JP3042403U - Charge time constant switching power supply circuit - Google Patents

Abstract

(57) Abstract: [PROBLEMS] To provide a power supply circuit capable of performing intermittent wave transmission of a large electric power equal to or higher than the rating of the battery by using a small capacity battery. In a power supply circuit including a battery for a main power supply and a capacitor for charging, a resistor for limiting a current supplied from the battery to a current within a rating when the power supply is started, and a means for detecting a terminal voltage of the capacitor. And a means for short-circuiting or lowering the resistance of the resistor to supply a current when it is detected that the terminal voltage has risen to a predetermined level, and the charging of the capacitor is completed before the start of transmission, and the battery is supplied at the time of transmission. Supply the transmitter with a current higher than the rated value.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a power supply circuit of a transmitter that uses a battery as a main power supply and includes a charging capacitor to perform intermittent wave transmission.

[0002]

[Prior art]

 Radio buoys and ultrasonic equipment used at sea or under the sea without an AC power source are required to be small and lightweight, and the primary batteries and secondary batteries installed in these are also required to be small and lightweight. Therefore, there is a restriction on the current capacity consumed.

In these devices, when transmitting a high-power intermittent wave (burst wave), a current higher than the rated value that allows the battery to continuously output is required. A voltage drop occurs due to the resistance, and it is not possible to obtain sufficient transmission power.

Therefore, first, before the start of transmission, the power source is started and a capacitor that has not been charged at all with a current within the rating of the battery is charged, and the current due to the charge charged in the capacitor during the transmission and the current within the rating of the battery are charged. It has been conventional to supply power to the transmitter by.

FIG. 3 shows an example of the above-mentioned conventional power supply circuit, 10 is a battery, 11 is a power switch, 12 is a resistor for limiting current, 13 is a capacitor for charging, 19 is a transmission switch, and 20 is an intermittent wave. Is a transmitter for transmitting. In FIG. 3, when the power switch 11 is turned on, the current limited by the resistor 12 is supplied from the battery 10 to the capacitor 13 before transmission is started. Then, when the transmission switch 19 is closed, the current due to the charge charged in the capacitor 13 and the current-limited current from the battery 10 are supplied to the transmitter 20, and the transmitter 20 starts transmitting the intermittent wave. To do.

[0006] FIG. 4 shows the time variation between the terminal voltage of the capacitor and the current consumption of the battery in the above conventional example at the time of power supply startup and transmission, (a) is the transmitter output signal, and (b) is the capacitor terminal voltage. , (C) show the battery consumption current. In FIG. 4, first, when the power switch 11 is turned on, the terminal voltage of the capacitor 13 increases with time depending on the time constant of the resistor 12, and the consumption current of the battery 10 changes from the rated current to the time. Decrease. Next, at the time of transmission of the transmitter with the transmission switch 19 turned on, during transmission of the intermittent wave (transmission of one burst), the current due to the charge of the capacitor 13 and the current from the battery 10 are supplied to the transmitter 20. .

[0007]

[Problems to be solved by the device]

 However, during the transmission of the intermittent wave, the voltage of the capacitor 13 decreases and the current from the battery 10 increases, but since the amount depends on the time constant of the resistor 12, the rated full current is immediately supplied. Never. Also, during the pause period of the intermittent wave, the current for charging the capacitor 13 still depends on the time constant of the resistor 12, so that the pause period ends before the capacitor 13 is sufficiently charged. Therefore, the current is limited during transmission of the intermittent wave and during the rest period, so that sufficient transmission power cannot be obtained.

[0008]

[Means for Solving the Problems]

 In order to solve the above drawbacks, the present invention is provided with a battery of a main power source, a resistor for current limitation, and a capacitor for charging, and performs transmission of an intermittent wave before and after transmission of a transmitter. In the power supply circuit that charges the capacitor during the rest of the time and supplies power to the transmitter from the capacitor and the battery during intermittent wave transmission, the resistor that limits the current supplied from the battery to the current within the rating when the power is started. And a means for detecting the terminal voltage of the capacitor, and means for supplying a current by short-circuiting or lowering the resistance of the resistor when detecting that the terminal voltage rises to a predetermined level. is there.

Since the present invention configured as described above can complete the charging of the capacitor before the start of transmission, it is possible to supply a current higher than the rated value of the battery during intermittent wave transmission, thus making the battery small and lightweight. Can be converted.

[0010]

【Example】

 FIG. 1 shows a connection diagram of an embodiment of the present invention, and FIG. 2 shows changes with time of the terminal voltage of a capacitor and the current consumption of a battery in this embodiment. In FIG. 1, the same reference numerals as those in FIG. 3 indicate the same elements, 14 and 15 are resistors connected in series and connected in parallel to the capacitor 13 to divide the voltage of the capacitor 13, 16 is a resistor, and 17 is a gate as described above. A K-type FET (field effect transistor) connected to the connection point between the resistor 14 and the resistor 15, 18 is a source-drain connected in parallel to the current limiting resistor 12, and the gate is the source of the FET 17. Is a J-type FET connected to.

The operation of this embodiment having such a configuration will be described with reference to FIG. 2 (a) shows the transmitter output signal, (b) shows the capacitor terminal voltage, and (c) shows the battery current consumption.

First, when the power switch 11 is turned on, the J type FET 18 is reverse biased by the resistor 16, and immediately after the power is turned on, the capacitor 13 is not yet charged. The divided voltage is still 0 volt, the K-type FET 17 is off and the J-type FET 18 is off (T1). After that, the charging current I passes from the battery 10 through the resistor 12, and the current is limited by the resistor 12 to charge the capacitor 13 (T1 to T3). At this time, the capacitor 13 is charged by the time constant of the resistor 12. When the terminal voltage of the capacitor 13 reaches a predetermined set level V1 (T3), that is, when the voltage divided by the resistor 14 and the resistor 15 reaches the ON level of the FET 17, the resistor 16 reverse biases the voltage. The FET 18 which has been turned on has a base voltage of 0 volt and is turned on to short-circuit the current limiting resistor 12. At this time, the charging current I flows through the FET 18 having a low resistance, so that the current from the battery 10 increases, and the capacitor 13 is charged by the increased current. Therefore, the capacitor 13 is charged to the charging end voltage V2 (the rated voltage of the battery 10).

Next, when the transmission switch 19 is turned on, the transmitter 20 is supplied with the current from the charged capacitor 13 and the current from the battery 10 through the low resistance FET 18, and transmits the intermittent wave. Start (T2). When the transmission of the intermittent wave (one burst) is completed, the electric charge consumed in the capacitor 13 is recharged by the current passing through the FET 18 in the ON state from the battery 10 to prepare for the transmission of the next intermittent wave.

In this embodiment, the transmission switch 19 is used to supply power to the transmitter, but any other switch can be used as long as it can control the transmitter. Although the FET is used for switching the time constant, a comparator may be used instead of the FET 17 and a relay having an equivalent function such as a relay may be used instead of the FET 18.

[0015]

[Effect of the invention]

 As described above, according to the present invention, when it is detected that the terminal voltage of the capacitor has risen to the predetermined level, the current limiting resistor is short-circuited or has a low resistance so that the charging of the capacitor is completed before the start of transmission. It is possible to supply a current higher than the rated value of the battery during intermittent wave transmission, and reduce the size and weight of the battery.

[Brief description of the drawings]

FIG. 1 is a connection diagram showing an embodiment of a power supply circuit of the present invention.

FIG. 2 is a diagram showing a time variation of a capacitor terminal voltage and a battery consumption current in the present invention of FIG.

FIG. 3 is a connection diagram showing an example of a conventional power supply circuit.

FIG. 4 is a diagram showing changes with time of a capacitor terminal voltage and a battery consumption current in the conventional example of FIG.

[Explanation of symbols]

 10 Battery 11 Power Switch 12, 14, 15, 16 Resistor 13 Capacitor 17, 18 FET 19 Transmission Switch 20 Transmitter

Claims (1)

[Utility model registration claims] 1. A battery for a main power supply, a resistor for limiting current, and a capacitor for charging are provided, and the capacitor is charged before the start of transmission of a transmitter that performs intermittent wave transmission and when the intermittent wave is stopped, and intermittently. In a power supply circuit that supplies power from the capacitor and a battery to the transmitter during wave transmission, a resistor that limits the current supplied from the battery to a current within a rating when the power supply is started, and the terminal voltage of the capacitor are detected. And a means for short-circuiting or lowering the resistance of the resistor when detecting that the terminal voltage has risen to a predetermined level, and supplying a current so that the charging of the capacitor is completed before the start of transmission. A charging time constant switching power supply circuit, which is capable of supplying a current higher than the battery rating during transmission of intermittent waves.