JPH04334927A - Power source for automotive electric accessory unit - Google Patents

Abstract

PURPOSE:To reduce a space, a weight and a cost of a power source in an automotive electric accessory unit by distributing an output of a protective circuit of the unit to not only the unit but also a control power source circuit of the other unit. CONSTITUTION:For example, electric accessory units 1A, 1B belong to a B system power source, power B is supplied to the unit 1A having a protective circuit through wirings 31, and power fed through the protective circuit of the unit 1A is supplied to the unit 1B having no protective circuit through wirings 32. Similarly, units 1C-1E belong to an IG system, ignition powder IG is supplied to the unit 1C having the protective circuit though wirings 33, and power fed through the protective circuit of the unit 1C is supplied to units 1D, 1E having no protective circuit through wirings 34. Thus, a power source of automotive electric accessory units is reduced in size and weight.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device for various on-vehicle electrical units mounted on a vehicle, and more particularly to a power supply device that is smaller and lighter by sharing a protection circuit.

0002

2. Description of the Related Art In recent years, vehicles have tended to be equipped with various on-vehicle electrical units (control units) due to the diversification of controls. For example, engine control units that control ignition timing and fuel injection, and AB that prevents brakes from locking.
Typical examples include the S unit, an auto cruise unit that enables constant speed driving, a suspension control unit that adjusts the strength and balance of the suspension, and digital meters that display various numerical values.

As shown in FIG. 8, all units of this type use the vehicle's battery 10 as an operating power source, and some of these units are directly connected to the battery 10 like units 1A and 1B (B system), and others are connected directly to the battery 10 like units 1A and 1B. Some, such as 1C, 1D, and 1E, are supplied with power when necessary through the ignition switch IG in the ignition key cylinder 14 (IG system). In addition to this, there is also a system (ACC system) that is supplied with power through the accessory switch ACC, but it is omitted here. Note that 11 is an alternator, 12 is a fusible link, and 13 is a fuse.

[0004] The units 1A, 1B, etc. described above have a common configuration in which they perform predetermined processing based on input data from a plurality of sensors and output various actuator outputs, as shown in the units 1 and 1' in FIG. However, the power input may be one system as in the unit 1, or the power source for power and the power source for control may be input separately as in the unit 1'.

[0005] Since these external power supplies have large fluctuations and are contaminated with various noises, they must be stabilized to a desired voltage value in the power supply device in the unit before use. Figure 10
is an example of this type of power supply device. This device includes a 5V controlled power generation circuit 20 that generates a stabilized voltage. This circuit 20 includes capacitors C1 to C6 and resistors R1 to
This control power supply circuit is composed of R4, an integrated circuit IC1, and a transistor TR1, and outputs a +5V stabilized power supply from the collector side of the transistor TR1.

The integrated circuit IC1 is for controlling the transistor TR1, and includes an input terminal BI, a control output terminal OUT, a comparison input terminal C, a power supply terminal VCC, a clock terminal CK, a reset terminal RS, and the like. In general, in-vehicle power supplies generate transient voltages during load dumps, when the ignition switch is turned off, and when various inductive loads (relays and solenoids) are turned off. It is customary to provide a similar protection circuit 21 at the input stage. The protection circuit 21 in the figure is made up of a diode D1, a surge absorber D2, and a coil L1, and the output voltage (+12V) of this protection circuit 21 is input to the 5V control power generation circuit 20.

[0007]

[Problems to be Solved by the Invention] Incidentally, the above-mentioned power supply device is, in principle, built into each unit. This is because the user selects which units to install, and the conditions under which each unit is used may differ.

However, when actually assembling the power supply device shown in FIG. 10, its layout becomes large in area as shown in FIG. 11. In particular, the area occupied by the protective circuit components L1, D1, and D2 is approximately 20 x 25 mm2, so when N units are installed, the total area is 20 x 25 x N mm2.
space. As a result, the component mounting board and case become larger and the weight of the unit increases. In addition, the large number of parts reduces reliability and increases costs.

An object of the present invention is to reduce the space, weight, and cost of an in-unit power supply device by sharing a protection circuit.

0010

[Means for Solving the Problems] In order to achieve the above object, in the present invention, in a power supply device for a plurality of on-vehicle electrical units operated by a vehicle battery, a protection circuit is provided in the control power supply circuit of some of the on-vehicle electrical units. The present invention is characterized in that the output of the protection circuit of some of the on-vehicle electrical units is branched and inputted without providing a protection circuit in the control power supply circuit of the other on-vehicle electrical units.

[0011]

[Operation] Since the power supply for control of an on-vehicle electrical unit generally has a small capacity, the output of the protection circuit of one unit can be distributed not only to the unit concerned but also to the power supply circuit for control of other units. Therefore, a protection circuit can be omitted on the side of the unit receiving the distribution, so space, weight, and cost can be reduced accordingly, and reliability can be expected to improve as the number of parts decreases. In addition, when driving a load from the unit, prepare a large-capacity load power source separate from the control power source. This is the same as before.

0012

Embodiment FIG. 1 is a block diagram of a first embodiment of the present invention. The in-vehicle electrical unit of this example is divided into groups for each power supply system B, ACC, and IG, and within each group, power is relayed through a protection circuit from a unit with a protection circuit to a unit without a protection circuit. For example, units 1A and 1B belong to the B power supply, and the wiring 3 to unit 1A, which has a protection circuit.
power supply B via 1 and unit 1 without protection circuit.
Power is supplied to B via the wiring 32 through the protection circuit of the unit 1A. Similarly, the IG system has unit 1C.
~1E belongs to which unit 1C has a protection circuit.
The ignition power supply IG is supplied to the units 1D and 1E via the wiring 33, and the power that has passed through the protection circuit of the unit 1C is supplied to the units 1D and 1E without a protection circuit via the wiring 34.

FIG. 2 is a circuit diagram of a power supply device (referred to as type a) built into the units 1A and 1C. This type A power supply device has a 5V control power generation circuit 20 and a protection circuit 21 similar to those shown in FIG. However, it differs from FIG. 10 in that it is configured so that the wirings 32 and 34 distributed to the units 1B, 1D, and 1E without a protection circuit are drawn out.

FIG. 3 shows units 1B and 1D without a protection circuit.
, 1E is a circuit diagram of a built-in power supply device (referred to as type b). This type B power supply device is the 5V control power generation circuit 2 in Figure 2.
The input is supplied from the type A power supply device in FIG. 2 through wirings 32 and 34.

FIG. 4 is a block diagram of a second embodiment of the present invention. In this example, power is supplied from unit 1A to all other units 1B to 1E via wiring 32. In this case, the unit 1A has a built-in type a power supply device shown in FIG. 2, and the unit 1B has a built-in type b power supply device shown in FIG. The remaining units 1C to 1E incorporate type c power supply devices shown in FIG.

This C-type power supply device adds a switching transistor TR2 to the B-type power supply device shown in FIG. That is, the transistor TR2 is
When the G signal is turned on, it is turned on, and power is supplied from the type A power supply device via the wiring 32 to the 5V control power generation circuit 20 at the subsequent stage. Since this transistor TR2 is turned off when the IG signal is turned off to disconnect the 5V control power supply generation circuit 20, the substantive grouping is the same as in the first embodiment shown in FIG.

FIG. 6 is a block diagram of a third embodiment of the present invention. In this example, the unit 1C has a built-in type d power supply device shown in FIG. This d-type power supply device is based on the c-type power supply device shown in FIG. 5, with a branch wiring 34 derived from the output side of the switching transistor TR2. This wiring 34 is b
This is the power input line for units 1D and 1E that have built-in power supplies. Therefore, in this example, all the units 1C to 1E belong to the IG system only by the switch function of the unit 1C. In addition, unit 1A has a built-in class A power supply device,
The power output through the protection circuit is supplied to the unit 1B containing the B-type power supply device and the unit 1C containing the D-type power supply device.

[0018]

As described above, according to the present invention, the power supply device of an on-vehicle electrical unit can be made smaller and lighter. In addition, reliability is improved by reducing the number of parts.
Cost reduction can be achieved.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of Embodiment 1 of the present invention.

FIG. 2 is a circuit diagram of a class A power supply device.

FIG. 3 is a circuit diagram of a class B power supply device.

FIG. 4 is a configuration diagram of Embodiment 2 of the present invention.

FIG. 5 is a circuit diagram of a class c power supply device.

FIG. 6 is a configuration diagram of Embodiment 3 of the present invention.

FIG. 7 is a circuit diagram of a class D power supply device.

FIG. 8 is a diagram of a conventional vehicle power distribution circuit.

FIG. 9 is a partial detailed view of FIG. 8.

FIG. 10 is a circuit diagram of a conventional in-unit power supply device.

FIG. 11 is a component layout diagram of FIG. 10.

[Explanation of symbols]

1A to 1E...In-vehicle electrical unit, 10...Battery, 20
...5V control power supply generation circuit (control power supply circuit), 21...protection circuit, 31-34...wiring.

Claims (1)

[Claims] [Claim 1] In a power supply device for a plurality of in-vehicle electrical units operated by a vehicle battery, a protection circuit is provided in the control power supply circuit of some of the in-vehicle electrical units, and a protection circuit is provided in the control power supply circuit of the other in-vehicle electrical units. without a protection circuit,
A power supply device for a vehicle-mounted electrical unit, characterized in that the output of a protection circuit of some of the vehicle-mounted electrical units is branched and inputted.