A hybrid power supply type injection molding machine system has a motor-driven injection molding machine body including an injection mechanism and a mold clamping mechanism that are driven by servo-motors; a control device giving a command to said servo-motors to drive said injection mechanism and said mold clamping mechanism in accordance with predetermined program commands; and an electric power supply device for supplying said motor-driven injection molding machine body with the electric power required for operating said motor-driven injection molding machine body, said electric power supply device including: a first electric power supply unit for supplying the electric power from a commercial power source; a second electric power supply unit having an electric power accumulation unit dedicated to said motor-driven injection molding machine; an electric power comparator for comparing outputs of said first and second electric power supply units; and a switching device for switching over a supply of the electric power given to said second electric power supply unit from said first electric power supply unit in response to a result of the comparison by said electric power comparator under predetermined conditions.

A state of a plurality of switches for performing application and cutoff of a plurality of electrical loads is stored in a memory circuit. A pattern of supply power after application of the load for each of the plurality of electrical loads and a load response priority order assigned previously to each of the electrical loads are stored in a memory table. A control circuit identifies a newly applied load on the basis of the turned-on state of the plurality of switches stored in the memory circuit and instructs an electric power supply circuit to supply electric power in accordance with the supply power pattern corresponding to the identified load, while the control circuit prohibits application of the newly applied electrical load when an electrical load having the load response priority order higher than that of the newly applied electrical load has been already applied. The memory table may store consumption power and an application priority order assigned previously to each of the electrical loads. In this case, a total amount of consumption power of the applied electrical loads is calculated. When an electrical load having the application priority order lower than that of the newly applied electrical load has been already applied and the control circuit judges that the total amount of consumption power of the applied electrical loads exceeds a predetermined value, the control circuit instructs to cut off the electrical load having the lower application priority order.

A combination battery includes a plurality of cells connected together in series. A switching element operates for selectively blocking and unblocking a power feed path between the combination battery and a load. The switching element is changed to its on state when receiving a drive voltage. When a starting switch is moved to its on position, a drive circuit is connected with at least one cell among the cells in the combination battery and uses the at least one cell as a power source to generate the drive voltage applied to the switching element. A power supply circuit receives an output voltage from the combination battery and starts to operate when the switching element is changed to its on state. At a later moment, a power source for setting the switching element in its on state is changed from the at least one cell to the power supply circuit.

In the case of an electrical wiring for a motor vehicle having a primary system which includes a voltage-controlled generator, a primary energy accumulator as well as at least one primary energy consuming device, and having a paralleled secondary system which includes a secondary energy accumulator as well as at least one secondary energy consuming device, the secondary system includes a control unit with a controllable resistor connected to the generator. The control unit monitors the charge condition of the secondary energy accumulator. As a function of the currently determined charge condition of the secondary energy accumulator, the control unit, on the one hand, controls the controllable resistor in such a manner that, during the charging of the secondary energy accumulator, the primary system is not overloaded. Furthermore, the control unit connects and disconnects the secondary energy consuming device or devices in such a manner that, during the discharging of the secondary energy accumulator, there is no falling below a predetermined residual charge value.

The voltage supply device for the motor vehicle electrical system includes e.g. a self- or separately-excited generator having stator windings (10,11,12) and an excitation coil (E); a main bridge rectifier device connected to the stator windings having a first connector (B+) at which a first voltage (UB+) is delivered; an exciter bridge rectifier device connected to the stator windings; an exciter voltage regulator device connected between the exciter bridge rectifier device and the excitation coil (E) for regulation of an excitation current passing through the excitation coil; an additional rectifier device connected to the stator windings (10,11,12) having a second connector (B2+) at which a second voltage (UB2+) is tapped and a device for regulating a load current delivered by the generator to the first connector (B+) or the second connector (B2+) that includes a thyristor (Th0,Th4) connected to the first or second connector and a triggering device (A) whereby the generator has an optimal power output. During full load operation the load current is limited with the load current regulating device, while during partial load operation the exciter current is regulated by the exciter voltage regulator device. The invention can also be applied to voltage supply systems with permanently excited generators.