JPH03107333A - Power supply - Google Patents

Abstract

PURPOSE:To enable stable power to be supplied without generating a rush current by controlling a voltage controlled current source through a voltage control means to gradually increase an inflow current to a load circuit through the voltage controlled current source from a power supply when it is switched in. CONSTITUTION:When a switch 2 is closed from its open state, voltage across a capacitor 3 is changed from 0 to the voltage of a DC power supply 1 by constitution of a charging circuit with a resistor 4. The inflow current to a load circuit 6 from a voltage controlled current source, being controlled by the voltages across the capacitor 3, is changed from 0 to a steady consumption current value of the load circuit 6. Accordingly, because a change rate of the inflow current to the load circuit 6 from the above mentioned voltage controlled current source can be arbitrarily set by a time constant of the capacitor 3 and the resistor 4, generation of a rush current can be eliminated when the power supply is turned on by closing the switch 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a power supply circuit that distributes and supplies DC power to a plurality of loads.

(Prior Art) Figure 3 is a circuit diagram of a conventional power supply circuit equipped with an inrush current prevention circuit. In the figure, (1) is a DC power supply, (2) is a switch, (6) is a load circuit, and (7) is a ) indicates a relay, (8) indicates a relay contact, (9) indicates a resistor connected in parallel to the relay contact (8), and each load circuit (6) is connected to a switch (
2) and a resistor (9) connected in parallel with the relay contact (8)
It is connected in parallel to the DC power source (1) in order to receive power supply from the DC power source (1) via the DC power source (1).

Next, the operation will be explained. Each load circuit (6) is
A plurality of DC power sources are connected in parallel to receive power, and the connection to the DC power source (1) is controlled by a switch (2). A relay (
A relay contact (8) whose opening/closing is controlled by a relay contact (8) and a resistor (9) connected in parallel with the relay contact (8) are provided.

Here, if only one switch (2) is open and all other switches (2) are closed, if the open switch (2) is closed, immediately after switch (2) is closed, Since the relay contact (8) is open, current is supplied from the DC power source (1) to the load circuit (6) through the resistor (9). Then, the load circuit (
When the charging of 6) has progressed to a certain extent, the relay (7) operates to close the relay contact (8), and the DC power source (1) and the load circuit (6) are directly connected.

[Problem to be solved by the invention]

Conventional power supply circuits are configured as described above, so if the time between closing the switch (2) and closing the relay contact (8) is short, the load circuit (6) cannot be fully charged and the relay contact When (8) is closed, an inrush current is generated, causing power fluctuations, which may cause malfunctions in the load circuits connected in parallel.Also, if all switches (2) are closed at the same time, the relay contacts (8) are also closed at the same time. There were problems such as inrush current occurring when closed.

The present invention was made in order to solve the above-mentioned problems, and an object of the present invention is to provide a power supply circuit that can supply stable power without generating rush current.

[Means to solve the problem]

The power supply circuit according to the present invention is a power supply circuit that distributes and supplies DC power to a plurality of loads connected in parallel, and includes a power-on switch between the DC power supply and each load circuit, and a power-on switch that controls inrush current when the power is turned on. The present invention further includes a voltage controlled current source for controlling the voltage controlled current source, and voltage control means for controlling the voltage controlled current source.

[Effect]

In this invention, the voltage control means controls the voltage controlled current source so that when the power is turned on, the current flowing from the power source into the load circuit via the voltage controlled current source is gradually increased.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, (1) is a DC power supply, (2) is a power supply switch, (3) is a capacitor, (4) is a resistor, (5) is a field effect transistor, and (6) is a load circuit. (2) A configuration including a capacitor (3), a resistor (4), a field effect transistor (5), and a load circuit (6) is connected in parallel to a DC power source (1), and the field effect transistor (5) is A voltage controlled current source is constituted, and the capacitor (3) and the resistor (4) constitute voltage control means.

Furthermore, FIG. 2 shows the characteristics of the gate-source voltage versus drain current of the field effect transistor (5), and this second
As can be understood from the figure, the field effect transistor (5)
The capacitor (3) is connected between the gate and source of the field effect transistor (5) so that the voltage across the capacitor (3) is set to a voltage. This becomes the control voltage for the control current source.

Next, the operation will be explained. When the switch (2) is opened and then closed, the voltage across the capacitor (3) changes from O to the DC power source ( due to the charging circuit configuration with the resistor (4).
The voltage changes up to 1). Also, it is controlled by the voltage across the capacitor (3), and the load circuit (6
) changes from 0 to the steady current consumption value of the load circuit (6). Therefore, since the rate of change of the current flowing from the voltage controlled current source into the load circuit (6) can be set arbitrarily by the time constants of the capacitor (3) and resistor (4), the switch (2) is closed and the power is turned on. It is possible to eliminate the generation of inrush current when the power is turned on.

In addition, in the above embodiment, a case was shown in which a DC positive power supply was used as the DC power supply (1), but a DC negative power supply may also be used.
When using a DC negative power supply, the same effect as in the above embodiment can be obtained by changing the field effect transistor from a P-channel type to an N-channel type.

(Effects of the Invention) As described above, according to the present invention, a voltage-controlled current source and a voltage control means are provided between a power supply and a load circuit, so that the current flowing from the current into the load circuit can be controlled. This has the effect of preventing the generation of inrush current when the power is turned on.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram according to an embodiment of the present invention, FIG. 2 is a characteristic diagram showing the gate-source voltage versus drain current characteristic of a field effect transistor, and FIG. 3 is a circuit diagram of a conventional example. (1) is a DC power supply, (2) is a switch, (3) is a capacitor, (4) is a resistor, (5) is a field effect transistor,
(6) is a circuit, (7) is a relay, (8) is a relay, and (9) is a resistance. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] In a power supply circuit that distributes and supplies DC power to multiple loads connected in parallel, a power-on switch and a voltage-controlled current source are provided between the DC power supply and each load circuit to control the rush current when the power is turned on. , A power supply circuit comprising voltage control means for controlling the voltage-controlled current source.