Radio telephone set used as portable set and vehicle-mounted set
First Claim
1. A radio telephone set which is to be used as a portable set and a set mounted on a vehicle with a vehicle battery, comprising:
- radio telephone circuit means including a load and first and second terminals, said load being provided with power through said first terminal;
battery means for powering said radio telephone set when used as a portable set;
third and fourth terminals for said vehicle battery, said fourth terminal being connected to said vehicle battery through an engine key circuit of said vehicle;
first switching means connected to said first and third terminals and to said battery means for connecting said first terminal to said battery means in response to a first control signal and for switching the connection of said first terminal from said battery means to said third terminal in response to a second control signal;
first gate means having two inputs connected to said third and fourth terminals, respectively, for providing said first control signal when either one or both of the voltages at said two inputs is low and for providing said second control signal when both the voltages at said two inputs are high; and
second switching means connected to said second through fourth terminals and to said battery means for connecting said second terminal to said battery means when a voltage at said third terminal is low and for switching the connection of said second terminal from said battery means to said fourth terminal when the voltage at said third terminal is high.
1 Assignment
0 Petitions
Accused Products
Abstract
A radio telephone set comprises switch circuitry, a telephone circuit and a battery for portable operation, which battery may be a built-in battery. When the radio telephone set is not mounted on a vehicle, the switch circuitry is not connected to a battery of the vehicle and feeds power from the built-in battery to the telephone circuit. Thus, the radio telephone set can be used as a portable set. When the radio telephone set is mounted on the vehicle, the switch circuitry is connected to the vehicle battery and this connection causes the automatic switching of the power supply to the telephone circuit from the built-in battery to the vehicle battery. Thus, the radio telephone set can be used as a vehicle-mounted, or onboard, set.
47 Citations
19 Claims
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1. A radio telephone set which is to be used as a portable set and a set mounted on a vehicle with a vehicle battery, comprising:
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radio telephone circuit means including a load and first and second terminals, said load being provided with power through said first terminal; battery means for powering said radio telephone set when used as a portable set; third and fourth terminals for said vehicle battery, said fourth terminal being connected to said vehicle battery through an engine key circuit of said vehicle; first switching means connected to said first and third terminals and to said battery means for connecting said first terminal to said battery means in response to a first control signal and for switching the connection of said first terminal from said battery means to said third terminal in response to a second control signal; first gate means having two inputs connected to said third and fourth terminals, respectively, for providing said first control signal when either one or both of the voltages at said two inputs is low and for providing said second control signal when both the voltages at said two inputs are high; and second switching means connected to said second through fourth terminals and to said battery means for connecting said second terminal to said battery means when a voltage at said third terminal is low and for switching the connection of said second terminal from said battery means to said fourth terminal when the voltage at said third terminal is high. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A radio telephone set comprising:
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battery means for powering said radio telephone set; first, second, third, and fourth terminals, said second terminal being connected to a vehicle battery through a vehicle engine key circuit; first gate means for providing a first switch signal in response to power application to said first and second terminals; first power switch means for selectively connecting said third terminal to said battery means and for switching said third terminal from said battery means to said first terminal in response to said first switch signal; switching means for selectively connecting said fourth terminal to said battery means and for switching power flow to said fourth terminal from said battery means to power flow from said second terminal to said fourth terminal in response to power application to said first terminal; and telephone circuit means connected to said third and fourth terminals. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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17. A method of supplying a radio telephone set with power from one of a battery for portable operation of said radio telephone set and a vehicle battery, said radio telephone set comprising a telephone circuit and first, second, third, and fourth terminals, said first terminal being selectively connected to said vehicle battery, said second terminal being selectively connected to said vehicle battery through a vehicle engine key circuit, said method comprising the following steps of:
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providing a first switch signal in response to power application to said first and second terminals; connecting said third terminal to said battery for portable operation in response to no power application to said first and second terminals; switching the connection of said third terminal from said battery for portable operation to said first terminal in response to said first switch signal; providing a second switch signal in response to power application to said first terminal; providing power to said fourth terminal from said battery for portable operation in response to no power application to said first terminal; switching the electrical connection of said fourth terminal from said battery for portable operation to said second terminal in response to said second switch signal; and connecting said telephone circuit to said third and fourth terminals. - View Dependent Claims (18)
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19. A method of supplying power to a radio telephone set from one of a battery for portable operation of said radio telephone set and a vehicle battery, said method comprising the following steps of:
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responsive to no power application from said vehicle battery to said radio telephone set, supplying power from said battery for portable operation to said radio telephone set; and responsive to power application from said vehicle battery to said radio telephone set through a vehicle engine key circuit, automatically switching said power supply to said radio telephone set from said battery for portable operation to said vehicle battery.
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Specification