JPS63254317A - Ignition device - Google Patents

Abstract

PURPOSE:To make the life of the battery of a power source longer by providing an ignition device which performs continuously high voltage electric discharges by a transformer and an oscillation circuit, condenser which is connected in parallel with the ignition device 3, and constant current section which passes electric current to the ignition device and the condenser with the current from a power source being kept constant. CONSTITUTION:The average electric current of electric currents required for the ignition by discharge is substantially equal to the electric current flowing through a resistor r1, and the value I of this current is the one obtained by dividing the voltage which is given by subtracting the voltage VBE between the base eimitters of a transistor Q2 from the voltage VF in the positive direction between diodes D1 and D2 by the resistance value R1 of the resistor r1, I=(2VF-VBE)/R1. If VF and VBE are made not to change much by the applied voltage, the current value I becomes almost constant. Because the ignition device 3 is not ignited with a constant current, it operates by connecting a condenser C in parallel. As described above by providing the ignition device 3 with a constant current section 6 and condenser C, the life of a battery if it is the power source 1 can be made longer even when the voltage of the power source 1 is high by trying not to pass electric current more than necessary.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to an ignition device for gas appliances and the like that uses a battery as a power source.

BACKGROUND ART When operating an ignition device using a battery power source, it is desired that the period (battery life) until the battery becomes exhausted and becomes unusable is long.

The conventional ignition device described above will be described below with reference to the drawings.

FIG. 3 shows a circuit diagram of a conventional igniter. Third
In the figure, 1 is a DC power supply, 2 is a switch, 3 is an igniter, τr1 is a primary transformer, Q is a transistor, R is the base resistance of transistor q, 'rr2 is a secondary transformer, 4
is a spark plug connected to the secondary side of the secondary transformer Tr).

The operation of the ignition device configured as described above will be described below.

First, the switch 2 is turned on in response to the ignition operation. The current from the power supply 1 passes through the transistor Q and the primary transformer Tr.
Although the current flows from the primary side coil of No. 1 to GND, the current acts to stop the base current of transistor Q, so transistor Q is turned off. Then, the base current of transistor Q begins to flow again, turning transistor Q ON. By repeating this operation, a current having the waveform shown in FIG. 4 flows through the primary coil /l/ of the primary transformer Tr1. Therefore, a voltage of several hundred ports is generated in the secondary coil of the primary transformer Tr1, and the spark plug 4 boosts the voltage to a voltage of more than ten kilovolts that can be discharged by the secondary transformer Tr2.

Problems to be Solved by the Invention However, in the above configuration, when the power source 1 is a battery, the current that flows changes depending on the voltage. If the number of ignition discharges is set to the lowest level of the igniter, the current and number of discharges will increase when the battery voltage is initial, but it is thought that unnecessary current is consumed and the battery life will be shortened. I had a problem.

The present invention overcomes the above-mentioned problems and provides an ignition device that extends the battery life of a battery power source by keeping the current flowing through the igniter substantially constant regardless of the voltage.

Means for Solving the Problems In order to solve the above problems, the ignition device of the present invention includes a power source, an igniter that continuously generates high voltage discharge using a transformer and an oscillation circuit, and the igniter. The device includes a capacitor connected in parallel with the power source, and a constant current section that supplies a substantially constant current from the power source to the firearm and the capacitor regardless of voltage fluctuations.

The present invention can extend battery life by setting the current to a substantially constant value so as not to fall below a current that can ensure the minimum number of discharges necessary for the ignition device.

EMBODIMENT OF THE INVENTION Below, an ignition device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a circuit diagram of an ignition device according to an embodiment of the present invention, and FIG. 2 shows a similar circuit configuration diagram. The same parts as those shown in the conventional example are given the same reference numerals, detailed explanations thereof are omitted, and only points different from the conventional example will be explained. Reference numeral 5 denotes a switch section which has an internal switch 2. 6 is a constant current section, which includes transistors Q2,
Diode D1. D2 resistance r1. r2 constitutes a current Shiller circuit. C is a capacitor, which is connected in parallel with the igniter 3.

The operation of the ignition device configured as described above will be described below with reference to FIGS. 1 and 2.

The current required for ignition discharge has the waveform shown in FIG. 4 explained in the conventional example, and this average current is almost equal to the current flowing through resistor r1, and this current value I is determined by the forward voltage VF of diodes D1 and D2. It is a value obtained by subtracting the base-emitter voltage '/BE of the transistor Q2 and dividing it by the resistance value R1 of the resistor r1.

1=(2VF-'i'BE)/R1 Here, if neither VF nor VBE changes much depending on the applied voltage, the current value becomes almost constant.

Since the igniter 3 will not operate with a constant current, by connecting the capacitor C in parallel, the current flowing through the igniter 3 will have the waveform shown in FIG. 4, and the igniter 3 will operate.

As described above, according to this embodiment, the constant current section 6 is provided in the igniter 3.
By providing the capacitor C and the capacitor C, it is possible to prevent more current than necessary from flowing even when the voltage of the power source 1 is high, thereby saving current and extending the battery life when the power source is a battery.

Note that the diodes DI and D2 may utilize the voltage between the base and emitter of the transistor to improve the voltage characteristics, and the temperature characteristics can be improved by connecting several thermistors to the resistor r1.

Effects of the Invention As described above, the present invention connects a capacitor in parallel to the igniter and allows a constant current to flow through the capacitor, so that current can be saved by not allowing more current than necessary to flow. If the power source is a battery, the battery life can be extended.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of an ignition device in an embodiment of the present invention;
FIG. 2 is a circuit diagram of FIG. 1, FIG. 3 is a circuit diagram of a conventional ignition device, and FIG. 4 is a graph showing the current of the igniter. 1...Power supply, 3...Igniter, 6...
...Constant current section, C...Capacitor. Name of agent: Patent attorney Toshio Nakao and 1 other person/
---Electric brother 3 one item, large volume Figure 1 6 constant electric steam section c---Condensing engine Figure 2

Claims (3)

[Claims] (1) A power source, an igniter that continuously generates high voltage discharge using a transformer and an oscillation circuit, a capacitor connected in parallel with the igniter, and a constant current from the power source to control the igniter. and a constant current section that flows through the capacitor. (2) The ignition device according to claim 1, wherein the igniter has a configuration in which the voltage is increased by a primary transformer by intermittent current flow by an oscillator, and the voltage is further increased and discharged by a secondary transformer. (3) The ignition device according to claim 1, wherein the constant current source is constituted by a current mirror circuit.