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.