JP2003154079A - Electric source for game machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce capacity of an inputting capacitor on a inputting side of an electric voltage converter and to minimize the capacitor in size and decrease in cost by classifying an output into two kinds of output, an output on which maintenance of an electric voltage is necessary and an output on which maintenance of the electric voltage is unnecessary when the electric current is cut off, and by stopping action of the electric voltage convertor for feeding the output on which the maintenance of the electric voltage is unnecessary by a signal for stopping of an electric source. SOLUTION: In an electric source comprising an electric voltage convertor for receiving feeding of an input DC electric voltage and feeding an output DC electric voltage being lower than the input DC electric voltage to a game machine and an input capacitor provided on the input side of the electric voltage convertor, an electric voltage convertor COV3 for feeding an output necessary for maintenance of an electric voltage to the game machine, an electric voltage convertor COV4 for feeding an output unnecessary for maintenance of an electric voltage and an electric power failure detecting circuit 2 for detecting an electric power failure from decrease in the inputted DC electric voltage and outputting the signal for stopping of the electric source are provided and only action of the electric voltage converter COV4 for feeding the maintenance unnecessary output is stopped by the signal for stopping of the electric source.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply for a gaming machine used (built-in) in a gaming machine such as a pachinko machine.

[0002]

2. Description of the Related Art A power supply used for a game machine such as a pachinko machine is required to have a rectified output obtained by rectifying AC24V and DC + 12V and DC + 5V output obtained by reducing the rectified output. The rectified output is used for driving a pachinko ball firing solenoid in a pachinko machine, and the DC + 12V output is a voice,
It is used for display devices, proximity sensors for detecting compensation balls, etc., and DC + 5V output is C for controlling display devices and pachinko machines.
It is used for PU (arithmetic processing unit) and the like.

FIG. 10 shows an example of a conventional power supply for gaming machines. 1 is a full-wave rectifier, C1 is a smoothing capacitor, which rectifies and smoothes an input AC voltage of AC24V to rectify an output terminal T20. Supply rectified output to.
COV1 and COV2 are voltage converters such as DC-DC converters and series regulators. Input capacitors C11 and C21 are provided on the input side and C12 and C21 are provided on the output side.
22 is connected. These capacitors also function as smoothing capacitors that remove AC components. The voltage converter COV1 has DC + 12V at the + 12V output terminal T1.
And the voltage converter COV2 outputs a + 5V output terminal T
Output DC + 5V to 2.

Further, the voltage comparator 3 and the reference voltage source 4 constitute a power failure detection circuit 2, and the reference voltage Vref of the reference voltage source 4 is applied to one input of the voltage comparator 3 to cause the full wave. Rectified output of rectifier 1 (each voltage converter COV1, COV
The input DC voltage of V2) is applied to the other input of the voltage comparator 3, whereby the power failure detection circuit 2 detects a power failure when the rectified output falls below the reference voltage Vref, and outputs a power-off signal as a power-off signal terminal. Issue at T21. The capacitors C1,
Since C11 and C21 are connected to the input side of the voltage converter, the power-off signal is not output due to the momentary voltage drop of the input AC voltage of AC24V, and the power-off signal is output after the power failure of the input AC voltage continues to some extent. coming out. However, the voltage converter CO
The reference voltage Vref is DC + so that a power-off signal is output before the normal voltage conversion operation of V1 and COV2 becomes impossible.
The voltage value is sufficiently higher than 12V.

The power-off signal is also supplied to the timer circuit 5, where the reset signal delayed for a predetermined time is output to the reset signal terminal T22.

The power-off signal and the reset signal are supplied to a CPU that controls a gaming machine such as a pachinko machine, and when the CPU receives the power-off signal, a predetermined power outage process (for example, memory with compensation) When the reset signal is received, the game machine is reset.

FIG. 11 is a waveform diagram showing the input state of AC24V and the state of the voltage at each terminal in the conventional power supply for gaming machine shown in FIG. 10. A power-off signal is not generated by an AC24V momentary interruption, but an AC24V power failure. After a predetermined time, the power failure detection circuit 2 outputs a power-off signal, and the reset signal is output with a delay time determined by the timer circuit 5. Rectified output,
DC + 12V and 5V output must maintain a normal voltage value at least until a reset signal is issued in order to operate normally the proximity sensor and CPU that require voltage retention in the game machine, and for this reason the input capacitor C
It is necessary to make 1, C11 and C21 sufficiently large in capacity.

FIG. 12 shows another example of a conventional power supply for gaming machines, which is a DC + of a voltage converter COV1 as an input of a voltage converter COV2 which outputs DC + 5V to a + 5V output terminal T3.
It provides a 12V output. Other configurations are the same as those of the conventional circuit shown in FIG.

In the circuit of FIG. 12 as well, in order to operate the proximity sensor and the CPU that need to hold the voltage normally, at least until a reset signal is output, rectified output, DC +
It is necessary to keep the 12V and 5V outputs at normal voltage values, and for this reason, it is necessary to make the capacitors C1, C11, C21 on the input side sufficiently large in capacity.

[0010]

In a gaming machine such as a pachinko machine, a load such as a sensor or a CPU that needs to maintain a voltage for a while during a power failure and a load that does not require a voltage such as a voice or a display are provided. However, in the conventional power supply shown in FIGS. 10 and 12, regardless of whether or not the voltage needs to be held, the input capacitor on the input side of the voltage converter is sufficient to hold the required voltage until the reset signal is generated for all loads. It was set to a large capacity. Large capacitors are expensive and large,
This has been an obstacle to the miniaturization and cost reduction of the power supply.

In view of the above points, the present invention divides a voltage-holding output and a voltage-holding unnecessary output into a voltage converter that supplies an output that does not require voltage holding when a power failure occurs. It is an object of the present invention to provide a power supply for a gaming machine, which can reduce the capacity of the input capacitor on the input side of the voltage converter and can be downsized and reduced in cost by stopping the operation.

Other objects and novel features of the present invention will be clarified in the embodiments described later.

[0013]

In order to achieve the above object, the present invention provides a voltage converter which receives an input DC voltage and supplies an output DC voltage lower than the input DC voltage to a game machine, In a gaming machine power supply including an input capacitor provided on the input side of the voltage converter, for supplying a holding-necessary output that requires voltage holding and a holding-unnecessary output that does not require voltage holding to the gaming machine, respectively. In addition to providing a voltage converter, a power failure detection circuit that detects a power failure from the decrease in the input DC voltage and outputs a power-off signal is provided, and only the voltage converter that supplies the output that does not need to be held is stopped by the power-off signal. It is characterized by that.

In the gaming machine power supply, a diode is provided between the input capacitor on the input side of the voltage converter that supplies the unnecessarily held output and the input capacitor on the input side of the voltage converter that supplies the unnecessarily held output. It is advisable to insert the voltage converter into the cathode side of the diode and to supply the holding required output.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a power supply for a gaming machine according to the present invention will be described below with reference to the drawings.

FIG. 1 is a first embodiment of a power supply for a gaming machine according to the present invention and shows the most basic circuit configuration. In this figure, 1 is a full-wave rectifier, COV3 and COV4 are D
A voltage converter such as a C-DC converter or a series regulator, which has an input terminal Vin, an output terminal Vout, and a ground terminal GND, respectively.
3, the rectified output of the full-wave rectifier 1 is applied between the input terminal Vin of the COV 4 and the ground terminal GND, and the input capacitors C31 and C41 are respectively connected. Capacitors C32 and C42 are connected between the output terminals Vout of the voltage converters COV3 and COV4 and the ground terminal GND, and a step-down output is obtained across the capacitors C32 and C42. The voltage converters COV3, COV4 input side capacitors C31, C41 and output side capacitor C
32 and C42 also function as smoothing capacitors for removing AC components.

The voltage converter COV3 supplies a holding-necessary output required to hold a voltage to the gaming machine serving as a load, and a DC output (for example +12) which is stepped down to the output terminal T3.
V, + 5V), and the voltage converter COV4 supplies a holding-unnecessary output that does not require voltage holding. The step-down DC output (for example, + 12V, +5) to the output terminal T4.
V) is issued. The voltage converter COV4 has an operation stop terminal Remote for stopping the conversion operation.

Further, the voltage comparator 3 and the reference voltage source 4 constitute a power failure detection circuit 2, and the reference voltage Vref of the reference voltage source 4 is applied to one input of the voltage comparator 3 to generate the full wave. Rectified output of rectifier 1 (each voltage converter COV3, COV3
The input DC voltage of V4) is applied to the other input of the voltage comparator 3, whereby the power failure detection circuit 2 detects a power failure when the rectified output falls below the reference voltage Vref, and outputs a power-off signal as a power-off signal terminal. Issue at T21. The capacitor C3
Since 1, C41 is connected to the input side of the voltage converter,
The power-off signal is not output when the input AC voltage of AC24V is instantaneously lowered, and the power-off signal is output after the power failure of the input AC voltage continues to some extent. However, the voltage converter COV
The reference voltage Vref is set to a voltage value sufficiently higher than the output voltage values of the voltage converters COV3 and COV4 so that a power-off signal is output before the normal voltage conversion operation of the COV3 and COV4 becomes impossible.

The power-off signal is applied to the operation stop terminal Remote of the voltage converter COV4 via the amplifier (gate) 6 and is also supplied to the timer circuit 5, where the reset signal delayed for a predetermined time is supplied. It is output to the reset signal terminal T22.

Output terminal T3 from the voltage converter COV3
The holding required output supplied to is given to the holding required load of a gaming machine such as a pachinko machine. Also, the voltage converter CO
The holding-unnecessary output supplied from V4 to the output terminal T4 is given to the holding-unnecessary load of a gaming machine such as a pachinko machine.

FIG. 2 shows A in the first embodiment of FIG.
It is a waveform diagram which shows the input situation of C24V, the voltage of each terminal, and the mode of the voltage of an input capacitor. Input capacitor C3
Since C1 and C41 are connected to the input sides of the voltage converters COV3 and COV4, the power-off signal is not output when the input AC voltage of AC24V is momentarily lowered. The power-off signal is output to the power-off signal terminal T21 after the power failure of the input AC voltage continues to some extent. This power-off signal is applied to the operation stop terminal Remote of the voltage converter COV4 via the amplifier 6, and as a result, the voltage converter COV4 stops the voltage conversion operation. Therefore, the output that does not need to be held at the output terminal T4 sharply drops after the power-off signal is generated, but since no load is required to be held in the gaming machine, the output terminal T4 does not cause a problem.

After the power-off signal is generated, the voltage converter COV4
Due to the stop of the operation of, the electric charge charged in the input capacitors C31 and C41 is substantially consumed only by the voltage converter COV3, and the voltage drop of the input capacitor is slow as shown in the voltage waveform of the input capacitor in FIG. become. As a result, the output required to be held at the output terminal T3, which is output from the voltage converter COV3, maintains the desired voltage value with a margin until the reset signal is output. Therefore, the voltage supply to the load connected to the output terminal T3 and needing to hold the voltage can be continued until the reset signal is generated, and the inconvenience on the gaming machine side due to the power failure can be avoided.

In the waveform diagram of FIG. 2, the case of the operation of the conventional circuit (when the operation of the voltage converter COV4 is not stopped) is shown by a dotted line, and the voltage drop of the input capacitor indicates the power-off signal in the operation of the conventional circuit. Since it continues with a constant slope even after the occurrence, it can be seen that there is a problem that the voltage reduction of the output required for holding also occurs earlier. In order to avoid this problem, it is necessary to make the capacitance of the input capacitor large enough.

According to the first embodiment, the voltage converter COV3 is provided for supplying the holding-necessary output that needs to hold the voltage to the gaming machine, and the holding-unnecessary output that does not require the voltage holding is provided. The voltage converter COV4 is provided separately,
Since a power failure detection circuit 2 for detecting a power failure from a drop in the input DC voltage and outputting a power failure signal is provided, and only the voltage converter COV4 that supplies the output that does not need to be held is stopped by the power failure signal, the input capacitor is used thereafter. The electric energy stored in the voltage converter COV3 that supplies the required output
Input capacitor C31,
Even if the total sum of the capacitances of C41 is small, it is possible to surely hold the hold required output at the desired voltage value until the reset signal is generated. Moreover, since the capacity of the input capacitor can be reduced, a small-sized and low-cost power supply can be configured.

FIG. 3 shows a second embodiment of the present invention, which is a rectified output obtained by rectifying AC24V, a DC + 12V holding unnecessary voltage, a DC + 12V holding required voltage, and a DC + 5.
A configuration for supplying a voltage required to hold V is shown. In the figure, 1 is a full-wave rectifier, and C1 is a smoothing capacitor, which rectifies and smoothes an input AC voltage of 24V AC and supplies a rectified output to a rectified output terminal T20.
COV5, COV6, COV7 are voltage converters such as DC-DC converters and series regulators, and input capacitors C51, C61, C71 are provided on the input side of each voltage converter COV5, COV6, COV7, and C52, on the output side.
C62 and C72 are connected. Further, the rectified output is supplied to each of the voltage converters COV5, COV via the diode D1.
6 and COV7. This diode D1 has a fast voltage drop of the rectified output of the output terminal T20 at the time of a power failure, and the voltage converters COV5, COV
6, when it becomes lower than the voltage on the input side of COV7, it is turned off, and each voltage converter COV5, COV6, COV
It has a function of preventing the charge stored in the input capacitors C51, C61, C71 on the 7th input side from flowing out to the rectified output side.

The voltage converter COV5 supplies a holding-unnecessary output that does not require voltage holding to the gaming machine as a load, and supplies a stepped DC + 12V to the output terminal T5. The voltage converter COV6 supplies a holding-required output that requires voltage holding, and supplies the stepped-down DC + 12V to the output terminal T6. The voltage converter COV7 supplies a hold-needed output that requires voltage holding, and supplies the stepped-down DC + 5V to the output terminal T7.

The voltage converter COV5 has an operation stop terminal Remote for stopping the conversion operation, and the voltage converter COV is supplied via the amplifier 6 when a power-off signal is generated.
5 is applied to the operation stop terminal Remote.

The rectified output of the output terminal T20 is used for driving a pachinko ball firing solenoid or the like in a pachinko machine, and the unnecessarily held voltage DC + 12V output of the output terminal T5 is applied to an unnecessarily held load such as a voice or a display. Output terminal T6
The required maintenance voltage DC + 12V output of the above is given to a required maintenance load such as a proximity sensor for detecting a compensation ball (hit ball), and the required maintenance voltage DC + 5V output of the output terminal T7 is given to a required maintenance load such as a CPU.

The rest of the configuration is similar to that of the first embodiment shown in FIG. 1, and the same or corresponding parts will be assigned the same reference numerals and explanations thereof will be omitted.

FIG. 4 shows A in the second embodiment of FIG.
It is a wave form diagram which shows the input situation of C24V, and the mode of the voltage of each terminal. Since the input capacitors C51, C61, C71 are connected to the input sides of the voltage converters COV5, COV6, COV7, the power-off signal is not output even if the input AC voltage of AC24V is momentarily lowered. The power-off signal is output to the power-off signal terminal T21 after the power failure of the input AC voltage continues to some extent. This power-off signal is applied to the operation stop terminal Remote of the voltage converter COV5 via the amplifier 6, and as a result, the voltage converter COV5 stops the voltage conversion operation. For this reason, the output that does not need to be held at the output terminal T5 drops sharply after the power-off signal is generated, but no problem occurs because the output terminal T5 is connected only to the load that does not require voltage holding of the gaming machine.

After the power-off signal is generated, the voltage converter COV5
Of the input capacitors C51, C61, C
The charged charge of 71 is substantially consumed only by the voltage converters COV6, COV7 for supplying the voltage required for holding, and the output required for holding at the output terminals T6, T7 from the voltage converters COV6, COV7 is , The desired voltage value is maintained with a margin until the reset signal is issued. Therefore, the voltage supply to the load connected to the output terminals T6 and T7 and needing to maintain the voltage can be continued until the reset signal is generated, and the inconvenience on the gaming machine side due to the power failure can be avoided.

Also in the case of the second embodiment, the capacity of the input capacitors C51, C61, C71 can be reduced, so that a small-sized and low-cost power source can be constructed.

FIG. 5 shows a third embodiment of the present invention, which is a rectified output obtained by rectifying AC24V, a DC + 12V holding unnecessary voltage, a DC + 5V holding unnecessary voltage, and a DC + 12V.
2 shows a configuration for supplying the required holding voltage of DC and the required holding voltage of DC + 5V. In this case, in the configuration of the second embodiment of FIG. 3, a voltage converter COV8 for supplying a holding unnecessary voltage of DC + 5V to the output terminal T8 and an input / output capacitor C
81 and C82 are added. This voltage converter COV8
Has an operation stop terminal Remote for stopping the conversion operation, and is applied to the operation stop terminal Remote of the voltage converter COV8 via the amplifier (gate) 7 when the power-off signal is generated.

The rest of the configuration is the same as that of the second embodiment of FIG. 3, and the same or corresponding parts will be assigned the same reference numerals and explanations thereof will be omitted.

FIG. 6 shows A in the third embodiment of FIG.
It is a wave form diagram which shows the input situation of C24V, and the mode of the voltage of each terminal.

In the third embodiment of FIG. 5, the input capacitors C51, C61, C7 are activated by stopping the operation of the voltage converters COV5, COV8 after the power-off signal is generated.
The charging charges of C1 and C81 are substantially consumed only by the voltage converters COV6 and COV7 for supplying the voltage required to be held, and it is necessary to hold the output terminals T6 and T7 output from the voltage converters COV6 and COV7. The output maintains the desired voltage value with a margin until the reset signal is issued.
Therefore, the voltage supply to the load connected to the output terminals T6 and T7 and needing to maintain the voltage can be continued until the reset signal is generated, and the inconvenience on the gaming machine side due to the power failure can be avoided.

FIG. 7 shows a fourth embodiment of the present invention, which is a rectified output obtained by rectifying AC24V, a DC + 12V holding unnecessary voltage, a DC + 12V holding required voltage, and a DC + 5.
A configuration for supplying a voltage required to hold V is shown. In this case, the diodes D2 and D3 are added to the configuration of the second embodiment of FIG. 3, the diode D2 is connected in series to the diode D1, and the input voltage is supplied to the voltage converter COV6 via the diode D2. , Diode D1 in series with diode D1
3 is connected to the voltage converter CO via the diode D3.
The input voltage is supplied to V7. In other words, the input capacitor C51 on the input side of the voltage converter COV5 that supplies the hold-unnecessary output, and the voltage converter C that supplies the hold-necessary output.
Input capacitors C61, C on the input side of OV6, COV7
The diodes D2 and D3 are inserted between the voltage converters 71 and 71, and the voltage converters COV6 and COV7 that supply the required holding output are connected to the cathode sides of the diodes D2 and D3.

The rest of the configuration is similar to that of the second embodiment described above, and the same or corresponding parts will be assigned the same reference numerals and explanations thereof will be omitted.

FIG. 8 shows A in the fourth embodiment of FIG.
It is a wave form diagram which shows the input situation of C24V, and the mode of the voltage of each terminal.

In the fourth embodiment shown in FIG. 7, since the diodes D2 and D3 are provided, the DC which is usually the heaviest load is used.
Voltage converter COV5 that supplies + 12V unrequired voltage
Even if the voltage drop of the input capacitor C51 is sudden and becomes lower than the voltage of the input capacitors C61 and C71 of the other voltage converters, the diodes D2 and D3 are turned off, so that the voltage converter COV5 and the input capacitor C51 are It can be disconnected, and the voltage values of the input capacitors C61 and C71 at the time of generation of the power-off signal and after that can be maintained high. In addition, the input capacitors C of the voltage converters COV6 and COV7
Since the diodes 61 and C71 are also separated by the diodes D2 and D3 so as to have independent voltage values, the input capacitors C61 and C71 can be set to appropriate capacitance values and the voltage converters COV6 and COV7 are reset. The operation can be continued independently until the signal is generated.

FIG. 9 shows a fifth embodiment of the present invention, which is a rectified output obtained by rectifying AC24V, a DC + 12V unnecessary holding voltage, a DC + 12V necessary holding voltage, and a DC + 5.
A configuration for supplying a voltage required to hold V is shown. In this case, the diode D2 is added to the configuration of the second embodiment of FIG. 3, and the diode D2 is connected in series to the diode D1,
The input voltage is supplied to the voltage converter COV6 via the diode D2. In other words, the input capacitor C51 on the input side of the voltage converter COV5 that supplies the hold-unnecessary output.
And a voltage converter COV6 for supplying the required output for holding are connected to the cathode side of the diode D2 by inserting a diode D2 between the input capacitor C61 on the input side of the voltage converter COV6 for supplying the required output for holding. There is.

The rest of the configuration is the same as that of the second embodiment described above, and the same or corresponding parts will be assigned the same reference numerals and explanations thereof will be omitted.

In the fifth embodiment shown in FIG. 9, the input side of the voltage converter COV6 which supplies a required voltage of DC + 12V for which the highest voltage value must be maintained from the generation of the power-off signal to the generation of the reset signal. By inserting the diode D2 into the voltage converters COV5 and COV7, even if the voltage drop of the input capacitors C51 and C71 of the voltage converters COV6 becomes steep and becomes lower than the voltage of the input capacitor C61 of the voltage converter COV6, the diode D2 is turned off. Becomes a voltage converter C
The OV5, COV7 and the input capacitors C51, C71 can be disconnected, and the voltage value of the input capacitor C61 at the time of generation of the power-off signal and thereafter can be maintained high. As a result, the output of the voltage converter COV6 can be maintained at a normal value with a margin until the reset signal is generated.

Although the embodiment of the present invention has been described above, it is obvious to those skilled in the art that the present invention is not limited to this and various modifications and changes can be made within the scope of the claims. Ah For example, the number of converters and the output voltage value can be changed according to the type of gaming machine.

[0045]

As described above, according to the power supply for the gaming machine of the present invention, an output that requires voltage holding during a power failure,
The voltage converter that supplies the output that does not require voltage holding is stopped by a power-off signal, which reduces the capacity of the input capacitor on the input side of the voltage converter and reduces the size. And cost reduction.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a basic configuration of a first embodiment of a power supply for gaming machine according to the present invention.

FIG. 2 is a waveform diagram showing an input state of AC24V, a voltage of each terminal, and a voltage of an input capacitor in the first embodiment.

FIG. 3 is a circuit diagram showing a second embodiment of the present invention.

FIG. 4 is a waveform diagram showing an input state of AC 24V and a voltage state of each terminal in the second embodiment.

FIG. 5 is a circuit diagram showing a third embodiment of the present invention.

FIG. 6 is a waveform diagram showing an input state of AC 24 V and a voltage state of each terminal in the third embodiment.

FIG. 7 is a circuit diagram showing a fourth embodiment of the present invention.

FIG. 8 is a waveform diagram showing an input state of AC 24V and a voltage state of each terminal in the fourth embodiment.

FIG. 9 is a circuit diagram showing a fifth embodiment of the present invention.

FIG. 10 is a circuit diagram showing an example of a conventional power supply for gaming machine.

11 is a waveform diagram showing an input state of AC 24 V and a voltage state of each terminal in the conventional circuit of FIG.

FIG. 12 is a circuit diagram showing another example of a conventional power supply for gaming machine.

[Explanation of symbols]

1 Full Wave Rectifier 2 Power Failure Detection Circuit 3 Voltage Comparator 4 Reference Voltage Source 5 Timer Circuit 6, 7 Amplifier C1, C11, C12, C21, C22, C31, C3
2, C41, C42, C51, C52, C61, C6
2, C71, C72, C81, C82 capacitors COV1 to COV8 voltage converters T1 to T8, T20, T21, T22 terminals

Claims (2)

[Claims] 1. A game provided with a voltage converter that receives an input DC voltage and supplies an output DC voltage lower than the input DC voltage to a game machine, and an input capacitor provided on the input side of the voltage converter. In the machine power supply, a voltage converter is provided for each of the holding-necessary output that requires voltage holding to the gaming machine and the holding-unnecessary output that does not require voltage holding, and a power failure occurs due to a decrease in the input DC voltage. A power failure detection circuit that detects and outputs a power-off signal is provided.
A power supply for a gaming machine, wherein only the voltage converter supplying the unnecessarily held output is stopped by the power-off signal. 2. A diode is inserted between the input capacitor on the input side of the voltage converter that supplies the output that does not require holding and the input capacitor on the input side of the voltage converter that supplies the output that does not require holding, and 2. The power supply for gaming machine according to claim 1, wherein a voltage converter that supplies the required output is connected to the cathode side of the diode.