JP2832446B2 - Power supply device for facsimile on vehicle - Google Patents

Description

The present invention relates to an on-vehicle facsimile power supply device, and more particularly to a power supply for a starter when an engine is started and an ignition key switch in an ignition position. When a vehicle is equipped with a power supply battery (main power supply battery) that supplies power to various electric devices on the vehicle when the ignition switch is on or the accessory position is on (accessory switch on), power is supplied to a facsimile also mounted on the vehicle. Power supply device.

(Prior Art) Japanese Utility Model Laid-Open No. 60-144730 discloses that an auxiliary secondary battery is mounted on a vehicle, and when an ignition switch is turned on, power is supplied from a main power supply battery to an on-vehicle electrical unit. When the power supply is off, a power supply device on a vehicle is disclosed, in which power is supplied from an auxiliary secondary battery and the auxiliary secondary battery is constantly charged via a charging circuit.

Japanese Utility Model Application Laid-Open No. 62-74455 discloses that the specific gravity of the electrolyte in the main power battery is detected, and when the specific gravity of the electrolyte in the main power battery exceeds a set value when the ignition switch is turned off (engine stopped). A power supply protection circuit on a vehicle for disconnecting a power supply battery from a load on the vehicle is disclosed.

Japanese Utility Model Laid-Open No. 62566/1987 discloses a single-wire connection between a voltage detection circuit block for detecting the voltage of a main power supply battery and a facsimile operation control circuit block.

[Problems to be solved by the invention]

As described above, when the ignition switch is on, power is supplied from the main power supply battery to the on-vehicle electrical unit, and when the ignition switch is off, power is supplied from the auxiliary secondary battery, and a facsimile is mounted on the vehicle. Therefore, according to these matters, the facsimile on the vehicle is supplied with power from the main power supply battery to the facsimile when the ignition switch is turned on (during engine operation) and turned off (engine stopped) when the ignition switch is turned on (during engine operation). Sometimes power is supplied from an auxiliary secondary battery,
In addition, it is presumed that the auxiliary secondary battery can be easily charged from the main power supply battery via the charging circuit.

In such an on-vehicle facsimile power supply, however, when the ignition switch is on (during engine operation), if facsimile communication and auxiliary secondary battery charging overlap, the load on the main power supply battery and the alternator (engine) will increase. It can be overkill.

For example, in facsimile reception, power consumption is much higher during reception than during transmission, such as when the recording power for thermal recording is large, and high power consumption occurs when the recording density is high, and low power consumption occurs when the recording density is low. Power consumption. Also in the charging of the auxiliary secondary battery, the initial voltage of the auxiliary secondary battery at the start of charging (when the ignition switch is turned from off to on) is equal to the off-time of the ignition switch (discharge time of the auxiliary secondary battery). Due to the length of the facsimile communication during the off-time and the amount of facsimile communication during the off-time, etc., there is a large variation between high and low, and the charging current at the start of charging varies large and small, and the charging current decreases as charging progresses. The charging current also varies depending on the elapsed time (the elapsed time since the ignition switch was turned on from off).

Accordingly, in the worst case, for example, the auxiliary secondary battery is greatly consumed, and when the ignition switch is turned on, an excessive charging current flows to the auxiliary secondary battery. When this charging is started, facsimile reception starts. If the facsimile power consumption is large due to the relatively high density recording performed, the load on the main power supply battery and the alternator (generator) that charges the main power supply battery is large, and the load on the alternator is also the load on the engine that drives the alternator. Therefore, the loads on the main power supply battery, the alternator, and the engine become excessive. At this time, if the amount of residual electricity of the main power supply battery is also low, a larger load is applied to the alternator and the engine. If such an overload is applied immediately after the ignition switch is switched from off to on, the startability of the engine, warm-up operation, and vehicle starting performance are impaired. Further, troubles in the electric circuit are likely to occur due to the overload current of the main power supply battery line.

In accordance with the teachings of Japanese Utility Model Application Laid-Open No. 62-74455, when the main power battery is consumed to some extent, if the main power battery is cut off from the facsimile, facsimile communication is not performed.

SUMMARY OF THE INVENTION It is an object of the present invention to prevent overload of a main power supply battery line and to enable facsimile communication at all times at least during operation of an engine.

[Configuration of the invention]

(Means for Solving the Problems) The present invention provides an auxiliary secondary battery (ABA); a power supply line (PSL) to a facsimile (FAX) on a vehicle, a main power battery (+ Bm) on the vehicle and an auxiliary secondary battery (AB). (ABA); a power connection means (10) for selectively connecting to the power supply line (PSL); a load detection means (20) for detecting a load on the power supply line (PSL); When the load is small corresponding to the load detected by (20), a charging connection is made from the on-vehicle main power supply battery (+ Bm) to the auxiliary secondary battery (ABA), and when the load is large, charging control means (50) restricts the charging connection. );
Further, while the on-vehicle main power switch (Ig) is closed, the power supply connection means (10) is set to a connection between the power supply line (PSL) and the on-vehicle main power battery (+ Bm), and the on-vehicle main power switch (Ig) is set.
Is switched from closed (H) to open (L), the power connection means (1
0) is defined as the connection between the power supply line (PSL) and the auxiliary secondary battery (ABA). The symbols in parentheses indicate the corresponding elements or the corresponding potentials of the embodiment described later shown in the drawings.

(Operation) According to the present invention, while the on-vehicle main power switch (Ig) is closed (during engine operation), the connection control means (100, 80) connects the power supply connection means (10) to the power supply line (PSL). -Since the main power supply battery (+ Bm) on the vehicle is connected, the facsimile is connected to the main power supply battery (+ Bm) while the main power switch (Ig) is closed.
Bm).

Thus, while the main power switch (Ig) is closed, the charging control means (50) determines whether the load on the vehicle main power supply (+) is low when the load is small corresponding to the load detected by the load detection means (20).
Bm) is connected to the auxiliary secondary battery (ABA), and when the load is large, the charging connection is restricted.

Therefore, overload of the main power supply battery and the alternator (and engine) connected thereto is prevented, and the auxiliary secondary battery is charged when the facsimile load is low. It is almost impossible to continue facsimile reception continuously during vehicle operation (during engine operation). For example, when facsimile communication is not performed, facsimile transmission is performed, or when power consumption is small even in facsimile reception, The auxiliary secondary battery is charged. As a result, when the main power switch (Ig) is on (while the engine is running), facsimile communication is always possible and facsimile transmission and reception requiring urgency are not hindered. The auxiliary secondary battery is also charged without applying a load.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

(Embodiment) FIG. 1 shows an embodiment of the present invention. A power supply connection circuit 10 is interposed between a power supply line PSL and a main power supply input terminal MBT to which a positive pole of an on-vehicle main power supply battery (not shown) is connected. The power supply line PSL is connected to a power output terminal OUT to which a telephone TEL, a facsimile FAX and a vehicle-mounted wireless communication mobile device (not shown) are connected via a current value detecting resistor 21 of a current monitoring circuit 20. Have been. An auxiliary power supply line ABL is connected to an auxiliary power input terminal APT to which an auxiliary battery ABA added according to the present invention is connected via a fuse for overcurrent protection.

Power supply connection circuit 10: The power supply connection circuit 10 connects the main power supply line MBL to the main power supply input terminal MBT.
Connect the main power supply relay 13 and the power supply line PSL to the main power supply line M.
It includes a switching relay 11 selectively connected to the BL and the auxiliary power supply line ABL. When transistor 14 is on (conducting), relay 13 is closed, and when transistor 12 is off, relay 11 is MBL / PSL.
It is a connection, but when it is turned on, it switches to an ABL / PSL connection.
The relationship between ON / OFF of the transistors 14 and 12 and the power supply for supplying power to the power supply line PSL is as shown in Table 1 below.

The base of the transistor 14 has an accessory switch input terminal ACT connected to a closed accessory switch when the ignition key switch is in the accessory position (engine stopped) or the ignition position (engine running).
When the accessory switch is closed (when the engine is stopped or operating), a positive voltage is applied to the base of the transistor 14 and the transistor 14 is turned on. When the ignition key switch is not in either the accessory position or the ignition position, the terminal ACT
Is at the equipment ground level, and the transistor 14 is off.

The output signal () of the automatic answering instruction circuit 80 is applied to the base of the transistor 12. When the signal is high, the transistor 12 is on, and when low, the transistor 12 is off.

Current monitoring circuit 20: The current monitoring circuit 20 monitors a current value flowing through the power supply line PSL, that is, a current flowing through the telephone TEL and the facsimile FAX (hereinafter referred to as a facsimile load current). A voltage proportional to the current value appears between both terminals of the resistor 21, and the amplifier 22 outputs a current having a level proportional to the potential on the high voltage side (10 side) of the resistor 21, and the amplifier 23 outputs the current at the low voltage side (FAX side) of the resistor 21. ) Are supplied to the positive input terminal (+) and the reverse polarity input terminal (-) of the operational amplifier 24, respectively, and the operational amplifier 24 is proportional to the voltage drop (current value) of the resistor 21. The level voltage is given to the comparator 25. The comparator 25 determines that the voltage drop (current value) 25 is equal to the first set value (10 A) given by the constant voltage circuit 26K.
In the above case, low level L (fax load current: large)
Then, when the value is less than the first set value, a signal () of a high level H (facsimile load current: small) is given to one input terminal of the AND gate 70. When this signal () is L (facsimile load current: large), the output AOS of the AND gate 70 is L, and the charging circuit 50 stops charging.

Another operational amplifier 26 generates a voltage indicative of the voltage drop across the resistor 21 (the facsimile load current). The voltage polarity at which this occurs is opposite to the voltage polarity generated by the differential amplifier 24, and is applied to the inverting input terminal of the negative phase input terminal (-) of the comparator 94 of the comparison circuit 2. When the voltage drop (facsimile load current) of the resistor 21 is equal to or more than the second set value of the comparison circuit 2 (two types, a high value when the accessory switch is on and a low value when the accessory switch is off), the output of the comparator 94 is L, flip-flop (83, 84) of answering instruction circuit 80
Is reset and it does not indicate absence answer (84
Is L), the output AOS of the comparator 94 is applied to one input terminal of the AND gate 70, the output AOS is L, and the charging circuit 50 stops charging.

Timer circuit 100: When ignition key switch is turned to accessory position or ignition position (accessory switch on or ignition switch on), capacitor 10
1 is charged through the diode 102, and the capacitor 101 is charged to about the voltage of the accessory power supply line. At this time, the output of the comparator 106 is H. When the ignition key switch is turned to the power-off position, the ignition switch and the accessory switch are turned off, and the capacitor 101 starts discharging in a loop of capacitor 101-FET 104-equipment ground-resistor 103-capacitor 101. The output of the comparator 106 is inverted from H to L for a predetermined time Tt corresponding to a time constant determined by the values of the capacitor 101 and the resistor 103. When the flip-flops (83, 84) of the answering instruction circuit 80 are set (answering instruction state), the output of the NAND gate 83 is L, and the positive-phase input terminal of the comparator 106 is connected to the device. Since the output of the comparator 106 is L due to the ground level, the output of the timer circuit 100 (the output of the comparator 106) is supplied to the flip-flop (83,8).
It becomes L from the point when 4) is set.

In summary, the timer circuit 100 outputs H while the accessory switch is on. After the accessory switch is turned off, L is output after Tt. If the flip-flops (83, 84) are set during Tt, the output becomes L from that point.

Answering instruction circuit 80: While the accessory switch is on (Acc = H), the transistor 87 is on, one input terminal of the NAND gate 81 is L, and the output of the timer circuit 100 is applied to the other input terminal. Therefore, the output of the NAND gate 81 is H while the accessory switch is ON (the output of the NAND gate 82 is L).

When the accessory switch is turned off, the relay 15 of the power connection circuit 10 is turned off, and the answering instruction circuit is turned off.
One input terminal of the NAND gate 81 of 80 becomes H, the output of the NAND gate 81 becomes L (the output of the NAND gate 82 becomes H:
PSL / ABL connection: power supply from auxiliary battery ABA to PSL), then H after Tt (output of NAND gate 82 is L: relay 11
Outputs PSL / MBL connection: No power is supplied to PSL because relay 13 is off, but flip-flop (8
3,84) is set, and from that point on, NAND gate 81
Is H (the output of the NAND gate 82 is L: no power is supplied to the PSL). However, when the flip-flops (83, 84) are set, the output of the NAND gate 84 becomes H,
As a result, the output signal () of the circuit 80 maintains H and the relay 11 continues to be turned on, so that the flip-flop (83, 8
4) When set, PSL / ABL connection (power supply from auxiliary battery ABL to PSL) while it is set
Is continued. If the flip-flops (83, 84) are not set during Tt, the relay 11 is turned off when Tt has elapsed, and the power supply line PSL is connected to either the main power supply battery (+ Bm) or the auxiliary battery ABA. No power supply.

When the output of the comparator 94 of the comparison circuit 90 is L (the facsimile load current is equal to or more than the second set value),
Then, since one input terminal of the NAND gate 81 is L,
The output of the NAND gate 81 is H (the output of the NAND gate 82 is L), the relay 11 is off, and power is not supplied to the power supply line PSL from either the main power supply battery (+ Bm) or the auxiliary battery ABA.

When the output of the NAND gate 81 is L (within Tt after the accessory switch is turned off; since the accessory switch is off, the transistor 87 is off and the NAND gate
83, the input terminal via the resistor is at H). When the answering instruction switch 88 is momentarily closed, the output of the NAND gate 84 becomes H, whereby the output of the NAND gate 83 becomes L, and the output of the NAND gate 84 becomes H. Maintained (set: answering instruction state). When the output of the NAND gate 84 becomes H, the output signal () of the answering / receiving instruction circuit 80 is H, so that the relay 11 is connected to the PSL / ABL, and the output H of the NAND gate 84 turns on the transistor 85 to turn on the light emitting diode. 86 lights up to indicate that it is in the absence receiving instruction state. When the accessory switch is turned on (Acc = H), the transistor 87
Turns on, whereby one input terminal of the NAND gate 83 becomes L, the output of the NAND gate 83 is inverted from L to H, the output of the NAND gate 84 is inverted from H to L (reset), and the transistor 85 is turned off. When the light emitting diode 86 goes out, the output signal () turns to L, and the relay 11 turns off the PSL /
MBL connection.

When the flip-flops (83, 84) are set (the output of the NAND gate 83 goes low), the positive-phase input terminal of the comparator 106 of the timer circuit 100 goes low.
The output of 00 becomes L, the output of the NAND gate 81 becomes H, and the output of the NAND gate 82 becomes L.

Charging circuit 50: When the output AOS of the AND gate 70 is H, the transistor 55 is turned on and the light emitting diode 56 is turned on to indicate that the charging circuit is on. When the transistor 55 is turned on, an on potential (equipment ground) is applied to the bases of the charging current control transistors 51 and 53 via a resistor. Transistor 5
By turning on 1,53, current flows from the power supply line PSL to the auxiliary power supply line ABL, and the auxiliary battery ABA is charged.However, if the charging current is large, the conductivity of the transistors 52 and 54 increases,
The base potentials of the transistors 51 and 53 are increased to reduce the conductivity of the transistors 51 and 53. As a result, the charging current is suppressed to a predetermined level or less.

AND gate 70: The input of the AND gate 70 is the comparator 25 of the current monitoring circuit 20.
(L when the facsimile load current is greater than or equal to the first set value), the output of the comparator 61 of the main battery voltage monitoring circuit 60 (L when the voltage of the main power battery + Bm is less than or equal to the third set value), and the ignition The output voltage of the switch (L when the ignition switch is off), the output of the comparator 94 of the comparison circuit 2 (L when the facsimile load current is equal to or higher than the second set value), and the output of the comparator 41 of the comparison circuit 40 (main power supply) When the battery voltage + Bm is equal to or lower than the voltage of the auxiliary battery ABA, L) is applied. When all of these signals are H, the AND gate 70 sets the output AOS to "Charge ON" indicating H. And

When at least one of the five signals is L, the output AOS is set to L indicating "charge off".

That is, first, when the ignition switch is off (Ig = L; while the engine is stopped), the charging circuit 50 is off, and the auxiliary battery ABA is not charged. The consumption of the main power supply battery (+ Bm) is prevented.

Second, even when the ignition switch is on (Ig = H; during engine operation), the facsimile load current remains at the first level.
When the value is equal to or more than the set value (the output of the comparator 25 is L), the auxiliary battery ABA is not charged. When the load is large, overload of the main power supply battery (+ Bm) and the alternator (that is, the engine) is prevented.

Third, even when the ignition switch is on (Ig = H; during engine operation), when the voltage of the main power supply battery + Bm is equal to or less than the third set value (the output of the comparator 61 is L), the auxiliary battery ABA Is not charged. When the voltage of the main power supply battery is low, overdischarge of the battery is prevented.

Fourth, even when the ignition switch is on (Ig = H; during engine operation), when the voltage of the main power supply battery (+ Bm) is lower than the voltage of the auxiliary battery ABA (the output of the comparator 41 is L). , Charging is not possible, and the charging circuit is turned off.

Fifth, even if the ignition switch is on (Ig = H; the engine is running), the facsimile
When the value is equal to or larger than the set value, the auxiliary battery ABA is not charged. The overload of the main power supply battery and the alternator (engine) is prevented.

Comparison circuit 40: The voltage (auxiliary voltage) of the auxiliary power supply line ABL (auxiliary battery ABA) is compared with the voltage of the power supply line PSL, and when the voltage of the power supply line PSL is equal to or lower than the auxiliary voltage, the auxiliary voltage of L is reduced. H over
To the AND gate 70. The output of the comparison circuit 40 only turns on / off the charging circuit 50. Since the first condition for turning on the charging circuit 50 is an ignition switch on (Ig = H; during engine operation), the comparison Circuit 40
Is a problem only when Ig = H. When Ig = H, the accessory switch is also turned on (Acc = H), whereby the relay 13 of the power supply connection circuit 10 is turned on and the relay 11 is connected by PSL / ABL. Is applied with the voltage of the main power supply battery + Bm.

Therefore, when the voltage of the main power supply battery + Bm exceeds the voltage of the auxiliary battery ABA, the output of the comparison circuit 40 becomes H
It is. When + Bm is equal to or lower than the voltage of the auxiliary battery ABA, the output of the comparison circuit 40 is L and the charging circuit 50 is turned off.

Main battery voltage monitoring circuit 60: The output of this circuit 60 also has the same Ig =
H only, at this time, the voltage of the feed line PSL is + Bm
It is. Thus, the monitoring circuit 60 outputs H when + Bm (voltage of the power supply line PSL) is equal to or more than the third set value. If it is less than the third set value, L is output and the charging circuit 50 is turned off.

Comparison circuit 90: The voltage of potentiometer 92 is applied to the positive-phase input terminal of comparator 94, and the output (facsimile load current) of differential amplifier 26 of current monitoring circuit 20 is applied to the negative-phase input terminal. When the accessory switch is on (Acc = H), since the transistor 95 is on and the transistor 96 is on, the current flows from the auxiliary power supply line ABL to the potentiometer 92 not only through the resistor 91 but also through the transistor 96. , The voltage of the potentiometer 92 is high (the second set value is high), but when the accessory switch is off (during engine stop), the transistors 95 and 96 are off and the voltage of the potentiometer 92 is low (the second set value is low). value). Thus, these voltages also depend on the voltage of the auxiliary power supply line ABL (voltage of the auxiliary battery ABA), and are high when the voltage of the auxiliary battery ABA is high and low when the voltage of the auxiliary battery ABA is low. As a result, when the accessory switch is on (the ignition switch is off or on; when the accessory switch is on, the charging circuit 50 may be on while the engine is running, but when the accessory switch is off, the engine is stopped and the charging circuit 50 is off). Corresponds to the correlation between the facsimile load current and the high value of the second set value (which also depends on the auxiliary battery voltage), when the facsimile load current is relatively high and the auxiliary battery voltage is relatively low. The output of the comparator 94 becomes L, giving L to the AND gate 70 to turn off the charging circuit 50 (meaningful when the ignition switch is on), and
L to one input terminal of the NAND gate 81 of
And set the output signal () to L and set relay 11 to PSL / MBL
Connection is established (supply from the auxiliary battery ABL to the power supply line PSL is interrupted, and power is supplied from the main power supply battery to the power supply line PSL).
This means that when the ignition switch is off (the charging circuit 50 is off; the engine is stopped), the auxiliary battery ABA is prevented from being over-discharged, and the facsimile is supplied with power from the main power supply battery.

When the accessory switch is off (the ignition switch is also off: the charging circuit 50 is off when the engine is stopped), the correlation between the facsimile load current and the low second set value (which also depends on the auxiliary battery voltage) is determined. Correspondingly, when the facsimile load current is too large compared to the auxiliary battery voltage, the output of the comparator 94 becomes L, and L is applied to one input terminal of the NAND gate 81 of the answering instruction circuit 80 to output the output. H, output signal () to L, relay 11
PSL / MBL connection (power supply from auxiliary battery ABL to power supply line PSL is cut off). That is, in this case, since the accessory switch is off and the relay 13 is off, the power supply line PSL
Is shut off from both the auxiliary power supply line ABL (auxiliary battery ABA) and the main power supply battery. This is for a predetermined time Tt after the accessory switch is switched from on to off,
Or, the flip-flop (83, 84) of the answering instruction circuit 80
Is set, i.e., when the relay 13 is off, the relay 11 is in the PSL / ABL connection, and the auxiliary battery ABA is supplying power to the power supply line PSL, or when supplying power, the auxiliary battery ABA is overdischarged. There is a meaning to prevent.

Next, the operation of the power supply device shown in FIG. 1 corresponding to the operation of the ignition key switch of the driver will be described.

(1) The engine key is removed from the key cylinder, and
A state in which the answering instruction circuit 80 does not instruct answering (the flip-flops 83 and 84 are in the reset state and the NAND gate 84
Output is L) and a long time has elapsed (parking is left): Both the ignition switch and the accessory switch are off (Ig = L, Acc = L), and the timer circuit 100 has timed out. Therefore, the output is L, the output signal () of the answering instruction circuit 80 is L, and the relay 11 is PSL / MB.
Although the connection is L, since Acc = L, the relay 13 is turned off, and eventually the power supply line PSL is connected to the auxiliary power supply line ABL (the auxiliary battery AB
It is cut off from A) and also cut off from the main power supply battery (+ Bm), and the main power supply battery and the auxiliary battery are not substantially discharged.

(2) When the engine key is inserted into the key cylinder, turned to the start position, and then placed in the ignition position (during engine operation): The engine is operating, and both the ignition switch and the accessory switch are turned on (Ig = H, Acc = H). A
When cc = H, the relay 13 is turned on and the main power supply line MBL is connected to the main power supply battery (+ Bm).

Although the output of the comparator 106 of the timer circuit 100 is H, in the answering instruction circuit 80, the transistor 87 is turned on, whereby the output of the NAND gate 81 is H and the output of the NAND gate 82 is L, (83,84) is A
The output of the NAND gate 84 is reset when the cc = H is reset.
Therefore, the output signal of the circuit 80 is L, and the relay 11
L / MBL connection. Therefore, the main power supply battery (+ Bm) supplies power to the power supply line PSL.

Since Ig = H, H is connected to the resistance input terminal of the AND gate 70.
Is added, the voltage of the main power battery + Bm is the third
If the facsimile load current is less than the set value (output of 61 = H), the facsimile load current is less than the first set value (the output of 25 is H), the voltage of the auxiliary battery ABA is less than + Bm (the output of 41 is H), and the facsimile load current is When all the conditions below the high value of the second set value (the output of 94 is H: the facsimile load current is relatively low compared to the auxiliary battery voltage) are all satisfied, the output AOS of the AND gate 70 becomes H The charging circuit 50 is on, and the auxiliary battery ABA is charged from the main power battery. If at least one of the above conditions is not satisfied (L), AOS becomes L, the charging circuit 50 is turned off, and charging of the auxiliary battery ABA is interrupted.

(3) The state in which the engine key is returned to the accessory position and rotated: the ignition switch is off (Ig = L), and the accessory switch is on (Acc). Since Ig = L, this sets the output AOS of the AND gate 70 to L, so that the charging circuit 50 is off and the auxiliary battery ABA is not charged.

Since the relay 13 is on and the output signal of the absence answering instruction circuit 80 is L, the relay 11 has a PSL / ABL connection,
The main power supply battery (+ Bm) supplies power to the power supply line PSL.

(4) The state in which the engine key is removed from the key cylinder: The ignition switch is off (Ig = L), and the accessory switch is also off (Acc = L). The transistor 14 of the power supply connection circuit 10 is off when Acc = L, and the relay 13 is off. That is, the main power supply battery (+ Bm) is disconnected from the main power supply line MBL.
The charging circuit 50 is off and the auxiliary battery ABA is not charged.

When the accessory switch is turned from on to off, charging of the capacitor 101 of the timer circuit 100 is stopped, the capacitor 101 starts discharging, and after a predetermined time Tt from being switched from on to off, the output of the timer circuit 100 is output. Turns from H to L.

During the time Tt from when the output of the timer circuit 100 changes from H to L (the output of the timer circuit 100 = H), the absence receiving instruction circuit 80
Transistor 87 is off and the output of the NAND gate 81 is L,
The output of the NAND gate 81 is H, the transistor 12 is on, and the relay 11 is connected to the PSL / ABL (the power supply line AB from the auxiliary battery ABA).
L).

Even in this state, when the facsimile load current becomes equal to or higher than the second set value (the facsimile load current is too large compared to the auxiliary battery voltage), the output of the comparator 94 changes from H to L and the NAND gate 81 The output of the NAND gate 82 changes to L, the output of the NAND gate 82 changes to L, the output of the answering machine instructing circuit 80 changes to L, and the relay 11 switches to the PSL / MBL connection (the power supply from the auxiliary battery ABA to the power supply line PSL is performed). Since the relay 13 is off, power is not supplied to the power supply line PSL.

When the time Tt elapses, the output of the timer circuit 100 becomes L, so that the output of the NAND gate 82 becomes L,
Switches to PSL / MBL connection (power supply line from auxiliary battery ABA)
The power supply to the power supply line PSL is stopped because the power supply to the power supply line PSL is stopped) and the relay 13 is off.

 Then, the state of (1) is reached.

If the answering switch 88 is momentarily closed before the time Tt elapses, the output of the NAND gate 81 is L at this time, and this is applied to one input terminal of the NAND gate 84, and the output of the NAND gate 84 is L. Is switched to H (the flip-flop is in the set state, ie, the answering instruction state), the transistor 85 is turned on, the light emitting diode 86 is turned on, and the output signal is maintained at H, so that the relay 11 is connected to the PSL / ABL. , And the auxiliary battery ABA supplies power to the power supply line PSL. This condition will occur when the engine key is later inserted into the key cylinder and turned to the accessory position (accessory switch on).
When 87 is turned on and L is applied to one input terminal of the NAND gate 83 and the output of the NAND gate 83 becomes H, the NAND gate 83 is reset (to a state where there is no answering instruction).

When the facsimile load current is equal to or higher than the second set value (the facsimile load current is too large compared to the auxiliary battery voltage) in the above-described set state (answering instruction state), the output of the comparator 94 changes from H to H. Turn to L and NAND gate
The output of 81 changes to H, the output of the NAND gate 82 changes to L,
The output of the answering machine command circuit 80 becomes L and the relay 11 becomes PS
Switch to L / MBL connection (from auxiliary battery ABA to power supply line PSL
The power supply to the power supply line PSL is stopped because the relay 13 is off.

〔The invention's effect〕

As described above, according to the present invention, while the on-vehicle main power switch (Ig) is closed (during engine operation), the connection control means (100, 80) connects the power supply connection means (10) to the power supply line (PSL). Since the main power supply battery (+ Bm) is connected on one vehicle, the facsimile receives power from the main power supply battery (+ Bm) while the main power switch (Ig) is closed.

Thus, while the main power switch (Ig) is closed, the charging control means (50) determines whether the load on the vehicle main power supply (+) is low when the load is small corresponding to the load detected by the load detection means (20).
Bm) is connected to the auxiliary secondary battery (ABA), and when the load is large, the charging connection is restricted.

Therefore, overload of the main power supply battery and the alternator (and engine) connected thereto is prevented, and the auxiliary secondary battery is charged when the facsimile load is low. It is almost impossible to continue facsimile reception continuously during vehicle operation (during engine operation). For example, when facsimile communication is not performed, facsimile transmission is performed, or when power consumption is small even in facsimile reception, The auxiliary secondary battery is charged. As a result, when the main power switch (Ig) is on (while the engine is running), facsimile communication is always possible and facsimile transmission and reception requiring urgency are not hindered. The auxiliary secondary battery is also charged without applying a load.

[Brief description of the drawings]

FIG. 1 is an electric circuit diagram showing a configuration of one embodiment of the present invention. ABA: Auxiliary battery (auxiliary secondary battery) FAX: Facsimile (facsimile on vehicle) PSL: Power supply line (power supply line), OUT: Power supply output terminal MBT: Main power supply input terminal, + Bm: Main power supply battery voltage MBL: Main power supply line , ABL: Auxiliary power supply line APT: Auxiliary power supply input terminal, 10: Power supply connection circuit (power supply connection means) IGT: Ignition switch input terminal Ig: Ignition switch output voltage ACT: Accessory switch input terminal Acc: Accessory switch output voltage 20: Current Monitoring circuit, 40: Comparison circuit 50: Charging circuit (charging control means), 60: Main battery voltage monitoring circuit 70: AND gate, 80: Answering instruction signal circuit 83, 84: NAND gate, 88: Answering instruction signal switch 90: Comparison Circuit, 100: Timer circuit

Continuation of the front page (56) References JP-A-50-152417 (JP, A) JP-A-51-97117 (JP, A) JP-A-55-58743 (JP, A) JP-A-56-96465 (JP) JP-A-63-275259 (JP, A) JP-A-2-262857 (JP, A) JP-A-4-501799 (JP, A) JP-A-4-505244 (JP, A) 55-106436 (JP, U) Fully open sho 59-94977 (JP, U) Really open sho 56-89633 (JP, U) Really open sho 59-107546 (JP, U) Fully open sho 60-55242 (JP, U U) Japanese Utility Model Showa 60-144730 (JP, U) Japanese Utility Model Showa 62-61566 (JP, U) Japanese Utility Model Showa 62-74455 (JP, U) (58) Fields surveyed (Int. Cl. ⁶ , DB name) ) B60R 11/00-11/06 H02H 7/10-7/20 H02J 1/00-1/16 H02J 7/00-7/12 H02J 7/34-7/36 H02J 9/00-9/08 H04B 7/24-7/26 H04M 1/64-1/65 H04M 11/00-11/10 H04M 19/00-19/08 H04N 1/00

Claims (1)

(57) [Claims] Power supply connecting means for selectively connecting a power supply line to a facsimile on a vehicle to a main power supply battery on the vehicle and the auxiliary secondary battery; load detection for detecting a load on the power supply line Means: while the on-vehicle main power switch is closed, when the load is small corresponding to the load detected by the load detecting means, the charging connection from the on-vehicle main power battery to the auxiliary secondary battery is performed, and the load is large. Charging control means for restricting the charging connection sometimes; and, while the main power switch on the vehicle is closed, the power connection means,
Connection control means for determining the connection between the power supply line and the on-vehicle main power supply battery and defining the power supply connection means as the connection between the power supply line and the auxiliary secondary battery when the on-vehicle main power switch is switched from closed to open; Power supply device for facsimile on vehicles.