Datasets:
Alignment-Lab-AI
/
StackStore

Dataset card Data Studio Files
xet
 Community
1
text
stringlengths
83
79.5k
H: The Conjugate Match I've been deriving transmission line theory from scratch, out of curiosity, and I'm a bit hung up on one seemingly insignificant point. When determining the real power drop on a reactive load with a reactive transmission line attached (and supplied by a voltage source), it is commonly accepted t...
H: How to calculate the address fields for a cache? I've a homework question about 32-bit cache memories: For a cache memory that has size 16kB (16384 byte) and blocksize 2 words, state the names and the sizes of each field of the address that comes from the CPU. My answer is: 3 bits block offset since 2³=8 and ...
H: JTAG Design for altera cyclone 3 I am designing the JTAG for a Altera Cyclone 3 (EP3C5E144C8N). I was only aiming at normal JTAG, and do not need Active Serial. I have attached the schematic and board in the *.zip file (http://www.mediafire.com/?0gt55eyperbm385) Or just a snapshot here: Would you please having a l...
H: IAR errors about extern and global vriables I want to get values of a global array in a c file. the print screen of code is shown below: 'data' is the global array and 'slave_buffer_rx' is another global array defined in this file to get values of 'data'.each red cross has two errors: Error[Pe094]: the size of an...
H: 0V LDO Adjustable Regulator I'm currently researching LDO adjustable regulators to make an adjustable supply that runs from 5V. I want my supply to be capable of supplying down to 0V. I've found the LT3083, which can adjust down to 0V, however has a 310mV drop out voltage. I would prefer to have a smaller drop out ...
H: IGBT vs. Power MOSFET for switching applications. Where to draw the line? For lower breakdown voltages, a power MOSFET is clearly the device to go for, in view of its higher efficiency, higher commutation speed and lower price. Where should the line be drawn, upwards of which IGBTs take over as the preferable solut...
H: Damped Oscillations Start with a Delay I feel like a total newb here, because I've built resonant tank circuits plenty of times before, but somehow I'm stumped on this one. I've run into a bizarre problem I can't figure out. See scope shot: The top channel is my signal to the gate of a mosfet. The mosfet is driv...
H: Surface Mount vs. PTH Components For Production I'm a hobbyist who has developed a product which uses ~20 PTH components. The device is essentially an Arduino UNO with some extra driver ICs and LEDs. I have had quite a lot of positive feedback on the product and am considering re-designing it so that I can put it i...
H: Creating an LED array light box I'm wanting to make a light box of sorts from LEDs and wanted to run it by you to confirm I have the right idea... I have ordered 500 super bright LEDs off eBay and want to wire loads of them together. The forward voltage on the specs says 3V and my supply voltage is 12V (max 2A). I ...
H: Using on and off switches and logic gates So I have 2 switches Representing: Bit A Bit B And then I have : AND gate OR gate Not gate Some other gates like adder and comparator I used the method described here because the Adder & comparator gates always get the input as 1 however the switch is on or off here. Wh...
H: What is the metal sheath surrounding a USB connector, and is it commonly connected? I was tearing apart a mouse for repairs and noticed that the small plug for the USB connection had a fifth connection. This connection had a much thicker wire than the other four. I assume it is connected to the metal sheath on the ...
H: Transistor Toggle Not Working I'm trying to learn about how transistors work. As a simple test I created the following circuit: My idea is that when the second transistor will keep the first one active after I click the button for the first time, but it isn't. What am I doing wrong? AI: What you are trying to crea...
H: Splitting a power supply between two circuits I have two separate circuit boards (clock & radio) that I'd like to place within the same enclosure. One takes 12V, and the other needs 3V. How can I utilize one AC adapter to power both boards appropriately? AI: Use a 12V DC output AC Adapter to power the 12V module di...
H: Adjustable clock in HDL I need to generate an adjustable clock in hdl (verilog) on altera cyclone II fpga using signal probes (blocks that can change their output value through jtag - there is no need to recompile the code). I came up with a solution which uses a counter and a comparator, the output of the comparat...
H: Easy resource to learn solving counter problems? Could anybody please point me some direction on where I can learn to solve simple counter problems like counting in a given sequence using a given flip-flop? For example: Create a counter counting in a sequence 3-1-4-7-2 and again from the beginning using the D-ty...
H: How do I buffer a high Frequency clock on a Spartan 6? I am trying to create a high speed clock on my Spartan 6 Atlys Board. The onboard clonck is 100MHz. I am trying to use an on chip PLL to get a faster clock. I am using a the clocking wizard IP to generate a higher speed clock. Things work fine as long as my clo...
H: RC circuit and tone Can I generate a tone on an 8-ohm speaker using a 5VDC power source, resistor and capacitor? For example if I want to generate a 440 Hz tone, could I use resistor capacitor values such that RC = 1/440? EDIT: power source AI: Everything has some resonance, so certainly you might be able to wrangl...
H: Does anyone remember this article about the Euclidean Algorithm? In the 70's I had a stack of old Amateur Radio magazines (50s-60s), and for a long time I saved an article about using the Euclidian Algorithm to combine a number of resistors to achieve a specific value. Does anyone recall and have a copy of this art...
H: What is the difference between a PLL and a DLL? Phase Locked Loops (PLL's) and Delay Locked Loops (DLL) are used in various applications but there isn't yet a salient discussion of the key aspects of these circuits, how they operate, in what applications they might be used, the comparison between the two circuits a...
H: Continous rotary input? I need something to work as an input for a rotary device. It must be able to rotate continously, accurate to a degree of rotation, and so that any extra full rotation will have no effect on the input, a+360 is the same as a. With no limit of rotations as well. So I have found no potentiomete...
H: Programming ATMega48 with Arduino Uno I'm trying to build a circuit that uses an ATMega48 PDIP-style chip and an ATTiny26. I'm stuck on loading code onto the ATMega48 using an Arduino Uno. I've been following these instructions. I got all the way to step 4 when I got this error: >avrdude -P COM3 -b 19200 -c avrisp ...
H: How was the first programmable microchip made Microchips have to be programmed to function. But if programmers (computers) are needed to program it, and they use microchips, how was the first one made? AI: The first microchips were designed to fetch their code from an external memory chip, whether that be RAM, ROM,...
H: Why does CPLD has four clock sources? Altera CPLD EPM570 series have four global clocks(GCLK0-GCLK3)，I want to assign two clock sources to CPLD: one from oscillator and one from a MCU. From "GLOBAL SIGNAL" part of "MAX II Architecture"MAX II Architecture, i get confused.the structure is shown below: why does CPLD ...
H: Driving a laser module from 5V supply I've got a cheapo 5mW red laser module (datasheet), it looks like its got an internal regulator, probably a thermal cutoff too. I've been having problems driving it. First thing I tried is I connected it to 5V via a resistor of varying value, (1k down to something like 200r) an...
H: Redefining Slave-Reset-Pin in MegaISP on ATmega2560 I want to make a Arduino ISP-Shield universal exchangeable between Arduino models. For this purpose I want to use the ISP-Header in combination with Pin 10 (like the Arduino Ethernet-Shield does). The reason for this is the different pin out on UNO, Leonardo and M...
H: what is the effect of a current-carrying wire through a solenoid? The solenoid coil concentrates the magnetic field lines through the interior when the solenoid wire carries a current. I am curious about a different case, however. If a (separate) straight wire went through the center of an unpowered solenoid coil, ...
H: Current sense magnetics with critical/boundary conduction PFC chips I was thinking of using a critical/boundary conduction PFC controller in a boost PFC. I'm not sure how convenient it is to find an inductor with an auxiliary winding. I can find lots of choke type inductors in the inductance and current range I n...
H: Measuring transistor beta (hFE) - Ib anomalies explanation needed I've been struggling with details of building accurate (\$\pm1\%\$ tolerance maximum) beta meter. The simplest idea I came with went to a diagram as shown below, with R set to a value providing a \$0.01\ \mathrm{mA}\$ current and a digital ICL7107 me...
H: What is this relay symbol? I have never seen a relay depicted as below: from here (pdf) Can someone explain what is going on for terminals 6, 7, and 8? AI: Terminal 7 is the common point between a normally closed contact (terminal 6) and a normally open contact (terminal 8). When the device is not powered, termin...
H: How to wire a Normally Open Button to a BeagleBone Black? This one should be simple, but I'm fairly new to this. The button has a COM and an NO terminal. Beaglebone pins can only take 6mA, so I don't have much room for error. My question is, how do I wire this and does it need voltage? More information: This butt...
H: PWM Motor Speed Control I recently bought one of these: When i hooked it up to my 24v power supply and a voltmeter, it was either 0 or 24v with the POT. Nowhere in between. Why is this? Is it becasue this is a PWM device and needs a PWM signal? If so, why did they even include a POT with it...? AI: Put a load on i...
H: Boosting a Lithium Coin Cell I made a board recently and just started checking it out yesterday. I used a typical lithium coin cell and a boost converter (Microchip MCP1640). With a battery plugged in I get no voltage out of the boost converter (i.e. 5V to GND measures 0V). Worse yet, I measure very nearly 0V from ...
H: ATTINY 84 Aref pin? I want to program an ATTINY84 microcontroller using Arduino UNO as an ISP. In my program I need to use the AREF pin that is located at pin P0 on ATTINY84. I know that I can call analogReference() on Arduino UNO ATMEGA328, but what about the ATTINY84? Do I have to program the IC with some fuses? ...
H: How can I safely power two 3v motors from a 9v battery? I'm making a Sumo Bot from scratch and I had purchased two 1.5-3v DC motors from Radio Shack to run with my Arduino Uno v3. I'm using a 9v battery to power my Arduino alongside an RF receiver, Quad Half-H driver, and the two motors. However, 9v is probably too...
H: LM13700 VCA circuit I'm trying to build a VCA from the LM137000's datasheet. The original circuit is with +-15V while I only have a 9V supply. I wonder how the resistor values should be changed so the OTA works with 9V (split supply)? Thank you for your help in advance! AI: If your 9V supply is actually a split su...
H: Cell phone battery with solar shield, arduino I was looking for your opinion on this product: http://www.seeedstudio.com/wiki/Solar_Charger_Shield_v2.0b Do you think I could use a cell phone battery (3.7v 1000mA) with this? I have a standard Li-Ion battery with these specs that seems to work fine with this product,...
H: Mathematical rigour in Signal and Systems I'm an electronics engineering student with high inclination to analysis and pure mathematics ( abstract algebra/linear algebra ... ). I was just wondering if there was any book ( or any resource ) that treats signal and systems and signal processing with a lot of mathema...
H: Could someone help me understand this simple circuit? This is a single-wire earth-return telephone system used in cave rescue communications. simulate this circuit – Schematic created using CircuitLab The ground is a metal casing to make contact with the users hand. Line is clipped to an exposed section of a wire ...
H: Minimum tolerable signal to noise ratio in modern communication systems What is the minimum tolerable SNR in today's (digital) communication systems for successful recovery of the message? I've heard that regular commercial systems can recover the message with a SNR as small as -60 dB (using robust coding technique...
H: Problem on output compliance? What is exactly meant by output compliance of a current source? I've read that it's the range of voltage over which the current source behaves well. What exactly does behaving well mean? I've got a little problem based on this concept, but Im not sure how to go about it. You have +5...
H: What does "6 V stop-start applications" mean? I read the following in the NXP TDF8530 leaflet: this ultra-efficient device supports 6 V stop-start applications and delivers audiophile sound quality What does that "6 V stop-start applications" mean? AI: What it actually says is "... is an ultra-efficient, quad-c...
H: Electrical properties of keyboard keys I'm looking to hack together a keyboard by taking an existing keyboard and connecting it to switches that I'll assemble separately. What I want to know: What should be the electrical properties of the switches that I'll buy? I'm new to this so I'm not sure whether I need "mom ...
H: How does less cable impedance, source/termination impedance, lead to longer cable length for higher data rates? This question is about high speed digital transmission on a transmission line, I need to know about how does the (1) impedance of the transmission line and the (2) source impedance and (3) termination ...
H: How to know whether a potentiometer is a linear potentiometer or audio potentiometer? In general, how can you tell? As a specific example, how would I know from looking at the following datasheet? http://www.alps.com/products/WebObjects/catalog.woa/E/HTML/Potentiometer/RotaryPotentiometers/RK09K/RK09K1130AV7.html A...
H: What is the difference between Flash memory and EEPROM? Flash memory storage and EEPROM both use floating gate transistors for storage of data. What differs between the two and why is Flash so much faster? AI: The first ROM devices had to have information placed in them via some mechanical, photolithographic, or ot...
H: Least noisy pre-amplifier design I am building a frequency generator circuit and need some advice. I am using the AD9833 DDS generator (programmed from a PIC16F876) to generate frequencies and I wish to be able to adjust the gain. Being unable to find a suitable Programmable Gain Amplifier I was going to use a non-...
H: PIC16: Out of Data Space - Make use all available banks I'm using a Microchip PIC16F1825 with the XC8 (v1.12) compiler and defining some arrays (size between 16 and 64 bytes). I was able to declare them (linker output below). However, as soon as I try to access a few of them in a for-loop, I get an error on build: ...
H: Why does an Oscillator produce sine waves? By the definition of Oscillator: 'An Electronic circuit that produces a repetitive, oscillating electronic signal, often a sine wave or a square wave' I'm familiar with RC Phase Shift Oscillator and Wien Bridge Oscillator. Both satisfy the Barkhausen criteria,so should pro...
H: Planning an amplifier using a transistor I want to plan design an amplifier of tension voltage using a transistor: but I don't know how I can choose the values of \$R_1\$, \$R_2\$, \$R_3\$, \$R_4\$, \$C_1\$ and \$C_2\$.. I want to obtain a gain of 3, and I want \$Z_{in}=15k\Omega\$ and \$Z_{out}=3k\Omega\$. Could...
H: How does a dual gate MOSFET reduce Miller effect? How does a dual gate MOSFET reduce Miller effect? I am trying to gain a global understaning of the physics behind them, not necessarily exact formula's that come with it other than maybe some for practical use. The Wikipedia article refers to a tetrode article based...
H: The electricity grid: what keeps small power generators from being 'driven' by large ones? This is a two part question and pertains to power generation: What prevents a larger plant (say nuclear) from turning an itsy-bitsy gas generator into an electric motor and drive current through it? (obnoxiously large diode...
H: De Sauty bridge with RC parallels The bridge is described in this way: Whit the equilibrium condition, when the current is zero between A and B, I'll have: $$Z_x*R_2=Z_c*R_1$$ derived by Wheatstone Bridge's relation. Evaluating the parallel impedances ( \$R_x\; ||\; 1/(j\omega C_x)\$ ), I obtain: $$ R_x/(1+j\omega...
H: wake up 8052 using external interupt : problems Heres the procedure I followed I set an edge triggered external interrupt. SET IT0 SETB EX0 SETB EA Then I set the PCON MOV PCON, #02H When the external interupt is applied (a high to low signal) the controller is comming out of power down mode, the code that ...
H: MOSFET symbol - what is the correct symbol I've been on this site now a couple of months and I notice various symbols used for MOSFETs. What is the preferred symbol for an N Channel MOSFET and why? AI: It is likely that you saw a Circuit Lab sysmbol and that this caused you to ask this question. The Circuit Lab N C...
H: How to uniquely identify USB HID class device? I would like to identify a USB keyboard uniquely(something equivalent to unique mac-id for the Ethernet cards) on a computer. Does the USB HID profile has a support for such identification ? If so what is the field called ? I understand that VID and PID uniquely identi...
H: what transformer should i use? OK, i am new at all of this and for my first project i desided to try to use the power from a coal (like the ones you sprinkle incense on), use a Peltier to convert the heat to dc, now i know i need 5v and i think 250 mAmps to charge a phone, thing is i dont know how to figure out bes...
H: What happens when the current fed to a device is higher than the specified value? I have a solar panel which provides the output of up to 500mA with 6v potential difference. .5A is the maximum current output, and the usual output will be around 300-350mA. Can I use it as a power source to run a computer-fan which i...
H: How exactly do all FPGAs work together on this board to carry out high speed calculations The board I am referring to is called "Merrick 3" from "Enterpoint (ltd)". The web page can be found here: http://enterpoint.co.uk/products/asic-development-high-performance-computing/merrick-3/ I can see that it uses PCIe and...
H: Using Single Ended Output with Differential Input by Grounding one Input I am making a frequency generator using the AD9833 (programmed from the PIC16F876). I wish to use a Programmable Gain Amplifier to adjust the signal level before being sent to a power amplifier (common collector coupled to class AB Push Pull)....
H: Battery powering an unknown DC motor I know nothing about motors. I have DC motor (sealed in a casing) that uses 6v/12v 1a (mains switching power supply) with 2.1x5.5mm DC connector. It has variable speed controller, reversible direction, and can operate at between around 5-100rpm. The only available spec states it...
H: What can be causing output voltage to drop on LT1763 with very little load? On a breadboard, I am using an LT1763 5V regulator connected as per the "Typical Application" diagram on page one of the datasheet (LT1763 DataSheet). From a benchtop power supply I give 12V at the input and measure a steady 5.011V on the ...
H: Reducing noise in an audio amplifer using opamp I am trying to make an audio amplfier using an opamp for a project. It works kind of okay but the only issue is there seems to be a lot of noise in the output of a 0.5 watt speaker. I have tried changing the various capacitor values but there still seems to be noise. ...
H: Circuit that switches one led or all three For an analog photo enlarger (yep, that vintage stuff) I own, I would like to build my own lightsource. For the prototype I found 3 colored super bright led panels they use 12V The problem is that I need to turn on the lights in a specific setting: The Green Led source...
H: Cortex M3 (ATSAM3N4B) Peripheral DMA read from SRAM ok, FLASH fails I've stumbled across a peculiar problem with my PDC (Peripheral DMA Controller) where using the PDC to transfer a constant string from flash over UART 0 seems to produce an unexpected result. The correct number of bytes is sent but they are all zer...
H: Its a good practice use dc-dc converters and linear regulators in the same design? Its a good practice use dc-dc converters and linear regulators? Or its better don't mix them? Better use all linear tecnology or dc-dc converters in "cascade" or dc-dc with multiple outputs? AI: The short answer: Yes, it is fairly c...
H: How to use integration or differentiation to optimize frequency in achieving a specific phase angle? Question: With source voltage kept constant at 8V peak to peak vary the frequency until the phase angle "theta" Vr referenced to Vs is approximately 45degrees. Record the Vpp value across R1 and the frequency at whi...
H: How will the output of a 12V transformer wall wart differ from that of a 12V SMPS brick? I have been working on a project to drive an electric door strike from an Arduino shield of my own design. Actually, I'm using a Freetronics Eleven and not an official Arduino, which is relevant because the Eleven accepts a wid...
H: How do I hijack a reading from the circuit of my digital meter I have a tri - meter (ph, ppm, temp) that reads and displays readings on three LCD screens. I'm trying to hijack the measurement at some point in the circuit and read it in through on of the inputs on my Arduino. Can anyone tell me where I might start b...
H: How to escape redundant stated when using J-K Flip Flops? I've designed a counter using three J-K flip flops, but I have two redundant states. How can I ensure that the system has a way to escape these states if they occur? I've tried searching for help on the internet, but all of the results I found either skipped...
H: How to Calculate the charge/discharge power of a battery? I need to measure the discharge power of a battery in general. At the end i want the maximum charge/discharge power as a function of the state of charge(SOC). So i need a curve that looks like the figure that is displayed here. I already calculated the po...
H: Convert between dBA, dBV and RMS values How do I convert between dBA, dBV and RMS values? For example, I have used a current probe (clamp) with a gain of 100mV = 1A to measure a series of currents in dB and I would like to know the equivalent RMS current values. AI: I'll assume dBA is for amperes and not the 'A wei...
H: Power Supply Design - Multiple Voltage Regulators I'm trying design a benchtop DC power supply for powering small projects, breadboards, arduino, etc. This is a list of what I want from it: Fixed voltage rails for 24V, 12V, 9V, 5V & 3.3V Edit: Current requirements: 1A will be alright, 2A I'll be happy with and any...
H: How good is coaxial cable? My question relates to the accumulated AC voltage that will appear on the screen of a length of coax: If the cable is properly terminated at one end and fed with data (or any signal) at the other end, what will be the voltage on the screen relative to ground? Will it be ground potential(...
H: What is important in computer clocks' signal: signal edges or intervals when signal is stable? Will multiple value propagation occur? I am trying to figure out some basics of digital electronics. We have all seen the squared graph of the computer clock signal: I have read multiple articles on the Internet and stil...
H: Multiplexing with or without transistors I'm doing something in where I need to multiplex 6 7-segment displays. About doing it, I found things like this: And things in where the same thing is done without the transistors, just by connecting the cathodes directly to pins of the microcontroller. What's the differen...
H: Are additional smoothing capacitors required off of a voltage regulator This is a subset of a circuit I am building to run motors off a PIC 16F884: simulate this circuit – Schematic created using CircuitLab I noticed last night as I was drawing up my schematics that I might have redundancy in the use of the smoo...
H: Make two bluetooth modules communicate directly? Can one buy two cheap (and identical) bluetooth chips and make them talk to each other without needing a PC or a mobile phone? I'm guessing the answer is a basic 'NO', but I might as well ask. i.e.: I want to design a PCB and make a number of copies that can talk t...
H: How exactly does switched capacitor system work, what exactly is the detail of the primitive that switches I have been seeing these switched capacitor circuits for some time now and have even seen Z-transform being used to model how these circuits behave. While I can see that there is some capacitor that switches, ...
H: Should one use resistors to protect an mbed when using it to simulate keyboard key presses One can use mbed to act as USB Host or as a USB Device. One use of the latter is to have it emulate a USB Keyboard by sending normal key presses. The general page on using mbed as a USB Device is in their handbook here: https...
H: Stability problem in unity-gain opAmp As a part of a controlled power supply for hardware-in-loop testing for a student driven project, I had to develop a current buffer (voltage follower) which could source up to 1 A. I had the (bad) idea of trying to implement this simple circuit: The PMOS inside the feedback lo...
H: should I use 2 SPI devices on Arduino UNO/PRO or 2 I2C devices? I am using a microSD breakout board and the accelerometer ADXL345 https://www.sparkfun.com/products/9836. each one alone works perfectly fine, but once I put both (sharing pins 11,12,13, but with different CS pins) nothing works. I'm using another sens...
H: How to calibrate an optical particle sensor (Mie scattering) I have a very simple sensor that basically emits infrared light (1 micron wavelength in the infrared range). The light scatters off particles whose diameter is of the same order of magnitude as the wavelength (Mie scattering). The scattering angle is appr...
H: basic math question about voltage, ohms, resistance total n00b here. After working on several projects by copy & paste from other people's schematics and code, I'm finally digging in and learning some of the math to know what I'm doing. If I have a pushbutton (this one, to be exact) that lists max amps as 50mA, and...
H: What's an easy way to supply power to a breadboard without using batteries? There are a number of kits available (for example sparkfun's Breadboard Power Supply USB - 5V/3.3V and Breadboard Power Supply 5V/3.3V or Adafruit's Adjustable breadboard power supply kit - v1.0) but these all come as kits. What is a commo...
H: Custom USB Impedance question I'm looking at making my own USB cable for a project. The primary issue I'm having is that I'm getting a lot of capacitance in my cable between D+ and D- (400ish pF) which is enough to throw off the signals being read by my pc. Is there an easy way to fix this? I understand this is ...
H: What is the minimum temperature for FR-4 PCBs? My company is working on developing a product that will go into commercial freezers, so my boss asked me to provide operating temperature specifications for the product. I can find "operating range" temperatures listed for everything but the PCB itself, which is just ...
H: Slowly turn a planisphere at the sidereal rate My problem is to rotate a planisphere (a star chart) at the sidereal rate. I will set the planisphere to its initial position manually, then turn on some device which rotates the planisphere on its central axis, to keep it in sync with the current sky at my location. ...
H: Synchronizing SPI ports for higher data rate I am designing a new board which uses the NXP LPC4330 (Cortex M4 microcontroller) with a XESS Xula2 FPGA development board. In this design, the Xula 2 has limited I/O pins since it is designed to fit into a DIP-40 form factor. The primary form of communication between th...
H: Faster IO on ARM Cortex-M3 (Sam3x8e) than PIO_SODR and PIO_CODR? I have a very simple C program that toggles a pin on a Cortex-M3 board (SAM3X8E) with a 84MHz clock speed. I built this using Atmel Studio 6.1. #include <asf.h> int main (void) { board_init(); PIOB->PIO_PER = PIO_PB27; //Enable PIO PIOB...
H: How to read RPM from 3-wire fan - PIC18F4550 I am working a PIC µC project. I am using 12VDC PC fan (Coolermaster) for my application. A part of the project is to return the RPM from the third wire of the fan to an LCD. First of all, How can I read the signal? Is it a sort of pulses every rotation? Also, Do I need ...
H: Is mVtt the same as mVpp? I am designing a driver circuit for S/PDIF, and in a couple different places, like this one, it specifies an amplitude of 500 mVtt. I'm not familiar with those units, and googling gives me nothing. However, I do see it specified as 500 mVpp in a few places, but I want to make sure one or...
H: why is wall voltage measuring 175V? I was trying to use a DM-4100A multimeter to verify a power supply, and I'm not sure I'm using the multimeter correctly. The multimeter is >10 years old too, so maybe it is not working correctly. When I set the meter to measure AC voltage, with a 500V or 200V max, it reports 170...
H: Accurately measure relative intensity noise (RIN) using RF spectral analyzer? I'm trying to measure the relative intensity noise (RIN) of a laser using an RF spectrum analyser. It's a fairly common method (outline: How to measure relative intensity noise in lasers) although I wondered if someone more experienced mi...
H: How does this circuit diagram work? I don't understand this circuit diagram here, but I'm sure that you can help me out. I'll explain what I have figured out so far. EDIT: It's a metronome circuit. Sorry for being unclear about that. In every circuit, current tries to connect "ground" (-) and "+9 VOLTS" in this ...
H: What is the purpose of capacitors and resistors in this USB bus? Trying to understand the purpose of the capacitors and resistors in this bus powered configuration for the FTDI chip, I think the capacitors are for filtering high frequency noise, not sure what the resistors for though, maybe line termination ? AI: T...
H: Why is the output from this astable 555 the reverse of it's simulation? The simulator in LTSpice looked OK ... so I moved to the breadboard with an LED (eventually replaced the LED with a buzzer) at pin 3. One more difference in the assembled circuit is the condenser at pin 5 is not electrolytic. The supply is a r...
H: What are those black things on the board? I'm a beginner in electronics, and I'm ignorant of many basic things. Check out these black things on the board: These are from a keyboard. I'm disassembling it and I want to connect my own switches to it. All the connections seem to go to these black things. But I have no...
H: Connect 8051 serial port to multiple 8051s I want to design a project in which one supervisor 8051 communicates with four other 8051s. I'd like the students to implement this project with some server-client view. That means that the TX port of the main 8051 will be connected to all other 8051s. I want to make sure ...
H: Energy efficient one button on/off with extra function (Old) cellphones have a button to turn it on (when off), end a call (when on, short press) or turn it off (when on, long press). I need something similar for a microcontroller. The device is battery-powered so the circuit should be as energy-efficient as possi...
H: xilinx schematics to truth table I have a somewhat complicated Schematics design. Is there a program which could convert my design into truth tables? If there is no such program, how can I represent the D flip-flops of the following design in a truth table? AI: I wouldn't bother looking for tools and I would bypass...