In this study, a complete model for a miniature excitation-powered piezoelectric generator (PG), analysis modes of operation and control of a full-bridge joule thief (FBRJT) circuit to identify the optimal points were investigated. The proposed model revealed the PG’s power dependency on mechanical excitation, acceleration, and frequency and defined the load behaviour for power optimisation. The proposed circuit, namely FBRJT, was integrated with the conventional full-bridge rectifier (FBR) in Stage 1 for AC-DC conversion and with the joule thief circuit in Stage 2 for DC-DC conversion. This integration acted as a boost converter without utilising the duty cycles and additional switching components. The electrical nature of the input of FBRJT with a simple structure, sensor-less control and auxiliary circuits showed a consistent agreement with the investigated testing scenarios using both ideal and impedance power sources. Additionally, the performance of the proposed circuit was also verified against the published results of power electronics circuits. The developed versatile circuit and control system can be utilised for many applications, such as mobile battery charging and energy harvesting.

Miniaturised piezoelectric devices are emerging energy harvesting sources that are appropriate for various implantable and wearable applications. However, these piezoelectric devices exhibit considerable internal resistance due to their internal impedance, which leads to self-start and low-energy conversion failures. This paper describes a dual-stage boost converter circuit by facilitating self-powering features and boosting the low voltage harvested by the piezoelectric devices into dc. The proposed circuit comprises conversion stages of ac-dc and dc-dc in Stages I and II, respectively. In addition, the proposed circuit does not require employing the auxiliary circuits to generate the train pulses by triggering the bidirectional switches to envelop the current being stored in Stage II and kick-start the self-powered circuit for piezoelectric energy harvesting systems. Theoretical assumptions and control strategies were tested and verified with ideal and impedance input sources. The proposed circuit could convert a low voltage of 3 V_ac into 19 V_dc. The maximum attained output power by the proposed circuit was 3.61 mW. The outcome depicted that the proposed circuit boosted the low voltage and outperformed the existing literature circuits in terms of output voltage and power.

A comprehensive model for micro-powered piezoelectric generator (PG), analysis of operation, and control of voltage doubler joule thief (VDJT) circuit to find the piezoelectric devices (PD’s) optimum functioning points are discussed in the present article. The proposed model demonstrates the power dependence of the PG on mechanical excitation, frequency, and acceleration, as well as outlines the load behaviour for optimal operation. The proposed VDJT circuit integrates the combination of voltage doubler (VD) and joule thief circuit, whereas the VD circuit works in Stage 1 for AC (alternating current)–DC (direct current) conversion, while a joule thief circuit works in Stage 2 for DC–DC conversion. The proposed circuit functions as an efficient power converter, which converts power from AC–DC and boosts the voltage from low to high without employing any additional electronic components and generating duty cycles. The electrical nature of the input (i.e., PD) of a VDJT circuit is in perfect arrangement with the investigated optimisation needs when using the proposed control circuit. The effectiveness of the proposed VDJT circuit is examined in terms of both simulation and experiment, and the results are presented. The proposed circuit’s performance was validated with available results of power electronics interfaces in the literature. The proposed circuit’s flexibility and controllability can be used for various applications, including mobile battery charging and power harvesting.