delabs-Portfolio

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In: Design, Handheld Portables

I once worked in Tek for a very short period. I got to experience the 2235 and 2465 analog scopes and their controls. The 2465 was a 400 MHz Digitally Controlled Analog Scope.

I also used the Plugin Scopes and Calibration systems that were Tek Culture and Tech contribution to the Instrumentation world, it probably evolved into VXI-PXI as uC systems took over.

delabs designs – The code has been moved from Google Code Hosting to github – delabs-dapj

delabs Web Widget and Application Interface Usability Experiments 2003-2008

I also had a chance to look at DSO/Logic Analyzers and the just developed TDS Series. The older tek analog scopes made me understand about usability and panel layouts. Many controls are inevitable in a Analog Scope with Electromechanical Interface.

In a Digital World that can be largely changed using the Monitor and Trackballs. The older BlackBerry phones are also good study for usability before Touch Screens came.

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In: Instrumentation, Power Electronics

This is a Regulated 0-30 V DC Power Supply manufactured by me in small numbers, 0-30V 5A and 5V -5A. It had a Switching Preregulator. This keeps the Vce across Transistor Bank at the Back of Instrument, at the lowest possible level, in order to keep them Cool. When Vce and Ic both are more in a Power transistor it will get heated more, then the efficiency of power supply is low.

Power Supplies Section – delabs

Variable Regulated Power Supply

The Output had both Constant Current Control and Constant Voltage Control. The CC control is also a Short circuit protection. The Output was protected from outside voltages damaging output circuits even when equipment is switched off. The back panel is a finned anodized black aluminum heat sink with many transistors.

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In: Process Control

Below is a Electrical Control Panel, It has a Strip Chart Recorder which is electro-mechanical, It has a PLC Inside. A handheld PLC Programming unit. The computer is showing the Ladder Logic Program. PLC is based on a embedded uC. The DIN Controllers are Analog + Digital circuits. So you see it is a Electrical Control Panel with Electronics and the PLC Ladder Logic means, Software too.

Process Control Application Notes

This is a PID Controller based Control Panel using a PLC from GE Fanuc Automation. The Computer is a 386 40MHz with 40MB HDD.

PID Controller PLC

Electrical Control Panel Wiring

Control panes have many DIN Instruments like Indicators, Controllers and Recorders. They also have in the back end contacters, drives and circuit breakers with orderly wiring and cable management.

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In: Basic Electronics

This is a demo of the popular 555 timer. you can try out the project on this page by a javascript simulation.Press the Red button below to turn on the circuit press it again to turn off. The 555 can source (LED2) or Sink (LED1) upto 200mA.

Screenshot of Astable 555 Timer Flasher

It can even drive a small motor or lamp with diodes added to protect from inductive kickback.Vary Ra, Rb and Ct with the controls given and see the change of frequency, period and duty cycle.

Screenshot

Astable Multivibrator with 555

Astable Multivibrator with 555

This is a tutorial with calculator to help learn the application of 555 which is a very rare chip innovation. It is simple, versatile, flexible and programmable (by tweaking of pots).

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In: Process Control

These are the circuits and boards of a Mini Temperature Transmitter for a Platinum hundred ohms temperature Sensor.

Transmitter RTD

The customer wanted a two wire system, this needs low power opamps which were ten times the price. If this transmitter works at 3mA it could have been two wire. Those parts were in short supply and the budget of customer was low. So i made it with regular opamps but three wire. The customer was satisfied as he got a cost effective solution. But now the situation of markets and products are different.

RTD  Three Wire Transmitter

If you need to transmit the temperature from a high voltage area or toxic environment. You will need to hermetically seal the transmitters, convert the Voltage to frequency, frequency to IR LED flashes or RF. This can be then remotely monitored. Then the transmitter has to be battery-solar operated, low power too. ICL7135 is a simple solution. It has a serial output that can be used to Drive IR Leds. Remotely sense these flashes in a Micro-controller and you have a reading. You may be able to use optic-fibers too. Where volatile liquids are present so that the risks of sparks can be eliminated.

3 Wire Transmitter RTD

More at Process Control Circuits

This is the same Mini RTD Pt-100 Transmitter but in its case. Encapsulated in epoxy, hermetically sealed against harsh industrial environment. This will work well even near fumes of Ammonia with no corrosion. But not near vapors which can be ignited by sparking as terminals are still open. The side view shows zero and full scale ten turn bourns trimpots heads, for calibration. After cal it can be sealed with RTV compound.

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In: Design, Handheld Portables

An Alarm Clock with Musical Alarms. This Web Widget was for the iGoogle Homepage, A Web-page or even a blog.  It was an Experiment in User Interface in small a small Facia or Front Panel.

You can set Five Alarms with Ten Selectable Musical Sounds and a small Text memo.- 2005

Digital Alarm Clock Gadget

The Project Page digital-alarm-clock

The simulation is as close as possible to a uC based Clock which you could build, The GUI is more like a electronic gadget than a Software Application. That should charge you to build your Alarm Clock today.

Eco Green Alarm Clock with Flash Sound

Get news Eco Version above, This page is of the Older Version of Digital Alarm Clock. The reason this is old is it sound integration is not very good.

Digital Alarm Clock Web Gadget with Musical Alarms

Usability and Ergonomics Research

This gadget has established usability problems. The were intended and demonstrated. It was an attempt to show the limits and strain associated with push button and key controls to operate an electronic equipment.

Many Apps, Appliance and Gizmos are constrained with a small control interface size, these pose a challenge for the User Interface design. I myself have problems with the keyboard phones and remote control. This can be seen even in the puzzling Monitor OSD controls in comparison to the easy analog Pot controls of old CGA/EGA Monitors.

Controls should be easy like the water tap or power switch. Not like a Puzzle, Maze or Quiz.

Technology needs to make things simple. Keep controls minimum and Human Friendly means (analog). A human Being is a “Real Time Analog Machine”. This gadget is a continuing experiment in ergonomics.