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H: Essential Nodes in a Circuit
My book says above that there are three essential nodes in the circuit above. I am seeing four essential nodes in total which are marked by those four black dots. Since each of those black dots connect three or more circuit elements? Can someone explain to me how there are 3 essential ... |
H: Vout = 12V, Iout= 15A, 180 W Switching regulator
I have experience of designing DC-DC converter upto 5A.
But now for one of my application, I need to design circuit with following specs:
Vin = 24 - 25 V,
Vout = 12V,
Iout = 15A,
Pout = 180W
So, Is there any switching regulator capable of such high power rating?
( A... |
H: DC Motor consuming too much current
I'm trying to use an H-bridge, which is connected to a wall power supply, to power a DC motor. The motor was originally powered by a 12V battery pack in a toy.
Now my motor is consuming too much current (2.5 A instead of 1A) (the theoretical maximum current of the power supply is... |
H: Output power vs idle power of an audio amplifier
Let's say I have a AB class power amplifier that is able to give an average output power of 30W on a 6 ohm loudspeaker. Now in general, how much power should the amplifier dissipate when there is no signal applied?
I am asking this because I have an amplifier that di... |
H: Is it necessary for "LDR R0, [R0]" when saving from r15 in arm?
From ARM® Developer Suite Assembler Guide
Saving from r15
In general, avoid saving from r15 if possible.
If you do save from r15, the value saved is the address of the current
instruction, plus an implementation-defined constant. The constant is
... |
H: Baud rate vs. Bit rate
When we initialize a serial communication, we usually have to set the baud rate (e.g. 115200)
I notice that many people assume that 115200 means 115200 bits per second. However, each baud(signal change) can encode more than 1 bit. baud 115200 means 115200 bits per second only if each baud = 1... |
H: What's the meaning of "x" in RxD and TxD of UART?
RxD means Receive Data.
TxD means Transmit Data.
Where the "x" come from?
AI: Comes from the 'good old days' of radio when Morse code ruled. Abbreviations abounded (c.f. text messages!), and TX was transmitter or transmit; RX was receiver or receive \$\cdot\cdot\cdo... |
H: How can I send keyboard input to USB port or Serial Port?
Now, I am using Windows 8 and have made Arduino buttons to operate as an keyboard's 4 arrow keys(up,down, right and left). From this moment, I am going to send this keyboard input event out to the USB port or 9-pin serial port(RS232) installed on the backsid... |
H: Hand soldering QFP component
I recently came across this video on YouTube, in which the guy is soldering a .5 mm QFP component.
Hand soldering a .5 mm QFP Chip
As I haven't done a lot of soldering in my life (and never used flux), I have a few questions.
The guy in the video uses only flux without solder to do all... |
H: Does an op amp needs an Input Bias Current to operate?
I'm confused about the source of Input Bias Current, is it generated by op amp, where the current "leak" from the op amp. or it's a must to operate the op amp? for example if I have in a data sheet a 1pA input bias current, should I provide a 1pA to the inputs ... |
H: My H-bridge can't control my 3v motor
I'm trying to control my 3v motor from my 5v arduino.
For this i use :
5 volt power source from pc for the arduino
L9110 H-bridge module
2 AA Battery as power source for the L9110 H-bridge
Here is the setup :
however if I touch the h-bridge pin with the 5v source from the ar... |
H: Erasing Flash with X-rays to remove security bits
Scenario: A chip is read/write protected by programming a security bit in its onboard flash memory. Normally this would mean it cannot be re-written. Would a dose of X-rays be capable of erasing the flash to the extent the part could be reprogrammed? So, a number of... |
H: LM317 Dropout Voltage
The LM317 Data Sheet doesn't appear to specify a dropout voltage in the table of electrical characteristics. 1.2V - 1.3V sounds about right for the dropout voltage; is "reference voltage" an alternate name for it?
AI: is "reference voltage" an alternate name for it?
No. The reference voltage ... |
H: Desoldering a TO-220 MOSFET from a plated through-hole board with SMD complications
I'm planning on replacing a TO-220F package MOSFET on a through-hole circuit board that also has SMD components on it. In this case, an SMD capacitor is connected to the source gate of the MOSFET by what looks to me like a small sol... |
H: If I flick the light switch on and off will it damage the light?
Ive heard that when you flick the light switch on and off repeatedly it damages the bulb. I know this is certainly not true for LED bulbs, but Im wondering if and how it damages other kinds of bulbs. I know that light bulbs run off of ac current so... |
H: Bipolar Square Wave Generator
The design requirement is to generate a +/-12V square wave from a 0-3.3V square wave at 1kHz.
Here is what I came up with:
PILOT_CTL is the 0-3.3V square wave and the end of R6 should be the +/-12V output.
I built the circuit, plugged it in and Q1 promptly blew up. I believe this is b... |
H: How does an ohmmeter measure different resistances?
An ohmmeter has set of range settings for the resistances to be measured.
When we switch to any range, what behavior of the test reference is being adjusted?
In other words; I'm wondering if we change lets say from a 200 to 1k ohm range, what exactly are we changi... |
H: What does Fujitsu call an "RFID LSI"?
Fujitsu offers ferroelectric RAM modules, including in "RFID LSI" format. I have no idea what those are, and the engrish documentation doesn't help at all.
AI: RFID = Radio Frequency IDentification
LSI = Large-Scale Integration (chip)
In this context LSI probably just means th... |
H: Diode preventing coil from latching?
So I've come across a case where an input from a little 5v I/O system will trigger the coil of a reed switch but not it's direct equivalent that has a built in flyback diode and changing the resistors that are in series with the input doesn't seem to work. Far as I can tell it's... |
H: Why do I have to use an additional resistor with a photoresistor?
I'm totally new to electronics and I wonder why we need to put a resistor in series with a photoresistor to measure the variation of light? I mean, photoresistor is already a resistor, why do we have to decrease the voltage in the circuit with an add... |
H: Using optocoupler with MOSFET for dimming a LED
I have a blue LED which I want to dim using an Arduino, an optocoupler and an N-MOSFET.
For achieving this I assembled the circuit on a breadboard as shown in the pictures, using a YwRobot breadboard power supply to provide power to the optocoupler's transistor, and t... |
H: Regarding CPU speed required for USB applications
I am working on a project for developing a USB keyboard, and I am new to USB protocol and I did initial study regarding basics of data transmissions through USB.
I am now checking for USB supported microcontrollers required for my application and any development kit... |
H: Something wrong with a 30 vdc variable power supply design
Recently I have designed a variable 30 vdc output power supply
When I tried it on the breadboard it worked fine and gave me a maximum voltage around 29.8 vdc
When I tried to design the PCB ( its my first PCB ever )
And it has a lot of mistakes I know
But ... |
H: What is the use of the 0.1Ohm Sense Resistor in Battery Charger
In the below circuit, can someone please point out the use of the 100m Ohm resistor?
Can i replace it with a 0Ohm Resistor?
AI: The purpose of the 0.1-Ohm resistor is to provide a measurable voltage that corresponds to the current being supplied to th... |
H: PLC rung definition and evaluation
I was reading a book about PLCs (Programmable Logic Controllers).
I found this paragraph: "A ladder diagram is read from left to right and from top to bottom... The top rung is read from left to right. Then the second rung down is read from left to right and so on....
Each rung m... |
H: M-Bus (Meter-Bus) Arduino / RPI
Is there some one that have manage to connect to a M-Bus (Meter-Bus)? With a Arduino or RPI? Maybe a M-Bus to serial is the way to go?
AI: If you want to connect as a master:
For a quick start: go with the RPI and have a look at the openmuc jMBUS lib:
https://www.openmuc.org/index.ph... |
H: Simulation of TDR using LTSpice
I'm trying to simulate a TDR based on the figure below, and one of the scenarios is a short circuit. The simulation should last for 140ns.
The parameters are
\$Z_A = 50 \Omega \$
\$T_A = 5ns\$
\$Z_B = 75 \Omega \$
\$T_B = 10ns\$
Rise time of source signal \$\tau_r = 0.1ns\$
I took... |
H: I2C with 1.8V levels without level shifters?
I have problems detecting an MPU-6050 I2C device on the Intel Edison Mini breakout board (it only supports 1.8V levels). According to the thread here, it might be possible to get the sensor working with 1.8V levels:
"The MPU-6050 also supports different supply (VDD) and... |
H: What is the physical explanation of electric breakdown?
I would like to know what is the physics behind the electric breakdown in gases so they become electrically conductive. So far, all the information that I have found describes the phenomenon in a macroscopic scale. I am interested in the microscopic explanatio... |
H: Updating outputs in PLCs
For all PLC manufacturers, is Mass I/O copying the choice for updating outputs?
I found that there is another possible method: the continuous I/O updating.
Can anyone tell me what is the reason for this choice (Mass I/O copying)?
Are there any advantages over the continuous I/O updating me... |
H: What are promising battery technologies for longer battery life?
Most electrical devices lack the capacity to work for longer time (e.g. smart phones work only for a day) without recharging. This is mostly as a result of low energy storage capacity in current chemical cells. I am not an expert in solid state physi... |
H: LiPo Charging Ciruit - Switching Help
I do understand that similar questions and maybe even the same question has been asked before, I've found them but unfortunately as a result of inexperience on my part I have been unable to adapt the posted solutions to my design specifically.
I am currently working to build th... |
H: Kirchhoff law in Electronics Workbench
I have a task to check Kirchhoff laws in this circuit.
If I understand everything right, I3 + I2 should be equal to I1, but it isn't. What's wrong?
AI: 9.649mA + 32.16mA = 41.81mA Your I3 meter needs to be flipped around, and you'll get the result you expect. Take this as a le... |
H: Eight bit ALU with Overflow in Verilog
I have the above assignment and here's what I have so far in verilog:
module eightbit_palu(input [7:0]a,
input [7:0]b,
input [1:0]sel,
output [7:0]f,
output ovf);
reg (f, ovf);
alway... |
H: calculate encoder period from motor rpm?
Let's say I have a stepper motor which rotate at a speed of 1000 RPM and I have an incremental encoder attached directly to the shaft with 4096 PPR (pulses per revolution).
How I can measure the period of the square wave of channel A or B of the encoder?
Thanks
AI: Pulse fre... |
H: Resetting a microcontroller with a button connected to Vcc
I would like to have a way to reset my PIC by removing power from the chip. My hacker self thinks that the simplest way would be to add a resistor between the output of my LDO and Vcc on the PIC, and then add a button between GND and after the resistor. T... |
H: What type of connector use smart phones adapter?
What is this type of connectors?
http://www.aliexpress.com/item/Universal-Qi-Wireless-Charger-Receiver-Charging-Adapter-Receptor-Receiver-Pad-Coil-For-Xiaomi-THL-OnePlus-Honor/32334054624.html?spm=2114.01010208.0.472.8hRw0V
AI: The connector at the top of the main pi... |
H: Relay for Intermittent Wiper Function
I want to add an intermittent function to the wipers on my 40-year-old car without any additional switches. The details of the wipers can be found here [http://www.globalsoftware-inc.com/coolerman/fj40/5G.htm]. The wiper knob closes the path to ground allowing the motor to be... |
H: What am i missing for this to work? (Zener Diode)
Since the zener breakdown voltage is set to 5v, i actually thought that the voltage would be 0, since it goes directly to ground, I just wanted to try a "simple overvoltage protection". How is it that the voltage is 5v instead of 0? Without the diode, the voltage i... |
H: Buck Converting Voltage, to Switch Original Voltage
I'm learning electronics, so I want to sanity check this approach in case I'm missing something.
I have an arduino (at 5V) controlling power to a set of lights at 12V, via a mosfet. This is all fine, using a separate 5V and 12V power supply.
Is there anything to s... |
H: 100nF MLCC bypass capacitor spontaneously exploding on 3.3V bus, how does this even happen?
A 1608/0603 multilayer ceramic chip capacitor was functioning as a bypass capacitor for the 3.3V supply of a InvenSense MPU-6050 6 axis (gyro + accelerometer) MEMS sensor. It somehow exploded forming an open circuit, without... |
H: Disagreeing 3-phase power
So this feels like a silly one but I'm absolutely stuck. I'm trying to balance the power between a 3 phase source and two 3 phase loads in parallel. One is a Wye and the other is a Delta:
So I figured out that the single phase source current is 5A per branch, so the source complex power i... |
H: Dangers of IR LED
I would like to build a DIY laser tag system.
The website milestag recommends a Vishay Tsal-6100 as IR-LED.
Here is a datasheet: http://www.mouser.com/ds/2/427/tsal6100-279822.pdf
Since I want to focus the light (maybe one or two degrees divergence after the lens) , I started thinking about potent... |
H: Is it possible to eliminate output ripple of SMPS's by using two parallel SMPS's to produce outphase outputs to each other?
simulate this circuit – Schematic created using CircuitLab
Obviously it can not be that way. But why? Imagine one converter with a phase detector of its switching frequency, outputs a flag wh... |
H: Sensitive AC detector circuit
I built a field mill based on this video link. This device generates a sine wave, where I am interested in the amplitude.
Once i have the peak, or average value (does not matter, but average would be better), I will send it over to an arduino data logger.
What circuit could I build to... |
H: Splitting AC voltage based on phase
Is it possible to separate the positive and negative portions of an AC voltage wave into two separate lines, where one line has the positive voltage portion (and is neutral when the source is negative), and another has the negative voltage portion (and is neutral when the source ... |
H: What is a startup code how it is related to bootloader or bootloader code?
I am doing a project on building a bootloader for a kinetis E series controller (MKE02Z64VLD2). My mentor told me to have a thorough knowledge about Startup code and linker files before starting the project. How are they essential for a boot... |
H: Proper Arrow Directions for Off Page Connectors / Symbols...
Good day everyone,
As I understand it, there are two kinds of objects that can be used on a schematic to indicate that the Net to which they are attached is connected to a location elsewhere on the schematic (maybe the same or a different sheet). The r... |
H: Power supply filter choke failure - how and why?
Trying to repair a non-working Fiber to Ethernet Converter. When connected to power, the unit made a hissing/sizzling/scratching sound and the all LEDs glowed dimly. I isolated a small surface-mount choke on the input power side, filtering 12VDC input from wall-wart... |
H: What does "V.A." mean in datasheet dimensions?
I'm looking at a datasheet for an LCD panel (pdf link to datasheet).
I don't understand these two encircled dimensions:
What does the acronym "V.A." mean for these dimensions?
I have referenced a couple of other questions here on EE, but they don't cover this:
Abstrac... |
H: Finding the equivalent Resistance of acircuit
simulate this circuit – Schematic created using CircuitLab
I am a little confused on how to find R equivalent of this circuit because of the wire.
Right now I have the following expression:Req= (R1//R2) +(R3//R4)
Is this correct?
AI: Redrawing the circuit should hope... |
H: Do I need a galvanically isolated step-down DC-DC converter to power my digital electronic from a battery pack that powers also the electrical motor?
I have a battery pack with lithium ion cells. The battery pack has a maximal voltage of 84V (it goes from 84V to ~50V -> depending about the current state of charge).... |
H: how to remove this error "ERROR 152: Port on instance does not exist in entity declaration for instance"?
I am new to Cadence Allegro HDL for schematic design and for my first design i got this error.
In 728 page document provided by cadence its is mention as follows,
"Open the symbol for the component in Concept H... |
H: Formula for electromagnet strength parallel, outside the coil
I am working on a electromagnet project to collect metal shavings off the floor after machining.
I have a formula for the magnetic strength at a distance from the ends, but not parallel to the coil. How do I calculate F parallel to the coil?
The formula ... |
H: Does AM Broadcast Use Sideband Modulation
Does AM broadcast radio in the United States use a sideband modulation, or are both sidebands and the carrier present in the signal? Please provide a reference.
AI: Commercial AM stations in the US use AM modulation. AM modulation carries the signal in sidebands on either ... |
H: Ideal transformer output voltage
I know that the output voltage and current of an ideal transformer depends on the number of wounding of the coils. It means that no matter how many resistors I put in a series in my secondary loop, the current would not change and it depends only on N (Number of turns in coil).
I ha... |
H: DIT-MCO hardware with Rotary switch & Nixie Tubes?
I really needed some help. I can't for the life of me find any information pertaining to this hardware manufactured by the DIT-MCO Electronics Division. The most information I can glean is that It's a Type 45 switch and was made in Northlake Illinois and that it's ... |
H: What does a black bar across transformer symbol designate?
What does a black bar across a transformer symbol designate?
This appears in a power electronics context, and in particular in this case with substituting a DC transformer as an equivalent circuit for the guts of a DC-DC converter.
AI: As you (and others) ... |
H: Does ground suffer from a voltage drop like effect?
I am currently working on a project where I need some very long wires (about 20 meters, and that is 40 meters both ways), that will be connected to a button which will be used to trigger a pin on the controller (ATmega8).
Due to expected voltage drop problems, I h... |
H: How to choose a bypass capacitor for a common emitter amplifier?
This site says: "To increase the gain for AC signals the emitter resistor bypass capacitor is added. This should be calculated to have a reactance equal to the emitter resistor at the lowest frequency of operation".
I assume that I have 1K ohm emitter... |
H: PWM ~100mA LED's
If someone knows of a prototyping solution for driving several LED's at >75mA I'd be grateful.
I've taken 8 LED's out of an existing product. They appear to expect 70mA to 100mA for max brightness. I've looked around for breakout board solutions to dimming or driving these LED's but most breakout b... |
H: Propagation across a surface
How do stud sensors actually sense current, what would cause the effect to propagate across an 8x8 foot surface area and remain strong enough to be detected?
I asked another group "what is happening", now I would like to ask your group "why". This is a question about electrical sensors... |
H: What is the pole frequency of a three-phase LC filter?
Suppose I have this configuration:
Assume L1=L2=L3 and C1=C2=C3. What is the pole frequency of this filter?
Edit: As mcmiln says, this is not identical to the question here:
Cut Off Frequency in three phase LC filter
I want the closed form (and preferably derr... |
H: Physics explanation of charging time by increasing dielectric constant
I am having a problem understanding in physics of the relationship between charging time and dielectric constant of a parallel plate capacitor.
I'd like about physics aspect not based on time constant.
If dielectric constant increases then cap... |
H: Need help in biasing TIP31 in common collector mode- edited
I am using an Arduino Uno board and R-2R DAC to obtain a signal which should vibrate a transducer connected across RL of common collector amplifier using TIP31C.
I need around 300mA of current to vibrate the transducer which is much like speaker (resistanc... |
H: Current flow from positive to positive between batteries?
If you have two batteries with different voltages, let's say 12 and 9 V, and you connect the negative terminals while you put a LED or whatever between the positive terminals, there will be current flow. I reason that is because there is a potential differen... |
H: Powering and operating dual electric linear actuators
I am in the process of building a height-adjusting desk. I am pretty good with computers (I'm a programmer), but I never learned much in the way of electrical engineering.
I recently purchased two Eco-Worthy brand linear actuators. They each have an 18-inch stro... |
H: Pull up on output pin of Buffer SN74HCT245
I am using SN74HCT245 Buffer operating on VCC=3.3V. So, I am getting 3.3V at each output pin of buffer (B1 to B8).
But if I want to drive a load with 5V input, what options are available to me by keeping VCC=3.3V?
Is 5V pullup on output pin of buffer is valid option?
Pleas... |
H: Bipolar Voltage to Current Converter
I need a circuit or component which converts bipolar voltage to bipolar current. I have found the XTR111 from Texas Instruments and the 1B22 from Analog Devices. However, they only convert 0-10 V to 0-20 mA current.
I to need convert -10V-0V to -10mA-0mA too (the opposite polari... |
H: Car battery capacity in colder countries
The capacity of the battery is affected when the temperature drops, particularly Lead-acid batteries. So how in cold countries this situation is solved.
In this PDF about automotive batteries at low temperature, they have mentioned the specific gravity of the electrolyte is ... |
H: Choosing voltage divider resistor values
Above is the circuit in question.
R1 and R2 forms a voltage divider to supply desired current for the load.
On the left side there is the original circuit and on the right side its Thevenin equivalent.
Lets say the ideal supply voltage is known and we want 0.01A current thr... |
H: Adaptation of the ICD2
I'm trying to adapt the ICD2 so that it can be used with a microcontroller family (dsPIC33F) that has a 3.3V supply.
Projects using the ICD2 must be 5V. How can I do this?
AI: According to this from Microchip the ICD2 works across 2.0V to 6.0V. http://www.microchip.com/DevelopmentTools/Produc... |
H: Short circuit when probing live ATX power supply primary section with voltmeter
I was probing around an old ATX PSU to inspect voltage levels in the primary section. The first 15 minutes went smooth (bridge rectifier inputs, big caps, Power IC Vcc, etc..) but as soon as I probed the solder pads of the large coil ci... |
H: Stabilizing the 12 volts from a car battery
I'd like to put a small gadget that I made into my car and power it from the car battery. The gadget works on 12 volts and the car provides 12 volts also. And the consumption would be somewhere around 2-4A.
However as I understand those 12 volts from the car are not very ... |
H: Humbucker-style microphone interference cancelling
For a recent experiment, I decided that it would be a good idea to try to add some electric guitar distortion effects to my otherwise Classical flute playing.
In order to do this, I attached a small electret microphone to my flute, which is powered by a phantom pow... |
H: Ways to use electromagnets to pick up metal shavings at a distance
I work at a rotor machining plant and there is an issue for shutting a line down to clean up metal shavings, causes too much down time. I was thinking of using a strong electromagnet to have a "pick up" radius under the machining cells, say 12". Aft... |
H: Driving a 5V IR led with a 5V charger?
I'm trying to build a remote control with IR led.
I'm experiencing low range with my 1.5V, If=50mA IR leds, so I looked for and found a 5V, If=100mA IR leds.
twice the current, hence probably better transmission capabilities.
The problem is, I'm not sure what to do about the c... |
H: Would you prefer a voltmeter or a scope when measuring average voltage precisely?
As far as I understood the DC setting of a voltmeter or a multimeter is measuring the average value of a periodic voltage signal(not rms but the average value).
On the other hand, an oscilloscope as well in DC coupling mode also meas... |
H: Probing with Oscilloscope Stops ADC Fluctuation
I've gone back to my constant current project to fix an annoying fluctuation in the required current display. See schematics below.
The entire circuit consists of a CCS section with signal outs for both the requested current (represented by Vreq) and the actual curre... |
H: AL value: nH/N² vs. nH/T²
I'm in the process of sizing some toroidal ferrites. My problem is that I am seeing the AL value on the datasheets shown two different ways as nH/N² or nH/T².
Are these two units identical? I believe they are, being that N and T both stand for "turn".
AI: You are correct, both N and T stan... |
H: Power in AC circuits
When I look at the graph of the power in AC circuits versus time (not the average power I am talking about the instantaneous power) it goes from a negative value to positive. On the other hand, I know that a positive value of p(t) represents dissipation and negative power represents generation.... |
H: Why is the power supply terminal is not connected to ground in this bridge rectifier?
Above is two identical bridge rectifier circuits. Input is a 12V sinusoidal voltage source. Red is the source. Blue is the output from the circuit on the right side. Green is the output from the circuit on the left side. It seem... |
H: Is an ideal transformer an ideal current source?
I define every circuit element of a primary coil of a transformer that is connected to a voltage source and calculate \$I_1\$ (current of the primary loop). I then connect it to a secondary coil with a known number (\$N\$) turns.
Regardless of the values of the sec... |
H: What does FG stand for?
I have an old 12V cooler master fan that I am converting into a fume extractor for soldering and am connecting it to a standard 12v computer power supply. I am trying to wire it and am confused about one thing.
On the fan's label it has a coding for the different wire colors (red, black, ... |
H: Should serial triac dimmers work for resistive load?
I have a cheap 120V hot plate that I assume regulates its temperature using a triac dimmer (because the heating element vibrates/hums at lower settings). But at its lowest setting it still gets too hot for my application.
So my first reaction is to put another h... |
H: How do I open a grill ignitor?
My grill rusted apart, so I decided to salvage the spark circuit.
But there's a problem - I can't find the polarity of the ports, and I can't open up the blackbox. https://i.stack.imgur.com/Q2Ku3.jpg
How can I crack this open without breaking it, or alternatively, is there a way to fi... |
H: Need Help In Creating and Debugging a 8Mhz CLK Circuit
I want to create a CLK generator circuit that will work at 8Mhz.
I'm following this design (from http://www.electronics-tutorials.ws/oscillator/crystal.html):
My crystal is 8Mhz HC49/US, with 20pF capacitance as described in the website I bought it from.
I'm... |
H: Analog PID controller (transferfunction questions)
I have to build an analog PID controller (with op-amps), I've made a schematic:
My questions:
Can I build my PID controller this way?
My PID tranferfunction (in the s-domain) looks like:
$$\text{H}(s)=\text{K}_{\text{r}}\left(1+\frac{1}{\tau_is}+\tau_{d}s\right)... |
H: What is the difference between high precision resistors and current sense resistors
Actually, I am trying to build a current monitor for a wireless sensor network. I am going to use a current sense resistor as the current will pass through the resistor. By measuring the value of the voltage, the current value can b... |
H: How to correctly wire this transformer for 240V?
I have an old transformer (without any details about brand and model) with dual primary windings. I need to set it up to take 240V, but I am unsure about the correct way to connect the windings in series.
Here is a photo of the primary side:
So what is the correct w... |
H: How to overcome transistor heat in slayer exciter?
I build this circuit and it works but I have two problems. The major problem is that the transistor becomes very hot quickly. I burnt my transistor due to excessive heat. How can I get rid of the very high temperature of the transistor.
The second problem is that ... |
H: Why do we need to rectify or amplify the current/voltage?
I am a beginner in Electronics. What i read now a days in my text book is about diodes,transistors etc. They are used for some rectification and amplification etc ? I wonder why do we need to give different shapes to voltage and current. For what these diffe... |
H: Finding L and R in AC circuit
Ammeter readings:
A1 = 4A
A2 = 2A
A3 = 3A
Voltmeter reading 24V.
Circuit is in AC.
I have to find R1,R2 and L.
While calculating R1 (R1 = 24V/2A= 12 Ohm) seems to be easy, next steps are not particular clear to me. I know that ammeter measure magnitude of complex current, but I cannot... |
H: What happens if I connect a solar panel and an AC/DC PSU in series?
I'm thinking about connecting the DC12V output of an ATX PSU with a solar panel in series.
I want an always-on power source with as much power coming from the Sun as possible.
AI: If they acted like ideal voltage sources, you could put them in seri... |
H: USB powering batteries without OS support?
On a bare-metal project I have in mind, I would like to know if I can avoid to implement the multiple USB specs (O/E/xHCI) and still benefit from usb charging my battery. It will run on a almost broken/useless flashed smartphone with one mini usb port.
I literally don't wa... |
H: Output State of comparator circuit for AC signal when open?
I am trying to design a circuit which would interface AC signals from pick-up coils.
Below is the circuit.
R4, R3 are for DC bias, and R2 is for feeding that bias to inverting input of the OP amp.
R5 and R8 is for hysteresis regarding noise immunity.
V2 ... |
H: Using Dither to achieve finer PWM resolution
In practical industrial applications (regardless of any particular industry), is there any use for a dither module that goes along with a PWM module considering HRPWM's are available. With my limited experience I can justify using the former as it's most likely cheaper t... |
H: What voltage is a 3-LED light from a LED-TV?
I have some "NDV rev1.1 4248 back lights" from a television.
There is a print that sais "94V" on the strip, and on the wire supplying the strips it said "96V".
Every strip has 9x buttons which have 3 LED's in them. So i devided 94 by 9 and figured that every button sho... |
H: Finding Vout of a Transformer
I am a little confused on how to read the ratios of a transformer
Suppose there is a ratio of 1:6, is this read as the following?
Number of turns on Primary: Number of turns on Secondary?
so suppose a question asked that there is a voltage of 20 voltages rms and it enters a transformer... |
H: Flash Magic for code dumping (LPC1778)
I was reading a book called "Insiders guide to the Phillips ARM7 based microcontrollers".
There it says "The easiest way to program the Flash is by the built in bootloader which allows the code to be downloaded via UART 0 into RAM and then programmed into FLASH".
In Flash magi... |
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