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Олександр Данилейко. Складні завдання стимулюють до постійного розвитку kpi чт, 02/13/2025 - 16:58

This design idea revisits another: “PWM power DAC incorporates an LM317.” Like the earlier circuit, this one implements a power DAC by integrating an LM317 positive regulator into a mostly passive PWM topology. It exploits the built-in features of that time-proven Bob Pease masterpiece so that its output is proportional to the guaranteed 2% precision of the LM317 internal voltage reference and is inherently protected from overloading and overheating.

Wow the engineering world with your unique design: Design Ideas Submission Guide

However, unlike the earlier design idea that requires a separate 15v DC power input, this remake (shown in Figure 1) adds a switching input boost preregulator so it can run from a 5v logic rail. The previous linear design also has a limited power efficiency that actually drops below single-digit percentages when driving low voltage loads. The preregulator fixes that by tracking the input-output voltage differential across the LM317 and maintains a constant 3v. This is the just adequate dropout-suppressing headroom for the LM317, minimizing wasted power.

Here’s how it works.

Figure 1 LM317 and HC4053 combine to make a PWM power DAC while Q1 forces preregulator U3 to track and maintain a constant 3v U2 I/O headroom differential to improve efficiency.

As described in the earlier DI, switches U1b and U1c accept a 10-kHz PWM signal to generate a 0v to 11.25v “ADJ” control signal for the U2 regulator via feedback networks R1, R2, and R3. The incoming PWM signal is AC coupled so that U1 can “float” on U2’s output. U1c provides a balanced inverse of the PWM signal, implementing active ripple cancellation as described in “Cancel PWM DAC ripple with analog subtraction.”

Note that R1||R2 = R3 to optimize ripple subtraction and DAC accuracy. This feedback arrangement makes U2’s output voltage follow this function of PWM duty factor (DF): 

Vout = 1.25 / (1 – DF(1 – R1/(R1 + R2))) = 1.25 / (1 – 0.9 DF),

as graphed in Figure 2.

Figure 2 Vout (1.25v to 12.5v) versus PWM DF (0 to 1) where Vout = 1.25 / (1 – 0.9 DF).

Figure 3 plots the inverse of  Figure 2, yielding the PWM DF required for any given Vout.

Figure 3 The inverse of Figure 2 or, the PWM DF required for any given Vout, where PWM DF = (1.111 – 1.389/Vout).

About that tracking preregulator thing: Control of U3 to maintain the 3v of headroom required to hold U2 safe from dropout relies on Q1 acting as a simple (but adequate) differential amplifier. Q1 drives U3’s Vfb voltage feedback pin to maintain Vfb = 1.245v. Therefore (where Vbe = Q1’s emitter-base bias):

Vfb/R7 = ((U2in – U2out) – Vbe)/R6
1.245v = (U2in – U2out – 0.6v)/(5100/2700)
U2in – U2out = 1.89 * 1.245v + 0.6v = 3v

Meanwhile, deducing what Q2 does is left as an exercise for the astute reader. Hint: It saves about a third of a wattage over the original DI at Vout = 12v. 

Note, if you want to use this circuit with a different preregulator with a different Vfb, just adjust:

R7 = R6 Vfb/2.4

In closing…

Thanks must go to reader Ashutosh for his clever suggestion to improve power DAC efficiency with a tracking regulator, also (and especially) to editor Aalyia for her creation of a Design Idea environment that encourages such free and friendly cooperation!

Stephen Woodward’s relationship with EDN’s DI column goes back quite a long way. Over 100 submissions have been accepted since his first contribution back in 1974.

 Related Content

• PWM power DAC incorporates an LM317
• Cancel PWM DAC ripple with analog subtraction
• A faster PWM-based DAC
• Parsing PWM (DAC) performance: Part 1—Mitigating errors
• Cancel PWM DAC ripple with analog subtraction but no inverter
• Parsing PWM (DAC) performance: Part 1—Mitigating errors
• Phased-array PWM DAC

The post Tracking preregulator boosts efficiency of PWM power DAC appeared first on EDN.

Партнерська підтримка Sense Bank kpi чт, 02/13/2025 - 15:23

Sivers Semiconductors AB of Kista, Sweden (which supplies RF beam-former ICs for SATCOMs and photonic lasers for AI data centers) has signed a strategic memorandum of understanding (MOU) with an optical infrastructure firm for large-scale AI workloads for the volume production of high-performance laser arrays...

India’s Defence Research and Development Organisation (DRDO) continues to push the boundaries of indigenous defense innovation, with the DRDO Abhyas standing as a testament to this progress. Abhyas, a High-speed Expendable Aerial Target (HEAT) system, is designed to simulate realistic threat scenarios, providing the Indian Armed Forces with a cutting-edge platform for testing and training. True to its Sanskrit name, which means “practice,” Abhyas plays a crucial role in enhancing combat readiness by replicating aerial threats, enabling the evaluation of missile defense systems and other critical military technologies. Engineered to meet the evolving demands of modern warfare, this advanced UAV underscores India’s commitment to self-reliance in defense technology.

Overview of DRDO Abhyas

The DRDO Abhyas UAV is an expendable, high-speed aerial target that replicates a range of aerial threat profiles. It is an essential tool for training and testing defense personnel and weapon systems. The platform has been developed by the Aeronautical Development Establishment (ADE), a key laboratory under DRDO. The primary objective of Abhyas is to provide a cost-effective and reliable solution to simulate enemy aircraft, cruise missiles, and UAVs during military drills and equipment testing.

Technical Specifications

Abhyas boasts state-of-the-art technology, making it a versatile and efficient platform for defense applications. Key technical features include:

1. Airframe and Propulsion:
   
   • The UAV features a lightweight composite airframe designed for high-speed maneuvers.
   • It is powered by a small gas turbine engine capable of achieving high subsonic speeds, ensuring realistic simulation of aerial threats.
2. Guidance and Navigation:
   
   • Abhyas employs a Micro-Electro-Mechanical Systems (MEMS)-based Inertial Navigation System (INS) integrated with a Flight Control Computer (FCC).
   • This configuration allows the UAV to perform autonomous flight along pre-programmed paths with precision.
3. Launch and Recovery:
   
   • The system utilizes a rocket-assisted take-off mechanism, ensuring a quick and efficient launch.
   • Parachute-based recovery enables the safe retrieval of the UAV after mission completion.
4. Payload Capabilities:
   
   • Abhyas can be equipped with various payloads, including radar cross-section (RCS) augmentation devices, infrared (IR) flares, and electronic warfare (EW) systems, enhancing its ability to mimic diverse threat profiles.

Development and Testing Milestones

The development of Abhyas has been a systematic process involving multiple stages of testing and validation:

• Initial Trials:The first successful trial of Abhyas was conducted in 2012, establishing proof of concept for its design and functionality.
• Subsequent Improvements:Over the years, DRDO has incorporated several enhancements, such as improved booster configurations and advanced augmentation systems for better simulation capabilities.
• Recent Achievements:In June 2024, DRDO conducted six consecutive trials at the Integrated Test Range (ITR) in Chandipur, Odisha. These trials validated the UAV’s endurance, reliability, and operational efficiency. Notably, two back-to-back launches within 30 minutes showcased its readiness for rapid deployment.

Applications in Modern Warfare

Abhyas serves a variety of roles in India’s defense ecosystem:

1. Missile Testing and Evaluation:
   
   • The UAV provides a realistic target for testing surface-to-air missiles (SAMs), air-to-air missiles (AAMs), and other defense systems, ensuring their operational readiness.
2. Training Exercises:
   
   • Abhyas aids in training defense personnel by simulating aerial threats, enhancing their combat preparedness and response strategies.
3. Electronic Warfare Training:
   
   • With its payload versatility, Abhyas can mimic electronic warfare scenarios, helping the armed forces test countermeasure systems.
4. Research and Development:
   
   • The platform’s modularity allows for the integration of experimental technologies, supporting ongoing R&D initiatives in defense.

Advantages of DRDO Abhyas

1. Indigenous Development:
   
   • As an entirely Indian project, Abhyas reduces dependency on foreign technologies and contributes to the ‘Make in India’ initiative.
2. Cost-Effectiveness:
   
   • Being expendable, Abhyas provides a cost-efficient solution for large-scale training and testing exercises without compromising on performance.
3. Operational Versatility:
   
   • Its ability to simulate a wide range of threats makes it adaptable to various defense scenarios.
4. Ease of Deployment:
   
   • The UAV’s rocket-assisted launch and parachute recovery systems ensure quick deployment and turnaround times.

Challenges and Future Prospects

While Abhyas has proven to be a valuable asset, certain challenges remain:

• Limited Endurance:
  • As an expendable system, Abhyas has a limited operational lifespan, necessitating frequent replacements.
• Continuous Upgrades:
  • To stay relevant against evolving threats, the platform requires regular updates in terms of payload capabilities and performance metrics.

Looking ahead, DRDO plans to enhance the Abhyas platform further by integrating advanced artificial intelligence (AI) capabilities and improving its stealth characteristics. These upgrades aim to make the UAV more effective in simulating next-generation threats.

Conclusion

The DRDO Abhyas UAV represents a significant milestone in India’s journey towards self-reliance in defense technology. By providing a robust and flexible solution for testing and training, Abhyas not only strengthens the operational readiness of the Indian Armed Forces but also showcases the country’s capability to innovate in the field of unmanned systems. As DRDO continues to refine and expand the platform’s capabilities, Abhyas is poised to play an even more critical role in safeguarding India’s national security.

The post DRDO Abhyas Pioneering India’s High-Speed Aerial Target Technology appeared first on ELE Times.

Infineon Technologies AG of Munich, Germany says that it has made significant progress on its 200mm silicon carbide (SiC) roadmap, and is releasing the first products based on the 200mm SiC technology to customers in first-quarter 2025. Manufactured in Villach, Austria, the products provide SiC power technology for high-voltage applications, including renewable energies, trains, and electric vehicles...

The Defence Research and Development Organisation (DRDO) of India has been at the forefront of developing indigenous unmanned aerial vehicles (UAVs) to enhance the nation’s defense capabilities. A notable addition to this endeavor is the Archer UAV, a progression from the earlier Rustom series, tailored for both surveillance and combat roles.

Developmental Background

The Archer UAV is an evolution of the Rustom-1 platform, which was initially designed for intelligence, surveillance, and reconnaissance (ISR) missions. Recognizing the need for a more versatile UAV capable of engaging in combat operations, DRDO initiated modifications to the Rustom-1, leading to the development of the Archer. This transformation began in mid-2022, focusing on equipping the UAV with weapon systems suitable for precision strikes.

Technical Specifications

The Archer UAV boasts impressive operational capabilities:

• Altitude: Capable of operating at altitudes up to 22,000 feet, allowing it to conduct missions above most ground-based threats.
• Endurance: With an endurance of 12 hours, it can perform extended missions without the need for frequent returns to base.
• Range: The UAV has a range of 220 kilometers, enabling it to cover substantial areas during operations.
• Payload Capacity: Designed as a multi-payload configurable system, the Archer can be equipped with various sensors and weaponry tailored to specific mission requirements.
• Autonomy: It features autonomous take-off and landing capabilities, even on short, semi-paved runways, enhancing its operational flexibility.

These specifications underscore the Archer’s versatility in both ISR and combat roles.

Weaponization and Combat Capabilities

A significant advancement in the Archer’s design is its weaponization. The UAV has been modified to carry out armed missions, with the integration of weapon systems such as the Smart Anti-Airfield Weapon (SAAW) and Anti-Tank Guided Missiles (ATGMs). These modifications enhance its capability to perform precision strikes, making it a formidable asset in combat scenarios.

Archer-NG: The Next Generation

Building upon the success of the Archer, DRDO has developed the Archer-NG (Next Generation), a Medium-Altitude Long-Endurance (MALE) UAV. The Archer-NG features a single-engine, twin-boom pusher configuration and is designed to meet the specifications of the now-downgraded TAPAS program (previously known as Rustom-II). It shares common avionics, software, Ground Control Station (GCS), and Ground Data Terminal (GDT) with TAPAS, ensuring compatibility and reducing developmental redundancies.

The Archer-NG has an all-up weight of 1,700 kg and can carry up to 400 kg of payload, making it a versatile platform for armed missions. Its roles include Intelligence, Surveillance, Target Acquisition, and Reconnaissance (ISTAR), artillery target acquisition, battlefield post-strike assessment, and precision strikes. The UAV is equipped with an indigenous Ground Control Station capable of operating 6-7 UAVs simultaneously.

Manufacturing and Deployment

In a significant move towards bolstering India’s indigenous defense manufacturing capabilities, Bharat Electronics Limited (BEL) has been selected to manufacture 20 Limited Series Production (LSP) units of the Archer UAV. These units are slated for delivery to the Indian Army and Indian Air Force for user trials. The initial four units will be utilized for air-to-surface missile fire testing, with plans to integrate various weapon systems upon successful trials.

Future Prospects

As of latest, the Archer-NG has completed high-speed taxi trials, with its maiden flight anticipated in February 2025, likely before the Aero India 2025 airshow at Yelahanka Air Force Station. The weaponized variant is expected to be completed within the next three years, with plans to integrate laser-guided rockets, bombs, and loitering munitions with ranges up to 100 km. The prototype is currently powered by an Austro Engine E4 powerplant inherited from the TAPAS-BH-201 program. However, two indigenous UAV engines of 180hp and 220hp are being developed by the Vehicle Research and Development Establishment (VRDE) to further enhance its capabilities.

Conclusion

The DRDO Archer UAV represents a significant milestone in India’s pursuit of self-reliance in defense technology. Its development from a surveillance platform to a weaponized UAV underscores the nation’s commitment to enhancing its aerial combat capabilities. With the upcoming advancements in the Archer-NG variant, India is poised to strengthen its position in the global UAV landscape, showcasing the prowess of its indigenous defense research and development.

The post DRDO Archer UAV: Advancing India’s Indigenous Combat Drone Capabilities appeared first on ELE Times.

Відкриття лабораторії відновлюваної енергетики та лекторію вітрової енергетики для підготовки фахівців kpi чт, 02/13/2025 - 12:51

Нова лабораторія сигналів і процесів у радіотехніці kpi чт, 02/13/2025 - 10:56

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Epiwafer and substrate maker IQE plc of Cardiff, Wales, UK says that, further to its announcement of 18 November 2024, it has entered into subscription agreements with a consortium of existing investors and certain senior executives and directors, led by its largest shareholder Lombard Odier...