Portable emergency vehicle battery charger with microprocessor
A portable emergency vehicle battery charger has a portable case, a battery and a circuit board. The battery and circuit board are mounted in the portable case. The case mainly has a power out socket connected to the battery through the circuit board, a power input socket connected to the battery and a power supply switch connected between the circuit board and the battery. The power output socket is a cigar-lighter socket. When a vehicle battery does not have sufficient charge to start an engine, the driver uses a jumper cable connected between a cigar-lighter in the vehicle and the power output socket to charge the battery. Then the driver turns the power supply switch on to provide a constant current to the vehicle battery.
1. A portable emergency vehicle battery charger, comprises:
a portable case having a handle, a power output socket, a power supply switch and a power input socket, wherein
the power output socket is a cigar-lighter type for being connected to a cigar-lighter socket in a vehicle; and
the power input socket for being connected to an external battery charger;
a battery mounted in the case and connected to the power input socket so the external battery charger can charge the battery;
a circuit board mounted in the case, connected to the power supply socket, the battery and the power supply switch to output a constant charging current to the power output socket and comprising
a microprocessor connected to the battery through a regulator to obtain a suitable DC voltage, the power supply switch and the illumination switch;
a booster having
a power source input terminal connected to the battery through the power supply switch;
a disable terminal connected to the microprocessor; and
a power output terminal connected to the microprocessor through a first rheostat;
and the booster comprising
an electronic switch connected to the battery and having an open and closed duty cycle;
a PWM generator and current compensation IC controlling the duty cycle of the electronic switch and having
a power input connected to the battery through the power supply switch;
a PWM output connected to the electronic switch;
a current feedback input connected to the PWM output; and
a clock signal input;
a booster inductance connected to the electronic switch, the battery and the power output terminal;
a resistor connected to the current feedback input of the PWM generator and current compensation IC, the electronic switch and ground;
an RC oscillator connected to the clock signal input of the PWM generator and current compensation IC and having a capacitor connected to the microprocessor; and
a fuse connected between the battery and the booster inductance;
a power supply controller connected to the power output terminal of the booster and having
a controlling terminal connected to the microprocessor;
a power input connected to the power output terminal of the booster; and
a power output connected to the power output socket and the microprocessor;
and the power supply controller comprising
a transistor having a base terminal connected to the microprocessor, a collector terminal and an emitter terminal connected to ground; and
a relay having a coil connected to the collection terminal of the transistor and a switch connected between the power output terminal and the power output socket;
a battery indicator connected to the circuit board and consisting of multiple different colored LEDs connected to the microprocessor; and
an alarm unit connected to the microprocessor and comprising
a transistor having a base terminal connected to the microprocessor, a collector terminal and an emitter terminal connected to ground; and
a buzzer connected to the collector terminal.
2. The charger as claimed in claim 1 , further comprising:
an illumination switch mounted on the case; and
an illumination device connected to the case and further connected to the battery through the illumination switch.
3. The charger as claimed in claim 2 , further comprising a fuse socket mounted on the portable case, wherein the fuse is mounted in the fuse socket.