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H: What is Power Supply Rejection Ratio and how does a high PSRR help me?
A lot of regulator datasheets give a figure of Power Supply Rejection Ration in decibals. I understand that a high PSRR is good, but how and where does it help me?
For instance, suppose I have a regulated wall-wart power supply that outputs 5V b... |
H: Safe to connect SDR to home Cable?
I have an SDR (RTL2832u) that connects to an antenna and can receive over the air just fine. I'm wondering if the signal of a home cable connection would be too strong to connect to the SDR input or is it safe?
Say for example my home cable modem transmit power is 35dBmv. Downstr... |
H: boosting 3.7V to 12V
What would be the best way for me to boost 3.7V to 12V with 300ma max draw?
I've been looking at this: LT1303 and this MC34063A.
I actually bought an lt1303 last week but I couldn't get anymore than 20mA from it, if I try to draw more, the avg voltage goes down, ~10v at 70mA (hadn't got the ch... |
H: What effect does switching frequency have on a switching booster circuit?
In what cases/application is a high switching frequency desired and vice-versa? I'm trying to choose a DC-DC booster IC and I don't quite know how the switching frequency will affect the circuit. Only thing I can think of now is the speed of ... |
H: Measuring Arduino internal voltage reference with respect to Vcc
How do I read the internal reference voltages of the Arduino (Ardino Mega, ATmega2560, specifically the 2.56v reference) with respect to the input voltage?
I'm trying to measure the remaining battery capacity of a device through a voltage divider. The... |
H: Why is this MOSFET's "pullup" resistor necessary?
I'm reading an basic electronics textbook, the chapter on MOSFETs, and it has started with a simple model of the MOSFET as a switch (the "S model"). It shows a circuit like this:
And says: Here we see the purpose of the load resistor R -- it provides a logical 1 ou... |
H: Replacing MOSFET with tube
I am working on making a flyback driver with a 555 timer. The only part I need is a MOSFET power transistor. I am wondering is it possible to substitute a triode vaccum tube (14GT8) for the MOSFET?
AI: Please clarify whether you wish to use a MOSFET or a vacuum tube in the final design.
I... |
H: Possible to output sinusoidal signal with an Arduino?
Is there a way to output a sinusoidal wave with an arduino? Perhaps using PWM? It would be nice to be able to simulate something around 10kHz. Is this even possible with the hardware on the Uno?
AI: Look for DDS (Digital Direct Synthesis) which uses a low pass f... |
H: Keep SPI/TWI master active?
I'm designing a data recorder application which uses an 8-bit AVR microcontroller. It uses the TWI and SPI interfaces with the microcontroller being the master. There is one SPI device, a microSD card, and one TWI device, the MMA8452 accelerometer. The accelerometer is going to be sample... |
H: How long a lead may be used to connect a component to a circuit?
When out of town I'm thinking of using an LDR with a 555-relay driver to periodically toggle the lights in a few rooms at night, and a thermistor near an incandescent bulb to kill the circuit when the bulb is sufficiently warm/hot.
This will involve ... |
H: How to interface with ultra-low voltage microcontrollers?
Cypress has PSoCs which can operate at 0.5V power supply. I was wondering how you interface these. 0.5V is too low for FETs and bipolar transistors, LEDs and even common diodes. So what ways are here to connect the PSoC to its peripherals? Low-power is also ... |
H: how to purchase simple custom devices with low quantities?
We have need for a few simple devices, mostly as adapters and connectors between other devices.
One example is:
6-pin Molex connector with 20-30V between two pins
24V to 12V DC-DC voltage converter
24V to 5V DC-DC voltage converter
2 x USB port (5V voltage... |
H: detecting if an object is present using a sensor of some sort
Yesterday I when I came home I found my soldering iron was still switched on from few hours before. I have one of those big aluminium holders you get with expensive soldering stations. I was wondering if it's possible to mount a sensor where the red blob... |
H: keep bathroom fan running for a few minutes after power off
What is the best way to keep the bathroom fan running after cutting the power to it? I assume a capacitor can be used, but which one should I use and how do I connect it?
AI: This module
uses the switch as input and replaces it in the circuit with a relay... |
H: Making a HDMI switch basic question
I am doing a hobby project and I found a place to get PCB HDMI jacks and I wanted to incorporate an HDMI switch into the board. My question, is there an IC that I can use as the "switch". It will be like a standard 5-1 switch. at the very least if someone could point me in the ri... |
H: What is a good way for the mcu to determine which hardware version it is running on?
I'm working on a new product design and there will probably be small or large hardware changes/fixes over the life of the product. For future firmware updates in the field I need a way to determine the hardware revision. What is a ... |
H: How do you remove the buzzer from this PCB whose solder side is inaccessible?
(Click on an image to see in original size.)
There is this buzzer in this UPS (uninterruptible power source) circuit. I want to remove it from this circuit because it make a lot of unnecessary noisy. Black-outs happen too much in my ar... |
H: PICAXE 8 Pin Proto Kit
I just soldered together the PICAXE 8 Pin Proto Kit, and I have a feeling there is one part missing.
Here are the images for the kit:
The part that I think is missing is the white component in the first picture and the blue component in the second image.
However, the list of components i... |
H: Measuring Power from Altera Dev. Kit (CycloneIII)
The Altera CycloneIII starter kit that I have provides a jumper (J6) that is connected to VCCINT of the CycloneIII FPGA core for what seems to be the purpose of measuring the core's power consumption.
Here is the reference page for the kit: http://www.altera.com/pr... |
H: Proper use of a voltage regulator
I want to power a prototyping kit for an 8 pin picaxe micro-controller with a 9v battery (the board itself requires a 5v input).
I have the following regulator:
https://www.sparkfun.com/products/107
On the 3rd page of the data sheet says that for that 5v regulator, the min voltage... |
H: Chip antenna on breadboard
Is it possible to experiment with chip antennas on a breadboard? Any circuits available to let me do that?
I am looking at this chip antenna, but any other is ok.
AI: There are a lot of problems with RF on breadboards. The main one is impedance matching. For maximum power to be radiated b... |
H: Protoboard components being used for applications with high current
If I have a few pins of a relay (which is rated for the correct current) that will carry 5A when the relay is triggered, what's the best way to wire this up?
Details: I have a breadboard with a circuit on it, but a small loop in the circuit will ca... |
H: How to implement and tune a LC band-stop filter?
I have designed a simple LC band stop filter with a center frequency of 433MHz. The schematic looks like:
The caps are NP0 0603 and the inductors are from the Coilcraft 0603HP series. The values shown don't give me a center frequency of exactly 433MHz but that's the... |
H: Is it possible to have a device with metal case and wireless charging?
Recently I encountered the following idea: that a mobile device manufacturer is not interested in including wireless charging in his devices because that prohibits him from using metal cases in the future (without excluding wireless charging fro... |
H: Is analog SPDT IC switch same as mechanical relay?
I am working on a project which require to trigger a SPDT switch using a button to pass a small signal voltage across (~3.3V).
reference circuit image below
The requirement is:
signal must still pass through (pass through NC) even when relay/switch power is
off ... |
H: How critical is the layout of USB data lines / how does my layout look?
I'm laying out the USB data lines on my board at the moment, and I'm just trying to get an idea of how well off my design is gonna fare. Here are the particulars:
4 layer board (from the top: signal, ground, split power planes, signal)
intern... |
H: Arduino USB host get raw events
For a project I'm planning, I'd like to be able to plug a USB device into an Arduino and capture the raw usb events (handshake, interrupts, etc) and reply to the device on an equally low level. I've been eyeing the Arduino USB Host Shield (Docs) for this project, but I had some quest... |
H: Help me interpret this part of the USB + Power Standard
It's the last two sentences of this section:
What does the last sentence mean exactly? And how do I apply it?
Basically I am building a USB + Power peripheral that will convert USB to RS-232 and drive a display that needs more than the 500mA you get from reg... |
H: Choosing my first oscilloscope
I'd like to repair older computers, such as C64's, Atari's, Apple IIe's etc and their power supplies. I have a multimeter already but I'd like to get an oscilloscope. I've been offered an Owon PDS5022S really cheap, would this be suitable to start with?
AI: Yes, the Owon should do oka... |
H: SPI: effective payload throughput per clock tick?
Let's say I'm clocking a SPI bus at 30 MHz.
What payload throughput can I actually expect? 30 Mbps, or less?
(E.g. are high overheads imposed by pauses, control packets, packet headers, packet checksums, etc? SPI noob here.)
AI: SPI only defines a very small part of... |
H: Thinest insulator between metal case and PCB?
For a miniature product, I want the smallest possible product enclosure around the PCB. I figure I can get away with a 1mm thick metal sheet enclosure.
But I (probably) also need an insulator between the circuit board and the case, so nothing shorts out. What's the thin... |
H: In the logarithmic compressor in PCM, which law is used in countries other than the US, Canada and European countries?
US and Canada use A-law and Europe use µ-law. I can't seem to find what India and other countries use?
AI: A few seconds on Google led to this: http://en.wikipedia.org/wiki/G.711
Short story: use A... |
H: Is this 'pmod' connector standard?
Here's an image of my Digilent Coolrunner II development kit:
Those connectors on the backside are 6x2, female, and seem to be on .1" pitch. Are these standard, and where could I buy the male counterparts? Much obliged. Just a few words to search on is all I need. '6x2 electro... |
H: CPLD best practice for resetting a counter
My application has a bog-standard count-until-a-certain-number-then-reset-the-counter section. My experienced friend tells me that when using actual chips, it's common to increment the counter on the rising edge of the clock and reset the counter on the falling edge. Tha... |
H: PSU with unspecified max safe amperage
Possible Duplicate:
Choosing power supply, how to get the voltage and current ratings?
I'd like to power my new LG M2450D monitor with a basicXL BXL-NBT-U02 universal AC-DC power adapter.
This PSU is rated 90W max and supports 15-24V output voltage.
The original monitor PSU... |
H: Is frequency for dc zero Hz?
We know the frequency of a direct current is zero. The reason is that there is no repetitive pattern.
But I was stumbled when I noticed, why can't that straight line be cut into smaller pieces, and can we treat it as infinite frequency? I have included a picture below as an example
As... |
H: What are the advantages of having two ground pours?
I've seen many 2-layer PCBs that have a ground pour on both the top and bottom layers, I was wondering why do that ? and wouldn't it be better to use the top layer for power and signals and the bottom layer for ground to simplify the routing and also taking advant... |
H: Alternative to inductor on IC
I was running through the datasheet of CC2500 (Low-Cost Low-Power 2.4 GHz RF Transceiver) which has a dimension of 2.40mm X 2.40mm approx. It was really amazing to find such transceivers to be fabricated in such a small area.Infact a transceiver requires a lot of R,C and even L.Resisto... |
H: 230V AC to 5V DC converter, lossless
Is there any IC which converts 230V AC to 5V DC? As lossless as possible. I want to connect my microcontroller to an ordinary electrical socket and I don't have enough space available. Thanks.
AI: There's no such thing as "lossless" anything in electronics, and there's not a sin... |
H: Faraday Cage - Detecting one
I am looking for a cheap and easy way of creating a small electronic device that is capable of detecting whether or not it is inside a Farraday Cage.
Hopefully, without an external sensor/emittor.
AI: A simple radar should give you some idea.
If it's inside a small enough cage, possibly... |
H: Can someone help me understand this H-Bridge?
I have an old RC car but without the transmitter so I built my own Rx/Tx using MCU and 2.4Ghz transceiver, however, I want to use the car's original H-Bridge but not sure if I understood how that circuit works.
Here is the schematic for the bridge:
My understanding is ... |
H: How to feed an SPI TFT display a signal from a composite video source
Here is the module I am looking at: 1.8" Serial 128X160 SPI TFT LCD Module Display + PCB Adapter with SD Socket
So my question is, is there any way I could convert a video signal from a composite source (i.e. DVD player, game console, etc.) to so... |
H: SD card sector address vs. physical location
I'm curious as to how SD cards map the supplied sectors for read/write to physical locations in the flash memory. Is this the real physical address, or is it just a virtual address that the SD controller then maps to the physical location?
I've read that SD cards have a ... |
H: Why is the voltage across a reverse biased diode equal to source voltage?
Why is it not equal to zero since a reverse biases diode is essentially an open circuit?
AI: You may be confusing open and short circuits. An open component is like a component which is not there. The voltage across a non-conducting diode bet... |
H: What electric part is on this manhole cover?
Here's a photo of a manhole cover
The letters form the word "ТЕЛЕФОН" ("telephone" in Russian in ALL CAPS).
What is on the picture in the center? Perhaps it is some part that should be associated with communications but I have no slightest idea what it might be.
I've Go... |
H: Does anyone have a manual or spec regarding an NEC JAPAN D78P0308GF
As the headline states.
It seems to be hard to get! The uC is in a Siemens Landsi & Gyr Dialog.
Power measurment equipment 3-phase ZMD120AMer53
AI: Here are a direct link to the microcontroller: http://documentation.renesas.com/doc/DocumentServer/U... |
H: Writing a VHDL Module
I am trying to get through this section of a course: http://hamsterworks.co.nz/mediawiki/index.php/Module_9
I am trying to write the 30 bit counter module (Project 9.1 on the page). I have the counter wrote in a normal .vhd file from the previous sections in that course. Here is the code:
libr... |
H: using led stripes with external battery: any side effects?
i have to power some led stripe from ikea with a drill battery:
On led stripe power is written: 12V 0,25A. and on drill power: 12V 2A.
Now i want to power n led strip (for example: n=4) and i want to understand if there are some side effects or some safet... |
H: Voltage regulator for linear constant-current (1.5A) LED driver?
I am considering building my own driver for a ~1.5A LED to power a microscope for my research.
For this application, efficiency isn't critical, but because exposure times to the camera can be short (~1ms), stability/lack of ripple is important. Thus b... |
H: Why is air pump making high pitch when it is overloaded?
Coming back from a nice camping trip, I noticed all air pumps made higher and higher pitch when the air bed were about to be fully inflated. It is heard like the the motor is speeding up when it is overloaded. I opened the pump but it seems very simple - elec... |
H: connect headphone to bluetooth module
I want to connect an old phone to a Bluetooth module. I first thought to use the original speaker and microphone, but the quality is quite bad, so I decided to rip apart an old PC-microphone and cheap headphones.
The microphone is a simple electret condenser, the headphone spea... |
H: Impedance of 4 conductor system spaced horizontally apart
I have 4 cylindrical conductors spaced equally and horizontally apart. How can I calculate the magnitude of Impedance (Z) using the Skin effect and Proximity effect?
I'm looking for an equation that will output Z given things such as the cross sectional area... |
H: P-Channel MOSFET high side switch
I am trying to reduce the power dissipation of a P-Channel MOSFET high side switch. So my question is:
is there any way in which this circuit can be modified so that the P-Channel
MOSFET will always be "fully-on" (triode / ohmic mode) no matter what the load is?
Edit 1: Please ... |
H: Carry Look ahead adder Propagate & Generate Outputs
I am taking comp architecture course, and we are given a task to write 32 bit look-ahead adder in VHDL. Instructor provided the instruction and diagram.
While reading, Wikipedia article, I stumbled on the following diagram.
Since C4 is already available, what is... |
H: What material and current do I need for a diy plant heater?
I want to heat my indoor plants with a DIY heater. I thought about using iron to heat up the soil, but I am not sure what material is the best for a heater. Also, what current would it need?
Thank you
EDIT: Could you at least explain why is my question bad... |
H: Transistor setup for large motor circuit
I am building a relatively simple circuit which essentially consists of two lead acid batteries rated at 12V and two motors rated at 12V. My original plan is to wire them all in series, and control them with a motor driver of some sort using a pwm signal. However, all of the... |
H: Why do standard cells typically have slower timing with high temperature, and faster timing with low temperature?
Threshhold voltage typically falls with increasing temperature, which would seem to indicate that high temperature operating conditions should result in faster gates than low temperature OCs. However, s... |
H: Trying to build gps tracking device
I am an engineering undergrad trying to build one gps tracking device with features like live streaming, current position, average speed, etc. (and if possible then sound etc.) from some computer located somewhere else.
I know coding very well and i am good in mechanical part, bu... |
H: Find total resistance
The book (Principles of Electric Circuits by Thomas Floyd 9th edition, International edition) says it's 1.955k Ω.
When I calculate I get (R1 || R2) + (R3 || R4) + R5 = 3.38k Ω.
AI: I assume the total resistance is requested from the + output of the 2V supply to GND. That gives:
(((R4 || R5) ... |
H: Reasons for Popularity of PowerPC for Embedded Designs
The question was asked before and is not active anymore, but I am not at all satisfied with the answer:
What's so great about PPC? There's gotta be something
According to David Kessner's answer, there were once reasons for PowerPC, but there are not any today.
... |
H: Can you store energy in an inductor and use it later?
My company uses supercaps to power the device if power is cut. I was wondering if you could do the same thing with an inductor. If you can't, why not?
AI: The magnetic field which stores the energy is a function of the current through the inductor: no current, n... |
H: How to power an arduino controlled string of RGB LED's from separate power source
I'm new to electronics and working on a hobby project that will have an arduino board running 5 separate strings of RGB LED's. I'll be using a PWM chip (TLC 5940) so I can independently control tho color's of each of the 5 strings of ... |
H: Processor Running C Natively
A friend of mine came up with an idea for something dealing with a micro-processor running C natively. Problem is, we need to be able to know if there is a processor out there already before we spend our time and money on something. Does anybody have any clue about such a processor?
A... |
H: Arduino Serial print changes behavior of program undesireably
I'm using a loop counter, declared in a header:
int loop_counter = 0;
I use this counter to trigger an event every so often. I used to use a modulo for this same type of behavior, but I simplified it so it's easier to work with (it still results in the ... |
H: What are pump probe measurements?
I was in class today, and we had a presentation by a student on how tunable lasers are used in fiber optics and change the wavelength. He also explained that by "pump probe measurements" a "sample gets excited and can be measured over time".
Can anyone explain what this means? Wha... |
H: Replacing a battery in a UPS
I recently replaced the battery in my APC Back-UPS CS 650 and of course I didn't opt for an original APC battery, but just bought a similar one from the corner electronics shop.
Apart from the label both batteries looked exactly the same, but still the old one used to provide 20 minute... |
H: Ground/short circuit confusion
I am reading the book Electronic Principles by Malvino and I found the circuit shown below.
It asks to find the A(gain) when the switch is in position 1 and in position 2.
I am not sure about this but in position 1 I found that A = 10k/10k + 1 = 2.
What about position 2?
AI: Adding on... |
H: RFI/AC Filter Rejection for Instrumenation Amplifiers
I'm attempting to measure the voltage developed across a very long piece of cable (upto 500m bundle). The issue is that the cable picks up a lot of noise from nearby radio stations and also has a 50 Hz component which I assume comes from the mains.
I would like ... |
H: TDA7386 mounting
I'm working on a little project to build an audio amplifier and I have everything ready except that I cannot figure out how to connect TDA7386 to the circuit. Is wire wrapping the only choice here? Or is there a simpler way to mount the chip? I would want to avoid soldering as much as possible sinc... |
H: What would happen if the output leads of a multi-phase transformer were shorted together?
Just what the question states, and there isn't any design rationale behind the question.
I just opened up a dead CFL (6 tubes; 3-pairs), and it looks to have an itsy little transformer within. This transformer has super-fine w... |
H: home brew isolated oscilloscope lead
The ground clip for an oscilloscope lead is normally connected within the instrument to the power supply earth, and there are surprising circumstances where this could matter. The situation is very well explained in "EEVblog #279 – How NOT To Blow Up Your Oscilloscope!"
Leads wi... |
H: How do I choose the right replacement fuse for my multimeter?
I have a BK Precision 2709B Multimeter. I managed to blow the uA fuse (500mA/500V fast blow ceramic) on it. Is it an ok to replace this fuse with a 500mA/1kV fast blow ceramic fuse? What impact would this have?
AI: The impact would be that the fuse shoul... |
H: What do you call the drawing which contains tracks, pads and drilling points of a PCB layer/side?
Example:
Does this drawing has a technical name?
I see that people usually call these drawings "PCB". But, PCB is physical object, physical implementation of circuit, isn't it? Is these kind of drawings really called ... |
H: Can you use an opto-coupler to isolate the incoming supply from the output
I would like to breakout the 5v and 12v outputs from my PC's psu. This is because of convience and accessibility. Would it be possible to use an optocoupler to isolate the supply coming from the psu? so that in the event of a dead short, it ... |
H: Logistical issue with power transistor and arduino
I have a transistor which will be triggered by an arduino digital pin. When the transistor switch is closed, ~5 A is going to flow from the collector to the emitter. However, I was under the impression that both the base and the emitter need to be grounded at the s... |
H: Transferring from Serial to RF communication
I am running an application that takes information and sends it over the serial port, with some processing etc done on my proprietary board (using an ATMEL simple Micro-controller). I am testing to check on how much stress I am putting on the micro-controller to verify w... |
H: Why do some laptop charges have ferrite cores on them?
I know why usb cables and other data cables have ferrite cores on them. My new laptop's charger also has a ferrite core on the side that connects to my laptop. Why is this?
I have a hunch that it might be to prevent the power cable from interfering with data... |
H: How do I construct a SPICE model from a data-sheet?
This may not be the ideal forum for the question; please migrate if a forum is better suited for the question.
I'm looking at a component for which my attempts at locating a SPICE model online were fruitless. There are, however, datasheets of the component availab... |
H: Increase Microcontroller frequency and Speed
I am in process of upgrading the micro-controller of our project from Renesas M16C to RX63N. In our current M16C project we use 16HMz crystal. If in the new micro-controller Rx63N if I use the frequency to 196MHz using PLL, what are the points I need to consider speciall... |
H: Are CMOS outputs high-Z when unpowered?
If a microcontroller I/O pin drives an external MOSFET, and the microcontroller's power is turned off, will that MOSFET's gate be floating? I know sometimes a resistor is added to ground, but are there risks if I don't place the resistor?
AI: When turned off, the output state... |
H: UART receiver clock speed
I was trying to understand UART fundamentals.It is understood that
It is an asynchronous communication protocol and hence the TX and RX clocks are independent of each other
The data reception is guaranteed by the usage of start bit and one or more stop bits.Additionally the receiver must ... |
H: Hall-effect switch or photointerrupter
I'm dealing with a small automation project, a rack and pinion system controlled by an Arduino card with two limit switches to ensure that the rack moves within the boundaries.
I have been trying both photointerrupters and hall-effect switches and both of them seems working wi... |
H: How to distinguish between voltage resolution and bit resolution
One might way that an ADC has a resolution of 12-bits. One could also say that it has a resolution of 1.22mV (5v/4096).
Is one of these uses of the word 'resolution' incorrect?
Is there a word to replace one of these uses of the word 'resolution'?
Con... |
H: Does an external interrupt interrupt ADC or does ADC stall interrupt?
I'm working on an RTC application with a 1Hz clock attached to the external interrupt pin on a PIC16f887. I also have continuous ADC operations happening along with the 1Hz clock.
My question is whether the ADC or the interrupt would get priorit... |
H: Are optical fibers full duplex?
Can optical fibers transmit in both directions simultaneously? Both single mode fibers and multi mode? What about if they we choose non-interfering wavelengths?
AI: Theoretically, such concepts are good to be imagined and, in fact, it is possible to make one that can communicate bidi... |
H: From a power consumption point of view, which should I use: SSR or Relay?
I'd like to find out which to use: a SSR (Solid State Relay) using TRIAC and optocoupler or a relay.
My consideration are from the point of power consumed, my challenge here is to choose the less power consumer one.
The biggest problem I foun... |
H: Volatile capacitance values at low frequencies
When I measure the capacitance of two cables I get very volatile values if I go to lower frequencies like 500 Hz. The capacitance is about 50 nF. Why does this happen?
AI: If this device measures capacitance by measuring the current at a given frequency, the current dr... |
H: Arduino as simple VT100 Terminal
In order to use my GLCD + Arduino as a display for LCD4Linux, using the LCD4Linux SimpleLCD Driver which sends out a subset of VT100 codes (CR and LF).
I have managed to isolate the VT100 codes from regular text using the following code:
// include the library code:
#include <glcd.h... |
H: Referencing flattened busses in module instantiation
I have a Verilog gate-level netlist generated by the Synopsys Design Compiler.
DC was directed to flatten all busses and ports when creating the netlist, and the module declaration is given below:
module DES_SBOX1 ( CLK, \ptext[5] , \ptext[4] , \ptext[3] , \ptext... |
H: Safely testing a DC supply with an unknown output configuration
This picture shows the connector for the DC end of a power supply I extracted from a dead HP MFD (Multi Function Device):
As you can see it consists of 4 pins in a 2x2 configuration. The sockets across the ascending diagonal are hexagonal, whereas the... |
H: Using a transistor instead of a relay to control a DC motor
I've made a simple relay circuit to switch power to a small DC motor
Here is a diagram of what I got right now:
Is it possible to replicate that with a transistor. Which one would be a good choice?
AI: You can use a logic gate MOSFET, like the FDC855, and... |
H: Servo vs. stepper for camera mount
I would like to make a camera mount where it can rotate automatically around the Z axis, and also make a variable angle against the ground plane.
The camera weighs about 500grams.
Is a servo motor adequate to make the camera make a variable angle against the ground, or is it a ... |
H: High input resistance - FET
What does high input resistance in fet mean? I always see this term when dealing with fet transistors like jfet and mosfets.
AI: For a MOSFET the high input resistance is caused by the isolation layer between gate and channel (blue in the picture):
The layer is made of SiO\$_2\$, which ... |
H: Capacitor in amplifier transistor
Why are capacitors use in transistor cicuits? What does it do with biasing operations? I always see capacitors on transistors being used as amplifiers.
AI: A capacitor blocks DC, so it can be used to pass a signal (e.g. audio, etc) without it's DC level interfering with the DC bias... |
H: Common mode operational amplifier
I have the circuit shown in the image. According to the the book I am reading when the opamp is in common mode Vout is always 0.
That means that also the gain is 0 because G=Vout/Vin.
Is this happening cause the circuit is completely symmetric?
AI: If that circuit is the one the b... |
H: Fast approaches for Soldering / PCB assembly
Our team (three hobbyists now developing our first serious device) is interested in soldering/assembling approximately 200 PCBs. We've already found a low-cost manufacturer for the raw boards, so just the assembly remains.
We'd like to keep the total assembly time and co... |
H: Hot Air Gun for Reflowing a Board?
I'm curious how well a hot air gun would work for reflowing an entire board. My circuit board has about 250 components (including 0402 passives, and a couple of 0.5mm pitch TQFPs) and it's a bit of a pain to assemble it using a soldering iron.
Here's what I was thinking might work... |
H: Transfer power effectively from one coil to another through air
I want to build my own wooden alarm clock.
I want the surface to be smooth without any connectors anywhere. My idea is to place one coil beneath the alarm clock, and another pickup coil inside. I suppose that I need to maximize the area.
What kind of... |
H: DIY Electrical Safety
I'm quite into DIY projects and I am looking at making an electrical unit out of a Raspberry PI and a computer monitor.
I was wondering if someone could provide me any information on what I should do to comply with the safety standards, for example when I integrate the Raspberry PI to use the... |
H: Are processors designed using different technologies?
Can/Are processors be designed using different technologies ?
What I mean here is: in, for example, Intel's 28nm processors, are all the gates in that processor built in 28nm technology or are only the most critical parts of that processor built in 28nm, the oth... |
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