Friday, May 10, 2019

RF Cafe - Microwave & Wireless Engineering

Resources for Radio, Radar, RF, Microwave, & Wireless Engineering. Collection of links to various application notes for different RF Vendors. Links to RF equations, technical data sheets, math notes and much more.

RF Cafe - Microwave & Wireless Engineering

Some important areas
  • RF Engineering Calculators
  • Electrical / Electronics Conversions, Formulas & References
  • Design Data Resources
E-flite Mini Pulse XT - Brushless ESC Waveform - RFCafe

E-flite Mini Pulse XT - Brushless ESC Waveform

This waveform shows the square waves that drives one of the three phases at a relatively low throttle setting (coming from the brushless speed controller). The peak amplitude is constant for all speeds.

"Much more than just a self-serving video of my new R/C airplane flight agility, this model represents a plethora of modern electronics. Although the radio control system in this plane is a standard narrow band FM variety on 72.170 MHz (as opposed to my 2.4 GHz, spread spectrum system), the motor is a state-of-the-art 3-phase brushless model (E-flite 450)with a sensorless electronic speed control (E-flite EFLA331, 20 A)."

FreePCB - PCB editor

FreePCB is a free, open-source PCB editor, released under the GNU General Public License. It was designed to be easy to learn and easy to use, yet capable of professional-quality work.

FreePCB - PCB editor

Some of its features are:
  • 1 to 8 copper layers
  • Board size up to 60 inches by 60 inches
  • Uses English or metric units (i.e. mils or mm) for most functions.
  • Footprint libraries courtesy of Ivex Design International Inc.
  • Footprint Wizard and Footprint Editor for creating or modifying footprints
  • Imports and exports PADS-PCB netlists
  • Exports extended Gerber files (RS274X) and Excellon drill files
Example - Logic Analyzer: This is an open-source logic analyzer called MiniLA contributed by Bob Grieb of the User Forum. The image on right is the Logic Analyzer PCB.

FreePCB - PCB editor

Some Features:
  • Up to 32 channels
  • 128 Kb of memory for each channel
  • Sampling rate up to 100 MHz (timebase in 1-2-5 sequence)
  • Input levels compatible with 3.3V and 5V logic
  • Selectable pretrigger/posttrigger buffer size in 8K step

Tuesday, May 07, 2019

4-20mA Conditioning - XTR101 TI BB

These are Burr Brown Devices from TI. The BB Chips are excellent devices and High Precision, but a bit more expensive. These can be used when customer demands a Higher Quality and Precision. These are good for High Reliability Industrial Instrumentation. - delabs

4-20mA Conditioning - XTR101 TI BB

The XTR101 is a microcircuit, 4-20mA, two-wire transmitter containing a high accuracy instrumentation amplifier (IA), a voltage-controlled output current source, and dual-matched precision current reference.

4-20mA Conditioning - XTR101 TI BB

The two-wire transmitter allows signal and power to be supplied on a single wire pair by modulating the power-supply current with the input signal source. The transmitter is immune to voltage drops from long runs and noise from motors, relays, actuators, switches, transformers, and industrial equipment.

Monday, April 22, 2019

Wide-Bandwidth Dual JFET Opamp LF353

These devices are low cost, high speed, dual JFET input operational amplifiers with an internally trimmed input offset voltage.

They require low supply current yet maintain a large gain bandwidth product and fast slew rate. In addition, well matched high voltage JFET input devices provide very low input bias and offset currents.

Wide-Bandwidth Dual JFET Opamp LF353

LF353 - Wide Bandwidth Dual JFET Input Operational Amplifier

Some Highlights
  • Gain Bandwidth 4 MHz
  • Slew Rate 13 Volts/usec
  • Offset Voltage 10 mV
  • Low Input Bias Current: 50pA
  • High Input Impedance: 1 Tera Ohms

Wednesday, April 03, 2019

ASQ - Resources for the Quality Professional

ASQ was born in the days when "quality control" usually meant ensuring that manufactured products were free of defects....ASQ organizational membership provides the invaluable resources you need to concentrate on product, service and experiential quality and continuous improvement for powerful top-line and bottom-line results.

ASQ - Resources for the Quality Professional

ASQ’s Emerging Quality Leaders Program is specifically designed to develop the leadership skills of quality professionals. The International Team Excellence Award program is designed to award achievements in improved performance in businesses of all sizes.

ASQ - Resources for the Quality Professional

The last decade has brought many changes to Iredell-Statesville Schools (I-SS) in North Carolina. In 2002, the district embarked on its journey to continuous improvement by using the Baldrige Criteria for Performance Excellence.

Tuesday, April 02, 2019

DC to AC Pure Sine Wave Inverter

Here are project reports on how to manage the various design needs of a inverter for a power ups. Even Solar Energy systems need inverters to create AC Sine Wave Power Supply from a DC Battery Array.

DC to AC Pure Sine Wave Inverter

Creating a Efficient and Inexpensive Inverter - By Jim Doucet, Dan Eggleston, Jeremy Shaw

This report focuses on DC to AC power inverters, which aim to efficiently transform a DC power source to a high voltage AC source, similar to power that would be available at an electrical wall outlet. Inverters are used for many applications, as in situations where low voltage DC sources such as batteries, solar panels or fuel cells must be converted so that devices can run off of AC power.

PWM Techniques: A Pure Sine Wave Inverter - Authors :Ian F. Crowley and Ho Fong Leung

This report documents the development of one component of an uninterruptible power supply, the DC-to-AC inverter. Through the use of analog signal processing techniques, a prototype which efficiently and accurately emulates the pure-sine wave power present on the power grid was created. The three-level PWM system within this report is created with the possibility of a feedback-regulated system to be implemented in the future.

MQP Terms A­B­C 2006 ­2007, Advisor: Professor Stephen J. Bitar

Wednesday, February 20, 2019

Benchtop DC Power Supply

After the DMM and Logic Probe we have DC Power supply as an Essential Workbench Instrument for the Electronics Aspirant. Hobby or Engineering; we need tools to get the job done.

Now you can drool on a vintage power supply with an Analog Dial Meter and Rotary Knobs with Push-Button Selector Switches.

Benchtop DC Power Supply

Small Variable power Supply

Features: 1.3-12.2 V, 1 A, over-current protection. This is a simple but reliable device based one of the oldest integrated voltage regulators of them all - the LM723.

Power Supply Adjustable 0V-30V DC/2A

It is a simple circuit regulated power supply, based on the known LM 723, that drive a transistor Q1 [2N3055]. The regulation of voltage, of expense becomes with potentiometer R1 from 0v-30v DC roughly. In order to we achieve 30 V,...

Build A 10 Amp 13.8 Volt Power Supply By N1HFX

Sometimes amateurs like to home-brew their power supplies instead of purchasing one off the shelf at any of the major ham radio retail dealers. The advantage to rolling your own power supply is that it teaches us how they work and makes it easier to troubleshoot and repair other power supply units in the shack.

delabs Notes

Always remember Amateur Radio Operator or Ham is an highly skillful, professional and prudent design engineer. A qualification is not to be valued in Engineering, it is the Practical Problem Solving abilities that some people posses. 

Tuesday, February 19, 2019

Sine wave Inverter 800VA

 Here are two Sine wave Inverter circuit applications that can be made into an UPS or Uninterrupted Power Supply. These are used in Home, Office and Shops. It provides emergency power when Mains power goes down or browns out.

Sine wave Inverter 800VA

These also help supply power while switching from Mains Power to In-house Diesel Generation  Power Stations or Integrate with Solar Powered Systems to provide 110 Volts or 220 Volts AC.

800VA Pure Sine Wave Inverter - High Performance Isolated Power

This application note describes the design principles and the circuit operation of the 800VA pure Sine Wave Inverter.

800VA Pure Sine Wave Inverter's Reference Design, slaa602 - TI.com

The pure Sine Wave inverter has various applications because of its key advantages such as operation with very low harmonic distortion and clean power like utility-supplied electricity, reduction in audible and electrical noise in Fans, fluorescent lights and so on, faster, quieter and cooler running of Inductive loads like microwaves and motors.

Power inverter is a device that converts electrical power from DC form to AC form using electronic circuits. It is typical application is to convert battery voltage into conventional household AC voltage allowing you to use electronic devices when an AC power is not available. There are basically three kinds of Inverter out of which, the first set of inverters made, which are now obsolete, produced a Square Wave signal at the output.

Texas Instruments, Application Report SLAA602 , June 2013

delabs Schematics