Researchers at MIT have created a power supply for small electronic devices that “sips” energy by turning devices on with packets of energy rather than a steady stream.
Most power converters release a steady voltage. This means they’re generally inefficient for small devices like sensors and other devices that don’t need to be constantly on. The MIT’s Microsystems Technologies Laboratories has created a power supply that can send power as needed, falling back into a “quiescent” state as necessary.
“Typically, converters have a quiescent power, which is the power that they consume even when they’re not providing any current to the load,” said Arun Paidimarri, formerly of the MTL. “So, for example, if the quiescent power is a microamp, then even if the load pulls only a nanoamp, it’s still going to consume a microamp of current. My converter is something that can maintain efficiency over a wide range of currents.”
The converter takes inputs of up to 3.3 volts and reduces them to .9 volts. “It’s based on these packets of energy. You have these switches, and an inductor, and a capacitor in the power converter, and you basically turn on and off these switches,” said Paidimarri.
This means a sensor can turn on, check for a certain state, and shut off. Further, this can happen over and over again and the IoT device only sucks in a tiny amount of power – enough for the sensing and the calculation.
It’s quite a clever solution. In short, if the device is only sensing and doing nothing else then only a few “packets” of energy will be released. If the device is transmitting, said the researchers, “it might need to release a million packets a second.” This means you can run part of a device at low power and only activate the high-energy parts as necessary. Ultimately they’re seeing a 50 percent repudiation in power usage which could make it far easier to control and power IoT devices on limited amounts of energy.