Audio Output Transformers – What & Why? – Miracle Electronics

An audio transformer  is one that works in the audio range, with a working frequency range being generally between 10 to 20,000 Hz, and the impedance often used to transform the voltage or change the load. These transformer types are generally used in radios, televisions, voltage amplifiers, and other such applications.

Construction of an audio transformer

The core of the audio transformer is superimposed by a high magnetic material, with the primary and secondary windings tightly coupled, so that the flux across the original winding almost all has a phase chain with the secondary winding, and the coupling coefficient is close to 1.

Working of an audio transformer

The lowest frequency of the passband is determined by the inductance of the original winding, while the highest frequency is determined by the leakage inductance of the transformer. The original winding inductance is large, and the leakage inductance is small, in order to ensure that the transformer has sufficient passband. The saturation of the magnetic circuit and the hysteresis loss of the core can cause signal distortion. To counteract this, there should be proper load distribution and increased load current. Also, the core section should be increased, and an air gap left to reduce the saturation of the magnetic circuit. Doing so can significantly reduce the distortion of the signal.

Audio output transformer

With multiple types of audio transformers available, what we’ll focus on in this blog is the audio output transformer, which is one that is intended to isolate an input circuit from an output circuit, while providing filtering to a signal that passes through it. It is designed to operate on signals with a frequency spectrum in the audible band. Output transformers basically perform two functions – completing the matching of output impedance, and completing the conversion of voltage to current, so that higher voltage signal can be converted to an electrical signal with lower output current.

Note: Close attention should be paid to the matching of the front and back impedance, in order to avoid signal distortion caused by the reflection. Also, the impedance of the load must be consistent with the impedance required by the power amplifier stage, through the impedance of the output transformer, in order to maximize the load.

Designing an audio output transformer

When you’re deciding on the kind of audio output transformer you want for your application, the choice of the core material and its size depends upon the frequency response, power levels, and harmonic distortion. Audio output transformers are generally preferred to use both high-permeability cores and the largest number of coil turns to create high primary inductance. Remember, by changing the number of wire turns in each winding, transformers can be manufactured to have various impedance ratios. You can choose to have your specific customized audio output transformer India to suit your particular application requirements at Miracle Electronics, where every transformer manufactured is of the highest quality, which is proved by their RoHS and REACH compliance certificates. So, get in touch whenever you are looking for the finest quality audio transformers!

Building A Box Build Assembly – Miracle Electronics

When you want a box build assembly made, you’ll try to search for the best and least expensive vendors. Obviously, who doesn’t want to save money! So, you’ll begin by sourcing components from one company, then send them to a manufacturer to sub-assemble the elements, and then forward the parts to another manufacturer who finally tackles the final assembly.

But, doing so can waste valuable time and money, while also compromising on the quality of your product, if any of the vendors are not up to the mark. Instead, why not send your project to only one manufacturer, who is dedicated to your project from start to finish, rather than opting for multiple sub-assemblers? Find a box build electronics manufacturer who can take care of everything, right from component sourcing to the final end product. A box build is a systems integration; a complete electronic assembly placed inside an enclosure, which is why it is advisable to get your project into the hands of an apt integrated service provider  who can handle it all effectively and successfully.

Designing

The designing phase involves the material and component selection, layout, concepts, and tooling. Combining all of this into one complete project is a task, which needs the skills of an expert manufacturer.

Assembling

Assembling involves combining all the components appropriately as per the design layout. In addition, the manufacturer will also help determine the input/output of the power, power sources, mounting options, and environmental constraints.

Cables and wire harnesses

No box build can be complete without the use of a combination of wires and cables. High or low voltage cables and wire harnesses will be incorporated into your box build. This could include standard or customized options, fabricated to meet your specifications, which again is the responsibility of the manufacturer.

Enclosure

The enclosure may require unique dimensions, special spacing, specific routing, or distinct mounting. Your manufacturer must look at all these factors, and determine the best shape and size that can hold every component easily in place, while also checking for the access of sensors and power.

Testing

Testing is a very important task within the manufacturing process of any and every electronic product. Testing ensures the quality and performance of the equipment, thus also ensuring reliability for the product to stand up to everyday use. Testing should be done after every phase of the manufacturing process, as well as after the final assembling of the box build.

Every box build is unique. It can range from a simple PCB in an enclosure to a large cabinet full of wires, complete with electronics and pneumatics. Whether your application requires a simple box build or a complex one, Miracle Electronics has the experience and expertise to meet your requirements. They are apt for surface mount and through hole assembly to cable manufacturing and complete electronic box assemblies in India; all in all a complete package, built with dedication to lean manufacturing techniques. 

The Basic Fundamentals About Defense Offset Guidelines – Miracle Electronics

A defense offset policy is drafted to leverage capital acquisitions in order to develop the Indian defense industry by fostering the development of internationally competitive enterprises, augmenting capacity for R&D, and encouraging the development of synergistic sectors like civil aerospace and internal security.

But, so as to achieve such a partnership, there is a list of defense offset guidelines that need to be followed. While the number of guidelines are umpteen, let’s help you get a brief in this blog below.

Application of provisions

The provisions apply to every capital acquisition, may it be outright purchase from a vendor, or purchase from a vendor that is followed by Licensed Production, where the estimated cost of the acquisition proposal is 300 crores or more. Generally, 30% each of both these costs of acquisition will be the required value of the offset obligations. However, the Defence Acquisition Council may prescribe varying offset obligations in special cases if required. Nevertheless, these provisions will not apply to procurements under the Fast Track procedure, and those under the “Option” clause, where an offset obligation was not stipulated in the original contract.

Discharge of offset obligations

The offset obligations may be discharged by one or more of the following methods –

ü Direct purchase or export orders for eligible products manufactured or serviced by Indian enterprises

ü Foreign direct investment in joint ventures with Indian enterprises for the manufacture and/or maintenance of eligible products and provision of eligible services

ü Investment in ‘kind’ in terms of transfer of TOT (Transfer OF Technology) to Indian enterprises for the manufacture and/or maintenance of eligible products and provision of eligible services

ü Investment in ‘kind’ in Indian enterprises in terms of provision of equipment through the non-equity route for the manufacture and/or maintenance of eligible products and provision of eligible services, excluding TOT, civil infrastructure and second-hand equipment.

ü Provision of equipment and/or TOT to government institutions and establishments engaged in the manufacture and/or maintenance of eligible products and provision of eligible services.

ü Technology Acquisition by the DRDO in areas of high technology

Then, there are a multitude of other offset obligation discharge policies that are divided into different sectors, such as vendor responsibility, performance bond, offset credits, offset banking, value addition, Buy Global procurements, offset valuation, and more.

Submission of offset proposals

Vendors are required to submit a written undertaking to the effect that every offset obligation will be met. Any failure on the part of the vendor to comply with the guidelines may result in disqualification of the vendor from any further participation in the contract. The proposals should be submitted by a specified date, failure of which may render the bid non-responsive, and liable to be rejected.

Evaluation of offset proposals

The Acquisition Wing in the Department of Defence is responsible for technical and commercial evaluation of offset proposals received in response to RFPs, and the conclusion of offset contracts. The Defence Offsets Management Wing in the Department of Defence Production is responsible for the formulation of the offset guidelines, auditing and reviewing or progress reports, and post contract management. And, both these wings work in close collaboration for the smooth implementation of the guidelines.

Processing of offset proposals

Technology acquisition – The Technology Acquisition Committee is responsible for assessing the offset proposals, covering both technical and financial parameters, including valuation of technology, and the timeframe and strategy for utilizing the technology.

Technical evaluation – The Technical Offset Evaluation Committee (TOEC), constituting of representatives of the Service Headquarters, Defence Finance, DRDO, DOMW, and other experts, is responsible for scrutinizing the technical offset proposals to ensure conformity with the offset guidelines. The TOEC report is then forwarded to the Technical Manager, who will then process the report for acceptance.

Approval authority – After the offset proposals are processed by the Acquisition Manager, they will be approved by the Raksha Mantri.

Penalties – If a vendor fails to fulfil the obligations as agreed to, a penalty equivalent to 5% of the unfulfilled offset obligation will be levied, after which the unfulfilled offset value will be re-phased over the remaining period of the contract. The vendor may also be liable for debarment from participation in future defence contracts for a period of up to 5 years, the decision that will depend upon the Director General of Acquisition.

Re-phasing requests – A vendor has the advantage of requesting re-phasing of the offset obligations within the period of the offset contract, providing valid reasons. If justified, the request may be granted.

Annual reporting – An annual report is submitted to the Defence Acquisition Council in June every year, regarding the details of the contracts signed, and the status of implementation of all on-going contracts.

Indian enterprises, institutions, and establishments engaged in the manufacture of eligible products and/or provision of eligible services are referred to as Indian Offset Partners, who are required to comply with all the above guidelines/licensing requirements and many more. Vendors are free to select such a partner. If you’re looking for the same too, Miracle Electronics can prove to the best Offset Partner For Indian Defense, thanks to their complete adherence to the obligations, proven industry capabilities, consistent R&D, and every necessary quality certification in place!