A Novel Ultra-Low Input Voltage and Frequency Self Starting AC–DC Boost Converter for Micro Energy Harvesting

In this letter, a novel low-voltage junction field-effect transistor (JFET) oscillator with self-starting capability to implement an ac–dc boost converter is introduced. The circuit is transformer free and can operate with very low–voltage and low–frequency signals. In order to operate with positive and negative input signals, a coupled topology of JFETs has been used. The circuit has been built using off the shelf components, and can be used with electromagnetic harvesters, thermoelectric modules, and/or wearable devices. Experimental results with a practical harvester are provided in order to demonstrate the proposed ac–dc boost converter.