Posts By: Jeffrey Jenkins

EV tech explained: Why do EVs restrict the amount of battery capacity that can be used for driving?

All EVs that use lithium-ion batteries are designed so that their full capacity can’t be used in driving – a few kWh are always left over as a buffer. Sometimes you’ll find this figure in spec sheets, which might (for example) quote capacity as “60 kWh (55 usable)” or some such. What is the reason… Read more »

A closer look at the semiconductor switch

In this article I’ll be giving an overview of that most important of power electronics components: the semiconductor switch. I’ll first address what a switch is, and then delve into some of the more important compromises and shortcomings that exist in real-world switches that engineers must contend with when designing chargers, motor controllers, DC-DC converters… Read more »

A closer look at back electromotive force

Why motors generate and generators motor In a previous article I took a closer look at regenerative braking, and mentioned an old engineering saying that every motor is a generator and every generator is a motor (along with the caveat that some are more suited to the opposite purpose than others). This time around I’ll… Read more »

A closer look at switched reluctance motors

The electronically-switched reluctance motor – often shortened to the switched reluctance motor, or SRM – has been gaining in popularity over the last decade because it is simple, robust, and arguably the least expensive of all motor types to manufacture. The reasons for the relatively late blooming of the SRM – the first reluctance motor… Read more »