JPS648878B2 - - Google Patents

Description

[Detailed description of the invention]

(a) Industrial Application Field The present invention relates to a remote control device used for thermal equipment such as a hot water boiler. (b) Background technology Conventionally, for example, as shown in Fig. 1, in the control circuit of a hot water boiler, a manually reset type safety switch b is connected to one end (positive side) of a DC power supply a, and the normally closed contact of the safety switch b is connected to one end (positive side) of the DC power supply a. A combustion control circuit c is connected between b1 and the other end (negative side) of the DC power source a, and an alarm circuit d is connected between the normally open contact b2 and the other end of the DC power source a. The combustion control circuit c includes a prepurge operation relay e, a combustion operation relay f, and a safety relay g.
Sequence circuits, switching circuits, memory circuits, temperature control circuits for operating each relay,
It includes a timer circuit, etc., and safety relay g operates when the temperature of hot water rises abnormally or when ignition cannot be detected despite combustion supply, and switches safety switch b from normally closed contact b1 to normally open contact b2. Switch to Further, the combustion control circuit c lights up the operation lamp h by being supplied with power from the normally closed contact b1 to notify that the hot water boiler is in operation. on the other hand,
The alarm circuit d is provided with an oscillator circuit, and when the safety switch b is switched, power is supplied from the normally open contact b2 to cause the alarm lamp i to blink, thereby notifying the user of an abnormal state. By the way, in the conventional example described above, two light emitting elements, the operation lamp h and the alarm lamp i, are used to operate and display alarms, so the installation work of the light emitting elements is troublesome and the cost is high. In particular, when the operation lamp h and alarm lamp i are installed and monitored at a location far from the hot water boiler as shown in the figure, four wires are required, which makes the wiring work difficult. An expensive multi-conductor cord had to be used. Furthermore, when it is installed in a remote controller having an operation switch or the like, there is a drawback that a multi-conductor cord is required. (c) Purpose of the Invention This invention was made to solve the above-mentioned drawbacks of the prior art, and uses two remote control wires that serve as a power supply line and a transmission line to transmit operation signals from the remote control side to the main body side. transmission and the transmission of abnormal signals from the main unit to the remote control without interfering with each other.Furthermore, the remote control can determine whether the operation switch on the remote control is turned on and whether there is an abnormality on the main unit. The purpose is to enable identification using one display element on the side. (D) Main points of the invention The feature of the present invention is that in a remote control device having a remote control circuit and a main body side control circuit connected by two remote control wires that also serve as a power supply line and a transmission line, is equipped with an operation switch connected between two remote control wires, a series circuit of a resistor and a light emitting element, and a variable resistance circuit connected in parallel with the resistor and light emitting element.The control circuit on the main body side is equipped with a DC power source and , a current detection circuit that detects the current flowing in the remote control wire, an operation control circuit that controls the operation and operating status of the equipment according to the output of this current detection circuit, and a safety system that forcibly stops the equipment when there is an abnormality in the equipment. A control means and a power supply control circuit that continuously supplies DC power supply voltage between the two remote control lines at all times, and intermittently supplies DC power supply voltage between the two remote control lines when the equipment is forced to stop using the safety control means. Therefore, the two remote control wires, which normally serve as power supply wires, are used to transmit operation signals (operation and operating status signals) from the remote control side to the main unit, and in the event of an abnormality in which the equipment is forced to stop. Two remote control wires are used to transmit abnormal signals from the main unit side to the remote control side, so that both transmissions do not interfere with each other, and one display element on the remote control side indicates operation and abnormalities. . (E) Embodiment of the Invention Hereinafter, an embodiment in which the present invention is applied to a control circuit for a hot water boiler will be described based on the drawings. In FIG. 2, S is a control circuit on the main body side, 1 is an AC power source, 2 is a power switch, 3 is a drive device that drives a combustion device such as a burner or a fan of a hot water boiler,
4 is a step-down transformer; 5 is a DC power supply circuit that performs AC-DC conversion, consisting of a rectifier, a constant voltage circuit, etc.;
A common terminal 6c is connected to the output end of the DC power supply circuit 5, and 6 is a single-pole, double-throw, manual return type safety switch equipped with a normally open contact 6a and a normally closed contact 6b. 7 is an oscillation circuit (power supply control circuit), which includes an alarm power supply terminal 8 connected to a normally open contact 6a and a normally closed contact 6b.
A first and a second diode 10 in the forward direction with respect to the DC power supply circuit 5 are connected to the operating power supply terminal 9 connected to the operating power supply terminal 9, respectively.
A first bus bar 12 is connected to the first bus bar 12 via a power supply terminal 11, a second bus bar 14 is connected to a grounded reference terminal 13 and sets a reference potential of 0V, and power terminals BA and BB are connected to both bus bars 12 and 14, respectively. op amp
OP1, a resistor 15 and a capacitor 16 connected in series between the output terminal C1 of the operational amplifier OP1 and the second bus 14, as well as resistors 17 and 18, and an intermediate connection point 19 between the first bus 12 and the resistors 17 and 18. Resistor 20 connected between, connection point 19 and operational amplifier
Resistor 21 connected between non-inverting input terminal A1 of OP1 and inverting input terminal B of operational amplifier OP1
Intermediate connection point 2 between 1 and resistor 15 and capacitor 16
2 and a resistor 23 connected between the two. 24 is a switching circuit (current detection circuit), which includes resistors 25 and 26 connected in series between the operating power supply terminal 9 and the second bus bar 14, and resistors 27 and 2.
8 and NPN transistor 29, the base is connected to the intermediate connection point 30 between the resistors 25 and 26, the collector is connected to the connection point 2 via the resistor 31, and the emitter is connected to the second bus line 1.
NPN transistors 32 connected to 4, respectively;
The emitter is the operating power supply terminal 9, and the base is the resistor 2.
A PNP transistor 35 whose collector is connected to the output terminal 34 is connected to the intermediate connection point 33 of 7 and 28, respectively.
and a resistor 36 connected between the base of the transistor 29 and the second bus line 14. 37 is a remote control circuit for a remote control installed far from the hot water boiler, and input/output terminal 3
8 and 39 are connected to main body side connection terminals 42 and 43 via remote control wires 40 and 41, respectively. In addition, the connection terminal 42 is connected to the operational amplifier via resistors 44 and 45.
Connected to output terminal C1 of OP1, connection terminal 43
are connected to the second bus line 14 and the base of the transistor 29 via resistors 46 and 47, respectively. The remote control circuit 37 includes a full-wave rectifier 48 whose input terminals d1 and d2 are connected to input/output terminals 38 and 39, an operation switch 49, a resistor 50, and a resistor 50 connected in series between the output terminals d3 and d4 of the full-wave rectifier 48. A light emitting diode 51 as a light emitting element, a series circuit of a resistor 50 and resistors 52 to 55 connected in parallel to the light emitting diode 51, and a temperature setting switch that short-circuits one to three of the resistors 53 to 55 depending on the input position. 56, and resistors 52 to 55
and temperature setting switch 56 constitute a variable resistance circuit VR. 57 is a temperature setting circuit (current detection circuit);
An operational amplifier OP whose non-inverting input terminals A2 to A4 are commonly connected to the connection terminal 43 via a resistor 58.
2 or OP4 and the positive feedback resistor 59 of the operational amplifier
61 and intermediate connection point 62 between resistors 44 and 45
and the second bus bar 14, and intermediate connection points 63 to 65 are operational amplifiers OP2 to OP2, respectively.
Resistors 66 to 69 are connected to the inverting input terminals B2 to B4 of OP4, and analog switches AS1 to AS3 have their input terminals connected to the output terminals C2 to C4 of the operational amplifiers OP2 to OP4, respectively.
, analog switch AS1, analog switch
Series circuit of AS2 and resistor R1, series circuit of analog switch AS3 and resistor R2, and resistor R
3 are connected in parallel to set signal lines 70 and 71. Note that the operational amplifiers OP1 to OP4 use a single power supply multi-power operational amplifier IC that shares the power supplied to the operational amplifier OP1. 72 is a combustion control circuit (operation control circuit);
A flame detection element 73 such as a CDS, a hot water temperature detection element TH such as a thermistor, and setting signal lines 70 and 71 are connected to the input side, and based on these input signals, a pre-purge operation relay 74 and a combustion operation relay are activated. 75
is operated to give a drive command for the burner and fan to the drive device 3, and in the event of an abnormality, a safety relay (safety control means) 76 is operated to switch the safety switch 6 from the normally closed contact 6b to the normally open contact 6a. This includes sequence circuits, switching circuits, memory circuits, temperature control circuits, timer circuits, etc. Next, the operation of the above-described embodiment will be explained. Assuming that the power switch 2 is always closed, the normally closed contact 6b of the safety switch 6, the operating power terminal 9, and the second diode 11 are connected between the first bus 12 and the second bus 14 from the DC power circuit 5. A predetermined DC voltage is supplied through the power supply. At this time, the transistor 32 of the switching circuit 24 is connected to the operating power supply terminal 9.
Since the base is biased by the resistors 25 and 26 that divide the voltage of
The voltage of the first bus 12 is emitting an "H" output, and the oscillation of the oscillation circuit 7 has stopped.
Further, when the operation switch 49 is open, the light emitting diode 51 is turned off, indicating that the hot water boiler is in a stopped state, and the base potential of the transistor 29 is equal to the potential of the second bus bar 14, and the transistor 29 is turned off. The transistor 35 is not conductive and the output terminal 34 and the reference terminal 1 are cut off.
Since there is no voltage across 3, the combustion control circuit 72 is not activated and the drive device 3 is also stopped. When the operation switch 49 is turned on in such a state, the voltage at the connection point 62 is divided by the combined resistance of the resistors 45 and 46 and the remote control circuit 37 because the operational amplifier OP1 is outputting an "H" output. , a current flows through the light emitting diode 51, causing the light emitting diode 51 to light up (continuously), indicating that the hot water boiler has entered the operating state. Also, input/output terminal 3
8 and 39 and the connection terminals 42 and 43, a base bias is applied to the transistor 29, and the transistor 29 becomes conductive, thereby making the transistor 35 conductive. Therefore, the DC power supply circuit 5 is connected between the output terminal 34 and the reference terminal 13. The power supply voltage is supplied, and the combustion control circuit 72 starts operating. Furthermore, depending on the closing position of the temperature setting switch 56, the operational amplifiers OP2 to OP4 and the analog switches AS1 to AS3 of the temperature setting circuit 57 operate as shown in Table 1, and the setting signal lines 70, 71 are connected to the combustion control circuit 72. A type of impedance signal is sent.

[Table] In Table 1, "H" is a state in which the voltage at the non-inverting input terminal of the operational amplifier is higher than the voltage at the inverting input terminal, and the voltage of the first bus 12 appears at the output terminal, and "L" In the opposite case, the output terminal of the operational amplifier is at the same potential as the second bus 14. When the operation switch 49 of the remote control circuit 37 is turned on in this manner, the combustion control circuit 72 is energized and starts operating, and while monitoring the presence or absence of ignition based on the input from the flame detection element 73, the hot water temperature detection element
The input from the TH is compared with the impedance input from the setting signal lines 70 and 71 to instruct the drive device 3 to perform pre-purge or combustion operations. For example, the hot water temperature is controlled as shown in Table 2 by changing the impedance of the setting signals 70 and 71 depending on the ON position A or D of the temperature setting switch 56.

[Table] In other words, when the temperature setting switch 56 is in positions A to C, the hot water temperature is 80°C and 60°C, respectively.
℃, maintained at 40℃, and 5-10℃ when put into d
This prevents freezing in the winter. If any abnormality occurs while the operation switch 49 is being turned on, the combustion control circuit 72 operates the safety relay 76, and the safety switch 6 is switched from the normally closed contact 6b to the normally open contact 6a. Therefore, the operating power supply terminal 9 loses its voltage, and instead, the predetermined DC voltage of the DC power supply circuit 5 is supplied to the alarm power supply terminal 8.
Then, a DC voltage is supplied to the first bus bar 12 via the first diode 10, but the second diode 11 acts in the opposite direction and no voltage is applied to the switching circuit 24, and the transistors 29 and 3
0 and 35 are all cut off to stop the operation of the combustion control circuit 72, and at the same time, the short circuit of the capacitor 16 of the oscillation circuit 7 is released. Therefore, all combustion operations in the hot water boiler are stopped, and the hot water boiler is maintained in a safe state. In addition, the oscillation circuit 7 alternately outputs "H" and "L" to the output terminal C1 of the operational amplifier OP1 by charging and discharging the capacitor 16 via the resistor 15.
In order to generate the output, the light emitting diode 51 of the remote control circuit 37 is blinked to indicate the abnormal state. In this case, the oscillation output of the oscillation circuit 7 is also supplied to the input side of the temperature setting circuit 57, but since the combustion control circuit 72 has stopped operating, there is no problem. Then, after turning off the power switch 2 and repairing the abnormality, manually turn the safety switch 6 to the normally closed contact 6.
By returning to b, the hot water boiler resumes normal operation. According to this embodiment, while the operation switch 49 is turned on, the direct current of the DC power supply circuit 5 is connected between the first bus 12 and the second bus 14 via either the operation power supply terminal 9 or the alarm power supply terminal 8. During normal operation when voltage is supplied and the safety relay 76 does not operate, the oscillation of the oscillation circuit 7 is stopped by the action of the switching circuit 24, and the output of the oscillation circuit 7 causes the light emitting diode 5 to
1 is lit continuously to indicate that the hot water boiler is in normal operation. On the other hand, when the safety relay 76 operates and an alarm signal is generated in which the voltage at the operating power supply terminal 9 disappears, the oscillation stop of the oscillation circuit 7 by the switching circuit 24 is released, and the oscillation output of the oscillation circuit 7 is used to connect the remote control wires 40 and 41. The voltage changes periodically,
The light emitting diode 51 blinks to indicate an abnormal state. Therefore, the presence or absence of operation and the presence or absence of an alarm can be confirmed with a single light emitting diode 51 from a location away from the hot water boiler, and only two remote control wires 40 and 41 are required, making wiring work simple and inexpensive. . In the above-described embodiment, since the full-wave rectifier 48 is connected to the input/output terminals 38, 39 of the remote control circuit 37, the remote control wire 40, Even if the connection by 41 is mistakenly reversed as shown by the chain line, there is no problem in controlling the lighting of the light emitting diode 51 having the polarity, and there is no fear of malfunction due to wiring error.
Further, by adjusting the closing position of the temperature setting switch 56, only the impedance signal is input from the setting signal lines 70, 71 to the combustion control circuit 72 as a temperature setting signal.
Even if 41 is very long, there is no need to worry about being affected by noise. Furthermore, two remote control wires 40, 4
In addition to the lighting control signal for the light emitting diode 51 mentioned above in Section 1, signals for operation stop and temperature setting can be transmitted simultaneously, making it possible to perform complex remote control with a cheap and easily available two-core cord, making it extremely practical. I'm here. (F) Effects of the Invention As explained above, the present invention uses two remote control wires that serve as a power supply line and a transmission line, and the main body side normally detects current changes in the remote control line using a variable resistance circuit. By doing this, operation and operating status signals are transmitted from the remote control side to the main unit side, and when an abnormality occurs in the equipment and the equipment is forcibly stopped, an abnormality signal is transmitted from the main unit side to the remote control side. While using two remote control wires that are inexpensive and easy to wire, it is possible to prevent both signal transmissions from interfering with each other. In addition, when the operation switch is turned on and the equipment is in operation, power is supplied to the display element of the remote control circuit via the remote control line, and when the equipment is normal, the display element is lit continuously, and when there is an abnormality in the equipment. Sometimes, voltage is intermittently supplied between two remote controller lines to make the display element blink, so one display element on the remote controller can be used to indicate whether the operation switch is turned on or not and whether there is an abnormality in the equipment. Not only can it be clearly identified even at a distance from the remote control, but it also eliminates the need for signal superimposition or discrimination circuits for identification, and is useful because it can be constructed at low cost.

[Brief explanation of drawings]

FIG. 1 is an electric circuit diagram for explaining a conventional example.
FIG. 2 is an electrical circuit diagram showing an embodiment in which the present invention is applied to a control circuit for a hot water boiler. 5...DC power supply circuit (DC power supply), 7...Oscillation circuit (power supply control circuit), 24...Switching circuit (current detection circuit), 37...Remote control circuit, 4
0,41... Remote control line, 49... Operation switch, 51... Light emitting diode (light emitting element), 57
... Temperature setting circuit (current detection circuit), 72 ... Combustion control circuit (operation control circuit), 76 ... Safety relay (safety control means), S ... Main body side control circuit,
VR...variable resistance circuit.

Claims (1)

[Claims] 1. In a remote control device that has a remote control circuit and a main body control circuit connected by two remote control lines that also serve as a power supply line and a transmission line, the remote control circuit has an operation switch connected between the two remote control lines. ,
A series circuit of a resistor and a light emitting element, and a variable resistance circuit connected in parallel with the resistor and light emitting element are provided. An operation control circuit that controls the operation and operating status of the equipment according to the output of the current detection circuit, a safety control means that forcibly stops the equipment when there is an abnormality in the equipment, and two remote controllers that control the voltage of the DC power supply at all times. 1. A remote control device comprising: a power supply control circuit that continuously supplies voltage between the two remote control wires, and intermittently supplies DC power voltage between two remote control wires when a device is forcibly stopped by a safety control means.