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H: Help to design an amplifier
I need help designing an amplifier that is capable of providing 1 W to an 8 Ohm speaker. I have 3.3 V, 5 V or 18 V supply available to power it.
I also have only one power supply available that has no negative output.
The signal is coming from an AVR as a 3.3 V PWM signal. I have followi... |
H: Extending LED length
Completely new to electronics, I've just begun to play with an Arduino. I was wondering, if I wanted to make an LED sculpture, what is the correct way to extend the legs of each LED so that they stand about 3 inchs long and are bendable? Is there a particular type of shielded wire that has enou... |
H: Arithmetic Overflow ATmega328
I have written the following function to calculate the current timestamp (since 00h Jan 1 1900). The output I get is:
Current Time & Date : 20:5:32 25/7/2014<\r>
2014 7 25 20 5 32<\r>
retval 1 3597523200<\r>
retval 2 3597523200<\r>
retval 3 3613161600<\r>
retval 4 3615235200<\r>
retval... |
H: Which is good method for step down 50Hz, 230V AC
Which is low cost and safe for step down 50Hz 230V AC into 12V?
Transformer or reactance or Regulator IC ?
simulate this circuit – Schematic created using CircuitLab
AI: Which is low cost and safe for step down 50Hz 230V AC into 12V?
The key word in the question ab... |
H: How to measure power of my device?
My device is working with ten 1 watt LEDs. How can I measure the power consumption of my devices?
AI: Power (P) is voltage (E) times current (I):
$$ P = IE $$
This works for any individual part, or an entire circuit.
If you wanted to measure the power used by your entire circuit, ... |
H: Relation between drift velocity & conductivity of a doped semiconductor
Here is the problem, and I am stuck.
When an electric field with strength \$1 \times 10^3 \text{V/cm}\$ is
applied to a p-type uncompensated Si sample at room temperature, the
electron drift velocity, \$v_d\$ is \$ 1 \times 10^6 \text{cm/s... |
H: How can I know how much power can I generate?
Let's say we have a wind power of 6,831 megawatts. How can know how much power (i.e, megawatts/hour ) it can generate per year?
AI: If you always had 6831 megawatts, then this is how you would calculate how many megawatt-hours in a year:
6831 megawatts * 8765.81 hours =... |
H: Connecting separately powered devices via serial
I have a small issue connecting an FTDI USB to 5V Serial adapter to an externally powered PIC microcontroller. They are connected via serial connection. The USB connection powered the FTDI and a battery powers the PIC.
Serial
Laptop --- FTDI ========... |
H: Question on 3DS power adapters, minor voltage difference
I am going to be traveling overseas and bringing my Nintendo 3DS which the adapter outputs DC 4.6V 900mA.
I found an unofficial USB cable to charge it and I was curious if the minor variance in the voltage would cause any issue. Say if I use an iPad 5.2V char... |
H: The same flag for an interrupt
I think I'm mixed up a bit in NVIC of stm32 MCUs. I took a look in the SPI.h of the STM32F10x standard peripheral library. I don't know that why while there is SPI_I2S_IT_RXNE for checking the status of recieved buffer we have SPI_I2S_FLAG_RXNE flag for this porpuse?
look:
AI: The SPI... |
H: How to select most efficient motor for generator?
First post. Please forgive me if this is a stupid question. This post can be broken down into two questions.
I am building a bicycle generator, but am new to the field of EE. I am trying to select the most efficient means of generating electricity, but have only be... |
H: Does any thermal fuse with the same cut off temperature work?
Would any thermal fuse cutoff for 216°C work as a replacement for the fuse in the picture below?
AI: Any similar 216°C thermal fuse with a 10A or better current rating and an appropriate voltage rating should be fine.
For example, a CANTHERM SDF DF216S... |
H: no-load voltage on ac-dc adapter
I recently acquired a toy that uses this transformer:
but since I live in a 220V area, I cannot use it directly.
I have this generic AC-DC adapter:
which in theory is all I need because it has a 4.5V output and enough amperage.
However, I'm a bit concerned since when measuring the... |
H: How do you cover up exposed high voltage pcb traces?
This is my PCB:
The thick lines should be able to pass a high voltage (230VAC) signal through it. The board will be kept inside a enclosed box.
In my case, the signal on the board is only one polarity so unless someone is purposefully trying to kill themselves, ... |
H: Fourier Transform in real life
what is the frequency spectrum mean in real life ? , if we said x(t) , we mean that each time we have an output which is represented by x(t) , also it can represent decaying ,growing of an object , it can represent the power of an object accroding to it's time . but how can i understa... |
H: How ADSL Demodulates (restores the order) the signal for dummies
I am not an electric engineer so sorry for questions that might miss some fundamentals.
I am trying to understand the ADSL modem. The ADSL modem sends the data over different frequencies in parallel. However I have learned that faster frequencies mea... |
H: Hooking up a 3 wire load cell and measuring the output on an ADC
I am trying to get 4, 3 wire load cells connected together in the form of a wheatsone bridge correctly to measure weight. I have the following schematic used from this http://www.nerdkits.com/forum/thread/900/:
I am giving e+ 3V and e- to ground. I am... |
H: How to use LM56 to switch on/off a 2kW heater
I have an oil heater at 220V/2000W so lets say 10A. I was thinking of creating a circuit to switch the oil heater on/off with a LM56 (http://www.ti.com/product/lm56). Is it possible using a relay or optocuplor? I don't have experience with high-power devices.
Thanks!
AI... |
H: How to check the source of reset in ATMEGA644p
I am trying to find the source of reset for ATMEGA644p, but I couldn't find the way to do it!
MCUCSR gives error in atmel studio as not declared and the datasheet also doesn't have it.
AI: According to the ATMEGA644p datasheet section 9.3.1 page 57 , there is the MCU S... |
H: Resistor Magnitudes in Voltage Dividers
I recently made a voltage divider that uses a 10 ohm (top) and ~90 ohm (bottom) to divide a source voltage of 5v to 4.5v. The resistor values I used was somewhat arbitrary, in that I just picked a random top resistor value based on the resistors I had and calculated the botto... |
H: How to install an embedded GPS patch antenna
How should I install an embedded GPS antenna?
Here is the antenna in question:
the antenna http://www.robotshop.com/media/catalog/product/cache/7/image/800x800/9df78eab33525d08d6e5fb8d27136e95/s/e/seeedstudio-embedded-gps-antenna-for-gps-bee.jpg
http://www.robotshop.com/... |
H: Logic design k-map question
Hi everyone I'm trying to minimize this boolean function F(A, B, C, D) = ∑m(7, 8, 9, 12, 13)
don't care terms(2, 3, 6, 10, 11, 14). My main question is about the row of don't care terms in the bottom row, do I include this as a group of 4 when minimizing? I assumed I should and got this... |
H: Reading switches without a common ground from Arduino
I'm trying to interface a steering wheel control interface with an Arduino.
The interface connector has 6 pins, A to F.
These pins are interconnected with 8 push buttons, SW1 to SW8:
simulate this circuit – Schematic created using CircuitLab
These buttons don't... |
H: Powering 12v led strip from 16v dc
I want to power up about 2 meters of led strip from a 16.5v dc battery (4s lipo).
I know there are dc-dc converters, but I rather avoid using them due to weight (rc plane)
The lights will not be used very often, probably they will stay on for about 30 minutes.
I have read somewher... |
H: Driving EL wire with Supertex HV850 family drivers
I was considering driving EL wire with Supertex'es ICs or some equivalent ICs from another manufacturer. The ICs are designed to drive EL panels not EL wire. Would this still work?
Supertex'es ICs are rated for "lamp sizes" up to 42 square inch. My wire is 2.3 mm i... |
H: Non-glass heating element for an etching tank
I have been using below glass heating element (the part name is ET20) on my etching tank.
The problem is that the glass is too gentle that breaks very easy for many reasons, I already needed to replace a few of them.
I wonder if you could suggest me any non-glass heati... |
H: G.711 for dummies
I am in midst of some online telephony course, and there are questions regarding which I have no one to ask but this community.
G.711 volume encoding. I have some difficulty to understand how exactly G.711 encodes the absolute volume, if at all. The standard does seem to address it in mapping the... |
H: Size of SMD pads for components with high tolerances
I'm building an Eagle component for an LSM115J.
The connectors on this part have fairly large tolerances (1.85-2.21mm width, 0.76-1.52mm length). There is no recommended land pattern.
Should I go for the largest size (so the part will never need to be partially s... |
H: Why do some diodes have a glass package?
Put simply, why do some diodes such as most Zeners and Schottky diodes have a glass package as opposed to the more traditional plastic package?
Is it ease of manufacturing, thermal properties, or some other electrical phenomenon?
AI: Early semiconductor diodes were mostly gl... |
H: What is the difference between TFT LCD interfaces?
I am looking at driving a small TFT and have found that the driver chip supports various interface methods, however I can't see why I would choose one over another.
The options are:
i80
SPI
VSYNC
RGB
Can anyone describe the pros and cons of the different interfac... |
H: K-map Minimization
I'm having trouble minimizing this k-map for ∑m(0,5,9,12,15) and converting the SOP into a design using only NAND's and NOR's. I think the SOP should be (ABD')+(A'B'D')+(AC)+(A'BC'D)+(AB'D), but I'm confused because there is a single 1 that I can't group. Sorry for the poor formatting and thanks ... |
H: Antenna Diversity: two Yagi antennas to the Rx and Rx/Tx u.fl-male points on the wifi-NIC?
I looked at the BCM4312 file - available as as doc or a pdf - and it says:
BCM4312 has 2 radio chains, one is a dedicated Rx chain, the other is shared by TX and > RX chain using an RF switch
Support Antenna Diversity
RF O... |
H: Independent watchdog (IWDG) or Window watchdog (WWDG)?
I'm still searching to find an answer for this question:
Since the STM32 MCUs already have a perfect watchdog (I mean the Window watchdog (WWDG)), why is there also a simple watchdog (Independent watchdog (IWDG)) ?
I found this page that has said:
ST Microele... |
H: Two amplifiers in single speaker with different frequency power
I have two amplifiers using LM386. One of them I plan to use for normal amplifier and the second one I want it to be a low pass amplifier/bass amplifier and both of them will be connected to same speaker. My question is: is it possible to run two ampli... |
H: Minimum cover for this K-MAP to find minimum SOP; which is better, and why?
I used this K-MAP to find the minimum sum-of-products expression for this collection of minterms.
I see that minterm-one could also have been "covered" by grouping it with minterm-five.
I opted to "cover" minterm 1 with the largest possible... |
H: CD4029 does not initialize at 0
I am attempting to build a very simple 4 bit counting machine using a CD4029 ic and a 555 timer. I have built my circuit on a breadboard and everything seems to be working perfectly, however on the power up of the circuit the outputs id the CD4029 seem to be set to random values and... |
H: Regarding Microchip XC8 compiler's registers and bits definitions
I'm going to take a random 8-bit Microchip microcontroller: PIC16F887.
Let's have a look at how the XC8 compiler (and the HI-TECH PICC, for that matter) is defining a register (SFR) and its coresponding bits in the header file of the device (/opt/mic... |
H: What are the advantages of a shunt resistor vs. a hall effect sensor?
I'm constructing a boost converter, and I need to measure both the input current and the output current. Currents range anywhere from 25A to 200A, depending on the model. My controller is referenced to the negative rail of the converter. I've bee... |
H: Low pass filter value for DAC
I was wondering, how to calculate the values needed for LC/RC filter when using it for digital to analog conversion?
Also, how does the square waves frequency affect DAC ?
For example: lets say I have 10 kHz 5V square wave output to the LPF. From it, I would like to get an analog val... |
H: How to choose what a power supply to drive 2 x 10watt RGB LEDS?
I'm trying to figure out how to determine what power supply I should be using for different types of LEDs for this and future projects.
I have 2 x RGB LEDS:
Forward Current: 350mA
Forward Voltage:
RED: 6V - 6.6V
BLUE: 9.6V - 10.2V
GREEN: 9.6V - 10.2V
... |
H: why making processors is Monopolized on 3 companies
why only there are only 3 companies allowed to make processor "intel - AMD -apple" why others can't make one ..
i know that making processor is difficult and needs a huge techno , but what about google or samsung aren't they have the qualified techno ? so why t... |
H: Understanding resistance in open and short circuits
I am continuing to try to learn a little about Electronics and I came across the following problem for which I am not sure I completely understand the calculations. In other parts of the book, they showed the calculations, but for this question they did not.
Ima... |
H: Unplugging a router from the wall socket
When the internet appears to have crashed, the service provider invariably gives this advice as a first line remedy: unplug the router from the wall socket, then wait 5 minutes, then plug it back in. Many times this remedy works.
Question: Why does the router care if it's b... |
H: DSP - practical even or odd functions
Signals can be classified as even, odd, or a neither - in which case they can be broken up into their even and odd components. Theoretically its all very nice to be able to say that yes that function is symmetric about the origin, but practically is this ever actually achievabl... |
H: Radio Receiver IC
I am a Junior EE student that is interested in putting together a small radio receiver project for fun and to get some general practice with design. I have found these receiver chips from Silicon Labs Si4732/34/35. I would like to hook up the final design with a small LCD screen to show the freque... |
H: What kind of PC board coating is this?
I recently came into possession of two large (approx. 3x4 ft) copper-clad fiberglass boards from a junk sale. These boards are consistent with typical printed circuit board material (thickness, flexibility, internal appearance, etc.), save for a blue coating on both sides. Her... |
H: C Documentation for AVR Atmel Studio
I am new to AVR programming and have tried couple of tests on assembly language and were successful.
However, I would like to try out programming in C with Atmel Studio.
Could somebody tell me where I can find the complete documentation of what is available for C language in Atm... |
H: Why do op-amps keep amplifying?
I was reading an old copy of Horowitz and Hill's The Art of Electronics and I am trying to wrap my head around operational amplifiers in negative feedback circuits.
As the book explains, as the op-amp sees a positive voltage at its inverting input relative to its non-inverting input,... |
H: Arduino I2C level conversion
I'm working with Arduino Uno (Rev 3) to interface a DRV2605 haptic driver to control several ERM/LRA motors using I2C.
As I look at examples on the web, I see everyone uses a I2C level conversor to drop the voltage from 5v to 3.3V, despite according to the driver datasheet and the I2C ... |
H: How to debug large I2C bus?
I have a circuit board with lots of soldered SMD chips. There are a few I2C components connected to the same bus and the bus is also connected to a "bus switch" isolation switch. Unfortunately the bus is behaving weirdly. It seems to have large capacitance, and my microcontroller seems u... |
H: GPS parity decoding, how to get D29 and D30 of previous bits?
According to ICD GPS 200C, to decode the bits of a word you need to have the bits 29 and 30 of the previous word, this means that to get the bits 29 and 30 of the previous word you should know the bits 29 and 30 of the word before and so on. Now my quest... |
H: Getting the right frequency from an oscillator circuit
I have constructed an oscillator circuit using the resistor and capacitor values shown in the diagram above (from the Proteus ISIS simulator).
I run the circuit and use a switch to trigger the oscillator. I get the following waveform.
Using cursors in the o... |
H: USB lights up simple circuit but not coin-cell
I have 13 adafruit LED sequins in parallel hooked up to a CR2032 coin cell. This cell is also hooked up to an adafruit Gemma board (Arduino-like board using an Attiny85). Pads D0 & D1 on the Gemma each connect to a single LED sequin. D0 & D1 can do PWM, so the Gemma's ... |
H: Powering SIM 900 gsm
I bought a sim900 (the chip itself, not a module) and have gotten stuck trying to figure out how to power it. I hope to power it using a pin from my RBBB arduino clone, which outputs 5 volts and though sources differ, either 250mA or 300mA. It uses a L4931 power regulator, if that makes a diff... |
H: What happens if SINR is < 1?
What happens if the SINR of a signal is less than 1 in a (wireless) network? Is that practical at all to have a SINR < 1? Using the Shannon capacity formula, it seems that we must be able to have SINR < 1, but we get a rate < 1 bits/sec/Hz.
AI: Yes, it is practical.
For example, if you ... |
H: DC shunt generators problem
One of the questions in my book goes like this...
'A shunt generator delivers 450 Amps at 230 volts...'. The resistance of the shunt field, armature and brush contacts are given.
I get that the 450 Amps is the current passing through the load. But how can the voltage(230 volts) be const... |
H: Meaning of temperature coefficient for resistors
Is temperature coefficient of a resistor about the temperature of the resistor or ambient temperature or are they the same thing? What I mean to ask is that: Lets say I have a resistor and I have no data sheet about it and I want to find the temperature coefficient. ... |
H: Accuracy in translating voltages to currents for shunt resistors
I apply a constant 4ma current I to a resistor R and I measure a voltage V across.
so the resistor \$ R = \dfrac{V}{I}\$.
But when I apply \$ I_2=20ma\$ to the same resistor R and I obtain the voltage \$V_2\$ then the resistor \$R= \dfrac{V_2}{I_2}\$... |
H: STM32F103 Systick Interrupt stopped working when debugging in ram - (Coocox IDE)
I tried debugging my code in ram in order to increase the flash's life (only rated at 10k writes minimum)
Anyways, I have tied the boot0 and boot1 pins to 3.3v and set the compiler to debug from ram like so:
When I debug my code this ... |
H: VHDL 'buffer' vs. 'out'
I was wondering about the 'buffer' i/o option for entities in the VHDL language. I have found that my code is much cleaner if I use the 'buffer' option instead of 'out' in any circumstance where I want to act on the outgoing signal somewhere within the entity. I find that I can think of very... |
H: making Tphl and Tplh equal
Let's say we have the following netlist
* Standard cell circuit
.global VDD VSS
.prot
.lib '.\reference_models.lib' TT
.unprot
***********************************************************
.SUBCKT ZP_NAND2 QN A B
M1I1 N1N9 B VSS VSS N W=WN L=LN
M1I2 QN A N1N9 VSS N W=WN L=LN
M1I3 ... |
H: LEDs flash at the same time and not one at a time
As you can see on the illustration below, I have a voltage supply (a keyboard made of two piezo elements) with two terminals. Each one drives one LED, but since I've added a buzzer in parallel with both LED, my circuit drives the LEDs at the same time
Do you have a... |
H: Help interpreting TIP127 datasheet
I'm trying to build a constant current 2A amplifier using a TIP 127. To be honest, I have a lack of transistor knowledge.
I decided to analyze a few existent circuits with a TIP127 and the datasheet.
One of circuits mentions a voltage drop of 1.2 v between Emitter–Base, Is this a... |
H: Charging 10 1.2V nicd batteries
I have 10 x 1.2V Sanyo NiCd batteries. They are connected in series. I would like to charge them. The thing is, I don't have a charger. I looked up chargers and they are all quite expensive(I live in India). I would like to know what voltage AC to DC adapter should I get to charge th... |
H: Theory question about "j" imaginary unit (AC circuit analysis)
I have just started to learn about AC network analysis and have some questions about "j" (or "i" on my calculator), the imaginary unit. My book doesn't go into a great deal about this, and jumps right into formulas and substitutions (more practical app... |
H: Calculating the peak output voltage from RMS power of an audio amplifier
I want to calculate the peak voltage output of an audio amplifier when driving at its maximum rated power, a loudspeaker.
For example, an amplifier rated at 50 W RMS into 8 Ω, driving an 8 Ω loudspeaker.
This wikipedia article tries to explai... |
H: How do I keep my constant current source constant?
So I am trying to created a current source that will be used to drain a battery at specific time intervals for a specified duration.
simulate this circuit – Schematic created using CircuitLab
Here is the circuit that I am attempting to use, pulses from the square ... |
H: How to keep rarely-used Li-Ion batteries functional?
I have many gadgets around the house that I don't use often, recently I notice that a battery failed on an Mp3 player not used for a year. The battery now has a life of 1 minute from the original 5-7 hours.
What would be the maximum amount of time to leave a Li-I... |
H: Will 74HC595 as LED sink damage LED when pin goes high?
If used as a LED sink, what happens if a 74HC595 pin goes high? Might the LED blow?
I expect that when a pin is low, current will sink and the LED will light.
What about the opposite condition? When a the pin goes high, might there be risk of blowing LED's d... |
H: Connecting power source to Arduino's 5V pin
I have an Arduino board connected to a Neopixel Ring. This Ring draws more than 0.5 Ampere, so it needs its own power supply (not drawing power via the Arduino board)
I found this schematic that connects a Neopixel and an Arduino to a single power adapter. To my surprise,... |
H: In what situation should I keep the brown-out detection feature OFF on a microcontroller?
When the power supply on a microcontroller falls under a certain threshold, a brown-out conditions occurs and RAM may get corrupted. Provided that every power down sequence of the circuit can mean a potential brown-out condit... |
H: What are .C1 and .C2 Gerber files in Altium 14?
I am currently working on a project and I'm about to get the Gerber files checked by FreeDFM.com. My question is, in my Gerber files, there are a couple that have the extension .C1 and .C2. In FreeDFM.com they want me to specify what these are (Inner copper layers, to... |
H: Energy dissipation in RC circuit given AC sinewave input
I'm implementing a low-pass RC circuit that as an input will have an AC sine wave voltage input. How can I calculate the average power dissipation in the resistor, given R, C, peak (or RMS) voltage applied, and frequency?
Edit: Please assume no current draw f... |
H: SRD-05VDC-SL-C 5V DC relay not working with XY-DJM-5V
I'm just a beginner and need some assistance. below is a diagram of a 4CH reciever which works fine with some leds and it reports 5V positive on Data0 when holding channel 0 on the transmitter. What's not working is when attempting to use a 5V DC relay as shown ... |
H: Neophyte question about AC vs. DC (especially for powering a home)
Here in the United States the electricity grid is AC. I have heard that AC allows transmission of power at greater distances with less loss. However, with the advent of solar panels, it would seem that one could generate DC power directly and powe... |
H: Adafruit trinket power question
I am reading the Adafruit Trinket tutorial here. It states that BAT+ is used for battery INPUT:
If you want to power the trinket from a battery or power adapter or solar panel or any other kind of power source, connect the + (positive) pin here!
So I'm slightly confused by the Ada... |
H: What is the difference between registers, flip flops and latches?
I want the answer to the very basic level. I know what they mean individually, but what I am looking for is connection between them.
AI: Flip-flops are single bit devices with two stable states. The outputs are typically Q and \$\mathsf{\small \over... |
H: Why isn't homemade hardware a thing
What prevents someone with some funding from creating and selling their own hardware? Let's ignore the legal side of things and assume the only limit is technology.
Could someone create something akin to a 1995-2000 time period processor without specialized equipment? What about ... |
H: Failsafe for home automation with Raspberry Pi
I have a Raspberry Pi driving a home automation system. I have connected a bunch of lights to the network. The GPIOs of the Pi connect to a relay board that switch the lights on and off. What I need is failsafe + alternative switches. These switches need to work even i... |
H: Creating with BGA
I have a project that I've begun to work on, it's sort of an embedded PC type project, with a iMx6 arm processor. However, since this is a (potentially) commercial venture, we can't use prebuilt boards like the Pi etc. I have a thorough understanding of creating PCBs, however I've never made one w... |
H: High frequency, low noise clamp circuit
I have an analog circuit that outputs voltage between 0-5V. A simple representative circuit is given below.
The ADC can tolerate up to 4V and the interesting signal that I like to digitize is between 0-3.3V. In other words, it is ok to read all 1's at the ADC if the signal ... |
H: Planar process vs. 3D chip
As far as I know, the planar process of making IC, especially CMOS IC, is already a 3D process because a layer is added on top of an existing layer to realize various things (cf. Wikipedia IC Layout). So, in my opinion, an IC is already 3D because there are multiple interconnected vertica... |
H: Initial state of SN74AUP2G80 dual FF
My understanding is that a basic FF will in general power-up into a meta-stable state that then resolves to either H or L (more or less quickly).
My question is, does this apply to current real-world parts such as the dual D-FF 74AUP2G80, or do these parts contain some circuitr... |
H: Patient protection resistors in the biopotential amplifiers
In biopotential amplifiers like ECG amplifier, I often see protection resistors (around 100kohm) between electrode and the input of instrumentation amplifier or ECG amplifiers like ADS1298. I understand that the resistor are supposed to limit the current f... |
H: Reverse current with Peltier (TEC)
Trying to control a Peltier to cool and to heat.
Does the following code allow me to reverse the current to switch cooling/heating depending on whether I input "a" or "z"?
Source: http://garagelab.com/profiles/blogs/how-to-use-a-peltier-with-arduino
int peltier = 3; //The N-Chann... |
H: Wien bridge using single potentiometer
I'm making a function generator which works in the audio range for a college project. I'm not allowed to use microcontrollers or any digital chips. So I'm using a Wien Bridge oscillator with a pot to generate variable sine wave. It is followed by a Schmitt trigger to generate ... |
H: Building a regulated power supply AC-to-DC
What components do I need to build a regulated power supply with an input voltage of 220V AC and outputs of 3V, 6V, 9V, 12V? Assuming max. current of 1A in each outputs.
AI: Option 1: A linear power supply:
transformer (at least 50 W output at 12 ... 15 V)
bridge rectifie... |
H: Can the power source for a USB device be different from the data source?
I was wondering if the data source (USB Host) for a USB device has to also deliver the power 5V circuit e.g. data and power need to have a common ground.
Or can I connect the data lines to the data source and have a separate power supply for t... |
H: Taking power from two different feeds
Probably a silly question I know but I'm not all that good when it comes to wiring but at the same time don't want to blow myself, or my car up!
I have a set of sidelights/ daytime lights that take a feed from the cars loom and turn the lights on when I a) unlock the doors (the... |
H: Is it possible to make a complete analogy between electricity and something more graspable? (e.g. fluids)
A similar question has been asked here, but mine is more general.
Here is the background: it seems to me that electricity is not so intuitive as it may sound. For example, many (unskilled, as I am) people think... |
H: Understanding current flow in example
When I have series circuit with 3 light bubbles the voltage in second should be less than in first and the voltage in third should be less than in second. Conventional current flow is from positive to negative while electron flow is from negative to positive. Which light bulb w... |
H: ATtiny External Clock not working
So, I've been wanting to break away from the arduino abstraction for a while now. I made a board that has an ATtiny10 on it with a crystal and an output. I cannot for the life of me understand what I am doing wrong.
Here's the problem: When I select the clock source, the AVR sto... |
H: Diodes and CMOS 4060 (14-stage counter)
Take a look at this popular circuit for a fridge alarm based around the 4060 binary counter (http://free-electroniccircuit.blogspot.co.uk/2012/02/refrigerator-alarm-schematic.html):
One thing I notice is that the diodes connected to pins 3 and 6 are "reversed". I think I un... |
H: STM32F102 USB Programming
I am currently designing a board for a STM32F102 chip which needs to be able to use the USB bus to transfer data while the chip is running. However I also want to be able to program the chip through usb while developing the software.
I want to make sure that while designing the board I won... |
H: Procedural blocks in verilog
We have two types of procedural blocks in verilog: initial and always block.
The statements inside these blocks are executed sequentially. Does that affect the timing of these signals? For example, in the code below:
initial begin
a = 1'b0;
b = 1'b1;
end
Will the assignment of b wi... |
H: Bluegiga BGScript Accelerator sample. I want to understand the example code
I started BGScript few days ago. I have many questions about BGScript. Any help will be appreciated. Thanks!
*My goal is advertising with accelerator data via BluetoothLE. I am going to use ADXL345 as an accelerator.
I could advertise with... |
H: Why is my microcontroller passing a current through it when not connected?
MCU: ATTiny13
I noticed this after trying to debug why pushing my switch (connected via R2, a 507kOhm pulldown resistor) makes the LED dimmer while depressed. The switch was powered by the same supply line as the Vcc input to the microcontro... |
H: How does USB 3.0 negotiate power states?
I noticed, in another question, a comment regarding USB power states. I know that USB 2.0 negotiated power by tying the D+ and D- lines to specific voltages but I can't seem to find any information on USB 3.0 power state negotiation.
Since USB 3.0 has two sets of D+/D- line... |
H: Are UV LEDs really dangerous?
I just bought some UV LEDs
I bought them for testing banknotes and identity papers. I read the documentation and saw some warnings about UV light in which the vendor advises not to look directly at the light and not to expose skin to the light.
Can I use these LEDs safely ?
AI: The lim... |
H: Compute for resistance (Resistance circuit)
Hi how do you solve this problem? I am confused.
simulate this circuit – Schematic created using CircuitLab
Find \$R_{AB}\$, \$R_{CD}\$, \$R_{EF}\$, \$R_{AE}\$
I came up with this:
\$R_{A-B}\$ = 1 \$\Omega\$ ,
\$R_{C-D}\$ = 4 \$\Omega\$ ,
\$R_{E-F}\$ = 7 \$\Omega\$ ... |
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