Embedded Linux is not only Open Source, but can be adapted to any type of dedicated embedded system. It is more like a configurable firmware for Embedded Equipment. Its ability to manage multiple tasks efficiently makes it more friendly and stable, compared to any other OS.

Related Reading

• uClinux - Embedded Linux Microcontroller
• LinuxDevices.com - Linux-powered Devices
• Embedded Linux Platform Specification
• Embedded Linux applications - IBM
• Timesys Embedded Linux

The Evolution of Temperature Control

• Bimetal Thermostat
• Analog Dial On-Off Controller.
• Analog Dial Proportional Controller.
• Digital Display - Analog Controller - On-Off.
• Digital Display - Analog Controller - Proportional.
• Digital Display - Analog Controller - PID.
• Microcontroller Based Process Controller. (On-Off, Prop., Universal TC, RTD, mA Input)
• Process Profile Controller (Microcontroller Based).
• Microcontroller Based Fuzzy or Auto-Tune PID Controller.
• Data Logger, Computer, PLC or SCADA based Solutions.

Even today, the controllers at every stage of evolution, from the thermostat to Auto-Tune, are used in many countries, for many different industrial applications. No solution above is obsolete! The developing Countries still use electro-mechanical or semi-automatic means for control in some areas.

A PC based multiplexed scanner controller with data-acquisition cards and I/O Cards can be solution for Laboratory or Research. This is used when real time control is not required or where the control failure will not lead to damage or loss.

A PLC or Microcontroller based controller should be used with a Analog Controller Protection or Over temperature Trip-Alarm.

Outputs could be Relay or SSR, Voltage and Current outputs like 0-10V and 4-20mA are needed sometimes to drive DC/AC Drives or to control Motorized Valves. Relays and SSR can be On-Off or Time proportional (PWM). The Cycle times can be 10-20 Secs for Electromagnetic Relay and around 1 Sec for SSR. This is because Mechanical Relays and contacters have limited number of operations. The zero crossing SSR has to be cycled slower than mains frequency.

In Curing rubber, which is one of the more complicated process, we need a profile based controller, which also triggers other timers or counters which need to be activated at different segments.

When a very big area is controlled, with materials or load placed un-symmetrically, Every corner or section has to have separate sensor and controller. These are then governed by a SCADA, Supervisory PLC or Master Controller.

Even a Big Die for Plastic Moulding with an Unsymmetrical Object or long object to be moulded; needs compensation for sides which will absorb more heat.

• 1/32 DIN Auto-tune Temperature Controllers
• Tuning a PID (Three-Mode) Controller
• On-Line Process Control Tutorial
• Glass Melting Furnace Fuzzy Control

The Virtual Robotics Lab is an exploration in top-down robotics that lets you create, control, and understand a virtual version of Iris.4, a real, physical robot.

Related Reading -

• Virtual Robotics Laboratory in Bratislava
• VirtualRobot - freeware software suite
• ROVer Ranch - learn robotic engineering

My Notes -

Robotics is the Magnum Opus of Engineering, It combines Electronics, Mechanical, Computing and also the toughest science know to mankind…. Wireless Networking!

Ethernet Networking itself is complex, A self healing, hack proof and plug-play Wireless Router has to be the first step to make safe robots.

Just imagine a Wireless Router or even a Internet Router as easy to tune as a FM radio, no entering numbers, no admin with browser. Just keep it in a room and all gadgets and computers form a fuzzy network, all by themselves. The very idea of technology is to make things simple, cost-effective and efficient.

The real need of robots now is to avoid Humans in Hazardous Environment. Right from Outer Space to working in a Plant with Toxic Chemical Gases, Even machinery and equipment that injures the limbs or damages the eyes.

Virtualization in Robotics -

If workers can wear a coat of sensors with force feedback actuators, they can control a semi-automatic robot in Real-Time. This enables a worker to navigate a robot into a hazardous environment, perform an upgrade or make repairs. An accident or mishap will damage the robot and it can be easily rebuilt or maintained.

The robot is automatic and will have reflexes defined by software. The wireless networking will connect the Robot mechanically to a human in a safe enclosure. This makes the Worker present virtually inside the Robot, because he is connected by optical, aural and mechanical-muscle feedback-sensors. This will create Virtual Anthropomorphic Robots for Industrial use and may help to finally develop Fuzzy Robots or Androids, which is still in the realm of science fiction. Heard of Robots with a Soul ?

Anantha Narayan

The ICM7217 is a four digit, presettable up/down counter with an onboard presettable register continuously compared to the counter. The ICM7217 is intended for use in hard-wired applications where thumbwheel switches are used for loading data, and simple SPDT switches are used for chip control.

This circuit provides multiplexed 7 segment LED display outputs, with common anode or common cathode configurations available. Digit and segment drivers are provided to directly drive displays of up to 0.8 inch character height (common anode) at a 25% duty cycle. The frequency of the onboard multiplex oscillator may be controlled with a single capacitor, or the oscillator may be allowed to free run. Leading zeros can be blanked. The data appearing at the 7 segment and BCD outputs is latched; the content of the counter is transferred into the latches under external control by means of the Store pin.

• Four Decade, Presettable Up-Down Counter with Parallel Zero Detect
• Settable Register with Contents Continuously Compared to Counter
• Directly Drives Multiplexed 7 Segment Common Anode or Common Cathode LED Displays
• On-Board Multiplex Scan Oscillator
• Schmitt Trigger On Count Input
• TTL Compatible BCD I/O Port, Carry/Borrow, Equal, and Zero Outputs
• Display Blank Control for Lower Power Operation; Quiescent Power Dissipation <5mW
• All Terminals Fully Protected Against Static Discharge
• Single 5V Supply Operation

delabs Notes-

This is another Intersil Masterpiece in days when using uP was complex and uC was not available.A 8085 could be used but with many supporting chips and it consumed power. This was a CMOS innovation low on power and just one ASIC had the fexibility for many digital operations.A ThumbWheel and Display Interface completed a Gadget.

Related Links

• ICM7217 4-Digit, Presettable, LED Up/Down Counter

“The WEBENCH environment provides the end-to-end design and prototyping tools you need to create power supplies or DC-DC Converters that meet your design requirements.”

Power Designer - Expert Tips and Techniques for Power Supply Design

Power Management - National Semiconductor

Simple Switcher, Power Supply, Voltage References, Lighting, Battery Management, Voltage Regulators, DC-DC Voltage Converters.

PowerWise - Energy Efficient Solutions and Products

These devices are low cost, high speed, dual JFET input operational amplifiers with an internally trimmed input offset voltage (BI-FET II™ technology). 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.

• Gain Bandwidth 4 MHz
• Slew Rate 13 Volts/usec
• Offset Voltage 10 mV

When you fill a Bucket with water, You keep an eye on the Level of water, as you open the Analog Tap, which is an equivalent of a Motor operated Valve. Your Eye is an advanced Optical Sensor, which is able to sense the level by the computation in the brain, which in turn operates the muscles of your hand, thru the nervous system. The hand along with the Water Tap is is the Actuator. As the water fills up close to the top, you start reduction of the water flow and keep observing, then as it tops up, you tweak the tap to a trickle. When it reaches the limit you shut off the tap.

While you are half way filling the bucket, what happens if you take a short nap, or a friend comes by and you are get absorbed in conversation, the water overflows and goes waste. Then someone raises an alarm after the Runaway process happens. This is of minor consequence, but it is not so in the case of Temperature, Pressure and also many common systems like the driving of an Automobile. Remember the gears, brakes, accelerator to control and steer the car to the correct destination, a Runaway Process causes an accident.

In Industrial Control when a Runaway process can result in danger or wastage, it is necessary to have a multi tier protection. It is also better to limit the open loop maximum to a level which will not cause much damage. So when you need that extra heat, power or flow, use booster actuators which will operate for timed bursts in the beginning of the process. An independent watchdog controller which will shut off power supply to the entire system when a runaway possibility is sensed. This can only be manually turned on after repairing the failed part or controller. A SCADA interfaced to communication systems can further alert the security, safety and fire departments.

Anantha Narayan

Related Reading

• The basic structure of closed-loop systems
• Electric Drives - Motor Controllers
• UTC Online Controls Lab
• Control Tutorials from Michigan
• Control Theory and Engineering
• Control Theory Principles
• Control Fundamentals - Athena

The Industrial Electricians Notebook -

Free online electrical books selection that features interesting and timely subjects: electrical theory, electrical reference information, electrical equipment and maintenance data, industrial electronics, and electrical safety regulations. If you like, you can download, print, and assemble your own electrical book.

• Electrical Books
• Free On-Line Electrical Books
• Industrial Electrical Systems
• Basic Industrial Electronics

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“After fifty years of electrical work I am retiring. The Kilowatt Classroom web site will continue and is being revised and expanded.”

Elwood Gilliland

Anantha Narayan

GE Industrial Systems

Programs available that provide analytical tools, advanced power quality analysis, monitor energy consumption, and manage loads.

CEPD offers a wide range of consulting services targeted at providing cost effective design options. With expertise in …

• Digital Signal Processing (DSP)
• Embedded Systems Hardware and Software
• Telemetry Systems
• Motor Control Systems
• Programmable Logic: FPGA / CPLD / EPLD
• Analog Circuit Design
• Switching Power Supply Design
• Printed Circuit Board (PCB) Design and Layout

News-

The picoUSB is a prototyping board for Altera CPLDs. The system is placed in the low-end, low-price segment. With the Quartus II Web Edition design software package, you will be programming your own designs into the device in no time. The picoUSB is ideal for introductory Digital logic courses.

picoUSB Features :

• picoUSB printed circuit board with 44 PLCC socket
• External access to each pin of socket/package
• EPM3032ALC44-10 (32 Macrocells, 600 gates, 34 user I/O); we reserve the right to ship a larger EPLD with the board
• JTAG output header allows it to be used as an Altera compatible programmer
• Programming interface for directly connecting the picoUSB to your PC
• Board dimensions: approximately 3.5 inches x 4 inches
• Patch field for your own circuitry.

Electronic design services for Industrial, OEM and Consumer clients in the areas of: Analog, RF, Digital, Microcontroller, Firmware, Software, Power Supply and high performance PCB board design.

Steve C. Hageman

Hagtronics - Articles and Schematics by Steve - Construction projects for homebrewers (homebrew electronics that is!).