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H: Implementing timeouts/timers in VHDL
What is the best way to implement a timeout, written in VHDL?
The purpose of this is to reset a state machine to an IDLE state if a certain amount of time has passed (a few seconds at most), to avoid a deadlock.
The only thing that come to my mind is a nasty clock counter with ... |
H: Are RC circuits suitable for use as power sequencers?
Are RC circuits suitable for use as power sequencers with EN pins on LDOs?
I know that there may be a problem with reverse sequence on power off, but some devices allow that on power down all power supplies must go down together or in reverse order, so cutting o... |
H: Measure both positive and negative voltages using ADC
I am looking into measuring both positive and negative voltages using ADC. My input voltage is in range from -55 to +55V, which is total of 110V. ADC I am using is MCP3424, since it is relatively easy to pair it with Raspberry Pi. MCP3423 is differential ADC wit... |
H: IAR ARM Place const symbols in flash
I have the following flash section defined in my linker file:
keep { section .SomeConst };
place at address mem: 0x0003F800 { readonly section .SomeConst };
In my code I have the following symbols defined:
#pragma location = ".SomeConst"
__root const uint8_t _value1[16] = {...}... |
H: Why does a current mirror have low input resistance?
I know that the output resistance needs to be high otherwise the output current will vary depending on the load. However, I don't understand why the input resistance needs to be low?
AI: The input of an ideal current mirror should look for the input circuit as ... |
H: Is there a relay to digitally check if mains is available
I am working on a system that will remotely turn on/off an appliance (RaspberryPi running a web server, sending input to a relay). One problem that I still need to get sorted is that, how can I check if the electricity is available. Is there some kind of a r... |
H: Heating a wire with DC current; why is it hottest in the middle?
I am putting DC current through a wire to heat it. I would think the wire would heat up evenly but I have found that it is hotter the closer I get to the middle, or, respectively, colder the nearer to the clamps. Can anyone explain this?
AI: There are... |
H: potential difference between emitter-base and collector base constant, i.e 0.6 or 1.2v approx?
i was solving questions on bjt, and i came across a question where i had to find voltage across emitter and collector and the answer was 2V, but i have read it's approx. 0.6v across both emitter base and collector base, t... |
H: What is the cut off frequency of the RC filter in this circuit
I have the circuit of a heartbeat sensor module from pulsesensor.com but I can't seem to understand the kind of filter in the schematic. They Said it contains a low pass RC filter with R = 100 ohm and C = 47uF. But from my analysis I see a hpf. Wh... |
H: ULN2803 - do i need COM(VSUP) for relays ?
I'm building a relay board with SRD-03VDC-SL-C relays and an ULN2803 Darlington transistor array. As I am a beginner I don't understand the purpose of the COM pin?
In the datasheet VSUP (Coil Supply Voltage) is rated from 12 V to 100 V, since I'm working with 3V3 will thi... |
H: A circuit to find 3D position of an object using changes in magnetic fields
There is a project at
http://www.instructables.com/id/DIY-3D-Controller/
to make a DIY 3D controller with capacitors to infer the 3D position of the object being tracked (hand) without using any wiring to hand. My question is it possible t... |
H: Monte carlo analysis cadence
I tried to do a monte carlo analysis of the opamp that I have designed. I ran the simulation for 100 samples with matching and process, suprisingly the results I get are very bizare. I have gains that are not even 1 dB which is something I completely dint see with a normal corner/proces... |
H: Sending 120VAC to a device for a certain amount of time after a single button press
I am trying to use a push button switch to send 120VAC for a certain amount of time after it has been pressed. I want it to only be pressed once, and not have to be held in the closed position. Is there some sort of timer/timed rela... |
H: ADC and DSP Requirements for FMCW Radar
I am building an FMCW radar that has a bandwidth of 1 GHz. The IF frequency is up to 1 MHz. Would the ADC requirements simply be that it has to b 2 times the IF frequency of 1 MHz? If that's the case can I simply put an ADC of 5 MHz and not worry about anything else? What are... |
H: How much surge protection do external power supplies provide?
This weekend a very close lightning strike took out several devices in my house. Among the casualties were:
2 TVs
1 cable modem
1 cable box
1 garage door opener
One of the TVs, the cable modem, and the cable box were all plugged into power supplies th... |
H: Boost converter drops to 4.5V when trying to achieve 6V with an 18650 cell
I don't have a lot of experience with this but I'm working on a prototype device which I want to run off a 18650 cell. I need to boost the voltage from 3.7V to 6V using a boost converter that uses a LM2587 chip that I bought on amazon.
When... |
H: Does fixed point number processing require ASIC hardware?
I've recently started diving deeper into DSP and have come across the term 'fixed point number'. The idea of a fixed point number is simple enough and makes since to me, however, I'm somewhat curious as to how fixed point operations are carried out.
Are fix... |
H: Measure voltage of 2 different batteries on Arduino
Currently I'm using a resistor divider to measure the voltage of a 6v battery that is connected to an Arduino via a 5v power regulator. I also want to be able to measure the voltage of another battery (7.2v) on a separate circuit with the same Arduino.
The issue i... |
H: Dual power supplies using 2 male to 1 female 120V AC power cable?
I've got a computer that needs redundant power supplies. Unfortunately, it only has one PSU. So I want to plug my computer both into the wall and into my UPS (a battery) that's plugged into the wall. I'm thinking I could buy or splice a cable that pu... |
H: N-Channel MOSFET as on-off switch between battery and load
I'd like to use 3v microcontroller to activate a small fan after the microcontroller wakes from sleep. I'm not quite clear on the placement of the load (i.e. fan) and the LiPo battery in a MOSEFT schematic. My understanding is that I can use an N-chanel MOS... |
H: Op. Amp instead of Push pull stage as power amplifier
I have been going through the push pull stage as power amplifier. Even though the gain in this topology is less than 1, still people use it. I am assuming this is because in emitter-follower OR source-follower topology the input impedance is high and output impe... |
H: Setting time of a LO
When we say the term 'setting time' of an LO,what exactly do we mean by setting time here ?
AI: The 'setting time', or more often the 'settling time', means exactly what you want it to mean. Different applications have different requirements, and it's only in the context of the application that... |
H: Controlling NiMH charging with power MOSFET: MOSFET before or after the linear regulator?
I am starting a project where I want to make a simple, Arduino-controlled NiMH battery charger. I imagine several iterations, but the first one will be really simple. It will charge at a constant current of around 0.1C (where ... |
H: UHF band repeater
I want to make a device which gets the TV antenna signals and transmits it again. Is there any module available in market which simplifies construction or i should make from scratch? Since my background is in software, please explain simple.
AI: What you describe definitely contains an amplifier;... |
H: Device Driver function behavior on interrupt
Suppose an embedded system is running FreeRTOS and an application program makes calls to a device driver interface (let us assume I2C). What exactly happens when this is interrupted by an external interrupt? In addition, how much sense does it make to implement the drive... |
H: Bias-tee for adding multiple frequencies to a DC line
Objective - To add multiple frequencies on sine waves onto a \$24V\$ DC Line.
Each frequency block (\$F_1, F_2, ...\$) generates a sine wave of unique frequency within the given range. When the \$n^{th} \$ frequency block \$F_n\$ is switched on, it's frequency m... |
H: Why use a localized ground plane?
It is known that the return current starts following the conductors as the frequency increases:
So as long as one keeps the distance between the conductors large enough there shouldn't be the need for local ground planes.
Why then some people suggest the use of localized ground p... |
H: Complex power, real power
Given:
\$U_q = 220 V, f = 50 Hz, R_i=10 \Omega, R_a=40 \Omega, L_a=95.5 mH\$
I'm asked to determine the real power transformed in \$Z_a\$. Here I break down the formulas that I use:
\$Z_{total}=Z_{La}+Z_{Ra}+Z_{Ri}\$
\$I={U_q\over Z_{total}}\$
\$P = Re[U_q . I^*]\$
I'm really sure that ... |
H: Heat sink calculation for TDA7376B
After years of programming, I'm trying to do some electronics again.
So I wanted to build an amplifier. I think I now have most of the information, but I'm stuck with the heat sink.
So, basically, I figured out that the calculation goes something like:
temperature increase = power... |
H: Differential Frontend Design for Mains Voltage Measurement
I am building a digital wattmeter intended for measurements on AC power lines. I have went through a lot of application notes and example designs, and stumbled upon a slightly confusing motif recurring in a number of designs from Texas Instruments' TI Desig... |
H: Is There an Alternative to Resistor based Voltage Divider for an DC Audio Signal with Less Noise?
I have a LMC555 which generates a audio signal between 440-880 Hz. The signal is DC between 0-3V after the chip. To use it as input for an amplifier. The amplifier, a LM386N-1, starts clipping the signal quite early, s... |
H: Relation between built in potential and doping
What is the relationship between the built in potential and the doping concentration of a pn junction diode ? I could only find the relationship between the depletion region width and the doping concentration.
AI: I don't know how you missed the first formula for the b... |
H: How DRAM refresh cycles work?
Nano capacitors in RAM act as leak bucket and continuously lose charge. For this RAM has to be refreshed periodically in order to charge those nano-capacitors again. "During the refresh cycles memory controller reads the data of each cell and recharge it". This thing puts me in doubt. ... |
H: Charging 2 li-ion batteries in series
For my project I need voltage of 2 li-ion batteries in series. For charging them I would use this charger (one for each battery):
Could I connect those two chargers (with one battery on each charger) in series and plug them on 9/12V adapter? Or should I use 5V voltage regulator... |
H: Regenerating the Gate of a Gated Pulse Wave
I'm looking for suggestions for alternative solutions to a design problem I have. Basically converting a gated pulse wave back into it's enabling gate. Bottom of the post lists the solutions I've come up with so far.
Background: Immediately following a user input to a bla... |
H: USB powered and battery powered on the same connector
I need to make this Arduino Nano-like board with one single connector: a mini USB type B which will of course be connected to the PC for programming and interface. Additionally, as it will be used away from the PC, I need to be able to connect a 6V+ battery pack... |
H: How to provide separate voltages from a common power source
Assuming the input voltage is regulated, how do I provide two different, specific voltages to the below devices? I specifically want 4[V] in the left part and 3[V] in the right part of the parallel sub-circuit on the right.
I thought a voltage-divider circ... |
H: GPS time accuracy (SIM808 or similar) - process between NMEA sentences and AT command response
In an SIM808 chip or similar you can get the GPS information with this AT command:
AT+CGNSINF
+CGNSINF:1,1,20150327014838.000,31.221783,121.354528,114.600,0.28,0.0,1,,1.9,22,1.0,,8,4,,,42,,
the UTC time is in the third d... |
H: PI filter (on PSU) and electrolytic capacitors after
I am designing a small DAC and I want to clean the power supply (it's noisy). I used a PI filter.
However, after the PI filter, I need an electrolytic capacitor (330 µF) to help with some transients. The problem is that the output of PI filter has a capacitor tha... |
H: Why does my UART connection still work without connecting ground?
On my prototype PCB, I have a microcontroller with reserved pins for UART communication with a debug terminal. I'm curious from a theory perspective about why my terminal works fine whether or not I connect ground to my USB UART adapter. I come from ... |
H: Connecting atmega328 to 9v battery
I'm trying to connect atmega328P-PU micro-controller to a 9v battery. I added 20M ohm resistor and got the voltage down to 4.8v, which is in the range of atmega, but it doesn't turn on. I replaced the atmega with LED and the LED is very dim, even though I'm getting 4.8v. When I tr... |
H: CD4017 Decade Counter Based LED Flasher Question
I am creating a simple LED Flasher with NE555 and CD4017. I am actually dividing the pulse frequency of NE555 by five. Because I have merged each pair of the output pins to finally get 5 outputs.
I have attached 4 pieces of 3V LEDs (draws approx 200mA current each) i... |
H: Is there a general method for switching between PCB power sources?
I'm working on PCB design that will typically be battery powered. However, the device needs to be programmed and thus will be plugged into a computer occasionally.
I'm running into the problem of switching between a battery supply and a PC power sup... |
H: I2C pullup resistors not working in simulation
I am trying to create a small project on PIC16F877a MCU, in which I am showing the lifetime of this project using RTC module and the temperature read from LM35 onto an LCD.
Working with PULLUP Resistor
Not working with 2k pullup resistors
The simulation of this proje... |
H: Purpose of diodes on ADC inputs in DRV8305 example circuit?
All sense pins in this schematic are used with diodes before the ADC input (on the MCU). Anyone can explain? And what diodes will work here? No info in datasheet.
AI: They are protection diodes (aka clamping diodes) which are there to ensure that if the vo... |
H: 2x2 Mimo antenna layout: Is it a requirement to length match the antenna traces
I am currently laying out a 2x2 MIMO antenna configuration for WiFI, using on board ceramic antennas.
While naturally the traces are impedance matched. Is it important to match the traces to the uFLs in length?
Is there any advantage t... |
H: Are SPI slave select lines hardware enhanced?
I have a question regarding SPI communications. I feel like I have a good understanding fundamentally of how SPI works. However, I'm often confused when implementing the slave select line of SPI.
Is the slave select line on a microcontroller, in general, enhanced via ha... |
H: Earth decoupled power supply
I have an electrocardiogram sensing circuit that uses an INA321 amplifier for common mode rejection on two measurement electrodes. The device is meant for hand-to-hand measurement of the heart rate and powered by a low voltage.
If supplied by batteries, the circuit works well. However, ... |
H: Enable-A and Enable-B of H-Bridge L293D (or L298N)
I am using both L293D and L298N for controlling the stepper motor NEMA17. It rotates and stop as expected. I am not sure about the usage of Enabling provided by the L293D bridge. In this attached file
the pin 1 and 9 are used to enable. I am currently setting high... |
H: Replacing old capacitors?
I am replacing a 4.7 uF 35v electrolytic axial leads capacitor near the cpu on an atari 2600. Can get away with using a 4.7 uF 50v capacitor?
AI: Yes you can .Using the higher volt is no problem.Many decades ago before I was born there were issues with forming voltages of electrolytic caps... |
H: PCB trace capacitance
I am designing a capacitive touch keypad using cypress MBR series. The design guide has an excel spreadsheet to help with max trace length and button dia requirements. The idea is to keep the button + trace capacitance in a working range. For the same, they have mentioned capacitance per inch ... |
H: Connecting a kitchen weighing scale to an AC/DC adapter
I have a kitchen weighing scale that uses a lithium 3volts cr2032 coin cell to power it. I also have an AC/DC power adapter that can be set to 3volts output. Would it be safe to connect the weighing scale to the adapter directly? What are the possible implicat... |
H: Why is my amplifier circuit amplifying more than I expect?
My Question
Why is my amplifier circuit amplifying more than I expect, and what can I do to fix it?
What I want to accomplish
I want to amplify an input that, at most, is 1.5[V] to, at most, be 2[V].
What I have tried
I have the below circuit set up. When I... |
H: neutral conductor in a three phase system
I do not understand the answer of the following question :
A three-phase power in the lab have symmetrical three-phase voltages 400 / 230V and
terminals marked L1, L2, L3 and N. A 60W bulb is connected between phase L1
and N. Another 60W lamp is connected in the same way, b... |
H: What abbreviation does they use for nominal voltage (Un) in Russian?
I need to translate the "Un" symbol for Russian client.
AI: Personally I'd go for "Uн" / "Vн", or "Uном" / "Vном" if you can afford longer labels. Note that equipment I have seen would cite the nominal voltage itself (i.e. "220/230 В", "380/400 В"... |
H: Driving BLDC motor directly from Generator
There are affordable BLDC motors up to 200kW. The Controllers, however, are double in price and the AC-DC inverters breach the 4 zeroes price scale.
Q1: Could one BLDC act as a Generator for spinning another, without any electronic components in between (no pulse correctio... |
H: Simple high current alarm using transistor
simulate this circuit – Schematic created using CircuitLab
I need a suggestion to build a minimalist short circuit alarm.
With this diagram will light a LED easily. But if I replace with a Buzzer, it will not make a beep. My input voltage will be 12 Volts, alarm should be... |
H: Filter only with capacitor
I have some questions about capacitor and the circuit shown below:
The original signal including noise is shown below:
There are three waveforms shown in one picture.
The top one, middle one, and last one is connected to 4.7µF, 0.1µF, and 100µF respectively. Why is the top one smoother ... |
H: Const type array in Vivado HLS
Could someone explain how HLS treats arrays that are declared constants? I declare an array as:
const uint8 myArray [100][100] = {....};
and then access the array by element in the loop. According to the UG902 on p.328, such array is implemented as a ROM and consequently I need to pa... |
H: How to find I(t)?
so I'm trying to find the current I(t) passing through the node above the switch.
I have already found the DC response of the RC circuit which is
in the form of:
so, after the switch closes a short circuit will be created, and here is the confusion, is the current going to take the shorter path... |
H: Does ISA bus (or PC/XT bus) have some means of arbitration to resolve bus contention?
My understanding of ISA bus is that the CPU places an address on the bus and any expansion card is free to respond to that address by taking control of the data bus. I presume that tri-state buffers are used. So my question is, ar... |
H: STM32F042K6U6 BOOT0 pin? Can not understand how to program it with DFU mode
I'm planning out a board and trying to make sure of how to go into DFU mode and the actual program on a STM32F042K6U6. I want to use the K6U6 for the small size, which also rules out using STLINK to program it (I don't want to use the board... |
H: Which resistors control the gain of this filter?
Update2: Nevermind the update1, question went far beyond its scope. Accepted answer was my expectation.
Update1: I have the filter(bandpass) design below, created using texas instruments filter design tool. I am also adding my specs to the question, in case it helps.... |
H: How to use arduino control an ESC and flash?
Basically, I want to use PWM wave or something alike from Arduino to directly control the speed of a brushless motor through an ESC.
I saw an example on the Arduino Brushless Motor Control Tutorial | ESC | BLDC by Dejan . However, I saw some other people mention about fl... |
H: Cannot initialize LPUART1 in STM32CubeIDE on b-l072z-lrwan1?
I was having a problem about initializing the LPUART1 on b-l072z-lrwan1 using the built-in CubeMX code generation in STM32CubeIDE.
The problem was when I started debugging, the code seemed to run fine until the execution reached MX_LPUART1_UART_Init(); Th... |
H: Circuit analysis with dependent current source and tricky voltage source
I've been wasting my time on this problem and I did get really close to a solution which took a long time but still wasnt able to get the solution.
I was wonderting that I might approach this problem in the wrong way which is the main thing t... |
H: Thevenin voltage question
I have to find V Thevenin in that circuit.
simulate this circuit – Schematic created using CircuitLab
I did :
\$(\frac{V_1}{R_1}-I_1)*R_2 \$
Appeared its not right.
Also Im not sure I can divide the volt source by the resistor to find the current there.
Thanks for your help
AI: Using KCL... |
H: PCA9456A i2c switch channel 1 not showing up
I am using an PCA9456A i2c switch to help me toggle between i2c devices with the same address, but i am having problems opening channel 1 (second channel out of 4) and i ran out of ideas what is causing it
Here are the code and schematics, I am using the busio and board... |
H: Equivalent circuit of a simple transformer?
EDIT: My question is: How can you translate the first circuit into one that uses simple (linear) electrical elements and, as a result, can be solved using mostly Kirchhoff's laws?
I am trying to analyse how the frequency of the input voltage affects the amplitude of the o... |
H: BNC terminator at end of T junction
I'm planning to get an oscilloscope and a signal generator.
It seems to connect the signal generator to the oscilloscope. And it seems a 50 ohms terminator is needed.
I wonder if I can use a BNC T junction, and put the terminator on one end, and the other end with a cable towards... |
H: What makes a input GPIO pin so sensitive?
I know that an input pin has a high impedance, but how a high impedance makes such pin be so sensitive?
According to https://forum.arduino.cc/index.php?topic=454553.0 -- #4 mentioned
If the input impedance is too high, say 100MΩ, then you'd need only
50nA to get 5V. Thi... |
H: What does the plus (+) mean in a voltage source symbol?
Does the plus in voltage source symbol represent the highest potential end or does it represent the positive end?
Is that answer true for IEEE and IEC and NEC?
It may seem trivial for those who know but I did my research and did not find the answer.
UPDATE:
My... |
H: Read serial data from unknown source using Raspberry pi
I have a fuel dispenser, which has one keypad and two displays, each display has three of 7 segment LCDs.
I want to control the fuel dispenser with a PC or a phone. The way to do this in my knowledge is by attaching Raspberry to the fuel dispenser; program the... |
H: Formula for how much power a motor generates
I'm interested in the formula for how much power a handcrank motor can generate.
I dont know much about electrical engineering but I'm assuming it's related to a few factor.
The speed on which you are cranking
The amount of copper wrapper
But what I'm confused on is t... |
H: Resistor parallel to optocoupler LED in Zener-stabilized circuit
I was watching a video about phone chargers where the following schematics was presented:
simulate this circuit – Schematic created using CircuitLab
In the video it was stated that this schematics is for the feedback circuit of a phone charger and th... |
H: Solving for inductance L in an AC series+parallel circuit is .. quartic?
This seems like a painfully simple question, but I keep ending up having to solve a quartic equation. So I'm missing something obvious.
Let's say we have a an AC source feeding a load consisting of a series resistor, Rs, and then in parallel a... |
H: Is there an easier way to signal this active low relay module for the pi?
Two parts to this question:
Part 1:
I am planning on setting up this relay module with my pi (which afaik has gpio pins set to LOW at startup).
1.) Does this mean if I hook it up as the picture suggests on that page, that all the relay sub-m... |
H: How does this transistor (pre-)amplifier work?
The following circuit is part of a larger circuit and processes analog audio. The input comes from the top-right and the output is the rightmost terminal of the pot, which then feeds into a straightforward audio amp chip (LM386N to be precise) before finally going to a... |
H: STM Cortex M7 memory map
I suppose this is simple one, but for me as first time reader of STM32F769 datasheet it is confusing. Memory map in this datasheet declares ITCM RAM at zero address, while this programming manual (pg. 32) declares that zero memory is code space (which by my opinion must not be RAM).
My exp... |
H: Turning off and Flickering of LEDs for some reason
I've been following Ben Eater's You Tube series on building an 8 bit computer. As I built and connected more modules to the same power source, the LEDs connected to the registers started to flicker and turn off. I added a few more batteries in parallel and it worke... |
H: Single chip level shifter from LVCMOS to 12 V
I'm working on a nixie clock based on a STM32L476RG microcontroller and HV5530 chips. The microcontroller uses 3.3 V logic while the HV5530 really needs 12 V logic, which is a pain to implement. There are buffer ICs that raise the level from 3.3 V to 5 V, but I was unab... |
H: Why shouldn't two AC sources be connected in parallel?
In data centers, servers usually have redundant power supplies, which makes it possible to plug them to two different UPS units. This way, the server continues to function correctly if one of the PSU goes down, or if one of the UPS units is shut down for replac... |
H: Bandgap Reference 1.25V
[Taken from Razavi's Design of Analog CMOS IC]
Hi, I'm just wondering, how does he get the 1.25V in 12.21?
AI: He multiplies the value of the thermal voltage, \$V_T\$, by 17.2 and then adds the nominal base-emitter voltage, \$V_{BE}\$. Both \$V_T\$ and \$V_{BE}\$ will have been discussed at... |
H: A logic circuit with a NOT condition
I have the following problem to solve and Im a bit confused:
I have a ceramic factory that is based on a circuit with 4 outputs:
timer that outputs "1" when the oven is on (timer)
sensor that outputs "0" when temperature of the oven is too low
sensor that outputs "0" when tempe... |
H: Flywheel current doesn't change direction
The motors are permanent magnet DC motors.
First I power the motor with a flywheel and a motor with no substantial load. (same kind of motor).
simulate this circuit – Schematic created using CircuitLab
I then disconnect the voltage source and the amperage dips negative for... |
H: How to modify an SD card so it will be read only?
I checked SD card pins and their descriptions and saw that there is a "data input" and a "data out". If I covered, removed the data in pin, would it block all the writing requests to the card?
AI: No. It would just render the card completely unusable. (OK, that's ki... |
H: Sample and hold circuit giving distorted output
I'm making a sample-and-hold circuit for a 3 bit Flash/Parallel ADC and to allow the conversion to have enough time to happen I want to maintain the input voltage steady for the duration the conversion will take. I intend on sampling an audio signal from a phone or mp... |
H: Switching MOSFET with isolated gate
I am trying to isolate the battery which powers the gate control circuitry from the battery which powers the hight-current load being switched by the MOSFET. Here is the basic circuit configuration:
simulate this circuit – Schematic created using CircuitLab
Do the sources V1 and... |
H: Signal fidelity from fiber optic crosstalk
I was watching a video about tapping fiber optic cables when it brought up some points from an early US govt document describing security concerns about fiber optic cables. The relevant part:
Tapping attacks are possible at several points within the network due
to comp... |
H: stm32f103 I2C Bare Metal Programming Question
I am trying to send a simple data from STM32f103 to another one. But I am having trouble with my code. I have been working on it since 2 weeks and I couldn't find any solution. I am using PROTEUS to simulate and KEIL to compile.
according to data sheet, after start even... |
H: TL431 Vs Error amplifier
When compensating switch mode power supplies we usually use IC that incorporates error amplifiers, but sometimes there are ICs that come up without internal error amplifiers and so we can either use TL431 or an external OP AMP for compensation.
My question is when TL431 is recommended over... |
H: Cut 3D chunk out of PCB?
I would like to cut a small square out of the middle of a large square PCB.
The tricky thing is, I don't want to cut all the way through the board, just about half way. This would create a 1mm-deep square pocket in a 2mm pcb board.
I could do this with my CNC machine easily, but I want to ... |
H: How does this high amperage LED dimmer work while being so small?
I am trying to make a custom dimmer circuit for an off the shelf LED lamp meant for aquatic plant growth. I found a generic dimmer that many people (in the aquatic plant community) use, and am very curious how they managed to make a dimmer so small.
... |
H: Do "multiplicative" current mirrors exist?
What I am talking about is something like a mismatched current mirror. Like the following where the left transistor and the right transistor are unmatched therefore the drain source current are different by a factor K. Is this possible?
AI: If you're designing the actual s... |
H: In Verilog, does an event control always execute once at the beginning?
As illustrated in the image below, there is an event control with the variable r (for reset). I have not initalized c in the top module, but it shows in simulations that it starts at a low state. The only reason I think this is is due to the c... |
H: How does efficiency of transformer change with respect to primary voltage?
Suppose we have a non-ideal transformer such that secondary load is fixed and we change the voltage applied to the primary side. How does efficiency change with respect to primary voltage? I know there is a relation for the change of efficie... |
H: Coupling aluminium electrolytic bipolar capacitors
Can I use two antiseries electrolytic capacitors to create a non-polarized one, and use it as coupling to the input of an audio amplifier?
I know that electrolytics change capacity as voltage and frequency change, but this doesn't really seem like a problem to me. ... |
H: Equivalent model of my (real) transformer
I have created a transformer using a small cylinder (a tube) made of ferrite. The primary coil has \$N_{1}=5\$ turns of coil wire, while the secondary \$N_{2}=50\$ turns. According to a recent question of mine, a real transformer has an equivalent circuit like the following... |
H: SMPS based on LDO
I present the following circuit found in the datasheet of MC7824 page 24/29 but without any explanation (just the schematic). It seems very strange for me on how to get a switching regulator by using a linear regulator.
Here is the circuit:
By taking a general look to the circuit, we can say that... |
H: Why turn-on speed of a MOSFET is linked to diode reverse recovery time
Here is a quote from section 3.4 "Speed-Enhancement Circuits" in "Fundamentals of MOSFET and IGBT Gate Drive Circuits" written by Texas Instruments:
When speed enhancement circuits are mentioned, designers exclusively consider circuits that spe... |
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