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H: Resistance Vs Impedance?
What is the difference between the Resistance and Impedance?
When we will say it is an Impedance and when we will say it as an
Resistance?
Can you explain it with diagram (If possible) and real time example.
And how the reactances will form in the circut where the Capacitors
and inducto... |
H: Do fuse blow on ampere or effect?
I have a faulty car (bad central locking engines) and a fuse is blowing every time I open/lock the it. I'm looking to do a quick fix, and just replace it with an automatic fuse. The car runs on ~12V, and the fuse is at 15 ampere.
Are fuses designed to operate on specific voltages, ... |
H: ADC sampling rate to MCU clock speed relationship
How can I determine the clock speed requirements of a mCU to manage a given ADC input?
This application is very simple - I just want to take an SPI stream from an ADC into a mCU and spit it out the mCU. No major DSP happening or anything like that on board. [added... |
H: How do I convert AC current at 110v to Watts?
So I'm trying to measure the power consumption of my home PC. I used to have a kill-a-watt meter which I can't find, so I wired up my multimeter to measure the current.
Now I'm not sure what to do next.
Is it just .6Ax110v = 66W? Or do I have to do one of those sqrt(2) ... |
H: Least expensive way to boost DC voltage
What would be the least expensive way to boost a DC voltage?
The aim is to convert 1.2 V/1.5 V (from an AA/AAA cell) to 3.3 V to power a small 8-bit microprocessor, like Atmel ATtiny45 or ATtiny2313, and also (if possible) 6 V to power a buzzer.
Also, what would be the maxim... |
H: Way to discharge solenoid without (heated) resistors?
Here is a simple simulation of a schematic for my solenoid:
Once the switch is closed, the solenoid will be activated with ~80mA charge. When it is open (where the screenshot is at) it will discharge via the resisters in a looped path, due to the diode.
Now tho... |
H: Is FR4 waterproof? What about soldermask?
I'm investigating ways of making a capacitive sensor that will operate in very moist environments, potentially even submerged. What I need is a way to make some conductive plates in a specific arrangement that are electrically isolated from each other and from the environme... |
H: Choosing a DSO, advice sought
As a tinkerer, hobbyist, wannabe-'maker' (as in the protagonists in the Make magazine), sometimes I feel the lack of better tools in some projects, although for most, I can make-do with my DMM for test/measurement. Have been considering buying a basic 2-channel DSO, because I am having... |
H: Reducing noise in elementary audio circuit
I wish to hook up the line-out from a digital piano to a surplus 4 ohm 15w speaker unit. I bought a simple Amplifier module and connected it up.
My plan was to roughly assemble the circuit and, if it worked ok, transfer to strip-board with RCA connector for Audio and a DC ... |
H: What do I need to do the following things with an arduino?
I need to do the following with an arduino board:
Drive something at a power higher than that of the usb, like max 50W. I guess I have to use analog output and then amplify the signal somehow, but I don't know how.
Do the opposite too, I mean safely measur... |
H: When is using latches better than flip-flops in an FPGA that supports both?
The Question:
When is using latches better than flip-flops in an FPGA that supports both?
Background:
It is a well-known principle that level-sensitive transparent latches should be avoided in FPGAs, and edge-sensitive flip-flops should be ... |
H: Taking input from a generic usb gamepad in controllers (preferably like MSP430g2231)
I was just wondering how can I take input from this cheap but awesome HID compliant generic computer gamepad into the launchpad. I know the launchpad could work at good speed so what it would take to take the input? The info doesn'... |
H: Why is the Nyquist data rate lower than the Shannon data rate?
In the book Computer Networks, the author talks about the maximum data rate of a channel. He presents the Nyquist formula :
C = 2H log\$_2\$ V (bits/sec)
And gives an example for a telephone line :
a noiseless 3-kHz channel cannot transmit binary (i.e... |
H: Understanding Flip Flops
I am trying to better understand how flip flops work. I am asked:
Desing a three-bit up/down counter using T-ff. It should include a
control input called Up(bar)/Down. If Up(bar)/down = 0, then the
circuit should behave as an up-counter. If Up(bar)/down = 1, then he
circuit should be... |
H: Systematic construction of the ODE system of a circuit containing opamps
I want to compute the voltages and currents in a circuit containing R,L,C, opamps and voltage sources. I perfectly understand how to do this for circuits containing only R,L,C and voltage sources, using mesh or nodal analysis. But as soon as a... |
H: How to convert voltage into digital signals?
How do I convert voltage into digital signals or pulses? For some reason I have to get voltage readings of the battery connected to the UPS of the computer systems.
For that purpose I am designing a device and computer program to monitor voltage and current readings.
Pre... |
H: What does edge triggered and level triggered mean?
I am studying 8085 microprocessor architecture and the terms edge triggered and level triggered confusing me really very much. Can anyone explain me it in layman's words ?
While studying the interrupts of 8085 named RST 7.5, RST 6.5, RST 5.5 and TRAP i came across ... |
H: Radio triangulation on millimeter scale plausible?
(For this question, let's throw away the skepticism of what's possible or practical today and instead focus on what's plausible in the future. This is all theoretical, but here's the idea:)
We'd like to design future nanobots (≈5-10µm in size) that navigate around ... |
H: How much current is consumed by an avr analog sensor?
I'm trying to measure a small analog device that emits about a volt (I believe up to 5V, but I've not measured at extremes yet) AC. I rectify the reading to DC, but I'm really interested in getting something a bit smoother out of it because I just want to know ... |
H: Simple spark gap for ignition - Looks correct?
I was wanting to build a simple fireworks igniter (single line, 1m cable to actual firework)
Here is my current circuit design:
I suppose after the switch is pushed, it will send 9+9 (18V) to the transformer, and for a short time causing an 180 or so volt spike.
It wi... |
H: Can you make a non-polar electrolytic capacitor out of two regular electrolytic capacitors?
There was some discussion on this question
What are some reasons to connect capacitors in series?
What are some reasons to connect capacitors in series?
which I don't see as being conclusively resolved:
"turns out that w... |
H: Demodulating a signal generated by IR LED/ phototransistor pair
I am driving an IR LED with a 20kHz square-wave signal (I may/ may not use PWM) and I am trying to demodulate the signal being generated by the corresponding phototransistor. I don't have access to demodulator ICs so that means I have to build a demodu... |
H: Measuring cpu load of interrupt routine
I have an isr that is updating a display at a fixed frequency. I would like to tune my routine to minimize overhead and keep as much cpu time as possible open for other processing, but I don't have any good way to collect metrics to determine my cpu load.
I could look at the... |
H: What electrical processes are behind RECCO system?
According to Wikipedia, RECCO system for finding people buried under snow uses reflectors each of which contains a pair of foil aerials, joined by a diode. The text further says the size of the aerials makes the unit a tuned circuit resonating at one specific frequ... |
H: Confused about frequency and bandwidth in BP filter?
I am trying to design a simple bandpass filter and I am confused what should be my central frequency and bandwidth should be.
I have a 1MHz square wave with 20% duty cycle, so the signal is on for 200nsec and off for 800nsec. I have a rise time and fall time of ... |
H: Why is RS-422 interface interference insensitive?
I am trying to understand differences between RS-232 & RS-485. I just don't grasp what is the core principle behind RS-422 inteference resistance? Is it number of wires (4 instead of 3)? Is it because these wires are twisted?
AI: Summary
In a balanced signal both wi... |
H: LED lifespan after current increase
I have a 3W LED that the manufacture states that if I 'feed' it with 750mA it will 'live' 100,000 hours (Very good heat sink, mid ambient temperature, etc....).
Assuming this is correct and the manufacture knows what he is talking about, how will the lifespan of the LED be affect... |
H: Blending RGB LED colors together
Although this question is more of an optics than electronics, it strongly involves LEDs so I think it is a good idea to post it here.
I have a simple 3W, RGB LED with a 5deg lens. Everything is connected and and works but when projecting the light on the wall I can easily see the 3 ... |
H: Lower Lifespan Components?
So i've searched around the site, and there have been some questions about Capacitor shelf life and it being a somewhat sensitive components.
But are there any other "Lower" life components that someone would need to be aware of (Both Shelf life and "In Use" life, or whatever you would ca... |
H: Using Logic-Analyzer to reverse-engineer ISM-band ASK/OOK encoding, possible?
Is it possible to use a Logic Analyzer (such as this one), to determine the waveform s.t. on the DATA out pin of an ISM-band ASK/OOK (315/433.92MHz) RF module, in turn to decode it's encoding scheme. I know for sure that it is not Manches... |
H: Why are digital oscilloscopes still so expensive?
I'm a beginner in hobby electronics and I am wondering
why digital oscilloscopes are still so expensive?
In times of cheap GHz CPUs, USB 3, ADSL modems, DVB-S receivers, blu-ray players which all of them have remarkable clock frequencies/sampling rates it makes me ... |
H: Plated Through Hole at home?
Is it possible to make PTH (Plated Thorugh Hole) at home?
Can somebody explain the procedure?
AI: As Majenko says, a few folk have tried the conductive liquid route. From what I have read it seems to work okay but requires fine tuning and experimentation (but then so do the rest of the... |
H: Complete alternatives to the Arduino IDE?
I'm not that big of a fan of the official Arduino IDE (in terms of visuals), so I've started looking for nicer alternatives. However, most of the projects I've found are in alpha/beta and are generally incomplete.
I'm 100% new to circuit board programming and I've never use... |
H: What device should I buy to cool liquids in a container
Basically I have a large Evaporative Cooler (one of those fans that you can put water in the bottom of). It has a really large container so it can last a day or two. The problem is once the water gets hot its doesn't work as effectively.
I was wondering if th... |
H: Simple, passive way to remove high frequency interference from low power audio
I have used the innards of a Korg Mini-KAOSS Pad to add some amusing effects to one of my electric guitars, but in order to do this I had to remove the original input connectors and wire my pickups directly to the input circuitry.
The in... |
H: What rechargeable battery is suitable for severe frost (−10 Celsius and below)?
Suppose I want a rechargeable battery for a hybrid electric vehicle like Toyota Prius - one that can power the vehicle traction motor at low speeds. The vehicle would have to operate in a region where −25 Celsius is not uncommon and −10... |
H: Assembling ARM computer
I want to assemble my own mini-computer with ARM processor, but I don't know the start point I must to start.
Can you advice me some articles or other sources where I can read something about that?
EDIT: I want to assemble computer with ~500-700 MHz CPU freq, 128-256 MBytes operational memor... |
H: Sources for cheap/free electronics for students?
I've just recently discovered an incredible interest in building my own circuits and my own logic. I'm in a computer architecture class and we're learning how to make ALUs based on a set of instructions.
Last year, we would create logic circuits on a breadboard using... |
H: programmer is not responding with stacked shields
I keep getting the following error when trying to upload my code with the Arduino IDE:
avrdude: stk500_recv(): programmer is not responding
I stacked the following shields:
Sparkfun ColorLCD shield (shieldlist reference)
Libelium XBee shield (shieldlist reference)... |
H: How does active power factor correction in computer power supplies work?
I'm not looking for very detailed explanation (although it would be welcome). I'm more looking to intuitively understand how it works.
Basically in computer PSU I have input followed by filters followed by PFC circuit followed by switch follow... |
H: Identify a fuse part
I'm trying to identify a fuse part that says 125V T 2A on it.
It seems to be a solid state fuse soldered in place. IE I can't just snap in another replacement fuse in a glass tube like I'm accustomed to. So I need to desolder this one and solder in another. Anyone know where I can order one or... |
H: Powering microcontroller off USB, load off wall-wart
I'm developing a light display thing using a Teensy 2 and a digitally addressable LED string that draws quite a bit of power, more than can be provided over USB. I have ordered a switched wall-wart style power supply that more than adequately meets the power need... |
H: How to find connectors for Densitron TFT displays
I'm having a hard time to find information about the connectors for a TFT display I just bought from Densitron. The cable is physically similar to FFC/FPC, but the terminals are not straight, so I can't use normal FFC/FPC connectors.
The measures are in mm, and thi... |
H: Benifits of using Breadboard instead of PCB
What are the main advantages of using breadboard instead of PCB?
AI: Works great for quick prototypes using through-hole resistors, capacitors, and DIPs with 22ga solid-core copper wire.
You need to be aware of the disadvantages though.
not meant for withstanding high vo... |
H: Can I log current using a voltage input and V=IR
I have a sensor which produces a current proportional to the variable it is sensing. My data logger only accepts input as a varying voltage, which it then encodes in 8 bits (scaled linearly to volts). Can I somehow use this and a knowledge of the equation V=IR to all... |
H: Various Memories?
Is the basic device to store the bits are Flip Flops or Not?
There are Various types of memories are available in the market such as RAM, ROM, FLASH Memory,SDRAM etc....
Then
what is the basic memory unit is used in it in order to change its
functionality?
Is clock is compulsary for a flipflop... |
H: Remote Control Design
I am want to design a remote control. All I need is the appropriate IR LED and the Receiver to use, that will yield optimal performance. i need real practical experience here.
What is the best receiver to use. Photo diode or a Photo transistor.
As regards the distance. This remote control... |
H: How many kilowatts (or amps) can I safely draw from the AC grid?
I rent a house in the SF Bay Area. The house is not exactly new, but it's in good condition; hopefully the AC installation is the same. Most AC outlets are without grounding; but fortunately, there are two outlets in the backyard that do have ground c... |
H: What's the 2N3904 / 2N3906 FET equivalent?
Is there a generic low-power switching FET that's multiply sourced, generally readily available, most simulators already have models for, etc.?
I'm not looking for FETs that have similar electrical characteristics to the 3904/3906; I'm looking for FETs that have similar ub... |
H: Simple capacitor use for buffering a battery?
I have a simple application where a 6V, 2A DC power supply is driving 4 hobbyist-grade servos. In most cases this is adequate, but there are cases (when all servos are suddenly loaded) when I think the power draw will exceed 2A for a short period of time.
It was sugges... |
H: Modifying a soldering iron for lower power
I have a 60W soldering iron, which is too much heat for typical electronic soldering purposes. I find myself constantly switching it on and off using a powerstrip to control its temperature so it does not get too hot. I was wondering if there exists some easy way to reduce... |
H: De2 Board reading sensor reading
I wish to operate a LVMAX Sonar EZ1 sonar rangefinder.
They say
With 2.5V - 5.5V power the LV-MaxSonar EZ1 provides very short to long-range detection and ranging, in an incredibly small package. The LV-MaxSonar-EZ1 detects objects from 0-inches to 254-inches (6.45-meters) and prov... |
H: relay power ratings - AC vs DC
I'm in the process of finding a suitable relay for switching the elements in a mini oven I want to use for solder reflow.
I've found what I think will be a good candidate, however I'm a bit confused by the maximum power ratings.
Here's the relay in question: http://www.rapidonline.com... |
H: RTU card of SCADA systems
In most of electrical SCADA systems, RTU (Remote Terminal Unit) panels are very common in power transmission & distribution companies. There are several cards inside each RTU panel, some are binary input/output cards and the others are analogue input/output. I would like to ask about the f... |
H: Shorting the output ports which have nominal bandgap voltages of 1.24V
I am using LED drivers (TLC5940) which allow one to fix the operating current \$I_c\$ flowing through LEDs. This is accomplished by connecting a resistor (of the desired value) between an output port, driven by a bandgap reference of 1.24V, and ... |
H: Problems with Wien Bridge oscillator circuit simulation in Mutisim
I am trying to build a Wien bridge oscillator that oscillates at 2.1kHz and that can be switched on by a transistor. The reason for me placing a transistor switch in the circuit is so that I can turn the oscillator on and off from a PIC MCU. However... |
H: Circuit for determining the dc mean of a wave-form
I need to find the DC mean of a waveform whose maximum and minimum values will vary. The input signal has a frequency range of 0 - 3Hz, and will have a voltage range of 0 - 5V. I would like to find the DC mean of the waveform after the waveform has gone through thr... |
H: Purchasing a Switch - AC vs DC Current Specifications?
I'm trying to purchase several switches for a DC system with moderately low current (a few amps at 12V). When browsing for switches in parts catalogs (e.g. Mouser and Digikey) there are always separate voltage ratings for AC and DC applications. I understand th... |
H: Building a large lead acid battery?
I am building a large water tank. I'm thinking to convert it into a big lead-acid battery. I am interested if exists a formula that could calculate how much will be the capacity of that battery, voltage, energy density, specific power, specific energy and other parameters ...
The... |
H: How can I improve this SMPS design?
In: 21-32V
Out: 12V, 3A
Working Frequency: 300 KHz
Controller IC: FP5138 from Feeling Technology
MOSFET: IXTP44N100T from IXYS
Schottky Diode: MBR20100CT from ON Semi
The MOSFET and the diode are going to be isolated from the heatsink. Should I connect the heatsink to the ground ... |
H: Does Tesla coil use near field or far field?
According to Wikipedia a Tesla coil
transfers energy (via loose coupling) from one oscillating resonant circuit (the primary) to the other (the secondary) over a number of RF cycles.
which I don't quite get. RF is likely opposed to near field and the near field spawns ... |
H: Shielding can, what is the proper way?
I like to protect a sensitive circuit of mine with a shield. I don't have a picture but basically, I have put together a 1 mm thick ground rectangle on the top layer, and I will place the shield on top of this such that it will contact to this ground trace.
I have some concern... |
H: TS317 voltage regulator falling voltage
I am looking for some help explaining a dropping voltage reading on a circuit I have built. Details below.
I have built a circuit to experiment with the TS317. The circuit is very similar to the standard application circuit on the data sheet.
R1 = 212 Omhs
R2 = POT makked wit... |
H: How to reduce voltage without using Transformer?
Is there any way to reduce voltage without using transformer? I have a supply of 24 volts AC @ 1500mA (1.5A) and I want to convert it into 6 volts @ 500mA. Because I have to supply the 6 volts to the 7" compact LCD screen via rectifier. Since, there is no enough spac... |
H: Calculating resistor and capacitor values for an op amp differentiator circuit design
I need help in designing a differentiator using an op-amp. I know that the equation for an op-amp differentiator circuit is Vo = RCdVin/dt, but I don't know how to calculate the component values to finish the design. All of the we... |
H: UART core Altera De2
I have to implement a rs232 receiver for my project. Does any one have any idea on how do I start learning / implementing this. Do i have to use the nios ii software or just implement it using verilog modules?
http://www.altera.com/education/univ/materials/boards/de2/unv-de2-board.html - The de... |
H: Resistor suggestions for colorblind person
I'm a developer who has always had a love of the low-level electronis, but I have always been intimidated by it since resistors all seem to be color based and as a color-blind person, this is difficult to work with.
So my question to everyone here is if they know a good, p... |
H: What IC is good for driving an array of smaller solenoids?
I have a 7 segment display where all segments are driven with a solenoid. In order to switch each segment I have to pulse a short current on the solenoid. To change the segment I have to pulse it in reverse polarity. This means that I have to use something ... |
H: Why exactly can't a single resistor be used for many parallel LEDs?
Why can't you use a single resistor for a number of LEDs in parallel instead of one each?
AI: The main reason is because you can't safely connect diodes in parallel.
So when we use one resistor, we have a current limit for the whole diode section. ... |
H: How to correct instability of op-amp voltage follower?
I am using a number of single-supply op-amps (OPA4344) in a circuit, and am using one of them to supply a VCC/2 value for a virtual ground to the + side of several other op-amps.
VCC is +5 volts. When I first power up the board, I get 2.5v from the output, but... |
H: Single resistor powering multiple LEDs in parallel where current through resistor is lower than max allowed current for an individual LED
While writing an answer about using multiple diodes connected to a single resistor, I stumbled upon a case about which I haven't read a lot: What happens when we set the resisto... |
H: Memory-mapped I/O address ranges
In Memory-mapped I/O, how does device allocation and address ranges are decided? For instance like, EPROM has control over address bus for address from > 0x0000 and <0x4000, RAM1 from 0x4000 to 0x8000
Especially curious about partial address decoding methods
AI: Pure address decodin... |
H: Square Wave Voltage Level Shifting
I have a square wave signal of 300 KHz which is 0.2 V to 1 V. It is the output of FP5138 Non-Sync PWM Controller IC. I want to drive a PMOS with this square wave but with the levels shifted to (Vin-12)V ... (Vin-5)V to Vin, where Vin is 20 to 32 V.
To explain it better, let me tr... |
H: What is this transformer-like component with only two leads
I found this while taking apart a PSU, the closest label was B1. It appears to be a transformer-like component with two leads, and the coils on the vertical part around the core seem to be connected opposite the leads. Googling the label got me nowhere.
AI... |
H: charging and discharging capacitors
I'm wondering if it's possible to charge say a capacitor with a stepper motor (~12V DC after rectifying), which when it reaches its maximum capacity discharges. I'd like the discharged power to activate a solenoid?
AI: You really asked two questions:
Can a stepper motor be used a... |
H: Building a treadmill speed sensor
I know very little about electronics so I was hoping to get some advise on a small project I want to do at home.
My home treadmill already has the standard dashboard that tells me the mph I'm going, time and so on, however it doesn't offer any way to get at that information - as yo... |
H: Modular PCB Design
I'm designing a basic harness continuity checker based on shift registers implemented in Max V CPLDs. I'm aiming for a modular/extendable PCB design for the project as it has several benefits (cost, less complexity).
A uC communicates with my CPLDs using SPI. What I'm not sure about is how to bes... |
H: address field and words of memory
"Consider as an example a typical computer of that era which might have had a 16 bit address field in its instructions and 4096 words of memory.A program on this computer could address 65536 words of memory."
I don't understand some of the terms. What is meant by "16 bit address fi... |
H: How and where is energy dissipated in a driven traction motor?
When a fully loaded elevator is moving down its potential energy is decreased and I guess is somehow converted by the elevator traction motor into heat.
How exactly does it happen? What exact elements of the motor or other parts do the conversion and ho... |
H: Is it safe to connect Arduino/Netduino to car voltage source
On Netduino homepage it is stated that Netduino can be powered by input: 7.5 - 12.0 VDC or USB. The car output voltage is 12V but the car voltage source can produce voltage spikes so I am not sure whether it is safe to plug netduino directly into car volt... |
H: How can I make a 15 minute egg timer circuit?
I want to make a 15 minute timer for a game. I would like it to count down 3 x 5 minute segments of time, and then ring a bell when the 15 minutes is up.
To do this, I want to push a button to initiate the timer, which will then light 3 x leds. After each 5 minute segme... |
H: Battery circuit power drain
Bit of a newbie question here...
I want to build a battery powered LED light for use outdoors. So basically needs to be pretty bright and last a while.
If I have battery rated like this:
5.0Ah 6V
Discharge current 20 hr rate 250mA
Capacity:
20hr rate (0.25A) 5.0Ah
10hr rate (0.50A) 4.3Ah... |
H: 9bits/signal element, what's the bandwidth?
If I encode 9bits/signal element, what is the minimum required bandwidth of the channel in Hertz?
With the information that 9bits/signal element, is it possible to find its bit rate or any other things so as to find the minimum required bandwidth?
AI: The bits/signal rati... |
H: Is it advisable to use lead-free PCB and solder paste on a first SMD assembly job?
I am sending my first PCB design to Sunstone for manufacture and I need to decide whether to order the board finish lead-free. All of the components are lead-free, and I have not decided on solder paste. There are about 25 chips on t... |
H: How do I set the speed of a 4060B chip?
Apologies if this is a bit simple, but I'm new to this!
How do I set the speed for a 4060B chip? I want it to trigger every 5 minutes (fairly accurately).
I've looked at the instructions here: http://www.reuk.co.uk/Timer-Circuits-With-4060B.htm
and it looks like I need to tri... |
H: How do I calculate the temperature rise in a copper conductor?
If I pass a current through a copper conductor, how can I calculate how hot the conductor will get?
For example, if I have a 7.2kW load powered by 240VAC, the current will be 30A. If I transmit this power to the load via a \$2.5mm^2\$ copper conductor, ... |
H: Square Wave Voltage Level Shifting (Take 2)
After my question before, I tried to design a circuit with zener diodes and transistors for this issue.
It seems to work in simulation. Am I overdoing it? Are there any other simpler ways to do this, if so, could you please give any example or pseudo circuits?
AI: Sorry -... |
H: Wake up on movement
My circuit application requires processing during physical activity, but it can be put to deep sleep for long periods of inactivity. I need a "true" or "false" output from a sensor that can be used to interrupt a microcontroller, i.e. an accelerometer would be massive overkill.
Is there a very ... |
H: Temperature-Controlled Fan
How do I trigger a fans function after a setpoint temperature is reached? I want to avoid using a PID Controller, and my heating element will be external of the circuit. Once the fan cools the thermister back to regulation, it should turn off.
I have a fan that operates at 24VDC(full spee... |
H: Can non-rechargeable batteries be used in place of rechargeable ones?
I am aware that attempting to charge a non-rechargeable battery is a terrible idea, and I have no intention of doing so. But supposing that, in a pinch, I needed to use non-rechargeable batteries in a device that originally came with rechargeable... |
H: mapping non existent addresses?
"In terms of this picture of mapping addresses from the address space onto the actual memory locations, a 4-KB machine without virtual memory simply has a fixed mapping between the addresses 0 to 4095 and 4096 words of memory. An interesting question is: "What happens if a program b... |
H: Have I understood what Arduino is correctly?
Just before I go out and buy an Arduino starter kit, can someone confirm I understand what it is?
As I understand it, I can use a simulator to create the behaviour I want. Once I'm happy with the code I compile it, connect the Arduino Uno to my computer (with a "blank ch... |
H: Forward Bias Photodiode circuit
I have made a quick search but couldn't find anything specific around.
I need to design a rudimentary circuit for a photodiode in conductive mode. I am interested in high speed rather than sensitivity, a wavelength around 550nm.
I have a notional idea of a battery connected across t... |
H: What are the pins of a MOSFET in a TO220 package?
I have an IRF3205 MOSFET in a TO-220 package, and I would like to know where the drain, gate and source are. I can't find this information.
AI: The information is available in the datasheet as you might expect (fourth hit on google).
Here is the relevant bit (page 8... |
H: Testing an 8-ohm speaker
I have been trying to test an 8Ω speaker, but I am having some difficulties. I have tried to test the circuit using multisim using the circuit below:
I used the 8Ω resistor in the place of the 8Ω speaker in the circuit. When simulating, I get about 106mA, which should be enough to power th... |
H: Is it safe to design board at fab houses minimum trace width?
I am working on my first board to have professionally fabricated. Right now I am planning on using seeed studio mainly because they are the cheapest I have found. 10 5cmx5cm boards for $10 is pretty awesome. Their site says they can handle 6 mil traces w... |
H: PCB (Auto-)Routability
Background
I'm working on a fairly dense mixed PTH/SMD (plated through hole / surface mount) component PCB design. I'm using Eagle CAD for it for the schematic capture / layout and I'm using the auto-router function to route. It's a two-layer board, and I'm trying to keep all the SMD componen... |
H: Calibration of reading of current measuring cicuit
I'm making a small current meter device. I was able to take the voltage coming from a "shunt resistance" which is a current transducer that gives me a specific analog signal that's proportional to the current passing through it. I take this signal into ADC, but I'm... |
H: Use only programmer power
Is it safe to program a Pololu 3pi robot from Sparkfun without batteries, using only a power supply from the AVR programmer?
AI: Looking at the manual I would say it's probably not a good idea.
It may draw too much current for your programmer (you would have to verify this yourself) and ... |
H: Faking poles on a simple switch
I'm making a simple switch box and I've done quite a bit of looking but I can't find a 4 pole single throw switch anywhere on the major component seller sites in the UK (farnell.co.uk etc.), although I imagine if there is one it wouldn't be reasonably priced.
So, can anybody think of... |
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