EnerCard™ Energy Harvesting-based Power Modules

EnerCard™ energy harvesting modules are small footprint, high efficiency energy harvesting power modules that incorporate the EnerChip™ Energy Processor and EnerChip Solid State Batteries. These EnerCard EH-based modules provide a complete power supply solution for powering devices such as wireless sensors, data logging tags, and actuators such as lighting controls, HVAC and security devices. The photo below is an example of a double sided EnerCard:

EnerCard Solar Module

The EnerCard embodies the top half of the Energy Harvesting powered Wireless Sensor diagram below. Notice that the EnerCard not only supplies power to the Microcontroller, Sensor and RF Module, but also supplies information about the input power, state of EnerChip charge and power management indicators.

EnerCard Block Diagram

Free Resources to Build an EnerCard

Cymbet has provided several resources for EnerCard design assistance:

 

Energy Storage Needs

In order to power systems using ambient energy harvesting, several factors must taken into consideration to calculate the power required to operate the system in various states:

1 - Identify the sources of ambient energy to be used and the type of Energy Harvesting transducer to be used

2 - Characterize the power output of the EH transducer over various ambient conditions

3 - Looking at all the system components, calculate the power required for all states operation (e.g. sleep, sensing, wireless)

4 - Identify the EH conversion and power management electronics to be used and add the power used to the overall total.

5 - Size the energy storage device (solid state battery) to cover all the system energy storage and power delivery requirements.

Reference schematics of these systems can be found in the Cymbet EVAL-09 datasheet and the EVAL-10 data sheet.

 

Using Maximum Peak Power Tracking

To optimize the performance of energy harvesting based systems, it is critical the high efficiency energy conversion technique of maximum peak power tracking (MPPT) be used. MPPT can adapt to either constant impedance or variable impedance EH transducers. MPPT is used to match the impedance between the energy harvesting transducer and the system load as seen in the diagrams below. The EnerChip EP Energy Processor CBC915 implements an optimized version of MPPT.

Maximum Peak Power Tracking

Energy Transaction Calculations

he definition of an energy transaction is "the amount of discrete energy required to perform a certain task or functional transaction". This concept of energy transaction is very useful in the design of energy harvesting-based systems. In order to calculate the power budget and power boundary conditions for an EH-based system, all operating and quiescent power states of the system must identified. Each of these states requires an energy transaction level to function. Identifying all the various energy transactions will determine the sizing of the Energy Harvesting transducer and the energy storage devices.

Physical Design

Designing electronics for compact, small footprint systems requires the use of new advanced technologies such as the EnerChip CBC915 Energy Processor and the EnerChip CBC050 Solid State Battery. These space saving devices can be surface mounted anywhere on a PCB and reflow soldered. EnerChip solid state batteries last the life of the product so they never have to be changed.

Application Examples

EnerCard EH modules can be used in many systems such as Energy Harvesting-powered systems, Wireless Sensors, and tiny Internet of Things solutions.

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