This Engineer Has Made Rural Electrification in Kenya Her Mission

The IEEE Smart Village director is also helping telehealth centers solve Internet connectivity challenges

4 min read
A woman holding a sign #wielead
Photo: Mercy Chelangat

Growing up in Sotik, Kenya, Mercy Chelangat saw firsthand how much technology can help underserved communities. When she was young, she and her family visited Nairobi, Kericho, and other Kenyan cities and saw how having reliable electricity could improve lives. It wasn't until 2016 that transmission lines were installed in Sotik, a town in the southern part of the Great Rift Valley ridge. Chelangat's desire to provide the town's homes, stores, and farmers with electricity motivated her to pursue a career in power engineering.

After graduating from college in 2017, she worked for several Kenyan companies striving to provide clean energy to communities around the country. But she felt as though she wasn't leaving a lasting impact on people's lives, so in 2018 she decided to become a full-time volunteer for the IEEE Power & Energy Society's Kenya Chapter. She was the secretary and treasurer and worked to increase membership through social-media outreach.

Through her work for the chapter she learned about IEEE Smart Village, a program that brings electricity—as well as educational and employment opportunities—to remote communities. IEEE Smart Village is one of the donor-supported priority initiatives of the IEEE Foundation. The group asked her to manage an electrification project inside Kenya's Maasai Mara National Reserve, where she assessed communities' needs.

For the project, Smart Village partnered with the Maa Trust, a nonprofit that aims to combine education, technology, and vocational training to enhance opportunities for children in Maasai Mara.

After completing her assignment last year, Chelangat joined Smart Village, where she is responsible for pursuing funding opportunities.

She hasn't left hands-on power-engineering work behind, however. She is helping to provide electricity and Internet connectivity to telehealth centers in Kenya so doctors can interact with patients who live in remote areas. The project is in partnership with IEEE Smart Village, the Rotary eClub of Silicon Valley, the Global Telehealth Network, and Rotary International.

For her humanitarian efforts, Chelangat received the 2019 IEEE Region8 Women in Engineering Clementina Saduwa Award. The honor recognizes female engineers who, through their engineering and career achievements, have demonstrated support for women in the profession and have established a record of excellence. It was named after IEEE Member Clementina Saduwa, who was killed at age 29 in 2007 in a random act of violence.

“Volunteering through IEEE has expanded my mind and has allowed me to meet people from different walks of life," Chelangat says.


After earning a bachelor's degree in electrical and electronics engineering from Moi University, in Eldoret, Kenya, Chelangat became a researcher for Industrial Promotion Services, in Nairobi. IPS focuses on providing farmers and rural communities with affordable energy.

Chelangat and her team were assessing if they could use solar-powered mini electrical grids. But the organization didn't find the projects feasible at the time, as there was little demand for power in the communities, Chelangat says.

She says she felt as though she wasn't using her engineering skills there, so she left in 2018 to become a trainee at OFGEN, an engineering, procurement, and construction company in Nairobi.

She learned more hands-on technical skills in solar power, smart metering, and power storage solutions. But she felt discouraged after a project manager would not let her install solar panels. She says he was concerned that, as a woman, she couldn't handle the equipment and might hurt herself.

Chelangat says she felt she was being discriminated against, and she decided to leave the company to volunteer full time for the IEEE PES Kenya Chapter.

“Leaving the company was quite difficult, but I don't regret it, because it was through my volunteer work that I was able to meet Robin Podmore," she says. Podmore, an IEEE life Fellow and cofounder of IEEE Smart Village, became her mentor.

Two men and a woman standing outdoorsChelangat at the IEEE Power & Energy Society and Industry Application Society PowerAfrica Conference in Abuja, Kenya, with IEEE PES President Frank Lambert, and Robin Podmore (right).Photo: Mercy Chelangat

The two met when he visited Nairobi to train systems operators and engineers for Smart Village projects. After the training session, Chelangat approached Podmore about some of her ideas on bringing power to underserved communities in Kenya.

He offered her an internship with Smart Village as the manager of a project in the Maasai Mara National Reserve.

Chelangat spent six months in the reserve assessing electrification, hardware, and networking needs for homes, schools, and businesses. She found that the schools needed electrification and Internet access.

The solar panels the program installed at the Maa Trust headquarters not only powered staff houses and businesses but also the school's new vocational IT hub. The trust plans to use the hub—built by engineers and locals—to train teachers how to use technology in the classroom.

The vehicles the villagers drove were used mainly to transport tourists around the reserve. The vehicles also transported goods. But the trucks relied on diesel fuel, which was costly. In order to reduce air pollution and costs, volunteers are researching which electric vehicles could be comfortably driven on the rough terrain. Electric trucks could be charged by the microgrid the engineers installed.

Chelangat continues to volunteer for humanitarian efforts in Kenya.

“Mercy is highly motivated and passionate about IEEE Smart Village and IEEE," Podmore says. “There is still a huge amount of work to be done, but Mercy has all the right stuff to succeed."

Chelangat is working remotely on a project to help Kenyan telehealth centers solve Internet connectivity and power challenges during the COVID-19 pandemic. As of 28 March, Kenya had more than 130,000 confirmed coronavirus cases and more than 2,100 deaths, according to the U.S.Embassy inKenya.


Chelangat joined IEEE in 2017 as a student member after her friend, IEEE Member Kithinji Muriungi, introduced her to the organization.

A year after joining, Chelangat and a few other IEEE members founded the IEEE PES chapter. She became its secretary and treasurer and was able to travel to conferences and meet members from around the world. She attended the 2018 PES Student Congress in Brazil—which, she says, helped her make more connections. She calls such experiences “networking without borders."

As the IEEE Region8 lead for the IEEE PES Women in Power group, Chelangat works to increase its membership. The group aims to get more women into the power industry, and it works to promote women to leadership positions.

“I'm passionate about empowering women engineers," she says. “There are so many challenges we face, so I took up this role to try and also give women in Region8 credibility and a community."

IEEE membership offers a wide range of benefits and opportunities for those who share a common interest in technology. If you are not already a member, consider joining IEEE and becoming part of a worldwide network of more than 400,000 students and professionals.

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The Inner Beauty of Basic Electronics

Open Circuits showcases the surprising complexity of passive components

5 min read
A photo of a high-stability film resistor with the letters "MIS" in yellow.
All photos by Eric Schlaepfer & Windell H. Oskay

Eric Schlaepfer was trying to fix a broken piece of test equipment when he came across the cause of the problem—a troubled tantalum capacitor. The component had somehow shorted out, and he wanted to know why. So he polished it down for a look inside. He never found the source of the short, but he and his collaborator, Windell H. Oskay, discovered something even better: a breathtaking hidden world inside electronics. What followed were hours and hours of polishing, cleaning, and photography that resulted in Open Circuits: The Inner Beauty of Electronic Components (No Starch Press, 2022), an excerpt of which follows. As the authors write, everything about these components is deliberately designed to meet specific technical needs, but that design leads to “accidental beauty: the emergent aesthetics of things you were never expected to see.”

From a book that spans the wide world of electronics, what we at IEEE Spectrum found surprisingly compelling were the insides of things we don’t spend much time thinking about, passive components. Transistors, LEDs, and other semiconductors may be where the action is, but the simple physics of resistors, capacitors, and inductors have their own sort of splendor.

High-Stability Film Resistor

A photo of a high-stability film resistor with the letters "MIS" in yellow.

All photos by Eric Schlaepfer & Windell H. Oskay

This high-stability film resistor, about 4 millimeters in diameter, is made in much the same way as its inexpensive carbon-film cousin, but with exacting precision. A ceramic rod is coated with a fine layer of resistive film (thin metal, metal oxide, or carbon) and then a perfectly uniform helical groove is machined into the film.

Instead of coating the resistor with an epoxy, it’s hermetically sealed in a lustrous little glass envelope. This makes the resistor more robust, ideal for specialized cases such as precision reference instrumentation, where long-term stability of the resistor is critical. The glass envelope provides better isolation against moisture and other environmental changes than standard coatings like epoxy.

15-Turn Trimmer Potentiometer

A photo of a blue chip
A photo of a blue chip on a circuit board.

It takes 15 rotations of an adjustment screw to move a 15-turn trimmer potentiometer from one end of its resistive range to the other. Circuits that need to be adjusted with fine resolution control use this type of trimmer pot instead of the single-turn variety.

The resistive element in this trimmer is a strip of cermet—a composite of ceramic and metal—silk-screened on a white ceramic substrate. Screen-printed metal links each end of the strip to the connecting wires. It’s a flattened, linear version of the horseshoe-shaped resistive element in single-turn trimmers.

Turning the adjustment screw moves a plastic slider along a track. The wiper is a spring finger, a spring-loaded metal contact, attached to the slider. It makes contact between a metal strip and the selected point on the strip of resistive film.

Ceramic Disc Capacitor

A cutaway of a Ceramic Disc Capacitor
A photo of a Ceramic Disc Capacitor

Capacitors are fundamental electronic components that store energy in the form of static electricity. They’re used in countless ways, including for bulk energy storage, to smooth out electronic signals, and as computer memory cells. The simplest capacitor consists of two parallel metal plates with a gap between them, but capacitors can take many forms so long as there are two conductive surfaces, called electrodes, separated by an insulator.

A ceramic disc capacitor is a low-cost capacitor that is frequently found in appliances and toys. Its insulator is a ceramic disc, and its two parallel plates are extremely thin metal coatings that are evaporated or sputtered onto the disc’s outer surfaces. Connecting wires are attached using solder, and the whole assembly is dipped into a porous coating material that dries hard and protects the capacitor from damage.

Film Capacitor

An image of a cut away of a capacitor
A photo of a green capacitor.

Film capacitors are frequently found in high-quality audio equipment, such as headphone amplifiers, record players, graphic equalizers, and radio tuners. Their key feature is that the dielectric material is a plastic film, such as polyester or polypropylene.

The metal electrodes of this film capacitor are vacuum-deposited on the surfaces of long strips of plastic film. After the leads are attached, the films are rolled up and dipped into an epoxy that binds the assembly together. Then the completed assembly is dipped in a tough outer coating and marked with its value.

Other types of film capacitors are made by stacking flat layers of metallized plastic film, rather than rolling up layers of film.

Dipped Tantalum Capacitor

A photo of a cutaway of a Dipped Tantalum Capacitor

At the core of this capacitor is a porous pellet of tantalum metal. The pellet is made from tantalum powder and sintered, or compressed at a high temperature, into a dense, spongelike solid.

Just like a kitchen sponge, the resulting pellet has a high surface area per unit volume. The pellet is then anodized, creating an insulating oxide layer with an equally high surface area. This process packs a lot of capacitance into a compact device, using spongelike geometry rather than the stacked or rolled layers that most other capacitors use.

The device’s positive terminal, or anode, is connected directly to the tantalum metal. The negative terminal, or cathode, is formed by a thin layer of conductive manganese dioxide coating the pellet.

Axial Inductor

An image of a cutaway of a Axial Inductor
A photo of a collection of cut wires

Inductors are fundamental electronic components that store energy in the form of a magnetic field. They’re used, for example, in some types of power supplies to convert between voltages by alternately storing and releasing energy. This energy-efficient design helps maximize the battery life of cellphones and other portable electronics.

Inductors typically consist of a coil of insulated wire wrapped around a core of magnetic material like iron or ferrite, a ceramic filled with iron oxide. Current flowing around the core produces a magnetic field that acts as a sort of flywheel for current, smoothing out changes in the current as it flows through the inductor.

This axial inductor has a number of turns of varnished copper wire wrapped around a ferrite form and soldered to copper leads on its two ends. It has several layers of protection: a clear varnish over the windings, a light-green coating around the solder joints, and a striking green outer coating to protect the whole component and provide a surface for the colorful stripes that indicate its inductance value.

Power Supply Transformer

A photo of a collection of cut wires
A photo of a yellow element on a circuit board.

This transformer has multiple sets of windings and is used in a power supply to create multiple output AC voltages from a single AC input such as a wall outlet.

The small wires nearer the center are “high impedance” turns of magnet wire. These windings carry a higher voltage but a lower current. They’re protected by several layers of tape, a copper-foil electrostatic shield, and more tape.

The outer “low impedance” windings are made with thicker insulated wire and fewer turns. They handle a lower voltage but a higher current.

All of the windings are wrapped around a black plastic bobbin. Two pieces of ferrite ceramic are bonded together to form the magnetic core at the heart of the transformer.

This article appears in the February 2023 print issue.