摘要:
A power safety system includes a first MOS, a second MOS, a switch and a body controller. The first MOS is connected between a power input and a power output. The second MOSFET is connected between the power output and a charging output. The switch has an end connected to the body of the first MOS, and the opposite end switched between the source and the drain of the first MOS. A body controller controls the switch according to the voltage at the power input and the voltage at the power output, to connect the body of the first MOS to the source or the drain of the first MOS. By switching the switch, the first MOS will have a parasitic diode effective to prevent a reverse current from the power output to the power input.
摘要:
The present invention discloses an overvoltage protection (OVP) circuit for use in a charger circuit system, comprising: a power transistor electrically connected between a voltage supply and a battery; an OVP circuit which turns off the transistor when a voltage supply exceeds a threshold value; and a multiplexing circuit electrically connected between an output of the OVP circuit and the gate of the transistor. The present invention also discloses a charger circuit with an OVP function, comprising: a single power transistor electrically connected between a voltage supply and a battery; an OVP control circuit which turns off the power transistor when a voltage supply exceeds a threshold value; and a charger control circuit which controls the gate of the power transistor to determine a charge current to the battery when the voltage supply does not reach the threshold value.
摘要:
The present invention discloses an overvoltage protection (OVP) circuit for use in a charger circuit system, comprising: a power transistor electrically connected between a voltage supply and a battery; an OVP circuit which turns off the transistor when a voltage supply exceeds a threshold value; and a multiplexing circuit electrically connected between an output of the OVP circuit and the gate of the transistor. The present invention also discloses a charger circuit with an OVP function, comprising: a single power transistor electrically connected between a voltage supply and a battery; an OVP control circuit which turns off the power transistor when a voltage supply exceeds a threshold value; and a charger control circuit which controls the gate of the power transistor to determine a charge current to the battery when the voltage supply does not reach the threshold value.
摘要:
A charger for a portable device includes a USB detector connected to a data pin to detect the effective resistance on the data pin before a USB transceiver is enabled, to identify USB or adapter plug in and control a charging current for a battery accordingly.
摘要:
A charging circuit with an application system thereof provides an error amplifier to control a transistor switch for controlling the charging power source to charges the battery. When the voltage difference between the power source and load terminals of the transistor switch drops along with the transistor switch being turned on, the output voltage of the error amplifier changes as well to increase the turning-on resistance of the transistor switch such that the voltage difference between the power source and load terminals is capable of maintaining at a value above a certain reference level for avoiding the unstable state resulting from the charging circuit being turned on and off frequently.
摘要:
A charger for a portable device includes a USB detector connected to a data pin to detect the effective resistance on the data pin before a USB transceiver is enabled, to identify USB or adapter plug in and control a charging current for a battery accordingly.
摘要:
A charger for a portable device includes a USB detector connected to a data pin to detect the effective resistance on the data pin before a USB transceiver is enabled, to identify USB or adapter plug in and control a charging current for a battery accordingly.
摘要:
The present invention discloses a charge control circuit for supplying power from an external power source to a first common node and charging a second common node from the first common node. A regulator circuit is coupled between the external power source and the first common node, and a transistor is coupled between the first common node and the second common node. The present invention detects an operation parameter of the transistor and controls an internal voltage source to generate a non-predetermined voltage difference accordingly. When the sum of the voltage at the second common node and the non-predetermined voltage is equal to or higher than the reference voltage, the voltage at the first common node is regulated to a level higher than the voltage at the second common node, and the transistor is in an optimum conductive state.
摘要:
The present invention discloses a charge control circuit for supplying power from an external power source to a first common node and charging a second common node from the first common node. A regulator circuit is coupled between the external power source and the first common node, and a transistor is coupled between the first common node and the second common node. The present invention detects an operation parameter of the transistor and controls an internal voltage source to generate a non-predetermined voltage difference accordingly. When the sum of the voltage at the second common node and the non-predetermined voltage is equal to or higher than the reference voltage, the voltage at the first common node is regulated to a level higher than the voltage at the second common node, and the transistor is in an optimum conductive state.
摘要:
Systems and methods are disclosed for rendering a presentation document on a plurality of client computing devices by a server. A method includes creating a base layer for a page in the presentation document, wherein the base layer comprises a plurality of placeholder elements wherein each placeholder element has an absolute position and size. The method further includes creating an interactive layer for the page in the presentation document, wherein the interactive layer comprises a plurality of interactive element overlays representing a plurality of interactive elements and each interactive element overlay has an absolute position and size that corresponds to the absolute position and size of a placeholder element in the base layer. The method further includes sending the base layer and interactive layer of the page to each client computing device for rendering, wherein each interactive element overlay is rendered on top of its corresponding placeholder element.