Simplify DC-DC Converter Characterization

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by Mary Anne Tupta @ edn.com:

DC-DC converters are widely used components that convert DC power from one voltage to another, producing a regulated output voltage. These devices are used in many electronic products, including laptops, mobile phones, and instrumentation. Like any device, DC-DC converters need to be characterized by manufacturers and by engineers evaluating them for a design.

Given the increased pressure to develop products that consume less power, design engineers are looking for ways to increase power conversion efficiencies. Thus, numerous measurements are required to characterize the electrical parameters of DC-DC converters.

Simplify DC-DC Converter Characterization – [Link]

How to Build PCB Online using Web Based EDA Tools

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by circuitstoday.com:

This is a brief review of the capabilities and ease of use of three of the most interesting, innovative and downright disruptive web-based EDA tools:

EasyEDA
Upverter
Autodesk 123D Circuits (formerly Circuits.io)

The same simple astable multivibrator circuit is entered into each tool and the design process followed through simulation (where offered), to PCB layout and Gerber download.

How to Build PCB Online using Web Based EDA Tools – [Link]

Weather Station

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Rui @ ruijc.webnode.com writes:

The fact of having a CNC available at home gave me the freedom to build stuff more easily and quickly than before. Without this machine parts would take some time to manufacture and most likely would not end so perfect. This caused new ideas to be easily implemented.

This was one of those ideas that was born only by the desire to build a small replica of a gaming machine without any electronica inside. However,i would not pass up the opportunity to invent and build something to install inside.
I wanted to have something different and unique for that cabinet and not have a mini game machine. I chose to create a small and simple weather station to show not only temperature and humidity values but also hours and if possible something else …
Weather Station – [Link]

Do you want to speed up to a “Long Term Evolution”? With Quectel modules it´s already possible…

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Company Quectel brings to a market its first high-speed module EC20 which you can try yourself. More than fifty developers worked for over ten months on this module.

We´d like to share with you its parameters, as well as hints, which can make your work with this module easier – this is our biggest bonus to sale of modules from company Quectel.

Are you interested in compatibility with previous modules?

Module EC20 arises from the M10 GPRS module and the UC20 UMTS module. These modules can be designed to a PCB in a way that you have ensured variability and a possible replacement in case, that you wish to have one board for several solutions …

From theory to the praxis…

Discussions about LTE already last for some time. One LTE transmitter (800MHz) manages up to six times bigger area than one UMTS transmitter (2100MHz). LTE protocol is already from the beginning (in contrast to UMTS) written as a high-capacity with a fast response. The first phase of area coverage is usually equal to speed of UMTS uplink/downlink. After reaching almost a 100% coverage, then usually starts the second phase, which actually speeds up to current theoretical speeds of 172,8Mbps (downlink) and 57,6Mbps (uplink).

Let´s have look at frequencies

In presence, 4 bands are functional – on frequencies 800/900/1800/2100MHz and the 2600MHz band is not used so far. EC20 manages all these bands. EC20 will be produced in 2 versions, as EC20-E (for Europe) and EC20-A (for USA). Do you know that in USA also the 1559 to 1610 MHz band was approved, which however should interfere GPS signal in 1525 – 1559 MHz band, according to measurements?

And at last – advantages of EC20
  • No doubt and after experience with developers – the LCC package offering a possibility to assemble by hand or by machine.
  • Module is not the smallest LTE module in the world, but belongs to the smallest LTE ones. EC 20 also incorporates implemented GPS/GLONASS receiver.
  • Supports MIMO technology – multiple-input multiple-output, i.e. – multi antenna systems.
  • The EC20 module is able to communicate via USB port in Windows, LINUX, as well as in Android.
Frequently discussed eCall

The EC20 module also supports „emergency call“. In the time of creation of this article it was decided that eCall will be compulsory in vehicles from April 2018. In every way, company Quectel is already prepared and supports this system in almost all its modules.

The eCall function also related to another advantages and functions in the module, for example:

  • Low power consumption
  • High RF power and high sensitivity <-108.5dBm
  • Fimware can be updated remotely – DFOTA (firmware over the air)


Do you want to speed up to a “Long Term Evolution”? With Quectel modules it´s already possible… – [Link]

Automatic Pet Feeder

This project is an automatic pet feeding system using NXP Semiconductors’ PCA8565. The PCA8565 is a CMOS1 real time clock and calendar optimized for low power consumption. A programmable clock output, interrupt output and voltage-low detector are also provided. All address and data are transferred serially via a two-line bidirectional I2C-bus with a maximum bus speed of 400kbps. The built-in word address register is incremented automatically after each written or read data byte. It provides a year, month, day, weekday, hours, minutes and seconds based on a 32.768kHz quartz crystal. It features alarm and timer functions, low current, and extended operating temperature range of -40 degrees Celsius to +125 degrees Celsius. It further contains an 8-bit year register that can hold values from 00 to 99 in BCD format. It also compensates for leap years, thus leap year correction is automatic.

The electronic part of the device is just an alarm clock based on NXP PCA8565. The alarm initiates an interrupt that awakes the microcontroller. The later one sends a signal to the motor to control its forward and reverse mechanism. The dc motor must make a full turn and stop in the initial position to be ready for the next loading. This is achieved by an opto-interrupter OBP625, which provides a feedback to the microcontroller to stop powering the motor. The motor itself is controlled by PWM based on the timer IC in order to slow it down to a practical speed. The current time and the alarm time are displayed by a 4-digit LED display combined from two HDSP-521E 2-digit displays. Time to display is selected by a 3-state slider connected to pins RA0 and RA1 of PIC16F684. In the middle position of this switch both inputs are pulled up (internally). Two buttons at inputs RA4 and RA5 accomplish time setting and alarm setting. The LED display is controlled by SAA1064. The controller and PIC communicate via the I2C interface. The display is turned OFF after 10 seconds upon release of any button. This is achieved by simply turning OFF the controller and display power by a MOSFET IRLML6402 when the voltage on pin RC2 of PIC becomes 5V.

Food and water are two essential elements for keeping pets happy and healthy. But what happens if you have to work all day, can you imagine that starving look when you come home? As a pet owner, you have to find a way that your pet is fed on time. Keep your pet well fed when you’re away using the automatic pet feeder. You never have to worry about rushing home or working late. It ensures that your pets never miss a meal and maintain their regular eating schedule.

Automatic Pet Feeder – [Link]

GPiO Audio Measurement Toolbox

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by Sagar Savant:

Measuring performance of audio components like microphones, speakers, converters, and amplifiers can be a difficult task. In this post, I’ll talk about some of the tools I use to make this job easier. Analyzers, reference transducers, calibrators, meters, and more come with various feature sets and price tags. The items below just happen to be my favorites.

Soundcheck (Listen Inc.): Soundcheck is a versatile audio analyzer that I’ve used for years in both R&D and production line environments. It’s built in a “modular” way, so you buy the features that you need. What I love about this software is the customization potential in everything from the granularity of frequency points in a sine sweep to the ability to post process measurements in a sequence automatically based on macros. Soundcheck is not cheap, but it saves me tons of time when I need to measure and report on audio components or subsystems.

GPiO Audio Measurement Toolbox – [Link]

App note: HV823 & HV825 EL lamp driver circuits

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App note from Microchip on their EL lamp drivers circuits utilizing (Supertex) HV823 and HV825, App note here.

This application note presents fourteen EL driver circuits utilizing the Supertex HV823 and HV825 drivers. They have been optimized for a variety of applications and may be used as-is or used as a starting point in designing a circuit for a particular application.

App note: HV823 & HV825 EL lamp driver circuits – [Link]

EEVblog #761 – Pebble Time Smartwatch Teardown

What’s inside the new Pebble Time Smartwatch?
Dave does a teardown after taking it through the torture test, and gives it a close up view with the Tagarno microscope.
How easy is it to disassemble and replace the battery?
How much do the components cost?
What is the manufacturing quality like?
How does the Bluetooth antenna work?

EEVblog #761 – Pebble Time Smartwatch Teardown – [Link]

Arduino Stepper Motors

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by cornelam @ instructables.com:

When we need precision and repeatability, a stepper motor is always the solution. With the way it is designed, a stepper can only move from one step to the next and fix in that position. A typical motor has 200 steps per revolution; if we tell the motor to go 100 steps in one direction, it will turn exactly 180 degrees. It gets interesting when we only tell it to go one step and it turns exactly 1.8 degrees.

Arduino Stepper Motors – [Link]