Power Alternatives for Commercial Drones

330 Power Drones for Web

Solution Options Expand

The amount of power a commercial drone can draw on has a direct impact on how long it can stay flying as well as on what tasks it can perform. But each kind of power source has its tradeoff.

By Jeff Child, Editor-in-Chief

Because extending flight times is a major priority for drone applications, drone system designers are constantly on the lookout for ways to improve the power performance of their products. For smaller, consumer “recreational” style drones, batteries are the obvious power source. But when you get into larger commercial drone designs, there’s a growing set of alternatives. Tethered drone power solutions, solar power technology, fuel cells and advanced battery chemistries are all power alternatives that are on the table for today’s commercial drones.

According to market research firm Drone Industry Insights, the majority of today’s commercial drones use batteries as a power source. As Lithium-polymer (LiPo) and Lithium-ion (Li-ion) batteries have become smaller with lower costs, they’ve been widely adopted for drone use. The advancements in LiPo and Li-ion battery technologies have been driven mainly by the mobile phone industry, according to Drone Industry Insights.

Batteries Still Leading

The market research firm points to infrastructure as the main advantage of batteries. They can be charged anywhere. While Li-Po and Li-Ion are the most common battery technologies for drones, other chemistries are emerging. Lithium Thionyl Chloride batteries (Li-SOCl2) promises a 2x higher energy density per kg compared to LiPo batteries. And Lithium-Air-batteries (Li-air) promise to be almost 7x higher. However, those options aren’t widely available and are expensive. Meanwhile, Lithium-Sulfur-batteries (Li-S) is a possible successor to Li-ion thanks to their higher energy density and the lower costs of using sulfur, according to Drone Industry Insights.

Photo 1 The Graphene Drone FPV Race series LiPo batteries provide lower internal resistance and less voltage sag under load than standard LiPo batteries. As a result, the battery packs stay cooler under extreme conditions

Photo 1
The Graphene Drone FPV Race series LiPo batteries provide lower internal resistance and less voltage sag under load than standard LiPo batteries. As a result, the battery packs stay cooler under extreme conditions

Meanwhile battery vendors continue to roll out new battery products to serve the growing consumer drone market. As an example, in June 2017 battery manufacturer Venom released its new Graphene Drone FPV Race series LiPo batteries. The batteries were engineered for the extreme demands of today’s first person view (FPV) drone racing pilots (Photo 1). The new batteries provide lower internal resistance and less voltage sag under load than standard LiPo batteries. As a result, the battery packs stay cooler under extreme conditions. The Graphene FPV Race series Li-ion batteries are 5C fast charge capable, allowing you to charge up to five times faster. All of the company’s Drone FPV Race packs include its patented UNI 2.0 plug system (Patent no. 8,491,341). The system uses a true Amass XT60 connector that attaches to the included Deans and EC3 adapter.

Chip vendors from the analog IC and microcontroller markets offer resources to help embedded system designers with their drone power systems. Texas Instruments (TI), for example, offers two circuit-based subsystem reference designs that help manufacturers add flight time and extend battery life to quadcopters and other non-military consumer and industrial drones.  …

Read the full article in the January 330 issue of Circuit Cellar

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Negative Feedback in Electronics

Lead Image Novacek

A Look at the Opposite Side

Besides closed-loop control systems, negative feedback is found in many electronic circuits—especially in amplifiers. And just like positive feedback, negative feedback can significantly change or modify a circuit’s performance.

By George Novacek

Following last month’s discussion of positive feedback, let’s now take a look at its opposite: the negative feedback. Besides closed-loop control systems, it is found in many electronic circuits, especially in amplifiers. As we have already seen, feedback significantly changes or modifies a circuit’s performance. The end of the 19th century and the beginning of the 20th century was the era of introduction of the telephone. For long distance calls, amplifiers were needed along the telephone lines to make up for their transmission losses.

Vacuum tube amplifiers of the day suffered from many ailments: drift, high distortion and generally poor performance, making the long-distance voice communications nearly unintelligible. Harold Stephen Black, an AT&T engineer, was one of many working to solve this problem. Eventually—because he was familiar with the effects of negative feedback in mechanical systems—he tried to apply it to a vacuum tube amplifier. The result was astonishing and amplifiers with negative feedback have been with us ever since.

FIGURE 1 Transfer function of an operational amplifier with negative feedback

FIGURE 1
Transfer function of an operational amplifier with negative feedback

The op amp is the epitome of feedback application in electronic circuits. Because its comprehension is valid for all electronic feedback circuits, let’s take a closer look at the op amp. To analyze the negative feedback mathematically, we’ll consider an amplifier as a combination of two functional blocks: The open loop gain (OLG) block with transfer function A(s) and the feedback block with transfer function β(s). With monolithic amplifiers, the feedback is usually applied externally. The overall transfer function follows the principle shown in Figure 1.. …

Read the full article in the November 328 issue of Circuit Cellar

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Analog ICs Meet Industrial System Needs

Jeff Lead Image Analog Inustrial

Connectivity, Control and IIoT

Whether it’s connecting with analog sensors or driving actuators, analog ICs play many critical roles in industrial applications. Networked systems add new wrinkles to the industrial analog landscape.

By Jeff Child

While analog ICs are important in a variety of application areas, their place in the industrial market stands out. Industrial applications depend heavily on all kinds of interfacing between real-world analog signals and the digital realm of processing and control. Today’s factory environments are filled with motors to control, sensors to link with and measurements to automate. And as net-connected systems become the norm, analog chip vendors are making advances to serve the new requirements of the Industrial Internet-of-Things (IIoT) and Smart Factories.

It’s noteworthy, for example, that Analog Devices‘ third quarter fiscal year 2017 report this summer cited the “highly diverse and profitable industrial market” as the lead engine of its broad-based year-over-year growth. Taken together, these factors all make industrial applications a significant market for analog IC vendors, and those vendors are keeping pace by rolling out diverse solutions to meet those needs.

Figure 1

Figure 1 This diagram from Texas Instruments illustrates the diverse kinds of analog sub-systems that are common in industrial systems—an industrial drive/control system in this case.

While it’s impossible to generalize about industrial systems, Figure 1 illustrates the diverse kinds of analog sub-systems that are common in industrial systems—industrial drive/control in that case. All throughout 2017, manufacturers of analog ICs have released a rich variety of chips and development solutions to meet a wide range of industrial application needs.

SOLUTIONS FOR PLCs

Programmable Logic Controllers (PLCs) remain a staple in many industrial systems. As communications demands increase and power management gets more difficult, transceiver technologies have evolved to keep up. PLC and IO-Link gateway systems must dissipate large amounts of power depending. That amount of power is often tied to I/O configuration—IO-Link, digital I/O and/or analog I/O. As these PLCs evolve into new Industrial 4.0 smart factories, special attention must be considered to achieve smarter, faster, and lower power solutions. Exemplifying those trends, this summer Maxim Integrated announced the MAX14819, a dual-channel, IO-Link master transceiver.

The architecture of the MAX14819 dissipates 50% less heat compared to other IO-Link Master solutions and is fully compatible in all modes for IO-Link and SIO compliance. It provides robust L+ supply controllers with settable current limiting and reverse voltage/current protection to help ensure robust communications with the lowest power consumption. With just one microcontroller, the integrated framer/UART enables a scalable and cost-effective architecture while enabling very fast cycle times (up to
400 µs) and reducing latency. The MAX14819 is available in a 48-pin (7 mm x 7 mm) TQFN package and operates over a -40°C to +125°C temperature range.  …

Read the full article in the November 328 issue of Circuit Cellar

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Note: We’ve made the October 2017 issue of Circuit Cellar available as a free sample issue. In it, you’ll find a rich variety of the kinds of articles and information that exemplify a typical issue of the current magazine.