost because I couldn't understand what the resistors in the circuit were actually doing.
For example, ... |
H: How come product makers tend to make their own boards rather than putting together modules?
It seems that most, if not all, companies that produce mass market goods use custom boards rather than putting together modules that are already available in the general market.
For instance, battery chargers use custom circ... |
H: ADC calibration in ATTiny88
I'm writing an embedded app for ATtiny88 - one of its task is to measure voltages of serial connected two 12 V car batteries.
The microcontroller is powered from around 4.5-5 V (LM317), measured voltages (~24 V and ~12 V) are connected to two ADC channels via proper voltage dividers. In... |
H: Detect change on D- D+ lines
How can i detect change on D- and D+ (puling one or both of them high) USB lines from Linux environment?
AI: After attaching 1k5 pull-up resistor from 3.3V to D+/D- unknown/unrecognized USB high/low speed device would show up. You can check for this device with e.g. lsusb.
Much riskier... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.