One day in 1994, seven world-leading technology companies sat down and created a new standard for connecting computer peripherals. By “one day,” of course I mean, “over the span of several months.” But all technicalities aside, the standard that they laid down became the Universal Serial Bus, or USB for short.
Today, USB is truly a ‘Universal’ standard and you’d be hard-pressed to find an electronic device that doesn’t have a USB port of one kind or another. But how do you know which USB cable will fit your device? Hopefully this buying guide will help you find the cable that you need for your next project.
What Does USB Do?
USB cables replace the huge variety of connectors that used to be standard for computer peripherals: Parallel ports, DB9 Serial, keyboard and mouse ports, joystick and midi ports… Really, it was getting out of hand. USB simplifies the process of installing and replacing hardware by making all communications adhere to a serial standard which takes place on a twisted pair data cable and identifies the device that’s connected. When you add the power and ground connections, you’re left with a simple 4-conductor cable that’s inexpensive to make and easy to stow.
We had earlier in 2 different posts discussed about a variable power supply using LM 317. But in this post we discuss clearly about the working and designing of the LM 317 power supply in detailed.
This circuit, like all voltage regulators must follow the same general block diagram
Here, we have got an input high voltage AC going into a transformer which usually steps down the high voltage AC from mains to low voltage AC required for our application. The following bridge rectifier and a smoothing capacitor to convert AC voltage into unregulated DC voltage. But this voltage will change according to varying load and input stability. This unregulated DC voltage is fed into a voltage regulator which will keep a constant output voltage and suppresses unregulated voltage ripples. Now this voltage can be fed into our load.
Firstly let us discuss about the need for the smoothing capacitance.As you know the out put of the bridge rectifier will be as follows
As you can see, although the waveform can be considered to be a DC voltage since the output polarity does not invert itself, the large ripples Continue reading
In a masterful publicity stunt, Amazon CEO Jeff Bezos announced on 60 Minutes — on the night before Cyber Monday — that his company has been working on a drone service that will deliver items under 5 pounds, and within ten miles of an Amazon fulfillment center, in under 30 minutes..
This is definitely exciting, but exactly how much does Amazon have to accomplish between now and Jeff’s launch goal of 2015? Getting the FAA onboard will be hard enough, but what about actually getting shipments out safely, when that time finally comes? Is this even possible, or simply a publicity stunt by the e-commerce giant? They’re definitely not the first to think about doing this. Matternet has been working on bringing drone-supported shipping to areas of the world where roads aren’t common, or structurally sound enough, to handle everyday deliveries. CEO Andreas Raptopoulos talked about his vision at May’s Hardware Innovation Workshop.
If Amazon is really going for it, here are the main challenges and some of my thoughts on how Amazon will handle them:
Probably the easiest to deal with. Amazon says they’re shooting for 30 minute deliveries, which I’m assuming means 30 minutes from take-off to landing, not order to landing. Jeff says they will deliver to within 10 miles of an Amazon Fulfillment Center, which is doable if the octocopter can go at least 20mph. The challenge here is giving them enough battery power to survive the trip to the customer and back home. Carrying that much weight at that speed for up to an hour is going to require some heavy batteries. Continue reading
Build a motion-sensing alarm with a PIR sensor and an Arduino microcontroller.
In this simple project, we’ll build a motion-sensing alarm using a PIR (passive infrared) sensor and an Arduino microcontroller. This is a great way to learn the basics of using digital input (from the sensor) and output (in this case, to a noisy buzzer) on your Arduino.
This alarm is handy for booby traps and practical jokes, and it’s just what you’ll need to detect a zombie invasion! Plus, it’s all built on a breadboard, so no soldering required!
Step #1: Gather your parts.
- This project requires just a few parts, and because you’re using a solderless breadboard and pre-cut jumper wires, you won’t need any tools at all — except your computer and USB cable to connect the Arduino.
Step #2: Wire the Arduino to the breadboard.
I bet some of you had the same problem. I was working on this circuit on breadboard and I found out I do not have means to power that circuit. Batteries are too expensive for testing one circuit. In the end I was able to build small power supply that solved my problems.
Many times we can build PSU with small amount of elements. That is the story in this case. I upgraded PSU that already have 12 V output to 9 V with help of linear voltage regulator.
Be careful and cautious while proceeding with any project.
Step 1: Parts and materials.
– low voltage connector
– 2 pins connector
– cooling element with nut and bolt and with isolating foil (foil is optional)
– piece of black and red wire and two pins
– 7809 voltage regulator
– 470 uF capacitor and 100 nF capacitor
– PSU with output between 12 and 16 V Continue reading
Whether it’s an electronic novice or an expert professional, a power supply unit is required by everybody in the field. It is the basic source of power that may be required for various electronic procedures, right from powering intricate electronic circuits to the robust electromechanical devices like motors, relays etc.
A power supply unit is a must for every electrical and electronic work bench and it’s available in a variety of shapes and sizes in the market and also in the form of schematics to us.
These may be built using discrete components like transistors, resistors etc. or incorporating a single chip for the active functions. No matter what the type may be, a power supply unit should incorporate the following features to become a universal and reliable with its nature:
- It should be fully and continuously variable with its voltage and current outputs.
- Variable current feature can be taken as an optional feature because it’s not an absolute requirement with a power supply, unless the usage is in the range of critical evaluations.
- The voltage produced should be perfectly regulated.
Every project needs a power supply. As 3.3volt logic replaces 5volt systems, we’re reaching for the LM317 adjustable voltage regulator , rather than the classic 7805 . We’ve found four different hobbyist-friendly packages for different situations.
A simple voltage divider (R1,R2) sets the LM317 output between 1.25volts and 37volts; use this handy LM317 calculator to find resistor values. The regulator does its best to maintain 1.25volts on the adjust pin (ADJ), and converts any excess voltage to heat. Not all packages are the same. Choose a part that can supply enough current for your project, but make sure the package has sufficient heat dissipation properties to burn off the difference between the input and output voltages.
Schematic of LM317 in a typical voltage regulator configuration, including decoupling capacitors to address input noise and output transients.
The LM317 has three pins: Input, output, and adjustment. The device is conceptually an op amp (with a relatively high output current capacity). The inverting input of the amp is the adjustment pin, while the non-inverting input is set by an internal bandgap voltage referencewhich produces a stable reference voltage of 1.25V. Continue reading
think that it is safe to say that most of the people who make (big or small) electronics-projects have a pc or laptop in theire hobbycorner and a lot of projects need 5V for IC’s or microcontrollers. So using power from a USB cable isn’t that farfetched and lets face it: a lot of devices around us use a USB-connection to get their power or to charge their batteries.
About USB-connectors and power
Whether you are watching it on television or searching for it on Pinterest, chances are you have admired a few Do It Yourself (DIY) projects recently. Have you taken it a step further and actually completed a DIY project? There are three key reasons why the trend of DIY projects is so popular.
The first reason that people want to try a DIY project is usually because it sounds like fun. You learn a new skill and the end result will be just what you are looking for. Since Halloween is just around the corner you may be thinking: “Should I go searching for the perfect costume or should I try to design and sew it myself?” Not everyone would have an interest and natural ability in making their own costume so learning to sew would seem like fun. Chances are you are artistic and enjoy ways to tangibly express that creativity. Now imagine taking it one step further and Continue reading
Touch screens are so ubiquitous that physical keyboards are becoming a thing of the past, at least for mobile devices. Now imagine if the capability of touch spread from the display to the entire device, allowing control by gently pressing on any part of the phone, or even making any household item into a touch-sensitive interface with your computer.
Anything solid vibrates a specific way when it’s hit physically with another object or with sound waves. The characteristic is called resonance. For example, when you tap on a crystal glass, it vibrates at a certain frequency, producing a ring. If you hit it with sound waves — for example, the ambient background noise in a room — it vibrates at a different frequency. Grip the glass while it rings, and the sound stops. Continue reading
For a device created to save lives, the household smoke detector sure takes a lot of heat for being annoying: the false alarms when the cookies get burned, the incessant beeping when the battery needs changing and all those times standing on wobbly chairs while trying to find minuscule buttons.
As your embedded project grows in scope and complexity, power consumption becomes an ever more apparent issue. As power consumption increases, components like linear voltage regulators can heat up during normal operation. Some heat is okay, however when things get too hot, the performance of the linear regulator suffers.
How much is too much?
A good rule of thumb for voltage regulators is if the outer case becomes uncomfortable to the touch, then the part needs to have an efficient way to transfer the heat to another medium. A good way to do this is to add a heat sink as shown below.
This is a quick how-to explaining everything you need to get started using your Flexiforce Pressure Sensor. This example uses the 25lb version, but the concepts learned apply to all the Flex sensors.
Necessary hardware to follow this guide:
- Arduino UNO or other Arduino compatible board
- Flexiforce Pressure Sensor
- M/M Jumper Wires
- 1 MegaOhm Resistor Continue reading
Capacitors are one of the most common elements found in electronics, and they come in a variety of shapes, sizes, and values. There are also many different methods to manufacture a capacitor. As a result, capacitors have a wide array of properties that make some capacitor types better for specific situations. I would like to take three of the most common capacitors – ceramic, electrolytic, and tantalum – and examine their abilities to handle reverse and over-voltage situations. Note: several capacitors were harmed in the making of this post.
The most common capacitor is the multi-layer ceramic capacitor (MLCC). These are found on almost every piece of electronics, often in small, surface-mount variants. Ceramic capacitors are produced from alternating laye Continue reading
Power factor is a measure of how effectively you are using electricity. Various types of power are at work to provide us with electrical energy. Here is what each one is doing.
Working Power – the “true” or “real” power used in all electrical appliances to perform the work of heating, lighting, motion, etc. We express this as kW or kilowatts. Common types of resistive loads are electric heating and lighting.
An inductive load, like a motor, compressor or ballast, also requires Reactive Power to generate and sustain a magnetic field in order to operate. We call this non-working power kVAR’s, or kilovolt-amperes-reactive.
Every home and business has both resistive and inductive loads. The ratio between these two types of loads becomes important as you add more inductive equipment. Working power and reactive power make up Apparent Power, which is called kVA, kilovolt-amperes. We determine apparent power using the formula, kVA2 = kV*A.
Going one step further, Power Factor (PF) is the ratio of working power to apparent power, or the formula PF = kW / kVA. A high PF benefits both the customer and utility, while a low PF indicates poor utilization of electrical power. Continue reading
Radio-Frequency Identification (RFID) is technology that allows machines to identify an object without touching it, even without a clear line of sight. Furthermore, this technology can be used to identify several objects simultaneously. RFID can be found everywhere these days – anything from your cat to your car contains RFID technology. This post will cover how RFID works, some practical uses, and maybe even some example code for reading RFID data.
What is RFID?
RFID is a sort of umbrella term used to describe technology that uses radio waves to communicate. Generally, the data stored is in the form of a serial number. Many RFID tags, contain a 32-bit hexadecimal number. At its heart, the RFID card contains an antenna attached to a microchip. When the chip is properly powered, it transmits the serial number through the antenna, which is then read and decoded. Continue reading