text stringlengths 83 79.5k |
|---|
H: LM317 and PWM grounds
I have a question regarding the LM317 and PWM. My circuit receives +12v and has three grounds (R,G,B) that are PWM. I need to drop the voltage down to 3.2 volts from the 12 volt source.
NOTE: I know this could be done with resistors, but that is not what I want to do. Also, I cannot change the... |
H: Looking for capacitance and voltage rating - How to read electrolytic SMD capacitor labels
I need to replace an SMD capacitor on a board. The printing on it says
F1
560
2.5z
I have googled intensely but have been unable to find information on how to read such a codes.
I need to find out its capacitance and voltage.... |
H: permittivity and conductivity vs. attenuation
Is there any direct relationship between permittivity of a medium and attenuation of an EM wave? What about conductivity vs attenuation?
edit: Ok for instance an EM wave traveling in sea water. I get that due to conductivity the ions would induce an opposite E field to... |
H: How to read firmware from Altera's FPGA (Cyclone IV) with USB Blaster?
I'm starting to investigate Altera's Cyclone IV FPGA to use in my projects. Now I borrowed from neighboring company a real device with USB Baster Rev.C. I'd try to use one instead of evaluation board which I don't have for the moment.
Before I w... |
H: Where did these Ohms come from?
I am new to electronics and am tyring to figure out something that is a bit disturbing to me. I am trying to figure out the amount of resistance I need to put in series before an LED, and the equation I keep coming across is:
$$R = \frac{V_S - V_{\text{LED}}}{I_{\text{LED}}}$$
Where ... |
H: Opamp constant on
I have a weak signal (from a photo-diode) which I need to amplify to drive an LED. I try to accomplish this with an OpAmp TL081 and the circuit given in the image.
What the circuit does: When there is no signal (even if the photo-diode is not even connected), there is a voltage at the LED (about ... |
H: Connecting shielding for high and low voltages
I have design a power distribution PCB with high AC(230V) and low DC(<10V) voltage power rails. Both are going to be connected to my board by separate cables. Each of those cables have shielding wire, i.e. a high voltage cable have four wires, three for phases wires (c... |
H: 3V6 Zener Diodes With Very Poor Accuracy
I have a question about the regulation accuracy (or lack of) of a 3V6 Zener diode. I wanted to confirm that I wasn't doing anything stupid.
I set up the standard test circuit shown below.
No load except for the DMM. The two Zeners in question are: BZX55C3V6 (3V6 - 500mW)... |
H: Precisely drawing component footprints in EAGLE
Whats the recommended way for placing components accurately and quickly when creating EAGLE parts?
For example in the drawing below, using grids with 0.01 grids will give us the control needed for components with separation such as 10.16 but scrolling 1000 0.01 grid s... |
H: Why are caps configured this way in EMC filters?
Every EMC filter I've seen has capacitors between the AC lines and earth, configured like this:
simulate this circuit – Schematic created using CircuitLab
Why are the caps not configured like this?
simulate this circuit
What is the advantage of having the extra cap... |
H: Temporary SMD Adhesives?
When I do prototyping I solder my PCBs by hand. That works fine most of the time, but I run into a problem when I have to solder chips with fine pitch (Google for VQ100 to get an idea of what I'm working with). The problem is not the soldering by itself but keeping the parts in place once t... |
H: Could a 4 pole 3.5mm jack be used to power a RGB LED?
I'm hoping to make my LED pluggable into a jack of some kind. Could a 4 pole 3.5mm jack be used? Could each pole carry 3v-5v?
Here's the LED: http://www.tandyonline.co.uk/5mm-full-colour-rgb-led-common-cathode.html
Thanks
AI: Technically, yes, it would work. B... |
H: Find system behavior: P or I type?
In control theory, how do I find out of which type a system is? P-type or I-type (P = proportional and I = integral)
Consider the following nonlinear system with x as output:
$$
\dot{x} = A(x) + Bu
$$
$$
y = x
$$
Is this system of I-type because of 1/s (integrator)
$$
x = \int\dot... |
H: LD1117 not providing fixed 3.3V
It is my first question on this site and I'm probably doing something wrong, try to be gentle! haha
I want to provide 3.3V to my ESP8266 module from my Arduino, but people say this WiFi module requires more current than that 3.3V pin can provide. So I'm getting 5V from Arduino and tu... |
H: IC to replace 4 FETs (switches)?
I have 4 data lines that I want to put to high-Z if a pin (let's call it EN_OUT) is high (or low, if necessary), otherwise connect through. I've successfully done that by putting an N-FET on each line (gate to EN_OUT). For space considerations, I'd like to replace that with a logi... |
H: Objections to use an RCA connector for antenna in broadcast FM receiver
Due to budget & space restrictions, I am thinking about replacing a PCB BNC connector used to attach an external FM antenna. It seems to me an RCA connector could be an option, given its good shielding, low impedance and the (relatively) low fr... |
H: How does one calculate the input impedance of a tube based preamp?
I'm finding tons of information and equations on calculating this for solid state devices, but nothing for good old fashion particle accelerator based amplifiers :P
Currently I'm revamping the K270 guitar preamp to use components that are readily av... |
H: voltage current converter by op amp circuit
I am trying to convert 5V to a constant current source
for op amp I use AD822.
for 250 ohm I use 180 ohm, so I should get a current of 28 mA.
I verified when Rload = 0, 28 mA across negative terminal to ground.
But when I put Rload to circuit, 680 ohm, my current exceeds... |
H: Is it OK to put LEDs in parallel?
I wonder if it's a good idea to put LEDs in parallel, as below:
I've heard that it might not be because the voltage threshold won't be exactly the same for each LED, so they'll shine all with very different brightness and you don't have a way to balance that. Is that true? So does... |
H: Intel IA-32 Protected Mode HW-Tasks: IRET return from interrupts within a nested HW-Task ( EFLAGS.NT=1 )
The INTEL manuals tell us that when a HW-task has been switched to using a 'CALL' instruction the destination task is considered a nested task:
The processor
copies the segment selector for the current TSS ( t... |
H: Identifying 40Hz frequency shift
I have a signal that is at 4 kHz. This signal shifts by 40 Hz depending on some user input. I like to detect this change in software as fast as I can. What should be the ADC frequency I should use?
I currently plan to sample at 40 kHz and use a window of 10 ms to do an FFT to find ... |
H: Flash IC/ CMOS RAM/ microSD in TFT LCD
I have seen cases where TFT module contains flash or SD card on module. What is the need of flash in LCD?
In simplest way, we connect RS,RD/WR,CS,RESET pins and 7/8/16/24 bits data pins of controller to LCD. So, why this memory provision is there on board.
AI: Images take up a... |
H: Logic Level Shifter
I am trying to connect two devices on a PCB. One operates with 3.3V digital high and the other works with 5V digital high. I actually grouped the input and output pins (There is no bidirectional pins). The ports have minimal current levels like 10mA. However, the speed of the channels are very i... |
H: Audio conversion to digital format
I am confused in my understanding in implementation of voice guide for one of the instrument. I am trying to implement voice guide while operating one instrument. Audio data will be saved in memory ( No mic provision since data will be saved hard coded )
Hardware consists of DAC c... |
H: What is the name of this AC power outlet?
I have these power outlets on the ceiling in a (newly built) house in Sweden, they are meant for lamps. I could not find any information on them, what is their name?
Power outlet with plug. The hole/pole distance is around 11.5 mm center to center.
Size comparison with CEE... |
H: Push-pull Amplifier Class AB
I am new to electronics and I am trying to build an audio amplifier with an input signal of 100mV @ 60 hz using 12V as VCC and expect an output of 70-75W power.
I have the following circuit:
I copied this one from my notes and simulated it just to find out that it does not amplify. I b... |
H: Complexity vs Space in Schematic
I got a screw terminal with the following pin configuration:
X1
+-------------+
| (X) (X) (X) | 1 = 24V 2 = SIGNAL 3 = 0V
| | | | |
+--|---|---|--+
1 2 3
My "requirements":
Convert 24V SIGNAL to 12V logic
Add bypass capacitor for supply
At the moment my s... |
H: Syncronization Flip-flops
I've a doubt about clock domains and synchronization FF. I'm working on a FPGA and I've two clock domains. In the firs clock domain there is a clock frequency of 125 MHz, in the second the frequency is generated by a PLL that has in input the 125Mhz and it generates a 12.5 MHz.
Are syncro... |
H: embedded programming flashing program
Hello All,
I'm new to this board and looking for some opinions. I've searched the board a bit and found similar questions but not quite what I'm looking for. I'm looking for some help deciding on an SoC to use for embedded system applications.
I've taken a intro embedded syste... |
H: Can you help me find the part number for this push button cap?
I've been searching high and low for the part number and manufacturer for this button cap. I've tried it out and it works perfectly for my project. Note: I do not want the button itself, as I've already found one that fits the "springiness" level that I... |
H: How to read this transformer label
I have the following transformer that takes in 117V and steps down to 12V and 9V. However, I don't understand the label. "PUR" and "RED" are listed as 117V, does that mean PUR is power and RED is ground? Or is PUR power and BLK ground (since its 0)? Basically, which two wires do I... |
H: Would an analog mux be able to output various voltages?
So from my understanding, an analog mux such as CD74HC4067E will be able to output diferent voltages based on its inputs.
Thus for an example if I connect 4V, 3.3V, 2.2V and 0V to a 4:1 mux with 00, 01,10,11 being the selectors for each of the above voltages ... |
H: How to populate unused flash for an armv7a processor?
I have a decision on how to fill unused memory in a flash device. I've heard of populating with reset instructions as a safe way to handle rogue pointers, etc. Is there a concept of an assembly reset instruction for armv7a processors? Is there an industry sta... |
H: ULN2803A PWM LED High Watt/Ampere
Reading the ULN2803A datasheet, especially the part "Figure 13. ULN2803A as Inductive Load Driver" and after various fails to properly drive 12v RGB led strips, as i can't find the proper mosfets. i was thinking to get more of those ULN2803 and use them like a "mosfet".
500-mA-Rat... |
H: How to choose components for a circuit
I designed a simple circuit:
that I would like to put components on - the point of the circuit is to light the LED when the voltage source is above 4 volts (it won't be more than 5), so I am looking for a transistor which would have a sharp on/off state at a fixed voltage (sa... |
H: RC network (Filter) output calculation
I have an RC circuit with a transfer function
$$
h(s)=\frac{1}{1+0.0033s}
$$
Is it possible to calculate theoretical output of this network for a set of input voltages? For this how do I solve this equation? Any clue for what transformation to apply and how?
AI: The system rep... |
H: Why do we need to use `avr-objcopy` after `avr-as`?
New to assembly, I'm surprised to see that we need to use avr-objcopy after invoking avr-as, in order to obtain an Intel Hex file, so where does this come from ?
AI: The *-as is the GNU Assembler utility, used to produce binary object files *.o. This format is inc... |
H: Why isn't this astable multivibrator oscillating?
This is the schematic for a modified astable multivibrator I've built. I incorporated the diodes in order to get a sharper rise time, and therefore produce actual square waves.
Principle of Operation (As I Understand It):
One transistor will turn on first due to m... |
H: Replacing a SMD inductor, alternatives?
Trying to fix a board that had a SMD inductor. it was labeled L1 on the silk and there was no marking on the part, and I have no schematics. ...or there may have been markings, but someone tried to fix the board before me and plastered the thing on solder. no way I can salvag... |
H: Output 2 PWM waveforms with 90 degree phase shift
So far, I was able to get two outputs at the correct resolution (35 kHz-75 kHz at a resolution no worse than 0.7 kHz) using the code below. I'm wondering, now, how I can get a phase shift between the two PWM outputs (which both use the 16-bit Timer1 and ICR1).
I tri... |
H: Printing the self designed PCB
I have designed the PCB on Eagle. Most of the components are SMD pakages. This is for the first time i have designed the PCB. I want to print this PCB in the industry (Chinese industry) but i have no idea how this works. What else do i have to mention except schematics and PCB layout.... |
H: The base resistor of the transistor with speed-up capacitor
I've designed a relay driving cuicuit like this
Under DC the current is limited by R1. R2 is added to limit the current flow through C1 and the base of the BJT when the Q from 0 to 1. Is resistor R2 neccessary? And how to calculate its value?
AI: The resi... |
H: What is a Namespace in SSD?
What is a namespace in NAND or NOR based Flash Memory?
Is it a range of addresses of NVM? If yes, then is it specified by SSD Manufacturer?
AI: Namespace is actually the list of LBAs(Logical Block Address) in an NVMe Dev. It is usually Vendor Specific & is embodied in the NVMe device. Ta... |
H: Electrical symbols, what does a dot before a triangle mean?
Good day.
Trying to recreate a circuit, but I'm not sure what the dot BEFORE the triangle means. I know after it means invertor, does before just mean it's inverted BEFORE, instead of after? Rather confused, and not having luck searching.
Really appreciate... |
H: Anti Aliasing Filter and the bandwidth selection
I am currently analyzing the raw measurements of a sensor with the sampling frequency of 400[hz]. According to Nyquist theorem, the bandwidth must be less than a half of the sampling frequency, which means less than 200 [Hz]. What will happen if I select the bandwid... |
H: Replacing the Arduino voltage regulator
I want to replace the onboard AMS1117-5.0 (broken) with a LM7805.
However, the pinout is different between the two voltage regulators; AMS1117: Gnd, Vout, Vin vs LM7805: Vin, Gnd, Vout.
I would like to know what is the best practice of how to approach this? Line-up the Vin a... |
H: What is the use of 'event in vhdl?
In vhdl code for synchronous counter, I replaced following part
process(clock)
begin
if(clock'event and clock='1')then
count <= count + 1;
end if;
end process
with
process(clock)
begin
if(clock='1')then
count <= count + 1;
end if;
end process
resu... |
H: What does this schematic of an Op-Amp and Capacitor mean?
I'm still learning about electronics and electricity.
But I'm puzzled by this question from a past exam.
I'm not sure if any voltage is getting across the capacitor, since Vin and 3v are seperated by the capacitor. Maybe if it was an AC Voltage, but I'm not... |
H: Solder wire antenna on XBee Pro u.fl
I'd like to buy one XBee Pro with Wire Antenna, and another with an u.fl connector. The problem is that, on the only website I can buy them, the U.Fl one costs 20 € less than the one with a Wire Antenna: I wish I could keep these 20 bucks.
On the other hand, I've already got two... |
H: Why is the signal inverted in a common emitter amplifier?
Why is the signal inverted in a common emitter amplifier?
AI: Why signal is inverted in a common emitter amplifier?
In simple terms: -
If base voltage (input) increases, base current increases.
If base current increases then collector current increases
For... |
H: Is stalling a DC Motor with rated current safe for the motor?
I know that stalling DC motor can cause overheat because of excessive current.
If i will limit the current to the rated current of motor, is there still issue to damage the motor ?
to be more specific I have 24v worm geared motor and I want to stall i... |
H: How to apply the Fourier Transform to this?
I have the equation \$5\cos(t)e^{-3t}u(t)\$ and the Fourier Transform of it is $$\frac{5(3+j\omega)}{(3+j\omega)^2 + 1}$$ I can't figure out how to arrive at this answer.
Using the FT pairs table, I have \$\cos(t)=\pi[\delta(\omega-1)+\delta(\omega+1)]\$ and $$e^{-3t}u(t... |
H: Use 4-pin S-video cable connector on RGB LED?
I'm hoping to make some 4-pin RGB LEDs (R, G, B, GND) easily hot pluggable, so I'm wondering if 4-pin S-video connectors could be used.
Now, 2 of the pins on a S-video connector are GND, so would it be a good idea to abuse it and connect it to one of the colours? I'm ... |
H: Fourier Transform using pairs table
I'm trying to find the Fourier Transform of: $$t^2e^{-2t}u(t)$$
I know that from the FT pairs table, $$ FT(te^{-2t})= \frac{1}{(2+jw)^2}$$
So I assume that we can just use the multiplication property and do $$\frac{1}{2\pi}\left(FT(t)*\frac{1}{(2+jw)^2}\right)$$
However when I tr... |
H: How do I work out the time when given current in a RC circuit?
So this exam question looked straight forward, but I can't get the right answer.
I'm trying to find the time, from when the switch is close,that the current will equal 2mA.
I've used a few formulas but none give the right answer.
What am I doing wrong?
... |
H: Why does a BJT act as an amplifier in the linear region?
I'm covering BJT's in my semiconductor class and in lecture, the professor said that BJTs are used as amplifiers in the linear region. I'm confused because I thought the gain was proportional to the base current.
By that logic wouldn't the highest gain be in ... |
H: Difference between DC-DC Switching "Controllers" and "Regulators" and "Converters" please?
I'm looking for a switching regulator for my design, and I head over to Digikey... Now I'm curious what the general difference is between these categories:
PMIC - Voltage Regulators - DC DC Switching Controllers
PMIC - Volta... |
H: How to determine servo signal encoding
I have a TowerPro SG90 servo which matches the "JR" brand wiring discussed here where the servo's 3 wires are as follows:
Red is +
Black is -
Orange is signal
According to that article:
The motor of an analog servo receives a signal from the servo amplifier (inside the serv... |
H: Circuit in neither series or parallel (is wye-delta transformation necessary?)
I have been trying out this one problem and I just want to know if I am on the right track, because it feels like a large amount of work based on such a simple circuit and it is getting quite messy. I have attached the picture of the pro... |
H: how big my track should be to handle this current
I've read before that each 1 mm\$^2\$ of copper can handle up to 1 A. Is that true? Is there an easier formula than the one used on online calculators that requires temperature and such?
To give more details, I have 3 main points in my circuit where current is going... |
H: Explaination of high current zener transistor regulator circuit
This is a high current zener TRANSISTOR regulator circuit. I want to know
What does "high current" mean here?
How is this circuit working as a zener regulator?
What is the purpose of transistor here?How is it working?
What is the main component in th... |
H: Pull-up or pull-down at the optocoupler output
For a normal optocoupler with a LED and a phototransistor, we can put the load resistor (RL) at the emitter or the collector of the phototransistor, just like this
But for a high-speed optocoupler with some other digital logic inside, like HCPL-060L, it seems the pull... |
H: LM324 Difference / Instrmentation Amp 1mV Signals
I need to amplify 1mV signal from a wheatstone bridge (no DS available). 5kg max weight; output is 1mV/Kg @ 5V. The resistances are 880+880 and 749+749.
Currently I only have LM324 and LM358. And can procure quickly OP177 (others will take a week, which I dont have... |
H: Avalanche diode circuit analysis of the current load
I have no idea how to work out this past exam question.
I'm kinda sure is that the diode is an Avalanche diode, but I'm not even sure how Zener diodes or this work.
All I think I know is that with a reverse bias voltage they wont break down? And they let some cur... |
H: Proteus ISIS Fast simulation
I want to display my output on 3 seven segment displays, I am doing that by serially switching them on and off.
I have taken some help from here :
http://www.avr-tutorials.com/projects/atmega16-based-digital-clock
When I start the simulation, it is showing a warning message:
Simula... |
H: What happens when a power metal film resistor is exposed to higher power?
What is the worst thing that could happen if a power metal film resistor rated for 2W is exposed to 15W due to a short in the circuit? I have seen smoke being emitted but switched off the power supply immediately. If I hadn't, what would have... |
H: Why is serial EEPROM preferred over parallel EEPROM?
In the wikipedia page for EEPROM: http://en.wikipedia.org/wiki/EEPROM it is given that "Parallel EEPROM devices typically have an 8-bit data bus and an address bus wide enough to cover the complete memory" and also "Operation of a parallel EEPROM is simple and fa... |
H: why there is no quad 1-to-4 demultiplexer?
I have 4 input signals to route on 4x4 outputs. it's not a 1-to-16 demux what i'm looking for. Outputs must be selected 4 by 4.
is there any demultiplexer that can do that on one IC ?
I didn't find quad demultiplexers, I only find dual ones.
like: this
AI: In the days when... |
H: I'm looking for a specific replacement PCB module connector
I wonder of anyone here may be able to help. I've been looking for some time now for a replacement for an old (c. 1980s or early 1990s) PCB module connector. I'm looking for anything similar in order to connect these modules to the PCB. I've tried looking ... |
H: Does biphasic wave mean current is bidirectional?
Does biphasic wave mean current is going bidirectional in a circuit?
AI: From what I can see, yes, the current flows in two directions during different parts of the defibrillation impulse. That is, there is a polarity reversal.
See the diagram on the linked site: |
H: How to bypass S-type connector for connecting a servo to an MCU/SoC
I have a TowerPro SG920 servo that I'd like to connect to an MCU/SoC (Pi or Arduino).
However, the servo has an "S-type" connector (see pic above) and its 3 wires (red, black and orange) are bound/glued/stuck together. In reality I need the three ... |
H: Why does my PWM amplitude vary with duty cycle?
I'm controlling a 4-pin PWM fan from a 5V PIC and before going too far I'll say that everything is working fine but I'm just not understanding what I'm seeing on my scope.
The fan has a 12V supply and an internal pull-up on its PWM control line, so I'm driving it from... |
H: Serial XOnXOff handshaking
I have the following code running on an atmega328 (ArduinoUno).
#include <stdint.h>
#include <avr/interrupt.h>
#include <stdbool.h>
#include <util/delay.h>
volatile bool receiveQ = true;
volatile bool transmitQ = true;
ISR(USART_RX_vect)
{
uint8_t byte = UDR0;
if( !receiveQ && b... |
H: Does JPEG compression is lossy or not?
As I know, generally, the JPEG is consist of DCT, Q ,Huff.
But I'm not sure which one is lossy? all of them? of just Q?
I think Q is lossy but else not. I just want to know that.
AI: The quantization stage is the lossy one, a number of bits is assigned to a certain DCT coeffi... |
H: What is the relationship between DMX and RS485? Are there any breaks in the protocol in relation to one another?
As far as the DMX is RS485 and at what points one moves away from the other? breaking the standard/protocol?
AI: Basically RS485 is a description of a bidirectional communications hardware interface in w... |
H: Comparing industrial vs. off-the-shelf analog input
Industrial controls are expensive and my company current spends a great deal of money installing them to monitor some rudimentary signals on equipment.
For instance, we're trying to monitor:
temperature from some thermocouples (https://cache.industry.siemens.com... |
H: NPN transistor: collector current flowing to emitter without connecting base?
I have a circuit where a LED has its cathode connected to the collector of my C8050 (or SS8050) NPN transistor, with the emitter grounded.
Even though the base is left floating, the current is still flowing freely to the emitter.
Applying... |
H: Automatic distinction between PC-USB and Wall Adapter-USB
I want to ask if it's possible and an advice on how to make an automatic distinction between an PC-USB port and Wall-USB adapter. I've a battery charger IC (for example http://www.mouser.com/ds/2/405/bq24074-556796.pdf) where I can set max. IN current. I hav... |
H: Metal Film Resistor: Coating Reliability
I am using this Power Metal Film Resistor - which as per the datasheet, is coated with a "red, non-flammable lacquer which provides electrical, mechanical and climatic
protection". Now, on my PCB, I have two vias to GND placed underneath the power resistor placed for thermal... |
H: Estimate the bandwidth required to transmit 1Mbits/s of data using a modulation scheme which comprises 32 different frequencies and 2 amplitude levels
Estimate the bandwidth required to transmit 1Mbits/s of data using a modulation scheme which comprises 32 different frequencies and 2 amplitude levels
Yes, this is a... |
H: Homemade capacitor - crafting and testing
I'm a laic when it comes to electronics, but I want to venture myself in creating things with my own hands.
Looking for that, I found a tutorial that teaches how to make a capacitor with foil sheets and wax paper.
I need to know the formulas and all the variables and how I ... |
H: Why SD card is less durable than internal storage in smart phones?
For instance, Raspberry PI managed to destroy SD card in few weeks. (It seems to be a common problem.) However, internal storage in a smartphone works well for several years (5-years-old Nexus One is still working well). Is the internal storage made... |
H: Can a photodiode distinguish between daylight and white/blue LED?
I am working with a photodiode that is supposed to detect very tiny amount of LED light(the light will be programmed by an attiny 85). Using different kind of lenses I succeeded amplifying the light amount that will fall on the photodiode. Making use... |
H: Designing an analog circuit that Fourier Transforms or Laplace Transforms an input signal
This is currently my pet project but I am a bit stuck on some problems.
First I'll go over my idea for the Fourier Transform:
The Fourier Transform is defined as
\$F(\omega)=\int^{\infty}_{-\infty}d\omega\ e^{i\omega x}f(x)\$... |
H: What are these things called in a bode plot
Here is a low pass filter bode plot:
In the bode plot theory, what is K called? What is ω0 called? What do these two represent for a low pass filter? Does K not represent an amplification or attenuation of the main signal regardless of the low pass filter?
A peculiar thi... |
H: PCB Integrated Chip Question
Hi I am building a PCB using eagle and its the first time I am using an IC. Two questions arose.
Do I need to connect the IC chip's ground, because eagle did not do it?
Do I need to make sure all of the ground orphans are connected?
Thank you guys in advanced!
AI: Basically what this... |
H: Can I tell if the HC-06 bluetooth is connected?
I seem to see that the HC-06 device behaves like a serial device with TX/RX. I also understand that this needs to be "connected" to a blue tooth master to send/receive data. Is there a way that I can tell from the HC-06 end whether or not it has a connection to its ... |
H: Can you implement WLAN on a ZigBee chip?
I've spent my afternoon browsing around the web looking for a microcontroller that has integrated WLAN (802.11), but I haven't managed to find any on the market. There are lots of cheap microcontrollers on the market that work in the 2.4 GHz band and usually they support the... |
H: Where exactly does the ground line go in an AC-DC power supply?
I'm working in the United States. I'm looking into working with mains power, and I cannot for the life of me figure out where the ground line connects. For example, a simple power regulator from mains power:
Assuming that I'm using the standard mains,... |
H: Powering a Raspberry Pi using 15A supply
I'm trying to power a Raspberry Pi off a 5V, 15A power supply. Measured with a multimeter, the voltage is actually a little more than 5 - ~5.25V. I've never powered a Pi with anything more than 2A, so will this be a problem long term?
AI: No, your supply will only supply the... |
H: Old-School RJ11-Based Phone
On an old-school RJ11-based telephone system, which of these statements is accurate:
1) Each wire contains a waveform constructed from the sounds detected by one party's handset
OR
2) One wire is the signal and the other is a ground wire
?
I say #1, but this homeless man I'm arguing wit... |
H: Wiring +5V to Micro USB
I'm wiring 5V from a power supply directly to a micro USB cable. I'm only using the +5V and GND connectors, and leaving Data+ and Data-. While I only plan to use the cable for power, do I need to do anything with that D+ and D- cables, or can I leave them disconnected from both ends?
UPDATE ... |
H: RF Energy Harvesting
Why can energy invested in RF radiation not be harvested fully? What are the main factors that affect this? Is there any significant research nowadays that fully describes this process? I stand on the conclusion: "Energy moves from one form to another.", but in this case why can it not be harve... |
H: charging battery directly from a source, what could go wrong?
I have a 100A lead acid deep cycle battery and also have a car's 12V 100A charger (alternator with AVR)
At 1500RPM the alternator will produce nearly 100A.. and the battery is directly connected to the battery, will the 100A be pushed into the battery? O... |
H: What for is L1 coil?
I can't understand why L1 has four windings? And how we get -12 V if there are two diodes connected towards each other. How will current of -12 V flow?
And do thos fours windings work as transformer?
AI: Yes the four windings are coupled inductors or in other words a transformer. I think it's... |
H: What does the arrow on VCC in a BJT bias circuit mean?
At the top, the VCC has arrows on it. What does that mean?
I thought it would be like in other circuits as empty holes that you could attach, but I'm not sure here.
AI: The arrows have no special pointing significance. The conventional symbols used on schemat... |
H: Energy in transients vs. steady state
In something like a regular household, how much energy consumed is transient power vs steady state and what kind of frequency distribution does it have, roughly?
I imagine the vast bulk of the energy being in the lower frequencies but have been unable to find any information ba... |
H: 4-20mA to 0-3V3 Converter
Looking for a simple design to convert from 4-20mA signals to 0-3V3, I'm thinkin about configuration shown at picture attached.
And I would like to discuss its suitability.
It is based on:
- A follower configuration for a Rail-to-Rail OpAmp, powered at 3V3.
- A 165Ohm resistor to get, 3... |
H: Sizing Photovolatic cells based on solar load
I'm designing a Photovolatic system to power up a certain electrical load (around 1000 Watts). I've just finished my solar calculations determining the optimum tilt angle and the optimum surface azimuth angle for optimum solar energy input over the year.
I picked a MITS... |
H: Proton current? and its potential effects in cars and circuitry
Is this statement true:
"Within the (lead-acid) battery, the electric current is primarily due to proton (hydrogen ion) current which is in the same direction as the electric current."
What are the implications of this statement?
Does proton current ex... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.