It is a kind of simple and reasonable, safe and practical that the purpose of this utility model is to provide, the safety-type forced-ventilated gas water heater of reliable in action.
The purpose of this utility model can reach by following measure: the utility model comprises that firing circuit, start delay circuit, magnetic valve keep attraction circuit, magnetic valve start-up circuit, spark detection circuit, exhausting motor, motor delay circuit, housing, it is characterized in that: the output of power supply reduction voltage circuit joins with exhausting motor and firing circuit respectively, and interchange ion sense flame circuit keeps attraction circuit with magnetic valve respectively and firing circuit joins.
The purpose of this utility model can also reach by following measure: the isolating transformer B1 in the power supply reduction voltage circuit is loaded on the outside of housing, and interconnects by four mutual connection terminal Z01.The secondary a end of isolating transformer B1 joins by terminal Z01, relay contact J1-1 and exhausting motor.The 2. end of terminal Z01 joins by diode D1 and capacitor C 29, and the grid by controllable silicon D28 in diode D8, resistance R 10 and the firing circuit of 8. holding of Z01 joins, and the elementary winding of the negative electrode of D28 and transformer B2 joins.The 2. end of terminal Z01 joins with the positive pole of capacitor C 33, feedback pin S joins by the negative terminal of resistance R 19 with capacitor C 33 in the interchange ion sense flame circuit, the negative terminal of C33 is by resistance R 18, the input anode of R36 and comparator A1A joins, the output of A1A is by blast switch K2, the base stage of diode D40 and triode Q1 is joined, the grid of the colelctor electrode of Q1 and controllable silicon D28 joins, K2 also joins by resistance R 17 and the base stage of triode Q4, the colelctor electrode of Q4 and magnetic valve are kept coil L1 and are joined, and join by diode D6 and capacitor C 5, C5 joins by resistance R 13 and triode Q2 base stage, the Q2 colelctor electrode joins by resistance R 12 and the base stage of triode Q3, and the colelctor electrode of Q3 and relay coil J1 join.The g end of B2 level of transformer joins with resistance R 8, R8 joins by the input end of comparator A2D in diode D39, resistance R 25, R6 and the spark detection circuit, 6. the output of A2D is held with the input of comparator A2B by capacitor C 4 and is joined, the output of A2B joins by the base stage of triode Q5 in resistance R 2 and the magnetic valve start-up circuit, and the colelctor electrode of Q5 and magnetic valve actuating coil L2 join.The output of comparator A3C and the base stage of triode Q1 are joined in the start delay circuit.
The utility model is described in further detail below in conjunction with accompanying drawing (embodiment):
With reference to Fig. 1, Fig. 2, the utility model comprises power supply reduction voltage circuit 1, firing circuit 2, start delay circuit 3, exchanges ion sense flame circuit 4, magnetic valve is kept attraction circuit 5, magnetic valve start-up circuit 6, spark detection circuit 7, exhausting motor 8, motor delay circuit 9, housing 10 etc.
Isolating transformer B1 in the power supply reduction voltage circuit 1 can provide low-voltage alternating current power supply 27V, 9V; The 9V power supply is supplied with each circuit and is used after three terminal regulator IC1 (7805) voltage stabilizing.Exchanging 36V powers to exhausting motor 8 and firing circuit use.Z01 is 18 mutual connection terminals, is loaded on respectively in housing 10 and the transformer housing 11, water heater is separated with power transformer B1 deposit, and makes things convenient for installation, maintenance and transportation.
With reference to Fig. 3, firing circuit 2 comprises transformer B2, controllable silicon D28, triode Q1, diode D1, D8, D9, capacitor C 29, C36, resistance R 10, R3 etc.; Start delay circuit 3 comprises comparator A3C, capacitor C 2, C28, C35, resistance R 15, R16, R7, R21 etc.; Exchange ion sense flame circuit 4 and comprise comparator A1A, capacitor C 33, C32, C31, resistance R 18, R19, R35, R36 etc.; Magnetic valve is kept attraction circuit 5 and is comprised that triode Q4, blast switch K2, magnetic valve keep pull-in winding L1 etc.; Magnetic valve start-up circuit 6 comprises triode Q5, magnetic valve actuating coil L2 etc.; Spark detection circuit 7 comprises comparator A2D, A2B and peripheral cell, sample resistance R8 etc.; The motor delay circuit comprises triode Q2, Q3, relay J 1, resistance, electric capacity etc.
In firing circuit, when establishing the positive half cycle of power supply, through diode D1 to capacitor C 29 chargings; During negative half period, trigger controllable silicon D28 through diode D8, resistance R 10, make its conducting, C29 produces pilot spark through transformer B2 discharge at the B2 high-pressure side; Triode Q1 is the IGNITION CONTROL pipe, stops igniting during conducting, igniting when ending.
Comparator A2D is a spark tester, and R8 is the spark sample resistance, and comparator A2B starts circuit for the magnetic valve actuating coil.Magnetic valve has actuating coil L2, keeps coil L1.L1 internal resistance big (600 Ω) is used to keep and inhales valve L2 internal resistance few (6 Ω), is used for starting.Its effect is to guarantee ignition circuit under the condition that produces spark, and magnetic valve just might be opened air feed.
Exchange in the ion sense flame circuit, the circuit of gas flame is a unilateral conduction, exchange 27V voltage and be added to the A point through C33, as do not have fire then B point be positive potential, when fire was arranged, A, B point became negative potential, comparator A1A reverses.Flame detection circuit can effectively prevent the interference to feedback signal of bathroom moisture, moisture content, feeds back the protection of pin S shorted to earth in addition.K2 is a blast switch, and closure when promptly blower fan reaches rated speed and forms normal blast provides flare up fire to make triode Q4 conducting, L1 energising, magnetic valve adhesive.
Comparator A3C provides about 10 seconds time-delay for start, but sets up then operate as normal of duty in 10 seconds, otherwise stops.
Triode Q3, Q4 form relay switching circuit.Capacitor C 5 provides time-delay in 10 seconds for motor remains in operation after closing water heater, guarantee to discharge all tail gas outdoor.