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H: Power consumed by an LED in a simple circuit
I am in the very beginnings of studying circuits and am a little confused on calculated Power.
If I have a 9V Battery, 4 x 10k Resistors and a single LED, how would I calculate the power consumed by this LED?
I have measured current of the circuit and voltage measured at... |
H: What is the purpose of the 10K resistor that is connected across the input and the supply?
I was checking out some transistor amplifier circuits online when I came across this one.
Now my question is what is the use of 10 kilo-ohm resistor that is connected between the power and the input terminals? What happens i... |
H: Should I have had a resistor before my transistor?
I've recently started playing with an Arduino and learning about circuit's. I was trying to learn a bit about using some transistors as a switch and I think in the process I ended up ruining one of the pins on my Arduino. When set to HIGH the pin only outputs 0.5... |
H: Differences between LM317, AMS1117 and L7805
I am trying get a 5V to power up AVR microcontroller. The power will be supplied either from 5V USB power adapter or from motorbike battery (about 11-13.7V).
I have one piece of both 7805 and LM317 voltage regulators, but I don't have any AMS1117. I would like to know th... |
H: Component keep-out on particular layer in Altium
I'm making a heat sink footprint for TO220 in Altium. I think route tracks under the heat sink is not a good idea. So I want to give the footprint a keep-out, but the keep-out region on Keep-Out layer applied to both top and bottom layer, though my heat sink sits on ... |
H: Is it good to route PCB tracks under a heatsink?
A heat sink is a piece of metal. If the solder mask on a PCB track is broken, it may be dangerous, right?
Below is a small heatsink for TO220, seen from bottom.
AI: A heat sink is a piece of metal. If the solder mask on a PCB track is
broken, it may be dangerous, r... |
H: Is 3D printing of PCBs possible?
I just saw this picture about PCB 3D printing on a website, can it work in real life?
It's would be so cool, if it could useful in the real life.
AI: It can work. I have recently seen an entire speaker built using a multimaterial 3D printer. In the future, it will certainly be possi... |
H: Industrializing a PIC micro-controller
I want to replace some timers with a PIC16F887 micro-controller. The problem is that the input voltages to the I/Os is going to be 24V which is too much. For the output part I was thinking about using a relay module. I'm stuck on the input part. How can I use the 24V as a inpu... |
H: Syncing 50+ wireless sensors
I am creating a set of 50+ remote imu sensors. They will all be in a small distance from one another. Less that 3 meters. Each remote board will have a on board sd card for logging the imu data and a led that flashes when the imu begins its sampling. My remote board needs to be small, a... |
H: How to determine low and high threshold levels of a Schmitt Trigger for a known input?
Imagine I have a pulse train input which goes into a Schmitt trigger for getting sharpened. Imagine the HIGH of the input pulse train is around 8V and LOW is around zero volt.
So what should one select the lower and upper thresho... |
H: Extracting footprint existing PCB in Altium
I'm in the process of designing a carrier for an existing PCB. The upper layer of the carrier should contain pads to connect to the holes on the side of the original board.
I can re-create the lay-out by hand, but this is an awful lot of work. Can I extract the lay-out of... |
H: Measuring display brightness decay
Our device is specified to have a display brightness of 500 cd/m² and it must not decay to less than 50% brightness in 50,000 hours. Now, I can't wait for 5.7 years for that test to finish.
I guess that this issue has been solved before. How is decay in brightness measured?
I know... |
H: Why do Schottky diodes have two anodes?
I was looking for a SMD diode to add reverse-polarity protection to a circuit I was designing, and the PMEG3020CPA looked like a good fit with regards to my current and voltage needs.
What confused me is why the data sheet shows two anodes, so I have a few questions about tha... |
H: Charging phone battery from DC supply
I am planning a project very similar to the one seen in the following gallery. (https://i.stack.imgur.com/FMecg.jpg) I like the idea of having my phone plugged into the same unit for charging. My only concern is I only want to have one power cable being attached. The power cabl... |
H: Transistors: Explain the key differences between SMALL and LARGE-signal analysis
I'm in an electronics class and I feel like this portion of the lecture was covered in a vague manner. I'm not really sure what the purpose of doing either a large or small signal analysis is, and what the difference is as applied to t... |
H: Understanding dielectric readings - Water vs Apple Sauce (for example)
I thought asking this question here might be the easiest way to get an answer. I'm not looking for an exact answer, just an explanation of why this is the case.
I used a Chirp! sensor connected to an Arduino Uno. The reading in AIR was 209, at 2... |
H: capacitor ripple current in buck converter
I'm designing a step-down buck converter and I'm a little bit worried about ripple current which flows through the output capacitors.
In my research on the internet I found that ripple current is given by Vrms_output/ESR. If Ι have 3.5A maximum output current and I want tr... |
H: multiplexing control signal on speaker cable
I need to put an alarm siren close to the location of one of my audio speakers. But I don't have a dedicated cable towards this siren. Because the alarm control unit is close to my speaker amplifier I want to use the speaker cable for transmitting a trigger signal for th... |
H: Output data from computer to light up LEDs
I'm a complete newbie at this, but the idea is to have a circuit board with, say, 10 LEDs, connected via USB to a computer running Linux. This will periodically (e.g. every second) send data to the board telling it which LEDs to light up. What the lights represent will be ... |
H: Class AB Amplifier Frequency Response
I have designed an AB Audio Amplifier, but even though the gain is acceptable, the frequency response is terrible.As seen in the schematic, there is a feedback/preamplifer stage and an output stage, I have used MULTISIM to perform AC Sweep of the only the preamplifier stage, an... |
H: What does the waveform for a Digital Addressable LED Strip look like?
I want to use this Digital LED Strip but with my own controller (i.e. NOT a raspberry Pi).
The link has sample code but I want to be able to understand clearly in terms of hardware waveforms what does the Clock IN (CI) and Data IN (DI) pins corr... |
H: Separating Two High Speed Digital ICs
Previously, I've designed a PCB incorporating this ADC chip. It has a digital bus of 10 signals some of which are 40MHz.
Right now we have a four layer PCB and the ADC is connected directly to a Spartan-S6 FPGA with ~1.5" traces, running over a ground plane. The system is worki... |
H: Why is inductance negative in this triphase mutual inductor?
Suppose I have a threephase circuit with a mutual inductor on the first and second phase (V2 and V3). One way of solving the circuit (ie finding the phase currents) would be the following: convert the mutual inductor in the corresponding Y inductor and th... |
H: How to make an .sof upload to an Altera Max10 stick
I have a Max10 dev board with a 10m08 chip on it. I made a simple counter to blink the LED's. My counters have asynchronous resets, and my asynchronous reset has a circuit to keep it low for two clock cycles and prevent metastablity. I reset the fpga and it the co... |
H: Power transformer dual secondaries connection
I am new to electronics and want to build simple circuit.
I bought Radio Shack Power Transformer which converts from 120 V to 12 V or 6 V, it says on the back that if I connect two yellow wires it will be 12 V and if I use black and yellow it will be 6 V. My question is... |
H: state-space model of non-linear system?
This is the equation for which I have to make a state-space model.
$$m\ddot y(t)+b\dot y(t)+k_1y(t)+k_2y(t)^3=u(t)$$
For my A matrix I have
$$\begin{bmatrix}
0 & 1 \\
? & \frac{-b}{m}\\
\end{bmatrix}
$$
where
$$ \begin{align}
&x' = Ax + Bu\\
&x_1=y \\
&x_2=x_1'
\end{align}$$
... |
H: Calculated resistance of an LED
I am working on some circuit lab homework this week and am a bit stumped by something I just can't seem to find anywhere in my Circuit Analysis I book.
The lab has me construct the following circuit on my breadboard:
simulate this circuit – Schematic created using CircuitLab
I then ... |
H: Power Factor - What is it a characteristic of?
I always thought it was a characteristic of a powered device, rather than the power source.
A generator (whether it's a station or a small petrol powered one) does not have a power factor. I've been told that the power source has a PF.
Is this correct? Does the PF chan... |
H: Pulse Low on High Signal
I am trying to build a circuit that disconnects the output for a brief time when power is connected. However I want the circuit to remain connected after power is removed.
I can achieve the first bit with a RC circuit connected to the base of an NPN transistor pulling the gate of a p-chann... |
H: How do you calculate the resistor value for a bicolor led
R4 and R5 have equal values. For both LEDs the forward voltage is 2V and the forward current is 30mA.
I know how to calculate the correct resistor for a single LED. However in this case I am using a voltage divider to create a 2.5V line so that the bi-color ... |
H: Currents when converting voltages down
Okay, so I have what could be considered a silly question I should've probably learned when I started working electronics way back when, but I just now thought of it and haven't really needed to ask it until now.
I noticed on a AC-DC adapter yesterday that the ratings going in... |
H: Convert USB3 to WIFI
What methods could be used to convert USB3 communication to WiFi, when there is no access to the device's OS?
AI: Buy a USB over Ethernet box and plug that into a wifi router/access point. Or get a small single-board computer with a wifi card. These are basically the only two options. Howeve... |
H: How do you block a signal with a tank circuit?
I have a signal generator outputting 60 hz AC. I've connected the output to a capacitor (922uf) and inductor (0.0076H) which are in parallel with each other creating a tank circuit. These two values will have resonance at approximately 60hz. However by the loud squeel ... |
H: Are there double sided servos?
I see servos a lot on robots that seem to be connected from both ends. Are there servos where the shaft are on both ends of the servo?
AI: Yes, They are sold as 'robotic' servos. Look in the Hobbyking or towerhobbies catalogues.
I got mine as part of a camera 'pan and tilt' bracket, b... |
H: Strange op-amp circuit FM radio
I am working on a simple FM radio receiver. Built the circuit and it works very well. Learned few new things, and got some questions, especially the output stage. The Op-amp 2822 is a dual op-amp, but the output is only mono. One of the op-amp output is connected to one side of the ... |
H: How to turn a 200~Khz AC voltage into a proportional DC voltage that does not exceed 3.3V
now, I have an induction heater, which runs at 200 Khz, and near the coil of the induction heater is another coil, now, if they coil is near the IH's output, currents will be induced into it, yes?
Now, if we have a 3.3 volt A... |
H: Who opens pipes in USB communication?
I just need to know who in the USB communication must open the pipes. Endpoints are already configured, descriptors was sent and now there should be a process of pipes opening (between correct endpoints). Who opens these pipes?
AI: This is all in the USB spec, of course.
In USB... |
H: Shielding effectiveness system
I've been working on a Shielding Effectiveness system of 120dB according to IEEE299-2006 standards. The frequency range covered is 9kHz to 40GHz.
I've designed it using an analog signal generator, power amplifier, antennas (varying antennas for varying frequencies), pre amplifier and... |
H: How do I decouple ground planes?
I have designed and built a motor controller circuit. The circuit has a microcontroller on which gets commands from a PC using an FT232R. Currently the FT232R is powered from the board's +5V supply. This +5V supply is generated using a regulator which converts the +24V power input t... |
H: RS-485 Idle Failsafe Is it really needed?
I'm planning on setting up a sensor network around my house using a Cat5 Cable as both the power source and the signal line for the sensors, I'm planning on using RS-485 Transceivers and and Arduino's for the sensors.
From reading through many application notes and whatnot ... |
H: Feedback Control: Unexpected result for block diagram simplifications using matlab
I made some simple calculations regarding block diagram algebra. The problem is that I don't get the same result using matlab.
Here is the system with it's corresponding blocks:
$$H_1 = z+2$$ $$H_2 = \frac{1}{z^2+2z+1}$$ $$H_3 = \fra... |
H: IC specification
I am pretty new to this, and I am trying to learn about what specifications I should be looking for when doing a chip replacement.
For example, lets say I know 100% sure my BIOS chip is broken. And I would like to replace this broken chip with a blank chip, which I will later reprogram.
How do it k... |
H: Creating a robust power MOSFET switch
So I have been researching about protecting a MOSFET. I have used MOSFETs for basic on/off switches but never really thought about fully protecting them. I have used them for on/off switches to engage relay coils. The only thing I did was place a fly back diode across the the i... |
H: Find dBm and watts of the attenuator?
The question says "A signal of 40 dBm is passed through the first attenuator. The first attenuator has a gain of 1. The second attenuator has 20 dB output. Find the dBm and watts
This is what I tried doing:
40 dBm = 10*log(Pout/1mWatt)
Pout = 10 W
10 W/Pin = 1 gain
Pin = 10 W
2... |
H: How to calculate or should I measure impedance for 1/4 Wave monopole?
I have this odd design that I'm trying to improve the antenna on. It has a mother board and a radio board above it, and it's densely packed with components. My idea was to try a monopole in the middle of the board and bring a feed line over to ... |
H: How to place "Power On" indicator lights?
I'm working on a replacement board for an old system. I have two terminal blocks.
Terminal Block 1 (left) is the input from the power supply to the board. This is the primary power supply to the board and rest of the circuit. Pin1 = +, Pin2= -, Pin3 = -.
Terminal Block 2 (... |
H: Change slope of Magnitude plot in 2nd order system
For the second order PLL with equation:
$$1-\dfrac{2\zeta\omega s + \omega^{2}}{s^{2}+2\zeta\omega s + \omega^{2}}$$
I used Matlab and obtained a Bode Magnitude (with zeta = 0.3, 0.5) like:
In the book "Phase Lock Loops and Frequency Synthesis" by V. F. Kroupa, t... |
H: Bulletproof ESD Powersupply Inputs
I have a power amp that is essentially functions like a benchtop supply, and you can connect banana plugs into it. I would like to protect it against ESD, but also protect the amplifier. People in our manufacturing floor are stupid and sometimes connect things like batteries to th... |
H: Why cellular modems (still) need a SIM card?
I'm designing an embedded system that will require a cellular modem (3G). I never used one but the designs I came across with they all use a SIM card slot.
I understand that this may be convenient but isn't there a way to avoid it? Why and how? What are the challenges of... |
H: Is it okay to use a power supply that provides slightly more voltage and amperage than what's rated?
To preface; I am aware that there are a lot of questions that are similar to mine. But I am finding mixed signals as well as jargon I don't understand; and I was really just hoping somebody could give me a yes/no b... |
H: Transformer output connected to another transformer. Measuring 'Real Power' at input of first transformer
I have a watt meter connected to the primary of one transformer to measure power. The output of this transformer is connected to the input of another transformer.
The watt meter is measuring the inductive load ... |
H: Solar Power Watts/Volts/Amps
I have a 12v battery that is rated at 220ah.
I have solar panels rated at 500 watts total.
I'm using a MPPT charge controller rated for 12/24 volts
I only have a rudimentary understanding of electricity, so please forgive the elementary nature of these question that I hope you can... |
H: Discharge / Bleeder resistors
I need to size and build a bleeder resistor network or could be as simple as two bleed resistors....im not sure but I have an application where a we have a step up transformer from 120VAC single phase to circa 1200VAC on the O/P side. When we power up the line, and the line could be an... |
H: Distributing Ground and Clock Between ADC and FPGA on Separate PCBs
This question is in reference to my previous question where some suggestions were made that went somewhat off-topic.
Basically I have a built a system with an FPGA and very sensitive ADC (sensitive to picoamp currents) which is working well, but no... |
H: Using MOSFET as switch
I am new here so I apologize in advance for any mistakes in the way I am going about this. I had a question regarding a project that I am working on.
I am trying to use a MOSFET as a switch that I am able to control using the digital pins of the Arduino. The switch is meant to control a valv... |
H: Is it possible that my UV LED is emitting white light? If so, how would I filter out the white light?
I recently purchased a 365 nm UV LED, and set up the proper circuit. When I turn the power on, the LED lights up very dimly. Is this white light (that's the color I saw) being emitted from the LED? If so, are the... |
H: Capacitors in parallel without resistance
For the following circuit, at time 0, the switch switches from A to B, figure out the voltage wave form at B.
The question I am concerned with is whether the voltage across the capacitors will change instantaneously or not? Will the output waveform at B be a step function?... |
H: Amperage limit of lead pencil resistor
What is a safe amperage limit for a homemade lead pencil resistor? I made a 25 ohm resistor with a regular wood pencil and would like to know what current it will take without getting hot to the touch. Anyone play with this and know?
AI: 2B or not 2B?
The 'lead' is a mix of g... |
H: A conceptual question about voltage multipliers
Imagine a micro-controller's pulse output is coupled to a voltage multiplier with many stages such as in the case of a Dickson voltage multiplier. We then can increase the DC "voltage" level of the pulse this way..
But since we still use the micro-controller as supply... |
H: RC circuit with two capacitors
Figure out the Vout wave form of the following circuit: ( assume the name of the 9u capacitor to be C2 and not C1)
Is there any way to intuitively plot the waveform by understanding the behavior of the circuit? Assume that initially all the capacitors are discharged.
My attempt at th... |
H: Can I charge a lead acid battery with a lithium ion battery?
I am asking specifically about automotive 12V lead acid batteries but I suppose the principles may be universal.
If I were to connect a fully charged 15V Li-ion battery to a discharged 12V lead acid battery (at around 11.5V), would the Li-ion battery char... |
H: Is it possible to use a MOSFET for Li-ion reverse polarity protection when protecting a charger?
I've made a simple charger out of 4 TP4056 modules and 4 18650 sockets. These modules have overcharge, undercharge and overcurrent protection included, but I also want to know how simple it would be to make it also reve... |
H: Termination resistors usage
My doubt pertains to the usage of termination resistors. This is a continuation of the discussion I saw in this link - Termination resistor.
I understand that any transmission line can be simulated using a set of LC components (viz a number of tank circuits).
When it says a transmission... |
H: Waterproofing a wire for fish tank
My fish at a part of the insulation on my filter. What is the best way to fix the insulation and also make sure that it remains waterproof?
The best option I came across is silicon gum. Can I apply it directly over the naked wire and pray for it to work?
AI: You can apply "aquari... |
H: Testing voltage continuity using a beeper?
I have a 48v rail and i wish to plug it into an audible oscillator to check for continuity when i am rattling the system under duress. What is the simplest circuit that i can plug into 48v to hear the voltage accurately?
I want an always on buzzer that makes a sound when i... |
H: Why is analog "voltmeter sensitivity" is defined as ohm/Volt?
What is the motivation to define a sensitivity of an analog voltmeter as ohm per voltage?
AI: Because the meter movement has a full scale deflection at some specified current. A series resistor is used to turn it into a voltage measuring device. The valu... |
H: Is a screw or push-in terminal better for vibrating environment?
I need to decide what connector to use on my PCB to connect low power wires. Among the available options on Farnell/Mouser etc. The price and size are almost similar.
I wonder if using a screw terminal or a push-in terminal would be better for a vibr... |
H: What is the impedance limit for using 10X probes with oscilloscopes?
I thought 10X probes are only used for impedance matching at high freq. circuits.
But I read in a text that they are also used in high impedance circuits to prevent loading. But isn't a scope's input impedance already huge? I mean what is high imp... |
H: How to determine sinusoidal steady state response from bode plot
I'm given a problem by the following:
Find the sinusoidal steady state response (in the time domain) of the following systems modeled by transfer function, P(s), to the input u(t). Use the Bode plot (in Matlab bode.m) of the frequency response as oppo... |
H: Boost converter for high side Mosfet
I recently came across an article explaining how to drive a high side MOSFET using a "separate isolated power supply whose ground and the ground of the MOSFET-based circuit are isolated". However after reading this article I still do not completely understand the driver circuit ... |
H: PT1000 2 wire probe. Can I add third wire?
I'v got 2 wire (81 cm) PT1000 probe which I want to utilize in a project.
I would like to use current source and couple of opamps to make the measurement through ADC (uC) just like described here: link1.
The point is I need to reach measurement spot which is 5 meters away.... |
H: LED's flash with music
I am wanting to put have a few LED's flash with the intensity of my music. I don't need a color organ, but just want the LED's to flash in sync with the music. I am amplifying the signal with a LM368 chip and playing music from a 4ohm 3W speaker and it's sound quality is great. The problem is... |
H: What is the purpose of a "BUF" in Xilinx ISE schematic?
I'm working on a schematic for a Xilinx CPLD using ISE. The schematic has a triangle symbol labeled "BUF" before every output, and also between some other nets. I can't really tell why some connections have "BUF"s and some don't. I read the documentation (Page... |
H: Using a relay switch to switch power to solenoid
I'm fairly new to electronics, so I'm hoping I'm not so misguided that I am wasting all of your time. Basically I need to power a solenoid which in turn controls a gate valve, and the solenoid requires 24V DC. The manual for the whole thing describes very little, and... |
H: Frequency Shift a Bode Magnitude Plot
for the 2nd order response of $$1-\dfrac{2\zeta\omega s + \omega^{2}}{s^{2}+2\zeta\omega s + \omega^{2}}$$
I get the plot shown in blue. How do I go about getting the plots shown in red and green that is basically frequency shifted?
AI: The term \$\omega\$ (natural resonant fr... |
H: Why can people touch high voltage?
So I know that you need a certain current flowing through you to die, I've heard from some people "its the amps that kills you", and from others "Its the volts that drive the amps" and I realize that these are true according to ohms law v=ir or i=v/r.
But I was watching this v... |
H: How to use a LM1117T-3.3 voltage regulator to convert voltage
I am doing a project where the components require 3.3v input instead of 5v, but my arduino pro mini can only supply 5v. Thus, I bought a lm1117t-3.3 voltage regulator to regulate the voltage, but the output from the voltage regulator is not 3.3v, but aro... |
H: Programming MSP432P401R on a custom PCB
I got a MSP432P401R LaunchPad and wrote/ran some applications with it.
What if I want to use it in a real life application. How can program the MCU when I design my own circuit and place it on the pcb. My guess I need to connect programming pins of the mcu to some pin headers... |
H: How does this wall-wart switcher work?
UPDATE
I've provided a full outcome report in one of the answers below with an updated schematic and description of the operating principles as I've come to understand it.
I'm studying switching converters to feed a strange craving to understand how
they work. I'm just gettin... |
H: MCU External Interrupt False Triggering
Above is the picture describing the configuration outside the MCU.
Vin is 0 to 5V Peak to Peak square wave which may have 0 to 50 KHz frequency, or even higher.
The MCU is supposed to handle interrupt every falling OR rising edge(configure as either one of them, but not both... |
H: Launchpad vs Development kit
Whats the difference between a Launchpad and a Development Kit? Many launchpads like the TI's Stellaris/Hercules launchpads even support In circuit debugging capabilities via USB. This eliminates the need of purchasing a JTAG debugger.
AI: "LaunchPad" is the name given to TI's developme... |
H: Problems involved in going from 0805 to (say) 0402 surface mount?
In order to reduce the size of a PCB I will probably have to use smaller SM components. I currently use mostly 0805 passives, and am thinking about going to 0402 or smaller. Apart from power dissipation considerations, any pitfalls I should be aware ... |
H: Meaning of infinite self inductance
I am reading about the characteristics of an ideal transformer and it is mentioned that self inductance of each coil is infinite. Could someone help me to understand the physics behind it? When self inductance goes to infinity that means that the voltage across the coil goes to ... |
H: SPI using one wire
I need to communicate between a transmitter and a receiver using visible light therefore i have only one communication channel. so i was wondering if SPI interface can be implemented using one-wire only? if not, what is the alternative that can reach high rates?
AI: The moment you implement the d... |
H: Is resisting DC motor bad for it?
If I keep the shaft of a DC motor in place while it is running does this harm it in any way? Is it bad for it at all?
AI: In general, yes, because the stall current for a motor can greatly exceed the rated current, and exceed the continuous current rating of the motor's windings, ... |
H: Integral non linearity in ADC
I am trying to understand the parameters in an ADC datasheet. The precise parameter being the INL(integral non linearity). Now, I was going through this website INL website.
.
Now, there is another website that shows the ADC error of a 12 bit ADC as 0.00024.
The other website.
.
In the... |
H: Why does a relay have a minimum applicable load?
I am trying to find relays for my application and I read a data sheet which looks fine but specifies
Minimum applicable load: 10mV 10µA
In my circuit, it is expected that the relay closes but no voltage and current is applied. You can think of it as 2 relays in ser... |
H: Microcontroller Interface with Modbus Serial
I'm a beginner and I'm trying to acquire data from a microcontroller with Modbus serial protocol in order to create an interface with LabVIEW. I'm using a Prolific Technology USB-RS232 converter and Windows 7 as OS.
I can't read data from the micro. I know that read only... |
H: Car DRL Led wiring beginners question
I bought this relay (http://www.ebay.co.uk/itm/400972235163) and this LED DRL lights (http://www.ebay.co.uk/itm/400757922989).
The questions are:
Can I attach 2 led lights to this relay (as it only has one red and one black wire) ?
If (1) yes, can I splice that red and black ... |
H: SD Card Reader with LPC43xx
I am trying to implement an sd card reader on lpc43xx devices. For this I can make use of the LPCopen examples that use the ROM based drivers. However for some reason the ROM based driver example states that it only supports sd cards up to 4Gb.
So now I probably have to port the outdated... |
H: converting 3.3v to 1.2v
I have a electrical problem that I hope to get some help with. Let me first start of by saying that I'm quite a noob in this field (I'm a IT guy), but I hope to learn something.
The problem I have is this: I have a sensor to monitor the humidity of soil.
When I power it with 3.3v I get a ou... |
H: Monitoring Lithium Polymer Battery Voltage from Microcontroller
I am working on a project in which a microcontroller (specifically an RFduino) is powered by a LiPo battery and the microcontroller needs to monitor the voltage of the LiPo. Five of the RFduino pins are already being used for sensors so I only have tw... |
H: Is program code copied to SRAM from flash on microcontroller?
On PC, program executable is read from hard disk, and loaded into RAM to execute it. On microcontroller, program is stored on flash.
Is it loaded into SRAM when microcontroller starts up?
If yes, then STM32F103 document says, flash is 64KiB, SRAM is 20K... |
H: How much binary data is transmitted across a physical wire in one clock cycle?
How much voltage change, what I'm calling binary data, can be transmitted over a wire at one time in one clock cycle? I understand, I think, binary data is what we call it and the wire doesn't really send out a one or a zero. It is con... |
H: Battery charger output power higher than input?
i would like to ask about battery charger i saw at work :) the plate on charger says:
Input voltage 3 phase ac
Min 400v
Nominal 400-415v
Max 456v
Input current
20A
Output
110v DC 9kW
28v DC 3kW
Now if we do simple math with no losses input is 9012W. How can be ... |
H: Attiny85 water plant with mini water pump
I`m new to electrical engineering, so it's probably a newbie problem.
I'm using a wall power supply(5V-2A) to power the DC Motor and the Attiny85.
A C1 470uF to make the power more stable. I don't know if it is necessary, but it helped.
A D1 green led to show if it's on.
A ... |
H: Why is my VHDL clock signal so far off from what I thought it would be?
I'm new to FPGA and VHDL. The following code was supposed to be 5MHz but I'm getting 4.167MHz on my scope.
The FPGA board I have is a Mojo v3 that has a 50MHz clock.
What am I doing wrong?
library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.NU... |
H: Why is wiring some LEDs in series better than wiring them all in parallel?
I noticed a lot of guides for making an LED array or matrix prefer to wire their LEDs in series first and then wire strips of leds in series in parallel. What is the benefit of this Vs wiring them all in parallel aside from energy usage, sin... |
H: Solder paste stencil application
I am trying to do reflow soldering with a stencil for the first time. I have done some reflow soldering before, but every time I manually applied the paste using a small syringe + needle. These attempts went well and I was able to solder some QFN and 0603 components. In my newest PC... |
H: about grounding on different circuit board
I got a STM32 development board, which is used to control another board for DDS output. The STM32 board send digital signal (TTL) for output control on the DDS chips. The STM32 board and the DDS board are powered in different supply. I wonder in this case, do I have connec... |
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