Design of a Three Phase Portable Reference Standard

Three Phase Reference Standard (TPRS) is a device used to measure the load and test the accuracy of three phase energy meters at residential as well as commercial installations. The device is used primarily by State Electricity Boards and electrical laboratories.

Being a low volume product, the TPRS is manufactured by only a handful of manufacturers across the globe, only one of them being Indian. The Indian model is relatively less expensive but leaves much to be desired in terms of functionality and styling. Emantras Product Design was approached by Signals & Systems India Private Limited (SANDS) to design and develop a new model of TPRS for the Indian as well as international markets. SANDS is a ISO 9001:2000 certified company specializing in DSP and embedded solutions for the power sector.

The product being highly technical, we were completely at sea when SANDS engineers showed us the bare circuit assembled on a table! The first step for us was to understand all the parts, accessories and their inter-relationships.

Our team observed SANDS engineers performing all possible operations on the TPRS, namely Calibration, Error Checking and Data Transfer. We prepared a flowchart of the steps involved in each of these operations. Based on our observations and discussions with the SANDS team, we optimized the Usability Cycles of the product for efficiency and fool-proof performance.

The next step was to work out a physical embodiment for the product. All the loose parts and accessories were measured accurately in order to have a dimensional database of our building blocks. We generated five different arrangements for encasing the main console and all the accessories.

For each of the arrangements, we tried numerous configurations and compared them in terms of volumetric efficiency, usability and number of casings required. One of the options in arrangement 5 was selected for development.

For the outer carry case (housing the hand-held unit and accessories), our client preferred to go for ready-made instrument casings due to the low volume of the product. We surveyed the internet for ready-made casing models suiting our dimensional requirements. The selection was made based on volumetric efficiency, material & construction, self-weight, available colours, appearance and of course, price!

The dimensions of the hand-held unit were frozen and styling possibilities explored for the same.

The selected design was modeled and detailed out in ProE.

Special attention was paid to the design of the keypad, with due consideration to ergonomics, logical clustering and relative frequency of usage.

3D rendered images were generated for the design so as to convey a realistic picture to the SANDS management, and in turn, to their customers.

A rapid prototype of the hand-held casing was generated through the FDM process. The internal components were assembled and the unit was tested for ergonomics and electrical performance. After some minor dimensional adjustments, the design was approved for production.

Being accustomed to designing consumer products, this project (an industrial product) was a welcome break for us. We realized that however technical or complicated a product may be, design has the power to significantly enhance its usability and of course, its aesthetics.

Shoubhik Dutta Roy

Pocket Torch using High-brightness L.E.D.

The invention of the high-brightness L.E.D. has opened up a world of possibilities in the realm of compact lighting products. When we were approached by L.E.D. manufacturer Lednium for developing a handy pocket torch, we carried out a quick survey of existing pocket torch designs. Much to our dismay, we found that a sheer lack of design effort, in terms of styling as well as usability. Most of the existing designs still follow the conventional form of a torch i.e. a uniform cylindrical form with symmetrical surface treatment. Little or no thought seems to have been given to stability on flat surfaces. The models that have pen-like clips use this as an add-on element having little or no correlation with the visual language of the product.

We started the design process with the objective of giving a fresh perspective to pocket torch design, making it a style statement rather than just a utility device. Extensive form exploration resulted in a bank of sketches showing diverse form factors and interesting design elements.

Some of the promising designs were shortlisted and refined.

One of the designs was selected for development in consultation with the client. The concept was assigned dimensions and put through a round of extensive feature refinement for finalizing the aesthetic.

The finalized design was subjected to a preliminary engineering review to understand the manufacturability aspects.

After some dimensional refinement, a CAD model was generated and rendered to explore different color schemes and finishes. The product form was reviewed for aesthetic appeal. This trendy design has a circular cross-section which varies throughout its length to create interest. The long depressions on the cylindrical body and the truncated front end further add to the excitement of the design. The recessed neck and color-coordinated clip help in maintaining a slender profile.

The concept proceeded to the design engineering phase, where it was detailed out in terms of parts and their assembly.

A rapid prototype of the design was obtained through the FDM process. The prototype gave a realistic feel of the product and vindicated our efforts towards ergonomic design. The design was approved and taken up for mass-manufacturing.

Being a small product with very little technical complications, the pocket torch often fails to get the design effort it deserves. Completing the design process in a detailed and systematic manner made us realize that the simplest of products can be made delightful to see and use through proper design.

Shoubhik Dutta Roy