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H: DS3231 on Battery Power and Use of Aging Register
Currently working with DS3231M RTC module with Arduino Uno and also creating a library for this. It is working perfectly but I have a doubt that DS3231M work on both VCC(main current) and VBAT (i.e the battery). So when I switch off the power from VCC it is not pos... |
H: usage of at24c02 eeprom with ethernet module
ı design a altium circuit schematic which consists of lan8720 tranciever rj45 and also at24c02 eeprom .However ı dont know exactly what MAC means and what it does. Why do we use eeprom with ethernet?
AI: All ethernet modules needs special mac adress to identify yoursel... |
H: How can an insertion loss provide gain?
I've been reading J.White's High Frequency Techniques. In one passage it says:
If the two port is a passive network, one might expect that the insertion loss could range from 0 dB (no loss) to some finite loss (a positive decibel value). But this is not necessarily so. For e... |
H: Digital Potentiometer 0.1 .. 10 Kilo Ohm
I would be very thankfull if you can propose to me a digital potentiometer with which I can have an electrical resistance between 0.1 and 10 K.Ohm
AI: You want to use a digital potentiometer IC for this.
There are multiple manufacturers, here is one from Microchip:
http://cd... |
H: Current draw calculations for a brush-less motor are way off
I've been attempting to calculate how much current a BLDC will draw given a known propeller size, thrust, internal resistance, Kv rating, Supply Voltage(Vin) and idle current. My propeller parameters are as follows;
Diameter=34; ... |
H: Inverted inputs with CMOS transistors
Lets say I want to realize a logic function in CMOS gates.
I have a function like this
$$Y = (¬A *¬B) + ¬C + ¬D$$
If I had a function without inverted inputs: $$ Y = ( A*B) +C +D $$ it does not present a challenge to me but with the inverted inputs this is much harder for me.... |
H: How do i get rid of a power-spike from consumer electronics?
Ive got a power-spike (im guessing here) when the amplification stage in a speaker turns on, that temporarily disables my tv (black screen, but recovers in a second) and my question is how do i get rid of it? The speaker actively turns on its amplificati... |
H: rc battery and connector issues when used in other applications
I purchased this battery for my robotics project and this charger along with it. Since the regular use for these types of batteries is for rc cars they have very specific connectors and so i am unable to connect the battery and charger together because... |
H: Why is the bunny-ears TV antenna normally connected to 300 ohm twin lead?
The bunny-ears antenna is similar to a dipole, which has an impedance of ~75 ohm.
Why are the elements of such antennas connected directly to 300 ohm ladder line? Wouldn't that cause mismatch losses (even with the other end going into a balun... |
H: High current power switch required?
I have a solenoid that I need to energize via a 12V car battery. The solenoid will only draw a few amps (2-3?) at the most. Do I require a high current rated power switching contactor (part# EV200AAANA) for this application due to the car battery? I would prefer to use somethi... |
H: Highpass and lowpass filter phase-shifted by 90°
If I wanted to build a circuit that consists of an highpass filter and a lowpass filter, what should I consider if I wanted to ensure, that their exits are phase-shifted by 90°?
AI: what should I consider if I wanted to ensure, that their exits are
phase-shifted by... |
H: How do 4-20 mA receivers work?
For a sensor device such as a positioner, do they sense 4-20 mA from two wires and supply from another two wires, or is this done with only two wires?
If only two wire, how can I do this?
AI: Despite the title, your inquiry seems to apply more to the transmitter design. The receiver, ... |
H: How to find current and voltage requirements of an LED lamp / strip using a multimeter?
I have an LED lamp who's current and voltage ratings aren't written on the lamp itself. How do I find the required input current and voltage to this lamp before powering it, using for example a multimeter?
For context: I have a... |
H: Beginner safety questions regarding voltage and current
I'm a complete beginner to electronics so please excuse the simplicity here :)
I have a phone charger that outputs at:
5V - 3A
or 9V - 1.6A
or 12V - 1.2A
I would like to use another charger while at work, which outputs at:
5V - 1.8A
I don't know what the i... |
H: Embedded External Flash Device using NAND architecture
Our SoC device supports both external NAND devices as well as Multi-IO/QSPI NOR devices.
I can use either of them.
Now, for NAND device, it will store only Program Code and Const Data.
That means SoC will never write anything back to NAND device. It will always... |
H: What are an amateur's options to put a high-end IC on a board?
I'm actually an experimental physicist who does software-development for a living. So my knowledge basically stops at writing micro-controller programs and putting them on a breadboard, and hooking the wires the simple way.
Back then in my student days... |
H: Is it safe to leave a SLA battery connected to 12v all the time for "trickle charging"?
I am considering building a 12v DC UPS for network equipment, and found this other question which contains a description of how one might build such a device. It suggests:
A Buck DC/DC converter handling charging, but a simple ... |
H: Wiring up 5+ meters of LED strips powered through USB
I am trying to power on about 5 meters of LED strips together with my ESP8266. The LEDs are called WS2812 and each LED is addressable.
After about 3.5-4 meters, the LEDs' colors starts to fade out (they start as white but end as yellow/orange). There are about 1... |
H: Circuit activated by pulse
Looking for a simple circuit which output is only active when its input is a low frequency (0.2-0.5Hz) pulse. The circuit output should be deactivated if input is unchanging.
I tried monostable 555 circuit, but its output is active as long as input is zero. I also tried a capacitor betwee... |
H: How to protect my 12 V, 10 A circuit? I am using a fuse but it failed
simulate this circuit – Schematic created using CircuitLab
My first question and first project.
I have a circuit. It works on 12 volt & 10 amp circuit. I need to protect it from OVER CURRENT & OVER VOLTS. I am using fuse of 10 A rating.
It is ... |
H: The value of the TCC counter on an ATSAM controller always reads as zero
I use an ATSAMD21 to generate a custom signal with the help of a PWM generator.
Basically, I set up TCC0 as a PWM generator, and use its overflow interrupt to set up the CC registers for the next pulse. It all works fine, the signal looks as i... |
H: Cascode Amplifier Gain
I've been going through Design of Analog CMOS integrated circuits 2nd Edition by Razavi. I'm currently at the Cascode amplifier section. The author does an example for calculating the gain for the circuit below, but I don't understand how he got his end result.
He first starts by obtaining Id... |
H: STM32 interrupt does not fire
I'm using an STM32F103C8T6 (aka blue pill).
GPIO Init and interrupt handler:
static void MX_GPIO_Init(void)
{
GPIO_InitTypeDef GPIO_InitStruct;
/* GPIO Ports Clock Enable */
__HAL_RCC_GPIOC_CLK_ENABLE();
__HAL_RCC_GPIOD_CLK_ENABLE();
__HAL_RCC_GPIOA_CLK_ENABLE();
/*Confi... |
H: Load sharing device from different power sources
Is there a circuit or device that can facilitate load sharing of different power supplies? For example, suppose I have a single 100 Watt Load that operates at 12VDC, a 9VDC source capable of delivering 75 Watts, and a 12VDC source capable of delivering 75 Watts. I ne... |
H: Why are there not more incompatibilities in 3.5mm audio jacks?
I use 3.5mm audio jacks for my boom box, laptop, android phone, iPhone, iPod Touch, portable personal analog FM radio (no external speakers), and my classical sound system on a shelf. I assumed that the signals were standardized, but Wikipedia says the... |
H: How to charge a 3cell 11.1V battery pack made out of 3 Nokia BL-5C?
I connected three Nokia BL-5C 3.7v 800mAh Li-Ion batteries in series for a robot project resulting in 11.1v @ 800mAh capacity. How do i charge the pack?
Should i get a 12v 5A adapter and limit the current or get a dedicated Li-Ion battery charger a... |
H: how does the filter capacitor work in a rectifier circuit?
My question concerns the following schematic
PICTURE NUMBER 1
If the Capacitor and the LOAD are in parallel, this means that there is more
than one path for the current to flow, therefore, the unfiltered direct
current from the rectifier will split b... |
H: Problem with breadboard wires overheating and melting
I have a problem with my breadboard jumpers. They overheat when I try to power many LEDs, but we're "only" talking 5.05V at 2.1A.
The wires are really thin and they melt after 10-15 minutes of constant use. Even the breadboard melts where the wires are installed... |
H: Power supply buzzing, LED strip insulation has almost turned black
I was changing some light bulbs at my mom's house and I noticed that a (water resistant) LED strip she has had turned stiff and almost black. As expected, it hardly gave out any light. The LEDs seem to be working so I think the reason it's hardly gi... |
H: ATMega128 A/D Floating
I'm working with an ATMega128 micro working with a joystick (pot in the schematic below) that's a .25-4.75V output with a 2ohm output impedance (Joystick Part Number is: ch products ts-2-r-1-u-05-a). When the line between the pot and the 33kohm resistor gets removed while the board is on how... |
H: Where does character pointer resides in memory, ROM or RAM?
I am running Embedded C on some ARM Cortex-M4 target which facilitates with both ROM and RAM support. I have a character pointer in my code:
char *temp = "";
Later in code I am modifying the variable as:
itoa(some_integer, temp, 10);
When I compile the c... |
H: Strange behavior of a Colpitts Oscillator
simulate this circuit – Schematic created using CircuitLab
I've built this schematic from this link (parallel tuned colpitts VCO), and changed it up a bit for my frequencies/components at hand. I temporarily replaced the varactor with a trimmer cap for tuning purposes and ... |
H: "Sniffing" into a Boiler's LED panel (Central Heating)
I've built an esp8266 based web thermostat to control my heating system. Everything seems to be working fine for the moment :)
What I want to accomplish is "sniff" or intercept the boiler´s status from the front panel's status LEDs, to see if this heater is a... |
H: Can you put a through-hole part behind an SMT part?
I'm wondering if it's possible to place a through-hole connection on the opposite side of an SMT microcontroller.
I have a small connector with a solder pin (for the shield) on one side of the board, and I'm hoping to place a microcontroller on the other side of t... |
H: Theory: Creating "LPS" transmitter for GPS receivers
As I understand it, GPS works by having transmitters with known locations send a timestamp, and calculating the time it took to receive it, so that you can triangulate your own position, (essentially an intersect of three or more circles with known centers).
I am... |
H: How big should my pads and holes be based on this datasheet?
I've been trying to decipher the many numbers on the top picture, and it just doesn't make sense to me.
Why would you need a hole of size 1.19 mm when the pins are only 0.45x0.58 mm? This leads me to believe that 1.19 mm is the size of the pad, but the... |
H: MOSFET operational amplifier - Exam
I am new to stackexchange. I have an exam tomorrow and i have a question from a past paper that i don't know how to answer. I would really appreciate if someone could possibly help me. Thank you in advance.
AI: The question does not specify whether the amplifier should be inverti... |
H: Modifying power strip in enclosure to attach to power entry connector
We are using an off-the-shelf power strip to distribute power to several devices in a large aluminum, painted Hammond brand enclosure. We'd like to be able to switch the power on and off with an externally accessible switch, so we had the idea t... |
H: Altium Designer - Method for changing the size of multiple pads at the same time
I want to edit multiple pads at the same time to have the same dimensions. I have tried selecting multiple pads and editing one of them, but that only changes the selected pad.
Is there a method for editing multiple pads at the same ti... |
H: Altium Designer - How to copy the parameters from one component in the SCH Library to another component
For context, I am using a component from Altium's Vault Explorer and I want to make a few edits to it. Thus I downloaded the component SCH, but the parameters did not copy over.
Is there an easy method to copy th... |
H: Advantages BJT over MOSFET?
There exists this qeustion about MOSFET advantages over BJT's Linear Regulator: MOSFET vs BJT
So my question is: What advantages do BJT's have over MOSFETS ?
So far I have these advantages:
They operate better under high load than MOSFETS
They operate better with higher frequencies than... |
H: Is that possible to know micro controller pin voltage and current without using multimeter?
So, the condition is there is a Photo Voltic (PV) module connected to a microcontroller (directly to pin 5 and assume that PV module is generating 3V, hypothetically!).
I am wondering if I can some how write a microcontroll... |
H: Why should we buffer reset line?
Today I saw the schematic of a lenovo G480-la-7981p (download or download). On page 6 you can see this part:
In the green box you can see a buffered Reset line. My questions are:
Why they've used a buffer? To filter noise?
If so, then why a buffer? why not a simple capacitor?(e.g.... |
H: Can this comparator input exceed its supply voltage?
I will use this comparator with 12V DC single supply.
Some of the pulse inputs to this comparator will exceed 12V that is to say the inputs to its inverting input can be up to 24V. So input voltage will exceed the supply voltage.
So my question is:
Can I use this... |
H: Integrating two I2C sensors into a single circuit
I have two I2C sensors that I want to combine into a single circuit. Here are the schematics for each sensor side-by-side (i.e. not combined into single circuit).
The BME280 datasheet states the sensor needs two decoupling capacitors: one across GND and VDD and ano... |
H: Why two N-channel MOSET instead of one P-channel?
Today I saw the schematic of a lenovo G480-la-7981p (download or download). On page 23 you can see this part:
I mean this part/configuration:
They've used two N-channel MOSETs instead of one P-channel. why?
Edit: Page of DMN66D0LDW
AI: The two N-FETs permit the si... |
H: Why does a body submerged in a more conductive fluid still conduct current?
Let's take for example an electric eel applying an electric shock by creating a potential difference across two points in the water. It would seem, however, that the current would find a "shorter path" across the potential difference by ju... |
H: Why do the normally closed and normally open relay contacts have different current ratings?
Please refer to the image below:
Taken from the datasheet:
http://www.songchuan.com/db/pictures/AdminModules/PDT/PDT090410001/201191913495127935.pdf
AI: The normally close contact is held by the spring pressure. The normall... |
H: How to output a voltage proportional to the speed of a DC motor?
Take a DC motor, as the one in the picture below:
I need some kind of analogic signal (preferably proportional to the speed of the motor) that can be used in a control loop.
What are two simple ways of achieving this? (One would be enough as well). I... |
H: Why not use a MOSFET instead of a BJT?
I'm seeing the schematic of a Notebook HP Pavilion dv9000 (download). On page 17 in the corner left you can see this part:
Two questions:
Why they didn't use a MOSFET instead of MMBT3904?
What's the usage of capacitor C851? haven't seen to use a capacitor for a BJT at its ba... |
H: When do you say two clocks are asynchronous?
I have a situation where reference clock of PLL_0 is coming from some clock source and giving out a clock (named C0) with freq0 and and C0 is going as reference clock to PLL_1 and giving out clock C1 and C1 is going to PLL_2 and giving out C2.
Please see the below figur... |
H: coil winding wire organization
In winding a coil for a generator, does the organization of the wires have an effect? Should I be very careful to lay each turn of each layer side by side in a neatly packed line, or can I be quick and messy and as long as the same number of turns fit into the same volume, I should be... |
H: How does this MOSFET with the configuration of its gate work?
I'm seeing the schematic of a Notebook HP Pavilion dv9000 (download). On page 33 you can see this part:
Take a look at the configuration of PQ37. I mean its gate. the gate is connected to PC170 and PC117 and PD15 and PD21. why? what and how does this co... |
H: Mosfet as a switch (on/off) and ground isolation
my question is simple (I hope)
So I have DC in.
On both + and ground line I have 2 mosfets (one for each line) (driven externally)
When I switch off both Mosfets , can I claim "full galvanic isolation" ?
Is there any leakage current or high frequency noise passing t... |
H: Semiconductor Devices- PN Diode
Why we use metal contact in PN diode at surface(both end)? We can have directly passed the current without using it.
Is it due to surface recombination velocity? If so then How.
AI: If you don't use a metal contact fabricated directly to the PN junction, an oxide or other surface con... |
H: How does this analog Op-Amp multiplier-divider work?
In AN-31 there's a 4 opamp analog multiplier divider. The quantity and complexity of feedback paths is staggering!
How does this even work? And how would one design something like this, short of divine inspiration?
AI: This circuit performs the calculations by u... |
H: How to calculate battery's energy?
To calculate battery's energy, one should use the nominal voltage or 100% SOC voltage?
AI: Nominal voltage. The battery voltage drops fairly quickly from 100% SOC so you would definitely get an over-estimate if you used the 100% charged voltage.
Nominal voltage is where the batter... |
H: Why are MOSFETs so expensive?
I know EE.SE isn't about economics, but the fact that a typical MOSFET can cost as much as a microprocessor, raises the question of why? Are they that difficult to make?
AI: I am not sure what you mean by 'typical' MOSFET, but prices of many types of components can vary. It also depen... |
H: Do dependent sources work in two directions?
For example if i have a voltage controlled voltage source and between the output terminals of the voltage controlled voltage source is an independent voltage source.
simulate this circuit – Schematic created using CircuitLab
Will the voltage source now work reserved? Pu... |
H: Find input resistance?
attempt:-
BY applying virtual ground i will get Vo=2v
now applying nodal at non inverting terminal i will get (V-2v)/R=I now from this i will get V/I=-R.
but the answer given is Option B mean only R
whats mistake i am doing?
AI: Input resistance -R is right as long as the circuit is not s... |
H: A question about sampling with an ADC device
There is a data-acquisition device with BNC inputs similar as follows:
It is single ended and when run by the software it is multiplexing all 16 adjacent channels.
I connect only first lets say the first three channels to signal sources by BNC cables; and the rest adja... |
H: Do we need a resistor to discharge capacitor of MOSFETs while connected to MCU?
I have an STM32 MCU at home. I was thinking of controlling a load with this MCU and a MOSFET. Let's assume this is my circuit:
In this circuit, we use a resistor (R2) to discharge the gate of the MOSFET. Now let's look at the structure... |
H: Is there a standard component that can "save" a certain current or voltage and what is it's name?
What I am thinking about is something like this analog equivalent of a flipflop:
____________
1 °-----|---| A |---|-----° 2
3 °-----|----||-----|-----° 4
5 °-----| |
_____________
... |
H: Can Cortex M4 data watchpoint trigger an interrupt without a debugger?
I am trying to diagnose memory corruption on a Cortex M4 (Kinetis K64). With the debugger (J-Link) attached I can set data watchpoints and the core will stop when a memory address is written.
I want to use this feature for field diagnostics. I s... |
H: USB short circuit on power - does it damage the PC?
I am building a circuit powered from a PC USB. Normally I put a diode in series with the input power to prevent damage from accidental reverse power being applied. However, over a long USB cable I want every millivolt I can get, so I am considering putting a diode... |
H: The reason for using air coils in LC tank circuits
I noticed that in LC tank circuit designs very often people use air coils as the L element as opposed to an axial inductor. I understand that the problem with the axial ones is that they tend to self-resonate. But I also thought that using an air core coil allows f... |
H: what does this mark mean on reed switch?
I have some used reed switches with no datasheets. all of them have a black mark on one side. I want to know what does this mark mean?
AI: They don't. Have a broader look at reeds from other sources. I have a bunch of them here, and install them professionally for burgla... |
H: Input leakage current
In the datasheet (like http://www.mouser.com/ds/2/149/NC7SZ125-98364.pdf), there is a spec of input leakage current ( +/- 10uA in this case).
I'm wondering about this current.
Is this current flow inside to the chip? or it can be out from the chip?
Why is there a -10uA current? Does it mean t... |
H: Op Amp Power Supply Consideration
When choosing a split supply for an op-amp circuit, how do I determine my power supply requirements? For a single supply, this is easily determined by finding the required current - but how is power distributed in split supplies? For example, if the op-amp in question states it dra... |
H: How can I plug my homemade Yagi Antenna into a wifi USB dongle?
I have made my own Yagi antenna and I would like to see if it works or not. I made the antenna based of these instructions: Easy to Build WIFI 2.4GHz Yagi Antenna
So I have soldered a coax cable to the pin 2 (the driven element). The center connector ... |
H: Kill Switch schematic
I want to make a kill-switch pedal with on/off LEDs for my guitar. I tested a simple schematic but every time I ground the circuit like the schematic i put below i get an error:
voltage source/wire loop with no resistance
Every kill-switch schematic I have seen, takes the Input sleeve to th... |
H: Will this Optocoupler and MOSFET be able to deliver 5V +2A?
I'm working on controlling the supply of an amplifier board with 5V 2.4A power in a manner which tries to eliminate noise from the speaker. I asked a few professors at my university and they said that an optocoupler would be the best way. Since I need a hi... |
H: How to cut the ADD to GND trace on a MPR121 capacitive touch sensor
I've been trying to setup two MPR121 capacitive touch sensors and from what I understand, I need to cut the PCB trace between the ADD and GND pins. I've tried scraping off a bit between them on the top side of the PCB, but they still are showing be... |
H: Do USB Data Wires (D+/D-) have 90 ohm differential impedance and single ended 45 ohm impedance to ground and if so how is this made?
I understand that USB data transmission is done over various speeds where transmission line effects could come into play(max 480Mbps which means a max frequency that is much higher co... |
H: layout of SPI and analogue signals
I am designing a board with mixed signals. There is an SPI bus and also an ADC chip. Now, during layout phase is it recommended to to have a specific impedance for these traces ? The length is not much for both SPI and analogue signals. Have seen some engineers do layout of SPI wi... |
H: Series RLC bandwidth independence from C
Why is bandwidth of series RLC circuit independent of the value of C ? Reason without derivation
AI: There is no 'reason' per se, it's just the way the mathematics works out.
The tutorial paper you mentioned in your comments (add link to your OP please) is pretty clear and t... |
H: Why does SendChar code of UART different between IRQ and Polling?
Now I'm trying to analyze STM32F103 Cortex-m3's UART code in IRQ and Polling mode.
Ans I found 2 types example code such as the below.
This is IRQ.
/*------------------------------------------------------------------------------
SenChar
transmit ... |
H: I2C layout considerations
I have a board in which there's two chips connected to I2C bus. I have tried to keep a distance and a ground plane between scl and sda lines. The routing topology is: mcu in the center and the two chips at the opposite directions (chip1-mcu-chip2) . The total length of SCL line is measured... |
H: Low power battery backup
I am currently working on a low power battery backed data logger.
An Intersil ICL7673 backup switch is used to switch between the battery and external power.
Because the circuit draws more than 30mA I have to use two mosfets (instead of transistors) as suggested in the datasheet:
simulate ... |
H: Efficient low current buck controller topology
In SMPS there are two sources of loss: parasitics, and the controller. Usually, the load consumes more power than the controller, and the parasitic losses dominate. I have the opposite situation. I have a buck converter with a load of 50mW, input voltage of 5V and outp... |
H: OpAmp circuit with diodes: conduction conditions
Consider the circuit below, where \$\ v_2\$ is an arbitrary input voltage and not necessarily equal to 3V as in the image. Both diodes and the OpAmp are ideal.
If only diode 1 is conducting or if both are, the output voltage, \$\ v_0\$, would be given by $$ v_0=v_2 ... |
H: How to minimize hash noise in amplifier mounted near boost regulator
I've designed an audio low power (20W) guitar amplifier circuit whose pre-amp section has somewhat high input impedance, as is best for a magnetic guitar pickup. Since it operates from a battery supply, I'd hoped to employ a boost regulator so tha... |
H: Vgs and semi-active rectification
simulate this circuit – Schematic created using CircuitLab
I'm new to the world of mosfets and am trying to learn them better. Would this rectifier IC be safe for input voltages of 24V if Vgs on these fets is 20V?
Vdss is 30V and reverse on D1 and D2 is 30V.
With L1_2 at 24V and... |
H: Measuring opamp output voltage (with virtual ground) on arduino
I have been working on a simple project to read the analog voltage input on Arduino. I'm having problem to read the correct value on Arduino. I know what's causing the problem. I'm using the virtual ground on the op amp non-inverting side but Arduino i... |
H: what is the frequency required to have all harmonics which have more than 10% DC value when we have 250 MHz clock?
A Digital board has a Unipolar square clock of 250 MHz. If the clock on the board at all places should have all the harmonic components which have more than 10% of DC value, the board has to be designe... |
H: What is this cap-like part?
I found a huge cap-like looking part in an old parts bin of mine. I tried making sense of its marking and I don't really understand what they mean. I googled for the part number and I found eBay listing and such, suggesting it's indeed a cap according to the eBay category, but even there... |
H: How to flash DM9000CEP V5 board
I am really new to the world of building hardware and software electronic devices and need help with a situation.
First off let me give a brief background on what I know about electronics and software programming so the community gets a good idea on what to expect from my knowledgeb... |
H: Differential pair in Altium
I have a difficulty with Altium giving me an error when I try to create a differential pair. I have placed my signal into blanket and created a net in the schematic. I also added differential pair directive pointing the two signal named with _N and _P
When I generate the ECO, Altium tell... |
H: How do you document bodges?
After making the PCBs, we decided on some bodges and implemented them on the PCBs. What's the standard way to document that on the schematics?
For now, I hand drew with the mouse, paint style, on the schematics PDF files, to convey the idea that it's a bodge, but is there a better way?
... |
H: How to read out data from this moisture sensor?
I found a cheap moisture sensor on Ebay that only came with the schematic attached. The moisture can be read with an analog or digital signal.
However, I am wondering how the opamp creates a digital signal, and how to read this signal from a microcontroller. The schem... |
H: What are the advantages of DSB AM with carrier?
I saw an exam question that asked what the advantages of using DSB AM with carrier are. I can't find anything conclusive in my books or by googling.
It seems to me that DSB AM with carrier is less power-efficient (compared to DSB-SC ΑΜ and SSB AM) and that it carries ... |
H: Connector with pcb
I would like to have a SMT USB C connector with many pins attached to a PCB I am about to design. Since they are quite tricky to solder I was thinking to buy one with a small PCB already attached, something like this:
http://eud.dx.com/product/cy-u3-206-diy-smt-type-24pin-usb-3-1-type-c-female-so... |
H: What is the terminology used for a (few)-bit permanent memory latch?
I would need a one bit permanent memory. With permanent, I mean able to maintain it value across power reset. Something like EEPROM or Flash. Ideally, something equivalent to a RS-latch.
Searching, I found several I2C EEPROM or PIC, but that would... |
H: Need some help about why this circuit (PSU) isn't working
Trying to make a current limiter for my LM317 power supply. This is the complete circuit:
I found the current limiting circuit on the web, I'am powering this circuit from a 12V 20A switching lab power supply. The problem that i have is that current regulati... |
H: what is the application of "one time programmable" bytes in my flash memory?
My flash memory device A25L032 has 64 one time programmable bytes. It also has software and hardware protection modes for blocks, sectors as well as the whole chip.
What application do one time programmable bits have since flash is nonvola... |
H: What is a weak transistor?
In implementation section of C-element at Wikipedia website: https://en.wikipedia.org/wiki/C-element there is a diagram that points to a weak transistor.
What is a weak transistor?
Below is the diagram that I am talking about:
AI: A "weak" transistor has a lower transconductance, which co... |
H: What is the difference between "normal read" and "fast read" in the flash A25L032
The Flash A25L032 has a normal read mode and a fast read mode. It also has dual and quad read modes that are self-explanatory. However, the difference between the normal and fast modes is not at all clear.
What makes fast mode fast? s... |
H: I can not understand this circuit diagram
I've many questions about this circuit diagram. I found it on the datasheet of NCP1012. It is a switching mode power supply SMPS.
Are E1 and E2 electrolytic capacitors and C1 and C2 Ceramic Capacitors?
What is the value of C2? Is it 2.2 nF? and what is the meaning of /Y n... |
H: Help me check the values for capacitors in a reference design
I have the following circuit diagram from documentatoin for an MC34167 which I'd like to use in a project.
Am I correct in assuming the capacitors are all in pF? which would give me:-
330pF
4700pF
0.1pF
AI: The capacitor values will all be in microfara... |
H: Is this pulse transformer in saturation?
I have the following schematic:
RB3 is connected to PIC microcontroller digital output.
I am wondering is it possible to know from the output voltage waveform is this pulse transformer in saturation.
2V/div - 500us/div
Blue signal is from the PIC and the purple one is out... |
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