Abstract: A toy helicopter with four electric motors having a main body, at least one battery, and front and rear coaxial rotor assemblies. The front coaxial rotor assembly is made up of front upper and lower rotors and a front stabilizing bar operatively connected to the front upper rotor. The rear coaxial rotor assembly is made up of rear lower and upper rotors and a rear stabilizing bar operatively connected to the rear upper rotor. The helicopter includes a means for concentrically rotating the front lower and upper rotors in opposite directions and a means for concentrically rotating the rear lower and upper rotors in opposite directions. The means for concentrically rotating the front lower and upper rotors in opposite directions includes first and second front electric motors, and the means for concentrically rotating the rear lower and upper rotors in opposite directions includes first and second rear electric motors.

Abstract: An electrostatic discharge protection circuit has a substrate; a first P-well installed on the substrate and having a first P+-doped region and a first N+-doped region, both of which are connected to ground; a second P-well installed on the substrate and having a second P+-doped region and a second N+-doped region, both of which are connected to a power supply voltage; and a third P-well installed on the substrate and having a third N+-doped region, a third P+-doped region, and a fourth N+-doped region, all of which are for input/output signals.

Abstract: A toy helicopter with four electric motors having a main body, at least one battery, and front and rear coaxial rotor assemblies. The front coaxial rotor assembly is made up of front upper and lower rotors and a front stabilizing bar operatively connected to the front upper rotor. The rear coaxial rotor assembly is made up of rear lower and upper rotors and a rear stabilizing bar operatively connected to the rear upper rotor. The helicopter includes a means for concentrically rotating the front lower and upper rotors in opposite directions and a means for concentrically rotating the rear lower and upper rotors in opposite directions. The means for concentrically rotating the front lower and upper rotors in opposite directions includes first and second front electric motors, and the means for concentrically rotating the rear lower and upper rotors in opposite directions includes first and second rear electric motors.

Abstract: An electrostatic discharge protection circuit has a substrate; a first P-well installed on the substrate and having a first P+-doped region and a first N+-doped region, both of which are connected to ground; a second P-well installed on the substrate and having a second P+-doped region and a second N+-doped region, both of which are connected to a power supply voltage; and a third P-well installed on the substrate and having a third N+-doped region, a third P+-doped region, and a fourth N+-doped region, all of which are for input/output signals.

Abstract: The invention is directed to an electric device featuring a ground shield structure. The electric device at lease comprises a plurality of first ground cells and a plurality of second ground cells. The first ground cells are distributed on a ground surface, wherein the first ground cell has at least one first outward section and at least one first inward section. The second ground cells are distributed on the ground surface, wherein the second ground cell has at least one second outward section and one second outward section of one second ground cell is compactly and complementarily embraced by one first inward section of one adjacent first ground cell.

Abstract: An oxygen absorbing appliance includes a container body having a bottom wall, a peripheral wall and a peripheral rim. The appliance further includes a closure member to matingly engage the peripheral rim. The appliance further includes an oxygen absorber composition for removing oxygen within the container and an oxygen detector circuit for indicating the presence or absence of oxygen.

Abstract: An electrostatic discharge protection circuit has a substrate; a first P-well installed on the substrate and having a first P+-doped region and a first N+-doped region, both of which are connected to ground; a second P-well installed on the substrate and having a second P+-doped region and a second N+-doped region, both of which are connected to a power supply voltage; and a third P-well installed on the substrate and having a third N+-doped region, a third P+-doped region, and a fourth N+-doped region, all of which are for input/output signals.

Abstract: A ground shield structure is suitable for use in a circuit structure. The ground shield structure has a plurality of ground cells that are arranged on a ground plane periodically, compactly and complementarily. The slots between the ground cells are used to reduce the eddy current generated on the ground shield structure. The ground shield structure increases the slow-wave factor to slow the waves so that the area of the circuit layout can be decreased. Besides, the ground shield structure can reduce the energy loss of the inner circuit of the circuit structure and can increase the quantities of inductance and capacitance in per unit area thereon.