JPS6216043Y2 - - Google Patents

Description

[Detailed description of the invention] This invention uses a battery with a large internal resistance as a power source, and switches and supplies the output to a light-load receiving section and a heavy-load transmitting section, which have significantly different load currents, via a stabilizing circuit. The present invention relates to a power supply circuit for a portable radio device for stable operation both during reception and transmission. This type of power supply circuit for a portable radio uses a dry battery such as a manganese battery or an alkaline battery, which has a large internal resistance, as its input power source. When a battery with such a large internal resistance is used as an input power source, the load current varies greatly between reception and transmission, and the output voltage accordingly varies greatly. This variation in output voltage is within the range where performance can be guaranteed (within a range of 10 to 15% down from the specified voltage) when the transmission output is not that large and the demand for downsizing the equipment is not that great.
However, in situations where a reduction in the number of batteries is required due to higher output power for transmission and miniaturization of equipment, even if the specified voltage is applied to the lightly loaded receiving section during reception, During transmission, the voltage drop due to the internal resistance of the battery becomes large, and a voltage significantly lower than the specified voltage is applied to the heavily loaded transmitting section, resulting in a drawback that performance cannot be guaranteed.

Furthermore, if the number of batteries is selected so that the specified voltage is applied to the heavily loaded transmitting section during transmission, a voltage that significantly exceeds the specified voltage will be applied to the lightly loaded receiving section during reception. There was a drawback.

The present invention was made to improve the above-mentioned drawbacks, and in a device that uses a battery with a large internal resistance as an input power source to supply power to an output load via a stabilization circuit, the battery can handle heavy loads. The auxiliary control transistor of the stabilization circuit is activated during light loads (during reception) to increase the voltage drop across the main control transistor, and the The auxiliary control transistor of the stabilization circuit is inactive and the main control transistor is almost short-circuited (in other words, the stabilization circuit does not operate at a constant voltage) to minimize the voltage drop in the main control transistor. By this,
This system adjusts fluctuations in the voltage drop of the battery's internal resistance due to fluctuations in load current, and applies a specified voltage to both light loads and heavy loads.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

Reference numeral 1 denotes a series control type stabilizing circuit using transistors. It is mainly composed of a first resistor 3 connected between the bases and a control auxiliary transistor 4 for controlling the base current of the main transistor 2 by an output voltage, and the base of the auxiliary transistor 4 is connected to the The auxiliary transistor 4 is connected to the connection point between the reference voltage setting Zener diode 5 and the third resistor 6 inserted between the emitter of the main transistor 2 and the ground, and the collector of the auxiliary transistor 4 is connected to the base of the main transistor 2. The emitter of the auxiliary transistor 4 is grounded via the second resistor 7 and the collector/emitter of the switching transistor 8.

A battery 9 having a large internal resistance, such as a manganese battery or an alkaline battery, is connected to the input side of the stabilizing circuit 1. This battery 9 is designed so that the number of batteries is appropriately selected in advance so that the terminal voltage will be the specified voltage for heavy loads even after subtracting the voltage drop in the internal resistance of the battery 9 caused by the load current during heavy loads. Keep it.

The input side of the stabilizing circuit 1 is grounded through a fourth resistor 10 and a transmit/receive switch 11 as a first switch, and the connection point between the fourth resistor 10 and the transmit/receive switch 11 is connected to the switching transistor. It is connected to the base of 8.

The output side of the stabilizing circuit 1 is a common contact 1 on the movable piece 13 side of a load changeover switch 12 as a second changeover switch for switching between light load and heavy load.
4, one contact 16 of the switching contacts 15 and 16 of this load changeover switch 12 is connected to a transmitter 18 as a heavy load, and the other contact 15
A receiving section 17 as a light load is connected to. The movable piece 13 of the load changeover switch 12 is configured to mechanically or electromagnetically interlock with the on/off state of the transmission/reception changeover switch 11.

Next, the effect will be explained.

During both transmission and reception, a battery 9 serving as an input power source is connected to the input side of the stabilizing circuit 1, so a base current flows from the battery 9 through the first resistor 3 between the base and emitter of the main transistor 2. flows, putting the main transistor 2 into operation, and an output voltage appears on the output side of the stabilizing circuit 1.

First, the reception operation (light load) will be described. When the transmitting/receiving switch 11 is turned off to enter the receiving state, the movable piece 13 of the load switching switch 12 comes into contact with the contact 15 on the receiving section 17 side. When the transmitting/receiving switch 11 is turned off, the switching transistor 8 is turned on, and the emitter of the auxiliary transistor 4 becomes approximately zero potential, so that the auxiliary transistor 4 becomes in an operating state.
Then, most of the base current that should flow from the battery 9 to the base circuit of the main transistor 2 via the first resistor 3 flows to the auxiliary transistor 4, the second resistor 7, and the switching transistor 8. Base current becomes small. Therefore, the resistance between the input and output of the stabilizing circuit 1 becomes a large value, and even if the load current supplied from the battery 9 to the receiving section 17 via the stabilizing circuit 1 is small, the main The voltage drop across the transistor 2 increases, the terminal voltage of the battery 9 is reduced by a predetermined amount predetermined by the elements constituting the stabilizing circuit 1, and a specified voltage is applied to the receiver 17. be done.

Next, the transmission operation (heavy load) will be explained.

When the transmitter/receiver switch 11 is turned on to enter the transmitting state, the movable piece 13 of the load selector switch 12 comes into contact with the contact 16 on the transmitter 18 side. When the transmitting/receiving changeover switch 11 is turned on, the switching transistor 8 is turned off, and then the auxiliary transistor 4 is also put into a non-operating state. Then, all of the current flowing from the battery 9 through the first resistor 3 flows into the base circuit of the main transistor 2, and the main transistor 2 becomes substantially short-circuited. For this reason,
Even if the resistance between the collector and emitter of the main transistor 2 is extremely small, and the load current is large, the voltage applied to the transmitter 18 is the voltage obtained by subtracting the voltage drop due to its internal resistance from the terminal voltage of the battery 9. , that is, the specified voltage.

Since the present invention is configured as described above, when a battery with a large internal resistance is used as an input power source and power is supplied by switching between a light-load receiving section and a heavy-load transmitting section via a stabilizing circuit, a changeover switch is required. By simply operating the , a predetermined regulated voltage can be supplied to any load and stable operation can be achieved.

Moreover, during transmission, the main control transistor inserted in series between the battery and the transmitter becomes almost short-circuited, and the voltage drop in this main transistor can be minimized, making it compatible with high-output transmission. When determining the number of batteries with large internal resistance, the number of batteries can be kept to the minimum necessary. That is, it is possible to simultaneously satisfy the two demands of high output power for transmission and miniaturization of equipment.

[Brief explanation of the drawing]

The drawing is an electrical circuit diagram showing an embodiment of a power supply circuit for a portable wireless device according to the present invention. DESCRIPTION OF SYMBOLS 1... Stabilization circuit, 2... Main transistor, 3... First resistor, 6... Third resistor, 7... Second resistor, 10... Fourth resistor, 4... Auxiliary transistor, 5... Zener diode, 8... Switching transistor , 9
...Battery, 11...First changeover switch, 12...Second changeover switch, 14...Common contact, 15...Other changeover contact, 16...One changeover contact, 17...Light load (receiving section), 18...Heavy load ( transmitter).

Claims (1)

[Scope of claim for utility model registration] The negative electrode side of the battery with high internal resistance is grounded, and the positive electrode side is connected to the collector of the main transistor for NPN control.
The emitter is connected to the common contact of the second changeover switch, one changeover contact of the second changeover switch is connected to the transmitter, the other changeover contact is connected to the receiver, and the collector base of the main transistor is connected to the common contact of the second changeover switch. A first resistor is connected between the base of the main transistor and
The collector and emitter of the NPN type control auxiliary transistor are connected to the second resistor, and the emitter of the main transistor is grounded via the Zener diode and the third resistor.
In a power supply circuit for a portable radio device in which the connection point of a resistor is connected to the base of the auxiliary transistor, the collector/emitter of an NPN switching transistor is inserted between the second resistor and the ground, and the positive electrode of the battery is connected to the base of the auxiliary transistor. The side is grounded through a fourth resistor and a first changeover switch that turns on and off in conjunction with the second changeover switch, and the connection point between the fourth resistor and the first changeover switch is connected to the switching transistor. A power supply circuit for a portable radio device, characterized in that it is connected to a base.