text stringlengths 83 79.5k |
|---|
H: Are large electrolytic capacitors necessary in a servo system that doesn't need to be precise
I have two servos in an autonomous sail boat. One controls the rudder, the other the winch. I try to use both sparingly to minimize power consumption, and so I disconnect each unused servo through an n-MOSFET, and addition... |
H: What are all of the pins of the Beaglebone Black Rev. C serial (debug) header?
The Beaglebone Black Rev. C has a serial debug header with 6 pins. I would like to know what each of these pins is. If numbered 1-6 starting closer to the 5v barrel connector, pin 1 is ground, pin 4 is RX, and pin 5 is TX. What are the o... |
H: Inverting or Differential Amplifier? (Or neither?)
I have been searching for how to calculate Vout in the following operational amplifier circuit, but so far I have come up empty.
I feel it is either an inverting amplifier or a differential amplifier. I have yet to find an equation for an inverting amplifier that ... |
H: Low output impedance vs high output impedance of an amplifier
I read that a low output impedance is desirable for an amplifier. I am unable to understand why from my analysis of the output side of the common emitter amplifier. So looking at the output of the Common Emitter amplifier below, the output impedance is \... |
H: CMOS inverter with feedback
In some circuits such as crystal oscillators, there is a CMOS inverter with a feedback resistor, they all simply say the resistor bias the 'amplifier' and force it to operate in the linear region, such as Fairchild: CMOS Linear Applications:
Due to the symmetry of the P- and N-channel t... |
H: Conversion Process From Single-Ended to a Differential Filter
I have a single ended filter which is quite similar to the one on the following picture;
My question is how to convert from single ended to a differential filter. Especially the inductors and capacitors which are going to the ground?
Should one multipl... |
H: General wiring questions: high power LEDs, relay and microcontroller
I think I understand the Raspbery Pi GPIO pins and most of how this diagram below works, at a high level at least.
First question, it's not clear to me exactly how the middle part with the resistors and transistors works. Can anyone help explai... |
H: Calculating resistor wire properties for my projects
I have a few things I wanna do with the resistor wire. They all involve getting approximate temperature using known voltage. I understand that temperature heavily depends on environment, but what I know now is nothing, which is much less that can be known in my o... |
H: Determining Bandwidth of any circuit
I am getting familiar to SNR, noise calculations, thanks to this forum, however I often come across Bandwidth of the system to calculate resistor noise, to get rms noise from nV/rt-Hz, etc.
I have a pressure sensor (wheatstone) connected to ADC through an Opamp and I have a sing... |
H: AVR simple bootloader - how to call application code?
I am using the atmega328. I want to create a simple test application using a bootloader. I want to: Blink an led at one speed in the bootloader section of flash, and then blink at another speed in application section of flash. these are my fuse bits:
From my k... |
H: Is my understanding correct in selecting ADC resolution? (Noise analysis)
I have posted a similar question before: ADC resolution, considering DSP. And finally I think I know the answer. Could you please have a check on it?
Here is the set up:
The input signal of the ADC has a noise floor with noise density of \$... |
H: What's wrong with my answer finding the resistance?
This is the question and the solution:
Here's my answer:
My answer was incorrect, though I believe my analysis was correct. Can anyone point my mistake? I hope it's not with the signs.
AI: I think I found it:
The mistake happened in Step 3: it should be:
$$
-(-2... |
H: Which is actually an active component?
"An active device or component is something which can provide an infinite energy or non-zero power for an infinite interval"
I learned this definition for an active device in a book, which is valid for capacitor, inductor and batteries (I have evaluated). I was wondering wha... |
H: Why don't we get shocked when we touch a car?
According to this answer to a question about car batteries:
[...] so the entire chassis is an extension of the minus terminal of the battery.
If this is the case, I would expect that you'd get shocked when you touch something metal on a started vehicle if you're groun... |
H: GPS Antenna | When is an Active Antenna really Necessary?
Many vendors provide positioning modules that support active antennas as well as ones that don't. I am using 4 positioning modules out of which 3 of them support active antennas and the other , CC4000 by TI , supports only passive antennas. To be honest I am... |
H: How does this PMOS circuit work?
I've been trying to figure out how this PMOS circuit is functioning.
B_VCC is 5V coming from a USB port on the board, while VCC5V is used elsewhere in a regulator to create 3.3V but otherwise does not exist anywhere else. PSELF is effectively grounded as nothing is being plugged in... |
H: What is this SB component on schematics
Is the SB19 component a "jumper" (0-Ohm resistor)? On the board itself, some of these are placed, and some aren't, leading me to believe that's what they are. There aren't any 0's on them, though.
EDIT: I put 0-Ohm resistor in parentheses because some people thought I was ... |
H: Why do different colored LEDs interfere with each other when connected in parallel?
My very basic electronics education has taught me that parallel circuits are equivalent to separated circuits. To my surprise, when I was playing around with some electronics I found the following:
Essentially I connected two red a... |
H: Determining Voltage and DC/AC from Wiring Diagram for Spark Door Buzzer
I'm looking to use my Spark Core to control my door buzzer in my apartment. I'd like to identify the correct parts I need to build the required circuit, but this seems to be dependent on the voltage and current type that the buzzer system uses.... |
H: Using a digital signal to turn on and off a vibrating motor
I'm designing a circuit with the IOIO-OTG board and a vibrating motor. The idea would be to have a digital pin on the IOIO board control the state of the motor (either ON or OFF).
The motor operates from 2.5 to 3.8 volts and the IOIO-OTG ports provide a 3.... |
H: Average Cycles Per Instruction
We have two different computers with the same instruction set. There are three classes of instructions (A, B, and C) in the instruction set.
Computer M1 has a clock rate of 80 MHz and Computer M2 has a clock rate of 100 MHz. The average number of cycles for each instruction class and ... |
H: PIC USB host and device
I have been designing PIC based systems for several years, but this will be the first time that I am involved in a project based on USB communication. I don't exactly know where to start but I have been searching around the internet for a few days for "PIC USB tutorials". Unfortunately I co... |
H: Bypassing a switching regulator
I am trying to design a power supply for a 3.3 V / max. 340 mA system.
It should provide the possibility for 5 V-12 V input as well as directly providing 3.3 V. Even though it is not intended to connect both input voltages, the system should not break down in that case (at least it s... |
H: Energy harvesting from AC wire
I'm designing a home automation module and finding a way to supply power.
Is it possible to harvest energy from existing AC wire using step-up current transformer?
Also I can only find step-down current transformer for current sensing, where can I get step-up transformer? (Or it's not... |
H: Ideal LC Tank Circuit
It is true that connecting an Inductor (L) and a capacitor (C) in parallel provides oscillation? If so, where do you take the output from?
Theoretically it is explained that once we connect L and C in parallel, we assume one of them has some initial energy either in form of voltage (in case of... |
H: EAGLE: Delete internal layers
I'm doing a Layout and I have some problems deleting an internal layer. As you can see in the pictures below I have 4 layers (1, 2, 15, 16). But somehow I also have a layer called Route 3 (3).
I get the error:
Can't delete internal layers`
as soon as I try to remove the layer in the... |
H: Why is the RC value of a demodulator near the geometric mean of the period of carrier and message signal?
The figure below is a AM demodulator. My instructor told me to chose RC so as to satisfy the following inequality :
Tc << RC << Tm
Where Tc is the period of the carrier wave and Tm is the period of the message ... |
H: Update ATmega168 program with serial
I'm working with an ATmega168 with a Linux based board (TI DM365). The ATmgea168 communicates with the TI over UART.
The Atmel is programmed using AVRMKII and is running fine. I was wondering if there was way to utilize the UART lines and program the Atmel from a Linux environme... |
H: What is this circuit symbol?
Does anyone know what this circuit symbol is? My guess is that it's a surge protector but I'm not sure
Context
AI: According to Edraw: Standard Process Flow Diagram Symbols and Their Usage, it is the symbol for a pump. |
H: What methods are used to protect floating devices against ESD
In conventional circuits you'd like to divert your strike to ground and through a path that diverts the current safely to a grounded chassis or output. That is not possible in hand held devices for example, i'd like to know what methods are chosen for th... |
H: Why do LCD Screens ripple through cameras?
I noticed that when taking pictures of an LCD screen (thank you, laziness to print), that while I look at the LCD screen through the cell phone camera, the screen has both 1) Ripples and 2) Moving waves.
1) You can clearly see in the picture below:
2) You can see them wh... |
H: Getting more information about a transformer
I'm trying to figure out more information about a small transformer on a old board that we are reverse engineering, can someone give me some advices about how can we reverse engineer this transformer? Do the numbers on it represent something?
4783
6610741
AI: The number... |
H: Trimmer pot to fixed resistor conversion
Sorry for the simplicity of this question but I've been struggling on this circuit for a while.
In the schematic link below you'll see a trimmer pot and I simply want to replace it with one/two fixed resistors.
I'm under the impression it will be two resistor to form a volta... |
H: Series capacitor equivalence
I have capacitors of 100uF, 10uF and 1uF; and need a series circuit with these capacitors to form a 0.1uF capacitor, is this possible?
AI: Capacitors associations
Series association
This association gives a lower total capacity than any of its component capacitors. The total capacity, f... |
H: CMOS gate logic switching time based on input vectors
My question is regarding CMOS logic gates switching time based on input.
Say I have a NAND gate and my input vectors are:
00 | 1
01 | 1
11 | 0
10 | 1
So, the output is not switching in case of the first 2 vectors and switches for the rest.
I would like to know ... |
H: Power, Voltage, Current Supplies
I am confused by the use of these three terms in conjugation with supplies.
I read somewhere that the prime objective of the circuit is to provide power rather than voltage? What exactly does that mean. Isn't \$Power = IV\$? So saying that you're supplying power rather than voltage ... |
H: How to determine how much current and or voltage a given circuit "needs"?
My apologies in advance if I make any wrong assumptions. Say you have an outlet that is rated at 120V and 10A. My power adapter for my MacBook says it is rated at 16.5V and 3.65A max. How was it determined that the power adapter needs to prov... |
H: Why is there heavy oscillation in my capacitor discharge circuit and is there anyway to fix it?
I have the following capacitor discharge circuit:
simulate this circuit – Schematic created using CircuitLab
When solving for the voltage across the primary and secondary inductors, I get the following:
Where in the cu... |
H: How do I find the resistance between three terminals?
I'm trying to self-study this problem and I found a bizarre problem with an unusual circuit.
I have never faced this in all the problems that I have solved. What do they mean by finding the equivalent resistance between b and e. I don't even know if this is pos... |
H: Use of the GPS 1PPS feature in a system
I'd like to know how synchronization between the GPS unit and any other sensors is done in a typical system. I understand that the 1PPS signal plays an important role.
Could anyone give me a very simple explanation of the 1PPS signals role?
AI: PPS is not a fundamental func... |
H: Help understanding onboard power supply measurement test connections
I recently came across this circuit for measuring the output of a TPS54620 switching regulator (12V->3.3V). I'm not a power engineer, so I'd like some help understanding the parts in red boxes (presumably used by the power engineer to measure the... |
H: PIC resets when motors work
I'm using a PIC18F452 in my project, and L293d for driving motors. I'm using two completely separate power supplies for driving motors and driving the PIC. completely separate two power packs. a 12 v 1A one for driving motors. the circuit diagram is as below:
My problem is when motors w... |
H: Why should PCB design be mirrored before toner transfer?
I am currently designing a PCB to make with the toner transfer method for the first time. I was reading a guide that said to mirror the image before printing it to the paper. However it seems that the paper should not have a mirror image because when you are ... |
H: How to write on SD card smaller than sector size (512 bytes)
I am writing a library for FAT file system management on STM32 for learning purpose.
I want to use a SD/MMC card connected through SPI bus.
I do some tests with a disk image on PC (I emulate disk_read(),disk_write() with fseek(),fread(),fwrite()) to under... |
H: Tuning LED circuit so LED turns on at specific voltage
I am attempting to add a signal activity LED to my dummy load box. I have constructed the following circuit and so far it does what it is supposed to (lights an LED with signal applied and does not interfere with overall load impedance). I am now trying to tune... |
H: Combine 9V and 1.5V power supplies to make a 7.5V supply
To save on cost, I wish to buy a 9V DC and a 1.5V DC power supply and connect the positive outputs together to create a 7.5V 200mA supply my Plantronics headset needs. That is, 9 - 1.5 = 7.5 across the two negatives at that point. Problems?
AI: The 1.5V suppl... |
H: Reading corresponding pins from a circuit diagram
I am completely new to Arduino tinkering and am trying to make sense on how to wire a 8x8 LED matrix using the following diagram:
This chart is supposed to correspond to this 8x8 LED, 12x12pin LED matrix:
Now, the question:
The physical led matrix has 12 pins on... |
H: Measuring band-limited noise coming from an amplifier
I have a strain gauge amplifier and from my analysis, it will produce a low level of white noise above approximately 1kHz i.e. the power spectral density is flat above 1kHz.
If I measure the output noise with a reasonably decent meter Agilent 34401A it gives me... |
H: Protecting a comparator in a tension measurement device
I am building a device to measure the tension of a conducting wire using an Arduino.
The basic circuit concept consists of two stages:
The wire is placed in a strong magnetic field. Then the Arduino send a 2 seconds saw-tooth pulse going up to 24V through the... |
H: Adjustable charge current from programming resistor for Li-Ion charger - how to change on demand?
I am designing a device which has an integrated Li-Ion battery (single cell, for simple low power portable digital device) and normally charges by way of a buck converter which goes from 12-16V Automotive supply to 5V,... |
H: Is there a good physical model for what happens when a light bulb suddenly goes out?
Sometimes a light bulb just stops working and goes dark for seemingly no reason. Can Dirac δ impulse to a light bulb serve as a mathematical model for what happens so we can assume that the electric current for the light bulb or t... |
H: Magnet that needs power to turn off? Inverse coil?
I have never heard of such thing. But it would really suit my needs.
I'm inventing a device and during it's operation, it should be able to catch an iron object any time (with a permanent magnet). The device should be mobile, so using inductor would really reduce t... |
H: Setting the absolute potential of an isolated DC power supply
I have a circuit that, for reasons out of my control, is powered by an bipolar +/-4V supply. This circuit includes instrumentation amplifiers and so forth that have input headroom requirements of over 1V.
I use an isolated DC/DC converter to produce a f... |
H: What is the rate at which a mobile/cell phone listens for an incoming call or a text in standby mode?
As I understand, a mobile/cell phone, in the standby mode, listens to some kind of circular buffer in its memory for acquired packets from the antenna to check if there's something that regards installed SIM card. ... |
H: Ohm's Law and in-series components
I am doing some practice problems based on what I learned today in lecture. However, I am stuck on this problem:
A 10Ω resistor is in series with a bulb and a 12V source.
a. If 8V is across the bulb, what is across the resistor?
b. What is the current in the circuit?
c. What is ... |
H: Formula for voltage drop vs PCB trace width, temperature, current, and trace length
I need to find out the voltage drop in the PCB traces with respect to the possible factors like: copper thickness, trace length, trace width, temperature, etc.
I found some calculators available at:
http://www.leiton.de/leiton-tool... |
H: Question about CMOS Inverter Oscillator
Using CMOS inverter with crystal and cpacitors, we can make a oscillator. And i find many docs mention the method 'negative resistance'. But, they are not all the same.
The method from TI's doc: Use of the CMOS Unbuffered Inverter in Oscillator Circuits, it separate the circ... |
H: Free spice Model to simulate integrated circuits design
I am using ltspice and I would like to simulate integrated full custom circuits for educational purpose.
I found the NMOS4 and PMOS4 models but there are not enough since there are too ideal there is i.e. no Early Effect.
Are there any possibilities to get a ... |
H: Converting PWM to bipolar square wave?
Is it possible to make bi-polar square signal from PWM signal?
Im talking about 40 kHz frequency and 0.5v /-0.5v peak to peak signal.
The PWM dose is %50. And the PWM frequency is 40 kHz too. The PWM is generated with an Atmel MCU with no extra parts. The MCU digital pins are ... |
H: Decoupling pair of microphones using noisy power source
I currently have a high quality microphone that I am powering from a relatively noisy 8V source, like that shown below. It has a built-in amplifier, and doesn't require any amplification. It just needs power and a bypass capacitor in place, and it handles the ... |
H: Transmitting HDMI/DVI over an FPGA with no support for TMDS
I'm hoping to be able to output HDMI/DVI-D for my next FGPA project but my FPGA doesn't have native support for TMDS outputs. The FPGA is a Spartan 3E and I believe it only has support for LVDS differential signalling.
I read a lot online about differentia... |
H: Do they make triangle-shaped headers?
I've been working with some PIR sensors from Panasonic, and I was wondering if there are any types of female headers/connectors that I could use to wire the three pins of the sensor without directly soldering wires to the connector. I've been looking, but I haven't been able to... |
H: Given a load, how do you calculate whether it is capacitive or inductive?
If the impedance at the load has the form of \$Z = R + jX\$, where \$R\$ and \$X\$ are positive real numbers, then then network is called inductive. If \$Z = R - jX\$, then the network is called capacitive.
Why is this the case and what do we... |
H: Image Sensor sensitivity
I am not sure what really the term "sensitivity" means when characterizing image sensors, so I will describe what I am looking for in the sensor at the following conditions:
the exposure time is very short
the intensity if light is very low
Therefore, I need a sensor that will allow me to... |
H: Can avrdude address individual usbtiny programmers?
I'm envisioning a panel programming jig. In my mind, it consists of a Raspberry Pi, a powered USB hub, and a collection of usbtiny clones each connected to a pogo jig and a target on a panel.
The only question I haven't yet worked out is, when invoking avrdude, I ... |
H: Automatically switching from 9V battery to DC wall adapter on insertion
I have a simple circuit that runs off of a 9V battery. I'm re-designing it so that it can also run off of an external 12V DC source (ie: a wall adapter). I want to design the circuit so that if both the battery and the wall adapter are connecte... |
H: Low battery level circuit - Changing "trigger" level
I am re-creating a simple low-battery level circuit that turns on a low-power LED to indicate that the battery needs to be changed. The circuit is shown below.
There are two things I would like to change on this circuit.
The cutoff voltage is approximately 6.9V... |
H: Low noise voltage regulation
I have a circuit which currently runs off of either a 12VDC wall wart adapter, or it falls back to a 9V battery if the wall wart adapter is not connected. My circuit currently uses a chip which requires a clean 8VDC source in order to run.
Right now, I just have an 8V LDO regulator bur... |
H: What happened when I join two different materials?
It is noob question cause I am noob, but if I have two different materials with different amount of electrons and I join them (just in hand if you know what I mean), why there is no electric current? They should try to balance the electrical potential or?
AI: There... |
H: Wheel speed from Shimano dyamo hub using arduino
I'm trying to figure out a way to extrapolate wheel speed from the Dynamo hub I just purchased. I outputs 6V 3W AC, and I would like to potentially measure it using an arduino if possible, I' assuming I would have to measure the sinewave somehow. Any ideas?
AI: The d... |
H: How to make valid harness port when generate sub-sheet from vhdl
I have an VHDL file (a block) with huge count of the different port that can't combined into the one bus because they have different names. These signals will be further connected to different parts of the circuit. I want to "create sheet symbol from ... |
H: Reliable connectors for digital sensors
I have designed a data collection device which is mounted on a moving vehicle. Is there any recommended connectors that can survive high vibrations for digital sensors?
AI: Delphi Connection Systems has some great products that are designed for automotive applications and som... |
H: Calculating DC Brushless Motor Position
I am using a brush-less motor in one of my projects and I need a decent method of sensing the motor position so I know what coils to turn on and off. I looked a bit into sensing Back-EMF, but I did not find anything that would suit my needs. I thought about a method to monito... |
H: Monostable and Astable 555 Timer
To begin with, I must say this is kind of a "homework" but I tried to do it on my own and I haven't succeed maybe someone can help me out with this matter.
We're learning about digital systems, circuits and so on. Therefore, our next laboratoy is going to be about Monostable and Ast... |
H: What are similarities between RTC DS1374 and RTC DS1307
I mostly work in software and not good in reading Hardware data sheets.
I need help in understanding the similarities between RTC DS1374 and RTC DS1307,From below link I could make out that both share the same address on I2C bus and have same set of registers ... |
H: Setup Time, Hold Time - What is the underlying principle for having them?
I'm learning about setup time and hold time of a FF connected to a bus. But the textbook fails to explain exactly why are those needed in an operation. Isn't a FF always powered on and attentive to bus signal changes? How does turning on the ... |
H: Splitting DC power supply risk?
I am looking into taking the power supply 12V output of my PrintrBot and plugging a very simple parallel circuit with some LEDs.
I know I can connect a parallel circuit similar to this Splitting a power supply between two circuits. And it would be particularly easy if they use the s... |
H: How to calculate current going through an LED
I'm a beginner to electronics. I want to find out how to calculate the current in the following circuit. (I know how to calculate total resister value in serial and parallel resisters in order to calculate the current, but is it possible to calculate without knowing the... |
H: My voltage multiplier (cockroft-walton) will not charge my capacitor bank past 150v. How can I fix this?
I got 5 free 450v 4700uf capacitors that I put in parallel to form a 23500uf 450v capacitor bank (2.4kJ) in hopes of building a can crusher and later a railgun. I built a voltage tripler from four 350v 10uf capa... |
H: Replace potentiometer with digital version (Speakers)
I am trying to get my PC speakers to be controlled by my arduino. I've taken apart the control and it seems very straight forward, just need a few questions about subbing the manual pots for digital ones.
Volume circuit looks like this (R/L for right and left ch... |
H: Apple iPod 30pin to micro usb
Not sure if this is off topic. I have an old ipod dock with a 30 pin male connect and I want to switch it out to a male micro usb. So that I can use the dock. I don't want to use an adapter as I want it to look natural.
I was simply going to rewire old connector to the micro usb.
Ipo... |
H: Understanding Transistors
I'm relatively new to electronics and I'm trying to understand how to use transistors, but I seem to be misunderstanding something.
I'm trying to implement a transistor switch as described in Electronic Formulas, Symbols & Circuits on p 118. The diagram above is based on my understanding ... |
H: Is it possible to control many microcontrollers using a single microcontroller/microprocessor?
I am presently working on Home Automation Projects, having no of home appliances. I would like to know the ways that I can control many micro-controllers using a central micro-controller/micro-processor(wired/wireless)?
A... |
H: Class A power amplifier: voltage and current
I am always having problems knowing the difference between providing a load with a voltage and providing the load with power.
So we have a Class A common emitter amplifier with a load resistor connected to the connector. As long as the transistor is in the linear region,... |
H: Mutual inductance of two loops
I got to measure inductance of circuit with two loops connected like this:
simulate this circuit – Schematic created using CircuitLab
simulate this circuit
The box measures \$L\$. I have this formula $$M=\frac{L_1-L_2}{4}$$ and when I compute \$M\$, it's negative. Is that ok? What d... |
H: Important Parameters to Check while Chosing a GSM/GPRS Antenna
what technical parameters decide the performance of a GSM/GPRS antenna? (excluding power consumption and size)
I have found out several antennas that have 3dBi gain. And I want to chose between them. Some are PCB antennas, some are external antennas and... |
H: Why are 5 Volt 7-8 Amps chargers not available for charging phones quickly?
Available phone s chargers have either 0.5, 1, 2 Amps rating depending on the batteries (varied capacity) used. Why is it that 7, 8 Amps chargers are not available ?
if the limitation is in the Lithium Ion batteries we use... then what's th... |
H: Gerber - is my understanding of solder mask layer (GTS / GBS) correct?
I've just had a PCB manufactured for me, but it seems like the solder mask is only applied to where the copper is.
I'm trying to figure out if it's my fault or not.
According to my understanding there supposed to be solder mask everywhere on the... |
H: PIC18F2550 Loop Counter Overwritten by sprintf
I have the following code compiled with Microchip's MPLab and XC8 compiler and running on a PIC18F2550 which is doing something rather odd:
char output[20];
int i = 0;
char currentStatus = readShiftReg();
for (i = 0; i < 8; i++) {
if ((currentStatus & (1 << i)) ==... |
H: Setting MSP-430 toolchain in linux
Can anybody please guide procedure to setup tool-chain for MSP430 in Linux (particularly Ubuntu)? I am using MSP430 launchpad (MSP-EXP430G2), and I need to setup compiler/build tools and debugger drivers.
AI: All the tools are in your apt repository:
$ sudo apt-get install gcc-msp... |
H: Does changing the gap between plates change the capacitor voltage?
Consider an ideal capacitor which has a length of \$\ell_1\$ between its plates. The capacitor terminals are open; they are not connected to any finite valued impedance. Its capacity is \$C_1\$ and it has an initial voltage of \$V_1\$.
What happens ... |
H: Is IRFD 014 an appropriate FET for switching an array of (about 40) UV LEDs?
We have an array of UV LEDs. The LEDs are rated at 3.2 V – 3.4 V at 20 mA, and we plan to use a 5 V supply for simplicity. We will be using a dedicated 100 Ω resistor for each LED (the power dissipated at each resistor is at max. 40 mW, so... |
H: Bluetooth headset button replacement
I have a Samsung HM1300 headset and want to emulate the call button signal via a microcontroller.
Here is a pic of the inside of the headset:
(Original)
The gold button is the call button. I see the solder points (the 4 points around the button). Do you think it's plausible to ... |
H: Should I assign currents to voltage sources in my circuit analysis
Mortals! I apologize if my question may seem, foolish, but I have a need of understanding a process in analyzing circuits. You see, when we are looking at resistors (non-sense, my lightning never meets such "resistance") in a circuit, and trying to ... |
H: Ethernet UDP diode
I want to create a device of some sort where I am absolutely positive that only UDP traffic can pass one way. Of course I could setup whatever old router I might have, the thing is I want to make it as small as possible and with as little power consumption as needed. What components could or sh... |
H: can SOT883B package BJT transistor switch a relay with 21.1mA coil current?
I am planning to use miniature BJT in a circuit , but I haven't used them before, The specs of NXP BC847BMB TRANS, NPN, 45V, 0.1A, SOT883B shows 100mA as collector current, I am worried if it can switch a G6K-2G-Y-DC5 relay.
The relay me... |
H: Voltage Regulation: Cascading vs. Individual
Consider my design:
Input power is either 8.4V (VBAT) or 15V (Wall Wart).
From there I need several voltages to power all the components on that board. Here is a list of voltages:
5, 3.3, 2.5, 1.85, 1.8, 1.5, 1.25, 1.2, 1.0 and 0.75.
Without going into the merits of what... |
H: Are NTSC and PAL affecting display rate
I understand that the NTSC TV signal is 30hz and PAL is 25hz, but if NTSC and PAL are TV signal standards how could they affect display rate(Hz) for input devices e.g. when you connected and old game console (signal goes from console to TV). If I am not wrong analog input was... |
H: Potentials at terminals of battery connected to ground
If we have a battery connected like so:
simulate this circuit – Schematic created using CircuitLab
Am I correct in thinking voltage on the positive terminal relative to ground is +9V and on the negative terminal is -9V?
AI: Trying to build this circuit in rea... |
H: Building "AND" and "OR" gates from tri-state drivers & inverters
I'm working on a digital circuits assignment which asks me to prove that if you have tri-state buffers and inverters, you can build any combinational logic circuit.
My attempt at doing so would be to create an "and" gate and an "or" gate, because "a... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.