Abstract: A drive circuit drives a normally-on high-side switch Q1 and a normally-off low-side switch Q2 that form a series circuit connected in parallel with a DC power source. The drive circuit includes a controller 10 that outputs a control signal to turn on/off the high- and low-side switches, a rectifier D2 having a first end connected to a connection point of the high- and low-side switches, a capacitor C2 that is connected to a second end of the rectifier and a first end of the DC power source and serves as a power source for the controller, and a driver (A1, AND1, Q3, Q4) that turns on/off the high- and low-side switches according to the control signal from the controller and a voltage from the capacitor.

Abstract: A gate driver of a switching element includes a first capacitor having a first end connected to a DC power source, a first switch having a first electrode connected to the first end of the first capacitor and a second electrode connected to a negative electrode of the DC power source, a second switch having a third electrode connected to the second electrode and the negative electrode of the DC power source and a fourth electrode connected to the first capacitor, a second capacitor connected in parallel with the third and fourth electrodes of the second switch and having a first end connected to the DC power source, and a negative voltage controller connecting the gate of the switching element to the second end of the first capacitor and a second end of the second capacitor when the switching element is turned off.

Abstract: A drive circuit drives a normally-on high-side switch Q1 and a normally-off low-side switch Q2 that form a series circuit connected in parallel with a DC power source. The drive circuit includes a controller 10 that outputs a control signal to turn on/off the high- and low-side switches, a rectifier D2 having a first end connected to a connection point of the high- and low-side switches, a capacitor C2 that is connected to a second end of the rectifier and a first end of the DC power source and serves as a power source for the controller, and a driver (A1, AND1, Q3, Q4) that turns on/off the high- and low-side switches according to the control signal from the controller and a voltage from the capacitor.

Abstract: A gate driver of a switching element includes a first capacitor having a first end connected to a DC power source, a first switch having a first electrode connected to the first end of the first capacitor and a second electrode connected to a negative electrode of the DC power source, a second switch having a third electrode connected to the second electrode and the negative electrode of the DC power source and a fourth electrode connected to the first capacitor, a second capacitor connected in parallel with the third and fourth electrodes of the second switch and having a first end connected to the DC power source, and a negative voltage controller connecting the gate of the switching element to the second end of the first capacitor and a second end of the second capacitor when the switching element is turned off.

Abstract: A light-sensitive heat-sensitive recording material is disclosed, which contains microcapsules resulting from a solution containing at least one component capable of undergoing color development or achromatization as a core material of the microcapsules and a volatile solvent which has a water solubility of 10% by volume or less and has a low boiling point such that it volatilizes during a process for preparing said light-sensitive heat-sensitive recording material leaving substantially no trace of the solvent in the resulting recording material. As the microcapsules, ones having a mean particle size of 2 .mu.m or less are preferred, and ones prepared using a modified gelatin as a protective colloid are also preferred. Further, as the support of the light-sensitive heat-sensitive recording material, a polyester support filled with a white pigment can preferably be used.