1. Date of download: 5/30/2016 Copyright © ASME. All rights reserved. From: Soft Switch Lock-Release Mechanism for a Switch-Mode Hydraulic Pump Circuit J. Dyn. Sys., Meas., Control. 2014;136(3):031003-031003-12. doi:10.1115/1.4026327 Circuit (a) is a generic virtually variable displacement pump circuit. Circuit (b) is equivalent to circuit (a), but uses two 2-way valves instead of a single 3-way valve. The relief valve and check valve illustrate two ways of reducing pressure rises during valve transitions. Circuit (c) illustrates the soft switching concept. Figure Legend:

2. Date of download: 5/30/2016 Copyright © ASME. All rights reserved. From: Soft Switch Lock-Release Mechanism for a Switch-Mode Hydraulic Pump Circuit J. Dyn. Sys., Meas., Control. 2014;136(3):031003-031003-12. doi:10.1115/1.4026327 High-speed valve orifice areas as a function of time during a switching period with a duty cycle of 60%. The vertical gridlines correspond with the beginning and end of each phase of the valve transition. Figure Legend:

3. Date of download: 5/30/2016 Copyright © ASME. All rights reserved. From: Soft Switch Lock-Release Mechanism for a Switch-Mode Hydraulic Pump Circuit J. Dyn. Sys., Meas., Control. 2014;136(3):031003-031003-12. doi:10.1115/1.4026327 Simulation results for the soft switch circuit using the diaphragm, Fig. 3(a), at 60% duty cycle Figure Legend:

4. Date of download: 5/30/2016 Copyright © ASME. All rights reserved. From: Soft Switch Lock-Release Mechanism for a Switch-Mode Hydraulic Pump Circuit J. Dyn. Sys., Meas., Control. 2014;136(3):031003-031003-12. doi:10.1115/1.4026327 Simulation results for the soft switch circuit illustrated in Fig. 3(b) at 60% duty cycle Figure Legend:

5. Date of download: 5/30/2016 Copyright © ASME. All rights reserved. From: Soft Switch Lock-Release Mechanism for a Switch-Mode Hydraulic Pump Circuit J. Dyn. Sys., Meas., Control. 2014;136(3):031003-031003-12. doi:10.1115/1.4026327 Simulation results for the soft switch circuit illustrated in Fig. 3(c) at 60% duty cycle Figure Legend:

6. Date of download: 5/30/2016 Copyright © ASME. All rights reserved. From: Soft Switch Lock-Release Mechanism for a Switch-Mode Hydraulic Pump Circuit J. Dyn. Sys., Meas., Control. 2014;136(3):031003-031003-12. doi:10.1115/1.4026327 Illustrating the implementation of the pressure-release soft switch concept on a virtually variable displacement motor circuit Figure Legend:

7. Date of download: 5/30/2016 Copyright © ASME. All rights reserved. From: Soft Switch Lock-Release Mechanism for a Switch-Mode Hydraulic Pump Circuit J. Dyn. Sys., Meas., Control. 2014;136(3):031003-031003-12. doi:10.1115/1.4026327 Diagrams of the virtually variable displacement pump soft switch circuits a–c Figure Legend:

8. Date of download: 5/30/2016 Copyright © ASME. All rights reserved. From: Soft Switch Lock-Release Mechanism for a Switch-Mode Hydraulic Pump Circuit J. Dyn. Sys., Meas., Control. 2014;136(3):031003-031003-12. doi:10.1115/1.4026327 Cross-sectional view of the novel soft switch lock and release mechanism Figure Legend:

9. Date of download: 5/30/2016 Copyright © ASME. All rights reserved. From: Soft Switch Lock-Release Mechanism for a Switch-Mode Hydraulic Pump Circuit J. Dyn. Sys., Meas., Control. 2014;136(3):031003-031003-12. doi:10.1115/1.4026327 Simulation results for the relief valve circuit illustrating the pressure in the switched volume, flow rate through the various valves, and throttling power loss as a function of time during a single switching cycle at a duty cycle of 60%. Note, the vertical gridlines mark the beginning and end of the valve transitions shown in Fig. 5. Figure Legend:

10. Date of download: 5/30/2016 Copyright © ASME. All rights reserved. From: Soft Switch Lock-Release Mechanism for a Switch-Mode Hydraulic Pump Circuit J. Dyn. Sys., Meas., Control. 2014;136(3):031003-031003-12. doi:10.1115/1.4026327 Results of the simulation for the circuit with a check valve in parallel with the pressure valve at a duty cycle of 60% Figure Legend:

11. Date of download: 5/30/2016 Copyright © ASME. All rights reserved. From: Soft Switch Lock-Release Mechanism for a Switch-Mode Hydraulic Pump Circuit J. Dyn. Sys., Meas., Control. 2014;136(3):031003-031003-12. doi:10.1115/1.4026327 Energy loss during one second of operation for the five circuits as a function of duty cycle Figure Legend:

12. Date of download: 5/30/2016 Copyright © ASME. All rights reserved. From: Soft Switch Lock-Release Mechanism for a Switch-Mode Hydraulic Pump Circuit J. Dyn. Sys., Meas., Control. 2014;136(3):031003-031003-12. doi:10.1115/1.4026327 Fraction of energy loss versus the fraction of energy delivered to the high pressure rail for the five circuits Figure Legend: