How do e-Bikes work? Explained!
Hey friends, Happy Wednesday!
Welcome to Season 2!
Thank you for your support throughout Season 1: Wellness Gadgets. Here we are with the next installation of One gadget at a Time. Welcome to the first issue of Season 2: “Travel and Transport Gadgets”. I’m including an extended summary of how a gadget works in my newsletter, from which you can understand the essence in less than 3 minutes. But you can choose to read the blog posts for a more detailed version involving the nuances, from the links I attach. Let’s look at how power-assisted e-bikes work this week.
The mission of this newsletter is for us to go about our day living mindfully by appreciating the gadgets around us through an understanding of how they actually work. I aim to write my newsletter issues in a way one can follow them while traveling on a bus, having a coffee, waiting for your food, etc. Let’s jump in!
Answer to the question I posed last week
Last week, I asked how a thermopile sensor works in an Infrared Thermometer. Here is an article that explains the features in depth.
How do power-assisted e-Bikes work?
I first used power-assisted electric bikes during my summer internship in 2018. The public Ford Go bikes were the solution to my daily commute. I didn’t exactly know they worked back then. But now I know, and so do you!
What kind of e-Bikes am I talking about here?
We’ll be discussing the kind of electric bike where instead of twisting or pressing a throttle to activate your e-bike motor, you just start pedaling and the motor will power up automatically. When you pedal harder, then an electric motor provides additional torque proportional to your effort. I chose this specific type as exploring this will help you imagine how other kinds of electric bikes work.
How is the pedal force measured?
As you start pedaling, a torque sensor attached to the rear hub of the bike detects how hard you’re pressing on the pedals. The harder you pedal, the larger the torque value detected by the sensor. This implies a larger pedal force applied by you! Thus, the torque sensor has converted the mechanical action of pressing the pedal into an electrical signal, which is then sent to a control unit that has a microcomputer.
Figure 1: Cadence-Torque Sensor
How does the power-assist work?
The algorithm running in the microcomputer constantly monitors the pedal force information it receives from the torque sensor. Once it detects a force more than a prescribed threshold, the motor is commanded by the control unit to provide power assistance. The harder you pedal, the more assistive torque the motor provides to the wheels (more current flows through the motor). The less intense you pedal, the lesser the motor output power.
What if the bike is tilted?
The gyroscopic sensor can detect orientations. So if the bike is titled to the sides, like while performing a turn, the power assist may be weakened as we don’t want to power the bicycle further as it could affect the stability. But while going uphill, the pedaling assist may increase as we expect more support going against gravity. Also, if the voltage sensor detects a reduction in the battery voltage, the power assist is weakened to prevent excessive battery discharge and extend the lifetime.
This is the basic essence of how a power-assisted electric bike works! But there are nuances such as the power assistance not being provided to the e-Bike if it’s pedaled harder but in the reverse direction. I’ve addressed these scenarios and a more detailed version of the work in my blog post - the link for the same can be found towards the end of this email.
Question of the week
There are electric bikes that power-assist once you start pedaling irrespective of the pedaling force. How do you think they work? Please share your thoughts by replying to this email. And we can have a discussion on the same. I'll answer this in the next week's issue.
Gadget of the week
Social Media: An app called BeReal notifies the users to post what they’re actually doing at a random time every day. You have a few minutes to click both from your front and rear camera, whether you’re reading this newsletter or just daydreaming about something. This brings out the natural lifestyle of people and adds intimacy.
Blog posts
My full blog post-S2E1 on Power-assisted electric bikes is out! Read it here, happy learning!
How do e-Bikes work? Explained!
The next episode S2E2 is coming out next week, but I haven’t decided what to write about. Let me know if you’d like to read about a specific gadget/device by replying to this email. Thank you for reading & Welcome to Season 2 again.
Have a nice rest of the week, and take care!
Until next Wednesday,
Chendur
