JPS584042Y2 - Burner control device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a burner control device that senses the flow of water to a boiler and causes the burner to burn. It has been skillfully constructed to exhibit various effects, and will be specifically explained below based on one embodiment shown in the drawings.

A burner circuit 1 includes an igniter 2, a fan motor 3, an electromagnetic pump 4, and a fuel valve circuit 5 for controlling the electromagnetic pump 4.

6 is a transformer, 7 is a rectifier, 8 is a smoothing capacitor,
9 is a discharge resistor.

10 is a one-point thermo circuit, and the next stage switch circuit 11
control.

12 is a power lamp, and 13 is a thermo circuit.

14 is a flame detection circuit, 15 is a timed spark circuit, and 16 is a safe operation circuit.

17 is a combustion lamp.

Next, to explain the configuration of each circuit, the igniter 2 and fan motor 3 in the burner circuit 1 are both connected in series with triacs 18 and 19 between the power supplies, and the gates of each triac 18 and 19 are connected to each other in series as described below. Phototriacs 22 and 23, which generate voltage due to light emission from the light emitting diodes 20 and 21 of the thermocircuit 13, are connected.

Further, the fuel valve circuit 5 is connected between the power sources in parallel with the fan motor 3 and in series with the triac 19, and the circuit 5 includes a Zener diode ZD1, a charging capacitor 03, and a Darlington-connected transistor Q1. The electromagnetic pump 4 is connected in series with the transistor Q1, and a light emitting diode 24 is connected in parallel with the electromagnetic pump 4.

The one-point thermocircuit 10 includes a thermomistor 25 whose resistance is varied by detecting the outside temperature, and a transistor Q3 whose switching is controlled by the resistance change of the thermistor 25. Q4.
Q5, and when the outside temperature drops, the transistor Q3
．． Q5 is conductive, and the transistor Q6 is connected in parallel with the transistor Q7 connected in series with the power supply line of the switch circuit 11.
It allows conduction.

Further, the water flow switch 26 disposed in the switch circuit 11 is a normally open type switch installed in the waterway of the boiler, and is closed when water is not flowing, and is opened when water is flowing.

The thermo circuit 13 includes a thermistor 2 placed in the hot water supply path of the boiler.
Transistor Q whose switching is controlled by resistance change of 7
9+QlO+Q1□, Ql□, transistor Q1
The conduction of □ causes the light emitting diode 20.21 connected to the collector pole of the transistor Q12 to emit light.

Note that 28 is a variable resistor. The flame detection circuit 14 has a flame detection element 29 such as CDS that senses flame and reduces the resistance value, and has the above-mentioned light emitting diode 24 in series with the flame detection element 29.
A phototransistor 30 is connected to the phototransistor 30, which becomes conductive when light is emitted from the transistor Q14.Q14. A timer circuit 1 consisting of resistor R47 and capacitor C9 in the time spark circuit 15 when the transistor Q16 is cut off.
When charging of the capacitor C9 is completed, the transistor Q18 is turned off and the transistor Q13 connected in parallel with the light emitting diode 21 of the thermocircuit 13 is turned on.

The safe operation circuit 16 has a transistor Q19 that performs switching control based on the flame detection signal of the flame detection element 29 and the deactivation (that is, burner circuit driving) signal of the thermo circuit 13, and a resistor R5□ in parallel with the transistor Q19. A capacitor CIO, which constitutes a timer circuit 21, is arranged.

22 is a transistor Q20. This is a safety lock circuit consisting of Q21゜Q2□. When the transistor Q22 is cut off, the transistor Q8 placed in parallel with the thermistor 27 in the thermo circuit 13 is made conductive. During safe operation, the thermistor 27 is short-circuited and the thermo circuit 13 activates the thermostat. It is something that sends out signals.

Q23 is a transistor that is made conductive by the flame detection signal from the flame detection element 29, and the conduction of this transistor Q23 lights up the combustion lamp 17 constituted by a light emitting diode.

The switch circuit 11 has a PN connected to the power supply line in the previous stage of control circuits such as a thermo circuit 13 that controls the burner circuit 1, a flame detection circuit 14, a timed spark circuit 15, and a safety operation circuit 16.
A P-type transistor Q7 is connected in series, and a resistor R23 is connected between the base of the transistor Q7 and the negative power supply line, and the base and emitter of the transistor Q7 are connected via a water switch 26, which will be described later.

A is the boiler, B is the burner, and C is the water supply channel to the boiler A. The water flow switch 26 is opened and closed by a water flow detection device installed in the water channel C, and the detection device is connected to the support shaft E.
It consists of a pressure receiving plate F that rotates around , and a magnetic body G installed at the free end of this pressure receiving plate F. When water is not flowing to the boiler, the pressure receiving plate F is in a stationary state and the magnetic force of the magnetic body 9 is applied. As a result, the water flow switch 26 is in a closed state.

Then, the pressure receiving plate F is rotated about the support shaft E by water flow, and therefore the magnetic body G is separated from the water flow switch 26, and the switch is opened.

(Dotted line in Figure 2) The present invention has the above-mentioned configuration, and since the water flow switch 26 closes its contacts when water is not flowing, the base potential and emitter potential of the transistor Q7 are equal, and no current flows through the base. Transistor Q7 is in the cutoff state.

Next, when water is supplied to the boiler, the water flow switch 26 opens its contacts, creating a potential difference between the base and the emitter, and current flows through the base, so the transistor Q7 becomes conductive, leading to the next stage thermo circuit 13, flame detection circuit 14, and time spark. The control circuit consisting of the circuit 15 and the safety operation circuit 16 is energized to control the burner circuit 1 and control the combustion of the burner B.

As described above, according to the present invention, the PNP type transistor Q7 connected in series to the power supply line is turned off in response to the opening and closing of the water flow switch 26, thereby controlling the energization to the control circuit that controls the burner circuit 1. , combustion in burner B can be reliably controlled depending on whether or not water is flowing to boiler A.

Also, a resistor R23 is connected between the base of this transistor Q7 and the negative power supply line, and a water flow switch 26 is connected between the base and emitter of the transistor Q7, which is opened when water flow to the boiler A is detected and closed when water is not flowed. Since it is connected, the load current flowing through the contacts of the water current switch 26 only needs to be small, so it is possible to prevent damage to the contacts due to overcurrent that would occur when the water current switch 26 was connected to a power supply line as in the conventional case.

In addition, even if the contacts of the water flow switch 26 were to be welded, in that case transistor Q7 would be cut off in the same way as when water was not flowing to boiler A, so burner B would not burn and would work on the safe side, increasing reliability. This type of circuit can be provided with high cost and safety.

[Brief explanation of drawings]

FIG. 1 is an electric circuit diagram showing an embodiment of the present invention, and FIG. 2 is a sectional view of the water flow detection device. 1... Burner circuit, 11... Switch circuit, 26... Water flow switch, Q7. Q'7・
...Transistor.

Claims (1)

[Scope of utility model registration request] A switch circuit is provided before the control circuit that controls the burner circuit, and the switch circuit is connected to the power supply line in series.
It has an NP-type transistor and a water flow switch that opens when water flow to the boiler is detected and closes when water does not flow, and a resistor is connected between the base of the transistor and the negative power line, and a resistor is connected between the base of the transistor and the emitter. burner control device connected via a water flow switch.