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H: Unknown Ψ variable in JFET's drain current equation
This question considers unipolar transistor, that is JFET.
I really didn't find any other formula than this one which applies only for linear/ohmic/triode region of JFET U/I characteristic.
What is the variables marked as "Ψ" (psi) in the next equation (underlined... |
H: Risk of driving solenoid with a higher voltage pwm signal
We have a solenoid which is rated to be controlled by PWM signal "Maximum 325 mA at 7.5 Vdc". The problem we have our controller sends in 12 V output voltage. There is a thought that we could still drive it using the the 12V PWM output. Is there any risk esp... |
H: Using MQ-4 Sensor without heating
Is there any way to correctly measure increase of methane in the air using MQ-4 without heating (Not linking heater legs to GND and V). It is needed to save power. MQ-4 is methane sensor, datasheet: https://www.sparkfun.com/datasheets/Sensors/Biometric/MQ-4.pdf
AI: No. A flammable ... |
H: Formatting DDS Sine Wave output to unsigned decimal
Currently, I am working with the DDS core on Vivado, using Verilog, to generate a sign wave using a phase width of 7 and output width of 12. I understand that DDS formats the output in 2's complement / signed decimal. However, I am required to output only unsigned... |
H: How can I drive 88 solenoids with an Arduino with PWM?
For a (crazy) upcoming school project I am converting a piano to be a computer-controlled player piano. I am currently planning on using solenoids mounted under the end of the keys (action side obviously, like Yamaha's DiskClavier system as well as the PianoDis... |
H: Can I Run An Appliance From a 24v Battery?
First, a little backstory. My wife is planning to operate a booth at some craft fairs and we require power for a piece of equipment (Silhouette Cameo, a computer controlled vinyl cutting machine). We've done this once before with success at a show that had power provided. ... |
H: Non invasive Method to measure if there is any current in a line
We have a project where we have to measure if there is any current through the a cable, but having not common ground and knowing that the current could come direct or reverse direction. We thought about the chance of set a differential opamp, but if ... |
H: LDR working differently than usual
I observed something different in LDR (Light Dependent Resistor) today. I made a "magic" LED circuit such that when lights are off, the LED glows, else when the lights are on, LDR creates resistance and the LED stops glowing.
Later when I connected just the LDR and LED (in series)... |
H: Producing K map using two numbers
I have found this problem in my textbook.
The system has 3 inputs. The first two, A and B,
represent a number in the range 0 to 2 (3 is not used).
The third input, C represents a second number in the
range 0 to 1. The output, f, is to be 1 if and only if the
two numbers equal to ea... |
H: Is the OPA860 a diamond transistor?
I was looking at using the OPA860 for a voltage controlled load. Reading in the OPA860 datasheet it says:
The OPA860 combines a high-performance buffer with a transconductance
section. This transconductance section is discussed in the OTA The
buffer section of the OPA860 is ... |
H: Transformer with different kinds of loads
How does the variation on the kind of the load of a transformer affects efficiency and regulation? If I use a capacitive load, will the efficiency be greater or lower than if I use a common inductive load?
AI: If you use a capacitive or inductive load, then the overall effi... |
H: Soft fade out circuit for turning off speakers
I have some loud speakers connected to an amplifier. The problem is when I turn the preamp off, it sends a loud POP noise through the speakers. The turn off of the amp is delayed by 1 or 2 seconds, but that's not enough to kill the amp. So here's what I'm looking to ac... |
H: What is this structure on PCB
My LED TV is broken, so I disassembled it, and saw this weird thing on the power stage:
Above it, there are two 3 ohm resistors. (owners of the large drill holes in image) What could be the purpose of these? The only thing I came up with is that it is a clever use of solder to help th... |
H: DC motor and smoked arduino
I just burned my arduino and want to understand what happened.
I tried to control 12V 4A DC motor with 5V Arduino Pro Mini, here is a PCB I made for this:
In the bottom part you can see arduino pins, I used Raw input to power my arduino with 12V and PWM pin 11 to control the motor.
I us... |
H: What should I use from given options to power a raspberry pi?
I have a system which consists of 2 12V DC motors(0.65 A on max load) and 1 RPi 2 model B. I want this system to be plug free. I have Li-Ion batteries to power up motors. I use a L298N module to drive motors. This module also can give a 5V output. Here i... |
H: Output current vs Supply current
Good morning,
I am still learning, and often I see a lot of datasheet value that I dont understand. For this case specifically, what is the difference between output current and supply current?
The data sheet is here http://assets.nexperia.com/documents/data-sheet/74HC_HCT08.pdf
1)T... |
H: MOSFET finite output resistance in saturation mode
Since MOSFET has finite output resistance in saturation/active mode, the slope of unsignificanlty rising drain current is defined by Ua and slope parameter as lambda:
This parameter (as I know) is not given in any MOSFET datasheet.
Question: Is there any other way... |
H: What are the usual types of loss sources in an Inverter?
What are the usual loss sources in an common Inverter?
Thanks,
Devin.
AI: The largest losses in an inverter are probably the forward drop losses in the switching semiconductors.
With inductive loads there are forward drop losses in the antiparallel diodes.
S... |
H: MOSFET switch using an optocoupler
With the parts in the mail, haven't had the time to test, but the simple question: will this work, or what improvements are needed?
What it's supposed to do: a MOSFET switch for 12V, 0.5-3A loads, driven by a 3.3V logic level (which turned out to be too low even for my logic level... |
H: Replace a stereo amplifier component
I would like to replace the tda2822m stereo amplifier on a music keyboard because it fried. Problem is I'm not sure which one to use. Some kind of reference is written on the component: wx14a08y. I don't know what it means exactly. I keep finding amplifiers with other references... |
H: Why do large PCB traces have solder points/islands/stripes on them?
This is from a power supply for an old PC monitor. I opened it up to see if I could fix it (likely bad caps) and saw this rectangle matrix. What's the purpose?
AI: Probably an attempt to reduce the resistance of the trace (and better dissipate hea... |
H: Connect one of 16 loads to power (12 V, ~300 mA), decoder IC?
I am wondering if there is an IC that performs the following task.
If I didn't know any better, then I would probably build the following circuit from discrete components.
simulate this circuit – Schematic created using CircuitLab
However, this seems li... |
H: What to wire ground to?
I have a circuit involving a DC motor and voltage regulator as following:
simulate this circuit – Schematic created using CircuitLab
What would I realistically wire the ground to? Would it be the negative side of the DC motor or some random hunk of metal? (Side note: am I using the voltage ... |
H: LED strip power supply requirements
There are a few questions on here that talk about LED power supplies and how to calculate their ratings but none address the issue that my 5meter long 5v addressable LED strip of 18watts power consumption per meter draws a ridicilous amount or current.
Current = (18watts*5m)/5v
C... |
H: How does colpitts and hartley oscillators start oscillation?
I know LC circuit will start oscillation only when the input current is cut off.
As of colpitts and similar oscillators, how do they oscillate when the input current is still passing in the LC?
AI: While it's true that if you have an LC circuit, pass curr... |
H: Problem in understanding bridge rectifier
Why does electricity not flow from the other two diodes after it has been through the load in a full wave bridge rectifier?
I'd asked this question on Physics SE but was told to ask it here.
AI: I totally agree with the comments made about lack of basic research before aski... |
H: Standard package footprints
I'm looking for footprint dimensions for the standard packages like 0402, 0603, 0805, etc.
I did a quick search on Google, but I got many different results and I got confused.
Is there something very common to use both for resistors and MLCC capacitors?
I don't want the pads to turn out ... |
H: Linear voltage regulator outputs 3.6 volt instead of 5.0 volt
A 5 V linear regulator supplies a 5 V constant output irrespective of load. Is that so?
I am asking this question because in a linear regulator circuit in a load condition it is maintaining a constant 5 V, but when a further circuit is connected the outp... |
H: Why is there no current sharing between neutral and ground?
In the first system, will lamp1 turn on?
If yes, then why is there no current sharing between neutral and ground as shown in the second system? I always read that neutral is a current carrying conductor but the ground is not. What is the reason behind tha... |
H: WiFi-CPU Direct Talk
I was reading this link. I am wondering to know how the WiFi could talk to CPU directly (and vice versa). I searched everywhere but no sign of such communication. AFAIK it's OS's job to handle this communication via WiFi driver, but is it a complete different way?
When you put both CPU and WiF... |
H: biasing of an NMOS
Suppose I have applied a constant current source(of value I) at the source of an NMOS ,the gate is grounded and the drain is connected to a voltage source with resistance R between them.
Equation of MOS in saturation region says that the potential of the source will be such that the current I flo... |
H: How to Change the status voice msg of Bluetooth module
I just buy a Bluetooth module XY-BT-MINI, when I turn it on, it says "The Bluetooth device is ready to pair". But I don´t like the voice. I just want a connected sound,
Can I replace the voice msg with connected sound ?
Can I change the name of the Bluetooth ... |
H: Am I insane to question that only with a closed path can electrons move?
First of all let me just state that I do not feel confident enough to tell anyone anything about how electric circuits work or anything about the physics behind them because I simply do not know or understand it all.
But I have many times read... |
H: Why does an analog oscilloscope have a frequency number written on it?
So in our lab, we are working with an oscilloscope, an Analog to be precise. It is the Tektronix 2205. My question is if it is analog, then why would it have "20 MHz" written on its box.
AI: Being an analog scope the signal is limited by the BW ... |
H: LED series and parallel connection 7S3P
using 21nos 3w led diode. I am using 24v dc and 3amp supply. Connected 21x 3w led
Can I add another parallel connection to run 5v dc 0.16 Amp fan ?
Now I am using 3 x 4.7 ohm , 2W resistors, which are too hot from 24V.
AI: May be a solution if thermally matched.
simulat... |
H: RC circuit: C appears to increase in size with frequency
I've come up with an RC circuit, which is using the output pins of a NodeMCU board to create an AC current for measuring conductivity of a liquid.
What I'm actually measuring is the discharge time of the capacitor, and that's what this question is about. At ... |
H: Can't understand where backlight pins are in this LCD module
I have this LCD display: RC0802A-BIW-CSX
It is supposed to have a backlight, but I can't understand where the backlight LED is since the connections are just 14 pin, and backlight is not mentioned. Any idea?
AI: connections are just 14 pin, and backlight ... |
H: Standard component size for antenna matching circuit
I am fairly new to the RF world. It was certainly not my strongest subject. I am currently designing a board that uses the SIM868 module (GSM) and I need to design an antenna matching circuit. In the case above what size component should L1 be? 201, 402?
simulat... |
H: Can I convert a 2.5W DC to AC with a 120W DC-AC Inverter?
I want to convert the output of USB to AC voltage, and I come across with this 120W 12V power inverter. Is it possible to step up the 5V DC to 12V, later convert it to AC with a 120W DC-AC inverter? If so, what will I get? As I know 120W is the max. output p... |
H: Which way to hook up boostrap diode for switching regulator?
In the datasheet for the switching regulator I'm using, it says you can supply an optional diode to put on the BST pin of the regulator, and in Figure 2 it says IN if Vin less than 5.5V, or OUT if Vout less than 5.5V. In the picture, I am unsure which way... |
H: 555 Timer: Does the discharge pin show ground when in reset?
It is not clear to me whether the discharge pin could be used to (for example) discharge a capacitor when a 555 timer is in reset.
I didn't see anything in the datasheets that gives hints about what will happen, aside from internal schematics. Block diagr... |
H: RC time constant changes with introducing LED
I am testing time constants for a capacitor. Practical implementation is almost accurate as theoretical calculation. But the Time const changes(rises) when I introduce an LED in series with R AND C.
cap=1000uF; Res=10K; Vcc=5V;
When only Cap and resistor is present, the... |
H: Good practice when designing a PCB and stencil?
While I generally use nothing smaller that SOIC chips or 0603 passive components, I have to design a PCB with a WSON-14 IC with tiny 0.5mm pin spacing and with an exposed pad.
While I generally use a syringe to apply solder paste I thought that, for such a small beast... |
H: PCB Layout - Best way to hand solder under pads
Currently i'm drawing a pcb board in Eagle. Can't get a viable solution to allow people easy handsolder this component (WS2812B).
I will have 60 of this in the PCB, and i like to use them instead of RAW LED because it already contains the capacitor and resistor, so i... |
H: Confusion about the use of AIGND in a differential amplifier
Above is a differential amplifier used to measure differential ended signals.
Here is what I understand:
The amplifier subtracts two input voltages with respect to its measurement ground(AIGND in the figure).
But this AIGND should also be connected to ... |
H: Are there 8 bit ARM processors?
Is there anything below 32-bits for an ARM processor? I was wondering if there is or ever was an 8-bit ARM processor. I've searched but not seen any and so it seems that ARM processors are either 32 or 64 bits. Why is that?
I also noticed while writing this question, that the tag for... |
H: Wirelessly program AVR with Bluetooth device and can be used for data communicationtoo?
I am Embedded Software developer.
Don't have much knowledge of hardware side but am trying some hardware stuff.
Is it possible to program AVR (ATMega328p) wirelessly using Bluetooth device (HC-05) and then use the same device ... |
H: How can I interpret the circuit of the voltage probe with cable between the probe body and the compensation box?
Let's take a look at the voltage probe circuit without the cable between the probe body and the compensation box.
This circuit is a typical RC voltage divider and the following relation holds; $${R_P} =... |
H: STM32F4 serial RXNE flag
I am trying to receive serial on a stm32f411.
I decided to monitor the the RXNE flag to check the serial buffer. I can get the flag to work, however, the issue is that I do not think it is working completely.
I set up a test to increment a counter based on how many times I need to read the... |
H: Powering a calculator's liquid crystal display (LCD)
Hello, so I'm trying to use a calculator's LCD for a project of mine and I want to put a current through it. However, the LCD is powered by the "sheet of plastic" shown in the picture, circled in red. Does anyone know what that "sheet of plastic" is and how does... |
H: Is there significance to length in a matched transmission line?
I am looking to dabble into some RF PCB design with a microstrip line to a WiFi chip antenna, and I am trying to understand if my intuition is correct.
I have used various calculators to determine the width of the trace I need for a 50\$\Omega\$ \$Z_0... |
H: How can you obtain SOP and POS (Boolean Logic) given the truth table?
Recently, it appears to me that few people on here are having issues determining SOP (Sum-of-Products) and POS (Product-of-Sums). So lets go through an example to help those people solve their future homework questions instead of giving them the... |
H: Power controller says 0/10vdc command signal what does that mean?
I have a power controller here and I try shorting these two prongs but it doesn't turn on and give me 12 volts. I'm new to electronic engineering so does the 10 vdc on the manual mean that I have to apply 10 volts dc to the prongs in order for the po... |
H: How do I integrate multiple IC circuits for audio?
My primary concern here is the correct way to apply power (and grounding) to an assortment of single and dual-supply ICs in a mixed environment for an audio application.
I constructed a portable audio mixer using different ICs to get (most of) the features I wanted... |
H: Arduino and SSR to drive 12V solenoid
So I'm using the an Arduino (Mega 2560) to control 9 little 12V solenoid valves (Gem Sensors) and my plan is to connect the Arduino to some small solid state relays (Broadcom Limited ASSR-1511-001E) which will be connected to a 12V power supply which will actually power the val... |
H: Trying to multiplex voltage reference gives incorrect output
I'm trying to make the voltage reference for an INA214 opamp selectable between GND, 4.5V and 10V. I'm using a CD4051B multiplexer.
However, the 10V VREF gets pulled down to 5.84V, and I can't figure out why.
simulate this circuit – Schematic created usi... |
H: Parallel circuit not working as expected
I have this setup,
simulate this circuit – Schematic created using CircuitLab
There is also a button connected to the Arduino and every time the button is clicked the arduino cycles 3 levels of brightness on the LEDs. The problem is that when the LEDs are at full bright the... |
H: Problem in understanding bridge rectifier
In a bridge rectifier (full wave) why do the electrons not flow from the other two diodes during a half cycle?
Pls help me in understanding the concept.
AI: Does putting some voltages and voltage-drops across the diodes help?
Note that the diode will only allow current fl... |
H: Why would a LED datasheet specify a minimum operating current?
I am looking at the datasheet for the OSRAM Golden DRAGON® Plus LUW W5AM, a high power white LED.
It has a forward current of 20-1000 mA, surge current up to 2500 mA, and I think they want you to run it at 350 mA; that is what they use for most of the t... |
H: Designing adjustable current source 30A to 60A
I am looking to design a constant current source that can give between 30A and 60A used for electroplating. Obviously, an LM317 isn't going to cut it for this project. Does anyone have any thoughts for a design that would allow for 10A steps (5A preferably).
My power ... |
H: What kind of wire can be used for CAN(Cotroller Area Network) protocol based communication?
Is the wire used for CAN communication protocol any different or normal. Can normal wires(a pair for CAN LOW AND can HIGH)also be used for communication? I am looking to connect CAN controller 1 to CAN controller 2 in same S... |
H: What does the diode do in this switch and lamp?
The following illustrations are from a pinball machine repair manual.
What purpose does the diode perform on the lamp and switch?
AI: See the wires labeled "row" and "column"?
What you have there is detail drawings of single cells of matrixed switches and lamps.
The p... |
H: 18650 battery protection board
I have bought a 18650 2S protection board on eBay (http://www.ebay.it/itm/222383859919) because I need to use and charge 2 18650 batteries in series for a project (a portable audio system) but, searching the protection board model (fdc-2s-2) on google, I have found this site (http://m... |
H: Need to fixate current of motor connected to a battery
I have a gadget which includes a small 80mAh DC vibration motor connected to a CR2032 3V coin battery. The motor needs to keep running as long as the battery has juice, but instead of having it run at full speed and slow down gradually as the battery drains I p... |
H: Getting fast performance from a STM32 MCU
I am working with the STM32F303VC discovery kit and I am slightly puzzled by its performance. To get acquainted with the system, I've written a very simple program simply to test out the bit-banging speed of this MCU. The code can be broken down as follows:
HSI clock (8 MH... |
H: How can I establish "frontiers" in the feedback resistor of an inverting opamp config, if I'm varying it with a pot?
simulate this circuit – Schematic created using CircuitLab
I replaced the feedback resistor of an inverting configuration by a pot. I'm meant to vary from edge to edge the pot so I can get a variabl... |
H: Where can I find the definition of SMI, SCI pins on a CPU?
I am trying to understand the SMI (System Management Interrupt) and SCI (System Control Interrupt) in IA32 architecture.
According to this thread, it seems a CPU should have dedicated pins for SMI and SCI.
I guess some cpu specs should cover this. I tried s... |
H: Common Emitter resistors interactions
Background: I did an "A" level in electronics 25 years ago; now been a professional programmer for nearly 20 years. I want to build some very basic circuits to interact with an Arduino but I've forgotten a lot, apparently :)
Question: I am playing around with the below circuit,... |
H: How to flip polarity of battery with DIY device
Say I have a small electric motor I'm spinning with a hand crank to generate electricity and charge a battery. Every ten seconds, I slowly slow down to a stop and start spinning the other way. This will flip the direction of the current, and I will "anti charge" the b... |
H: Can I use this power supply DC output terminals to create a dual power supply?
I have this power supply.
And here is the photo:
I named the DC outputs as A, B, C, D in red color to ask my question.
I saw in some bench power supplies they create dual supply.
Can I make a +24V -24V dual power supply by tying B and C... |
H: LM78xx Reverse Polarity and Reverse Bias
I'm building a circuit that will use a LM7805 and LM7812 to produce 5VDC and 12VDC respectively, with the input power being ~16VDC from an external wall wart.
I already fried one of each regulator because I'm apparently not capable of keeping track of polarity.
I figure I mi... |
H: adapter between thicker and thinner AWG wires
I'd like to connect two different AWG wires, sizes 18 and 24. Preferably made specifically for outdoors underground usage.
More to the facts, the 24 AWG is part of a 8-wire CAT 5E cable that I need too tuck into some irrigation valve connectors which is not supposed to ... |
H: Why is the power factor always 0.8?
If reactive power means losses, why don't we correct the power factor and make it 1? For example, on marine vessels that I have been working on, the power factor is always 0.8. We could add capacitors in parallel, or over-excite a generator.
Why this is never the case?
AI: Power ... |
H: 4x4 Pressure Sensor Grid Pin Saving
I'd like to make a 4x4 pressure ( force resistance) sensor grid to use with an arduino. But 16 sensors sure need a lot of pins.
During my research on this topic I stumbled upon a couple of suggestions. An example I've seen at least 100 times is the one which generates a 4x4 LED-... |
H: Why does shorting/putting heavy load on a motor slow it/stop it?
I am doing a simple circuit which includes using a motor in theory (I am using a stepper-motor) as a break. One of the random fun-facts that I have known for a long time is how shorting a stepper motor (or putting very high load ) will cause high curr... |
H: How to Limit Current to a Hot Plate
I have a 1200 Watt hot plate that works great when connected to the grid but I want to be able to run it off of two deep cycle batteries wired in series to an inverter in an off grid situation. The thing is i want to be able to limit the current going to this device to have more ... |
H: Why isn't this VHDL falling edge detector reliable?
I'm trying to write an RS232 decoder for my Mojo v3 (Spartan 6 XC6SLX9). I know I can find existing libraries to do this - I'd just like to do it myself. As part of the decoding, I need to detect the high-to-low transition for the start bit.
Many sources, such as... |
H: What are the names of these 2 connectors?
These two types of connectors I do not know the name and I would like to.
1.
2.
AI: PCB mount screw connectors (ideally, use crimped ferrules on the wire ends with these).
Bullet connectors. |
H: Why is the relay switched by a NPN transistor still on while the Arduino out is off (low)?
I have a circuit as shown below:
simulate this circuit – Schematic created using CircuitLab
Note:
In the above schematic some pins of Arduino Nano are not shown for simplicity purposes. Also, SW1 and SW2 are not switches but... |
H: Induction machine: Question regarding field weakening region limited by breakdown torque
I have a question regarding the entry point to the field weakening region limited by the breakdown torque of an induction machine marked red in the following picture:
Under nominal conditions, this point may be located at (ws1... |
H: Overall and partial MOSFET voltage gain
I am researching studies for common source MOSFET amplifier and I found two different terms for voltage gain - overall and partial.
What is the difference between overall and partial gain when talking about MOSFETs?
What do each one of them mean?
Are both used in practice wh... |
H: Ultrasonic generator - a couple of questions
Here is the ultrasonic generator circuit I'm trying to understand:
It is powered by USB and it produces 100V at 100kHz on the piezoelectric speaker BQ1.
Two mutually inverted PWM signals go from the micro-controller to the transformer T1.
Questions:
1) Is this the simpl... |
H: Relay: higher voltage allowed at lower current?
Is it safe to use a 30VDC/1A relay for a voltage of 60V but a current of <100uA?
E.g. this one:
http://www.mouser.com/ds/2/315/mech_eng_gq-1075992.pdf
AI: Is it safe to use a 30VDC/1A relay for a voltage of 60V but a current of <100uA?
No, the ratings for voltage and... |
H: Which fab for DRAM device? (ASIC design at Europractice)
I would like to ask for advice.
Europractice supports many fabs and technologies for custom asic design (fab list). Lib support list of those technologies are public (for example UMC 130 nm LL). I checked all of public lists, and nowhere found dram support.
I... |
H: INA125P Strain gauge amplification problem
I'm using the INA125P to amplify the strain of a 350 ohm strain gauge in a self-built Wheatstone bridge circuit for measurement. I'm testing using a 351 ohm resistor to mimick a strain gauge under maximum strain.
This is the basic circuit I have (modified circuit from http... |
H: Connect two batteries in parallel with transistors?
I am trying to figure out how I can connect two small 12V lead acid batteries in parallel using transistors, but when testing this circuit on the breadboard, the voltages didn't equalize so that tells me the two batteries weren't connected to each other.
How coul... |
H: Designing a breakout for crenellated (castellated?) pads
I am brand new to PCB design, so far all i've made a simply 555 timer circuit with an led, a few resistors, a capacitor and a 555 timer and got it printed by OSHpark.
That was my first experience getting a board printed and with pcb design and i used it as wa... |
H: Arduino Uno short circuits
When I connect the 5V of my Arduino to the GND why does it get short circuited ? And why does the Arduino Uno doesn't really get short circuited and the Arduino Nano does get short circuited ?
AI: When we by mistakenly connect 5v and Gnd It gets short circuited.
Lesson learned. Gnd is te... |
H: Bypassing 220v - 5v relay
Beginner Warning!
I am trying to automate lights and fan in my house with the help of a raspberry pi. I read couple of guides in the internet. I finished the basic circuit. Now I can control a relay with my pi remotely. If I connect the relay in Line, I will be able to control my light bu... |
H: How would linear voltage regulators behave in series?
How would this behave in real life? When I simulate it, I get stepped voltages across the LVRs and odd output voltages.
simulate this circuit – Schematic created using CircuitLab
AI: If you draw no current then yes, you get stepped voltages as you "expect".
But... |
H: Convert VAh to kWh
Sorry, this might be a stupid question as I'm not an electrical person.
I'm analyzing an electricity consumption dataset and the consumption is measured by apparent energy (VAh).
How do I convert this VAh to kWh as normally seen on a power bill? Or are they the same thing, just different ways to ... |
H: LED switch behaviour
I'm going to use one of those LED-buttons to switch a certain (5V) appliance. It's possible to use a couple of connection types:
Le left side scheme is OK, but I don't like it.
I would go with the right side one, but the problem is in that situation the voltage drops... 5V drops to ~3V and 12V... |
H: Does clock speed matter when recovering from I2C bus lock up?
When there is I2C lock caused by slave device driving the SDA line low you need to manually generate a few clock signals by doing a simple bit banging on the SCL pin. I thought that this need to be done with the same frequency as the I2C communication wa... |
H: does heat kill hard drives? hhd lifespan due to heat
These days it's hard to buy an external 3.5" hard drive with a fan inside or well heat dissipation design. I have 4 of such hard drives, and two have already failed in first few months. Here is the deal; They all run very hot in few minutes of copying some files... |
H: What is this Op-Amp Configuration doing?
This Op-Amp Arrangement is part of an analog signal processing for a knock sensor of a combustion engine and I'm very curious about what this part actually does, as my google research didn't help me at all.
AI: I think it is a precision rectifier...
If A goes positive WRT B,... |
H: Cooling buck converter mosfets by placing on bottom layer of PCB - a problem?
I have a design and layout for a buck converter which currently sits on one layer of a 2 layer PCB. I would like to force-cool the heat generating components of the board by placing them directly onto a flat heatsink.
Because there are m... |
H: Fixing ground "open circuit" on printed circuit board
I was installing a RV roof vent fan and accidentally shorted it (connected it in reverse polarity).
The short seems pretty clean and I was able to manually confirmed that nothing else was broken by manually bridging the short with a piece of wire held in place... |
H: any 8 bit fast adder designs
so i'm trying to design a CPU and in all my previous designs i have used a cascade adder but i want to try using a fast adder to speed things up. when i search for "8 bit fast adders" all i get is the 4 bit fast adder designs and i don't want to link all the carry ins and outs together ... |
H: How to charge lithium ion battery?
I have purchased and received this battery from eBay. Upon opening it delivers 3v as oppose to 12v-10v and it has a petty output current. I am going to assume this is because it has not been charged much. I have a dc adapter similar to this and i am wondering if i can plug the ada... |
H: Converting S parameters to Z parameters - divergence
I have cause to convert some Z parameters to S parameters and vice versa. Here is the conversion for \$Z_{11}\$;
$$Z_{11} = {((1 + S_{11}) (1 - S_{22}) + S_{12} S_{21}) \over \Delta_S} Z_0$$
where
$$\Delta_S = (1 - S_{11}) (1 - S_{22}) - S_{12} S_{21}.$$
I though... |
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