JPS6310330B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ignition device suitable for use in gas appliances, petroleum appliances, etc., which uses a DC-DC converter using a battery as an input power source to discharge sparks between discharge electrodes, and which is suitable for use in gas appliances, oil appliances, etc. The present invention relates to an ignition device equipped with a timer circuit that automatically stops spark discharge afterward and a battery voltage checker circuit that checks battery consumption.

Conventionally, there are ignition devices equipped with a timer circuit that stops spark discharge after a predetermined period of time, but the timer circuit is constructed by connecting a switching transistor to the connection point of a resistor capacitor, and the potential of the capacitor is adjusted after a predetermined period of time. As the voltage increases, the switching transistor becomes conductive, thereby suppressing the base voltage of the oscillation transistor of the DC-DC converter and stopping oscillation. With a device configured in this way, the charge stored in the capacitor is difficult to discharge, and if the power switch of the ignition device is opened and then closed again before the capacitor is completely discharged, the timer circuit will not be activated. This had the problem of shortening the time.

In addition, there are conventional ignition devices equipped with a battery voltage checker circuit to check battery voltage consumption, but these devices take the trouble of providing a secondary winding for the battery voltage checker circuit in the oscillation transformer of the DC-DC converter. Since a rectifier circuit or the like is connected to the secondary winding, there are problems in that the number of parts increases, making assembly complicated, and also disadvantageous in terms of cost.

The present invention has been made in view of these points, and is an ignition device that uses a DC-DC converter that uses a battery as an input power source to cause a spark discharge between discharge electrodes. This battery voltage checker has a simple configuration that includes a timer circuit that accurately stops spark discharge at a preset predetermined time even if the circuit is closed again after the circuit is closed, and a light emitting element is connected to a part of the timer circuit. The object of the present invention is to provide an ignition device equipped with a circuit.

Another object of the present invention is to provide an ignition device in which a timer circuit and a battery voltage checker circuit operate reliably even when the voltage of a battery as an input power source is low.

To this end, the present invention provides a timer drive winding that is magnetically coupled to the transformer of the DC-DC converter, and connects a rectifier circuit to the timer drive winding to lower the voltage of the battery as an input power source. Take out a large DC voltage, and with this DC voltage
A timer circuit including the PUT is operated, and the light-emitting element is made to emit light by a resistor-divided voltage supplied between the gate and cathode or between the anode and cathode of the PUT, thereby checking battery consumption. It is characterized by the fact that

An embodiment of the present invention will be described in detail below with reference to the drawings.

In Figure 1, 1 is a DC-DC converter,
For example, the blocking oscillation circuit is constructed by using a battery 2 with a nominal voltage of about 1.2V to 1.5V as an input power source via a power switch 3, and comprising an oscillation transistor 4, an oscillation transformer 5, and the like. 6 and 7 are base resistances of the oscillation transistor 4, and 8 is a rectifier diode connected to the secondary side of the oscillation transformer 5.

9 is a spark discharge generating circuit, which includes a capacitor 10;
Step-up transformer 12 with discharge electrode 11 on the secondary side
A first switching element 13 is connected to the output side of the DC-DC converter 1 via a resistor 14 in a series circuit with the primary winding. This first switching element 13 is
PNPN diode (Shockley diode)
13a and a normal diode 13b are connected in parallel with each other with opposite polarities, and the cathode side of the PNPN diode 13a is provided in such a direction that it is connected to the step-up transformer 12. The configuration up to this point is a circuit of a conventionally known ignition device, and operates as follows. In other words, battery 2 as input power source
DC voltage is boosted by DC-DC converter 1, and the boosted DC voltage causes capacitor 1 to
0 and the capacitor 10 is charged in a charging time determined by the CR time constant of the resistor 14. When the voltage reaches a voltage that makes the first switching element 13 conductive, the discharge current of the capacitor 10 flows through the primary side of the step-up transformer 12, and a spark discharge occurs at the discharge electrode 11 due to the voltage induced on the secondary side. This spark discharge is caused by the LC of the capacitor 10 and step-up transformer 12.
By repeating charging and discharging of the capacitor 10 at a predetermined period of the series resonant circuit, the operation is continued while the DC-DC converter is operating.

It goes without saying that the spark discharge generating circuit 9 is not limited to the above-mentioned configuration, but may have the circuit configuration shown in FIG. 2. In short, the capacitor 10 is discharged to a predetermined value by the DC voltage obtained from the DC-DC converter 1, which causes the first switching element 13 to conduct, and the discharge current of the capacitor 10 to the primary side of the step-up transformer 12. Flowing,
It is sufficient that the capacitor 10, the step-up transformer 12, and the first switching element 13 constitute a closed circuit. In addition, the first switching element 1
SCR can also be used for 3. When using an SCR, a circuit configuration as shown in FIG. 3 may be used, for example. In other words, in this circuit, when the oscillation voltage of the oscillation transistor 4 increases and reaches a predetermined value, the
This is designed to trigger the SCR.

17 is a timer drive winding wound magnetically coupled to the transformer 5 of the DC-DC converter 1; 18;
is a rectifier diode connected to this timer driving winding, and together with the smoothing capacitor 19 connected thereto, constitutes a rectifier circuit. The DC voltage obtained from this rectifier circuit needs to be higher than the voltage of the battery 2 as the input power source in order to stably operate the PUT 22, which will be described later. It is wound with the number of turns that satisfies the requirement. 20 is a timer circuit driven by the output voltage of the rectifier circuit consisting of the diode 18 and the capacitor 19;
A second switching element 21 such as an SCR (silicon controlled rectifier) connected between the connection point of the base resistors 6 and 7 of the oscillation transistor 4 of the DC-DC converter 1 and the ground is connected to the second switching element 21 of the DC-DC converter 1. PUT (PROGRAMABLE
UNIJUNC-TION TRANSISTOR) 22. In other words, PUT22
The gate G of PUT22 is connected to the connection point between resistors 23 and 24, the anode A of PUT22 is connected to the connection point between resistor 25 and capacitor 26, and its cathode K
is connected to the second switching element 21 via the resistor 27.
It is connected to the gate G of the SCR that constitutes the . Note that 28 is an operation stabilizing resistor connected between the gate G and cathode K of the second switching element 21.

The timer circuit 20 configured in this manner operates as follows. Now, DC-DC converter 1
When the power switch 3 is closed and a DC voltage higher than the voltage of the battery 2 for driving the timer is taken out, a voltage divided by the resistors 23 and 24 is applied between the gate G and the cathode K of the PUT 22.
A voltage of a capacitor 26, which is charged in a charging time determined by a CR time constant of a resistor 25 and a capacitor 26, is applied between the anode A and the cathode K of the PUT 22. Therefore, after a predetermined period of time has elapsed, the voltage of the capacitor 26 changes from the gate G to the cathode K of PUT.
When the voltage applied between the two switches reaches a predetermined value, the PUT 22 becomes conductive and a predetermined voltage is applied to the gate G of the second switching element 21. 21 becomes conductive. Then, the base voltage of the oscillation transistor 4 is changed to the second switching element 21.
The oscillation is suppressed by the voltage between the anode A and the cathode K, and the oscillation is stopped. In other words, spark discharge at the discharge electrode 11 is stopped. The reason why the base resistors 6 and 7 of the oscillation transistor 4 are divided into two and the second switching element 21 is connected to the connection point is to ensure that the base power supply is suppressed when the switching element 21 becomes conductive. This is to ensure that the oscillation is stopped.

Note that when the PUT 22 becomes conductive, which causes the second switching element 21 to conduct and stops oscillation, no voltage is induced in the timer drive winding 17, so the timer circuit 20 receives the voltage of the battery 2. When only a small voltage divided by the rectifier diode 18 etc. is applied, the timer function stops, and as a result, the second switching element 2
No voltage is applied to the gate G of 1. However, once the second switching element 21 becomes conductive, it remains conductive unless the current flowing therein becomes equal to or less than the holding current, and oscillation does not start again. As is clear from the above explanation of the operation of the timer circuit,
The timer time is CR of resistor 25 and capacitor 26
Since it is determined by a time constant, the value can be set to a desired value. In the timer circuit configured in this way, the voltage of the capacitor 26 is almost discharged after the PUT 22 becomes conductive, so even if the power switch 3 is opened and then immediately closed, the predetermined voltage will not be reached. The timer time is obtained, and the inconvenience of shortening the timer time as in the conventional case does not occur. In other words, PUT2
The voltage of the capacitor 26 after 2 becomes conductive is such that it is charged with a small voltage obtained by subtracting the forward voltage of the rectifier diode 18, the voltage across the resistor 25, etc. from the voltage of the battery 2. The voltage supplied to the timer circuit 20 when the power switch 3 is closed once and then again is set to a value larger than the voltage of the battery 2 by the timer drive winding 17. This allows the timer time to be set with high precision.

Note that the timer circuit 20 is not limited to the above configuration, but may have a configuration as shown in FIG. 4, for example. The device shown in FIG. 4 uses a PUT like the above embodiment, and as the charging voltage of the capacitor 29 increases, the voltage between the gate G and the cathode K of the PUT 22 decreases, and the voltage between the anode A and the cathode K decreases.
When the voltage between cathode K becomes lower than
PUT22 becomes conductive. After the PUT 22 becomes conductive, the voltage charged in the capacitor 29 is discharged through the resistor 31 and between the anode A and the gate G of the PUT 22, so the power switch 3
Even if the circuit is opened and then closed again, the predetermined timer time will be obtained. In other words, PUT22
After the capacitor 29 becomes conductive and the electric charge stored in the capacitor 29 is discharged, the capacitor 29 remains charged with a small voltage obtained by subtracting the forward voltage of the rectifier diode 18 from the voltage of the battery 2. , the voltage supplied to the timer circuit 20 when the power switch 3 is once opened and then closed again is applied to the battery 2 by the timer drive winding 17.
Since the voltage is set to be larger than the voltage of , the timer time can be set with high precision. Note that the resistor 30 determines the charging time of the capacitor 29, and the resistor 32 determines the charging time of the capacitor 29.
At the same time, a constant voltage is applied between the anode A and the cathode K of the PUT 22. In any of the embodiments of the timer circuit 20 described above, the forward voltage is increased by, for example, using a plurality of rectifying diodes 18 connected to the timer drive winding 17 connected in series. This will further improve the accuracy of the timer time.

Furthermore, as is clear from the above description of the operation, the second switching element 21 may be any element that maintains the conductive state once it becomes conductive as long as the current does not drop below the holding current. It goes without saying that a triax or the like can also be used.

33 is a light emitting element such as a light emitting diode, and its anode is connected to the connection point between resistor 23 and resistor 24 to which gate G of PUT 22 is connected, and its cathode is connected to ground to form a battery voltage checker circuit. It is. In the battery voltage checker circuit configured in this way, when the PUT 22 is still in a non-conducting state after the power switch 3 is closed, the gate G of the PUT 22 is connected to the rectifier diode 18 and the smoothing capacitor supplied to the timer circuit 20. The DC voltage obtained from 19 is connected to resistor 23
Since the voltage divided by the resistor 24 is applied to the light emitting element 33, the same voltage as the voltage between the gate G and the cathode K of the PUT 22 is applied to the light emitting element 33, and the light emitting element 33 emits light. become. In other words, while spark discharge is occurring in the discharge electrode 11, the light emitting element 33 emits light. By the way, when the battery 2 is exhausted and the voltage reaches a point where spark discharge does not occur at the discharge electrode 11, the resistor 23 is adjusted so that the voltage applied to the light emitting element 33 becomes a value such that the light emitting element 33 does not emit light. resistance 24
By determining the ratio between the two values, it is possible to know that the battery is depleted when the light emitting element 33 stops emitting light even though spark discharge occurs at the discharge electrode 11.

Note that the connection of the light emitting element 33 that constitutes the battery voltage checker circuit is such that if the circuit around the PUT 22 is configured as shown in FIG. All you have to do is connect it to the connection point. In other words, the light emitting element 33 constitutes the timer circuit 20.
It is sufficient if the connection is made such that light is emitted by a resistance-divided voltage supplied between the gate G and the cathode K or between the anode A and the cathode K of the PUT 22.

Since the ignition device of the present invention is configured as described above, even if the power switch is once opened and then closed again, the spark discharge will always be stopped at a time close to the preset time, and the spark discharge will always be stopped at a time close to the preset time. In addition to ensuring ignition, there is no need to set the timer time well in advance, so no extra power is consumed, and as a result, the life of the battery can be extended. Furthermore, since it operates reliably with a low input power supply, there is no need to increase the number of batteries, and the overall size of the device can be reduced. Furthermore, the battery voltage checker circuit that checks battery consumption can be configured by simply connecting a light emitting element to a part of the timer circuit using PUT, which simplifies the circuit configuration and reduces costs. It has various excellent effects, such as being advantageous.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of an ignition device according to an embodiment of the present invention, FIGS. 2 and 3 are circuit diagrams showing modified examples of the spark discharge generating circuit section of the ignition device according to the present invention, and FIG. FIG. 7 is a circuit diagram showing a modification of the timer circuit section of the ignition device according to the present invention. 1...DC-DC converter, 2...Battery, 3...
...Power switch, 9...Spark discharge generation circuit, 17
...Timer driving winding, 18... Rectifier diode, 19... Smoothing capacitor, 20... Timer circuit, 33... Light emitting element.

Claims (1)

[Claims] 1 A timer circuit that connects a spark discharge generation circuit consisting of a closed circuit of a capacitor, a step-up transformer, and a first switching element to the output side of a DC-DC converter that uses a battery as an input power source, and controls the spark discharge generation circuit. and a battery voltage checker circuit for checking the consumption of the battery, the timer circuit comprising:
It operates with a DC voltage higher than the battery of the input power source taken out from the timer drive winding provided in the transformer of the DC converter via a rectifier circuit, and the base circuit of the oscillation transistor of the DC-DC converter is connected to the ground. The battery voltage checker circuit includes a second switching element connected between the first and second switching elements, and a PUT that makes the switching element conductive after a predetermined period of time. 1. An ignition device characterized in that the ignition device is configured to emit light by a resistor-divided voltage supplied between the anode and the cathode.