CN101235968A - Intelligent type high energy igniting means - Google Patents
Intelligent type high energy igniting means Download PDFInfo
- Publication number
- CN101235968A CN101235968A CNA2008100185962A CN200810018596A CN101235968A CN 101235968 A CN101235968 A CN 101235968A CN A2008100185962 A CNA2008100185962 A CN A2008100185962A CN 200810018596 A CN200810018596 A CN 200810018596A CN 101235968 A CN101235968 A CN 101235968A
- Authority
- CN
- China
- Prior art keywords
- circuit
- output
- energy
- signal
- network
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Abstract
The invention discloses an intelligent type high-energy ignition device, belonging to igniters. Ignition power supply employs high-frequency inverter power supply electric technique. The invention comprises a surge suppression network, an EMI filter network, an input rectifying smoothing circuit, a high-frequency inverter circuit, an output rectifying smoothing circuit, a detecting circuit for output peak energy and a control circuit for discharging valve value which are sequentially electrically connected, and further comprises a working power supply of wide output range connected with the input rectifying smoothing circuit, a PWM control circuit connected with the high-frequency inverter circuit and a shaping circuit for output peak signal connected with the detecting circuit for output peak energy, and simultaneously the PWM control circuit is further connected with the working power supply of wide output range and the shaping circuit for output peak signal. The intelligent type high-energy ignition device has the advantages that the controlling is accurate, response speed and setting of output features are quite swift and accurate, fluctuating range of adapting electric network is wide, in addition, and an ignition state display and non-polarity touch output in ignition state are provided, and has the advantages of low discharging voltage, large sparkle energy, small contour and volume, convenient operation, safety and reliability, corrosion resistance and the like.
Description
Technical field
The present invention relates to a kind of igniter, specifically is a kind of intelligent type high energy igniting means.It adapts to the ignition energy requirement of multiple different fuel, can be widely used in the various combustion gas of high-tech areas such as electric power, petrochemical industry, metallurgy, Aeronautics and Astronautics, the igniting of oil burner.
Background technology
High energy ignition unit is made up of high-energy igniter, output cable and burning torch; at present; high-energy igniter wherein generally is made up of power supply, Industrial Frequency Transformer, rectification circuit, storage capacitor and flip flop equipment; many defectives of this kind high-energy igniter are: big relatively heavier, the output ignition energy of Industrial Frequency Transformer volume with power network fluctuation fluctuate, uncontrollable and the output transient response is poor to output parameter; can't realize current limiting pressure-limiting, over-current over-voltage protection function, the duration of ignition is short etc.
Summary of the invention
The purpose of this invention is to provide a kind of intelligent type high energy igniting means, its control accuracy, response speed and output characteristics setting are all very flexibly accurately, security and reliability are high, there is fired state to show in addition and fired state passive contact output, can realize communicating by letter with DCS system (scattered control system), improve the service life (about ten times) of equipment, shortened the maintain and replace cycle of equipment greatly.
The object of the present invention is achieved like this: a kind of intelligent type high energy igniting means, form by high-energy igniter, output cable and burning torch.High-energy igniter comprises: the surge of circuit connection suppresses network successively, the EMI filter network, the input rectifying smoothing circuit, high-frequency inverter circuit, the output rectifier smoothing circuit, output peak energy detecting circuit, discharge threshold values control circuit, also comprise the input wide region working power that is connected with the input rectifying smoothing circuit, the pwm control circuit that is connected with high-frequency inverter circuit, the output peak signal shaping circuit that is connected with output peak energy detecting circuit, pwm control circuit also is connected with output peak signal shaping circuit with input wide region working power simultaneously; Wherein: surge suppresses the peak value size that network is used to control surge current; The EMI network is used for suppressing the harassing and wrecking signal; The input rectifying smoothing circuit is used for the 50Hz alternating-current voltage source is transformed to Voltage pulsating direct-current supply, uses for back level inverter; The output rectifier smoothing circuit is exported voltage multiplying rectifier with power transformer and is obtained specified output high direct voltage; Output peak energy detecting circuit is used to finish the control of collection peak power and the igniter state shows signal and fault-signal output; Output peak signal shaping circuit is mainly realized peak detection signal integration broadening, edge output signal filtering.
Operation principle is: when 220V or 110V AC power frequency supply, obtain level and smooth relatively dc source V+ by the input rectifying filter circuit, at this moment accessory power supply is that the wide region working power is started working and provided stable working power to relevant control circuit.This moment, pwm control circuit also entered duty, at first circuit enters the self check process, whether detect the relevant feedback amount normal, enter slow start-up course after the end, pwm pulse is to gradually change from narrow to wide in the slow start-up course, this impulse wave is added on the high-power switch tube after amplifying through overdriving, and makes switching tube according to control law work, goes to promote high frequency transformer output.After high frequency transformer is set up output, also just to finish it and transmitted the task of energy, this mode with inversion is delivered to the electrical network energy in the load, is commonly referred to as high-frequency inversion.The output high pressure also is to set up gradually until the closed loop rated value from low to high in this course.Discharge current transfers to the burning torch semiconductor discharge plug through discharge tube, shielded cable etc., forms high energy electric arc.After igniter quit work, the residual charge on the capacitor was released by bleeder resistance.
Adopted modern the most popular Power Electronic Technique (high-frequency inversion power technology), all very flexibly accurately from control accuracy, response speed and output characteristics setting; Adapt to the power network fluctuation wide ranges, belong to the low-voltage capacitor discharge device.
Good effect of the present invention is: utilized modern high-frequency inversion power technology under lower cost, realized the needs of high-energy ignition, can show output igniting status signal simultaneously accurately and reliably.
Description of drawings
Fig. 1 is a structural representation of the present invention;
Fig. 2 is a high-energy igniter electricity theory diagram;
Fig. 3 is one embodiment of the present of invention circuit diagrams.
Among Fig. 1: 1, high-energy igniter, 2, output cable, 3, burning torch.
The specific embodiment
Below in conjunction with drawings and Examples the present invention is described in further detail.
As shown in Figure 1, intelligent type high energy igniting means is made up of high-energy igniter 1, output cable 2 and burning torch 3 three parts.
As shown in Figure 2, high-energy igniter 1 comprises that the surge of circuit connection suppresses network RT1-1 successively, the EMI filter network, the rectification smoothed filter circuit, high-frequency inverter circuit, the output rectifier smoothing circuit, output peak energy detecting circuit, the discharge threshold control circuit, also comprise the accessory power supply that is connected with the rectification smoothed filter circuit, the pwm control circuit that is connected with high-frequency inverter circuit, the output peak signal shaping circuit that is connected with output peak energy detecting circuit, pwm control circuit also is connected with output peak signal shaping circuit with accessory power supply simultaneously; Wherein: surge suppresses the peak value size that network is used to control surge current; The EMI network is used for suppressing the harassing and wrecking signal; The rectification smoothed filter circuit is used for the 50Hz alternating-current voltage source is transformed to high-voltage dc power supply, uses for back level inverter; The output rectifier smoothing circuit is exported voltage multiplying rectifier with power transformer and is obtained specified output high direct voltage; Output peak energy detecting circuit is used to finish gathers peak power control and igniter state demonstration signal, and fault-signal output; Output peak signal shaping circuit is mainly realized peak detection signal integration broadening, edge output signal filtering.
The circuit diagram of embodiment as shown in Figure 3:
This high-energy ignition system core characteristics are ignition power and whole control structure.
Ignition power adopts high-frequency inversion electricity PWM technology, in conjunction with high-leakage impedance transformer, and supper-fast, extra-high-tension rectifier, new devices such as high sensor carry out the renewal on the control structure.Thereby make that the priming supply structure is little, light weight, high efficiency, plurality of advantages such as high reliability.
On the control mode, ignition power has carried out FEEDBACK CONTROL to a plurality of critical quantity.As: power inverting main circuit current, output peak power, output voltage etc., thereby reach firing characteristic is accurately adjusted.Also very convenient when revising the igniting characteristic curve simultaneously, make the service life of igniter load and reliability all improve greatly.The burning torch that during experiment the conventional point firearm can't be used is connected on this igniter, and after adjusting the ignition power output parameter, nearly 90% burning torch can normally use, and has so also saved operating cost greatly.
Surge suppresses network: the ignition power input is provided with current rectifying and wave filtering circuit, has very big surge current to impact in the moment of starting shooting to electrical network, so the loop must be provided with the inhibition circuit, controls the peak value size of surge current.Main circuit is RT1, and this element is a thermistor, when start self resistance value ratio bigger, can play the effect of limit circuit maximum current.When flowing through certain electric current, this element self produces power attenuation, and temperature rising resistance value reduces thereupon, finally is operated in the stability range.
The EMI filter network: the EMI network is mainly used to suppress the harassing and wrecking signal.In the power grid environment of complexity,, necessarily require product to have anti-harassing and wrecking ability in order to guarantee product working stability, reliable; Simultaneously, equipment self work the time can produce altogether, the DM EMI signal produces electrical network and pollute.This network is set can suppresses also can prevent the harassing and wrecking of equipment self electrical network from of the harassing and wrecking of electrical network outside to equipment, thus the safety of assurance equipment and electrical network and purification.This network mainly is made up of elements such as L1, C1, C2, C3.
The rectification smothing filtering: this partial circuit is made of full-bridge type rectification, big capacity high-voltage electrolytic capacitor.Main effect is with the 50Hz alternating-current voltage source, is transformed to high-voltage dc power supply, uses for back level inverter; Because this igniter equipment is finally exported high energy pulse, the quality quality of the level and smooth power supply of this grade rectification will directly have influence on the transient state regulating effect of entire circuit, thereby influences the job stability of this igniter.This partial circuit mainly is made of elements such as BR1, C3, C4.
Working power is an accessory power supply: be input wide region working power.This part adopts high frequency to integrate the IPM new device, and electric circuit characteristic is operating efficiency, reliability height, and various defencive functions are more perfect etc., also is that main system is stable, one of the condition of reliably working.It mainly is made up of IPM element, high frequency transformer, sampling adjustment, rectifying and wave-filtering etc.
The high-frequency inversion part: main inverter circuit adopts half-bridge structure, in conjunction with high-leakage impedance transformer, works by the PWM mode.This partial circuit mainly is made up of following C7, C10, R8, R11, T1, T2, B2, R7, R25, B1, B2 etc.T1, T2, B1, C7, C10 constitute the half-bridge main circuit, R8, R11 are the equalizing resistances of C7, C10, and R4, R28 are the biasing resistors of T1, T2, and R7, C13, C17, R25 are respectively the absorption network of T1, T2, also have high frequency, high-leakage impedance transformer B1, brachium pontis current sensor B2.The present embodiment electric circuit characteristic is that number of elements is few, and circuit structure is simple, concise; When the power supply input, on C9, C14 filter capacitor, obtain dc source, accessory power supply is started working, and out-put supply Vcc supplies with each relevant control circuit.PWM main control circuit IC1 enters duty after obtaining Vcc, the detection coherent signal is differentiated each Key Circuit earlier fault-free, as detect normal IC1 output pwm signal, produce the two paths of signals that two-way has certain promotion ability through drive circuit, be connected to grid control T1, the T2 of T1, T2 according to control law work by R9, R25 respectively.T1, T2, B1, C7, C10 have constituted the half-bridge main circuit, the wherein also important effect of in circuit, playing every straight, balance, dividing potential drop of C7, C10, and R8, R11 are the equalizing resistances of C7, C10.R4, R28 are respectively the biasing resistors of T1, T2, and R7, C13, C17, R25 are respectively the absorption network of T1, T2, are to prevent MOSFET overvoltage damage in high-frequency work.
B1 is high frequency, high-leakage impedance transformer, and its main power transmission is finished by it.B2 is the brachium pontis current sensor, gets peak inrush current in the brachium pontis to play the effect of protection power device.
The output rectifier smoothing circuit: voltage doubling rectifing circuit is adopted in output.Power transformer is exported voltage multiplying rectifier obtain specified output high direct voltage, this is the classical circuit of high-voltage output power supply, and characteristics are simple in structure, dependable performance.Because the ignition power working method is high energy pulse output, relatively large to the element impact of this part, so will pay special attention to choosing of component parameters and quality.As: rectifier cell V
R〉=10KV, IFSM 〉=10A etc.This part mainly is made of elements such as D1, D2, C3, C5, C6, C8.
The detection of output peak energy: this part is mainly finished and is gathered peak power control and igniter state demonstration signal, and fault-signal output etc.Core component adopts the ultracrystallite material sensors, its stable working state, and the little and signal attenuation degree of discreteness, the distortion factor are little etc., and control provides prerequisite with stability to plurality of advantages to system.This part main element is compositions such as POW1, R49, R48, D16, C31
The shaping of output peak signal: this partial circuit is mainly realized peak detection signal integration broadening, edge output signal filtering;
1) signal integration
Because quite complicated in the high-energy discharge process, it pounces on the signal of catching all is that the high frequency group pulse signal pulse width is very narrow, be very difficult as each pulse signal is controlled, also cause the stability decreases of whole system simultaneously easily.Therefore, this system adopts recurrent pulse control scheme, promptly picks up the pulse signal in one period cycle, carries out integration and averages to amplify and provide the control parameter, delivers to controlled stage.
(2) signal broadening
Because this ignition system possesses various states demonstration and output fault warning function etc.It is to be finished by the high-brightness LED stroboscopic that state shows, if the output high pulse signal cycle little (nanosecond), LED does not respond or be not visible, and having only the pulse train broadening is F≤5Hz signal, could guarantee that LED finishes demonstration work.
Fault-signal output is the broadening signal to be carried out integration again average and compare, and is processed into high and low level signal and goes the work of state of a control relay.
(3) edge output signal filtering
Make system's control accurately reliable, must possess high anti-harassing and wrecking ability.In this system, the intrinsic edge-triggered process of loaded work piece, just critical triggering and critical ending, if this part is not controlled processing, can produce the control mistaken ideas, cause control step-out phenomenon.
Therefore, critical triggering and critical by phenomenon, shadow must be disappeared.This part signal is more weak during work, pulse width; Maximum not being both do not have rule, and frequency-distributed is quite big etc.Utilize these these circuit of phenomenon effectively with its filtering.
PWM control: the igniter control circuit adopts the PWM mode, and the circuit that is adopted is present very mature and stable integrated chip.Defencive function is perfect, have quick response to block end, accurate reference voltage is arranged, two control ports etc. of error adjuster, two-way PWM output and the way of output independently.
Be that output high direct voltage dividing potential drop is obtained the Vf value of feedback in native system, compare, produce error signal by pi regulator and realize pulse-width regulated with reference voltage.If output loading characteristic or parameter change, when requiring system's output valve to change, it is just passable only to need to regulate a reference value.This system can be for adjustable range from 1KV---4KV.Simultaneously, output voltage can be regulated by the PI parameter the response speed of load;
Native system also has another current loop adjuster, system is when work, with the major loop pulsating current by sensor take out, behind the absolute value with the output peak power signal, carry out computing by multiplier, obtain the If feedback quantity, feed back to pwm control circuit and reference set value compares, produce error signal by integral controller, thereby control output maximum current Io reaches the control purpose.If according to some requirement, when needing change system output characteristics, as long as regulate the given benchmark of electric current loop.
In use as need to increase remote computer control also very convenient, this system possess that remote on-off, parameter are given, interfaces such as duty and fault-signal output.
This part main element is made up of IC1, IC3, R12, R13, R22, R26, C12, C19, VR1, Q5, D3, D4, D5, D6 or the like.IC1 adopts the pulse width modulation circuit of TL494 fixed frequency.
Claims (3)
1, a kind of intelligent type high energy igniting means, by high-energy igniter (1), output cable (2) and burning torch (3) are formed, it is characterized in that high-energy igniter comprises: the surge of circuit connection suppresses network successively, the EMI filter network, the input rectifying smoothing circuit, high-frequency inverter circuit, the output rectifier smoothing circuit, output peak energy detecting circuit, discharge threshold values control circuit, also comprise the input wide region working power that is connected with the input rectifying smoothing circuit, the pwm control circuit that is connected with high-frequency inverter circuit, the output peak signal shaping circuit that is connected with output peak energy detecting circuit, pwm control circuit also is connected with output peak signal shaping circuit with input wide region working power simultaneously; Wherein: surge suppresses the peak value size that network is used to control surge current; The EMI network is used for suppressing the harassing and wrecking signal; The input rectifying smoothing circuit is used for the 50Hz alternating-current voltage source is transformed to Voltage pulsating direct-current supply, uses for back level inverter; The output rectifier smoothing circuit is exported voltage multiplying rectifier with power transformer and is obtained specified output high direct voltage; Output peak energy detecting circuit is used to finish the control of collection peak power and the igniter state shows signal and fault-signal output; Output peak signal shaping circuit is mainly realized peak detection signal integration broadening, edge output signal filtering.
2, intelligent type high energy igniting means according to claim 1 is characterized in that the igniter control circuit adopts the PWM mode.
3, intelligent type high energy igniting means according to claim 1, it is characterized in that the half-bridge main circuit that high-frequency inverter circuit is made of T1, T2, B1, C7, C10, equalizing resistance R8, the R11 of C7, C10, biasing resistor R4, the R28 of T1, T2, the absorption network R7 of T1, T2, C13, C17, R25, reach high frequency, high-leakage impedance transformer B1, brachium pontis current sensor B2 forms.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2008100185962A CN101235968B (en) | 2008-02-29 | 2008-02-29 | Intelligent type high energy igniting means |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2008100185962A CN101235968B (en) | 2008-02-29 | 2008-02-29 | Intelligent type high energy igniting means |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101235968A true CN101235968A (en) | 2008-08-06 |
| CN101235968B CN101235968B (en) | 2010-12-29 |
Family
ID=39919772
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2008100185962A Expired - Fee Related CN101235968B (en) | 2008-02-29 | 2008-02-29 | Intelligent type high energy igniting means |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101235968B (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102345878A (en) * | 2010-08-03 | 2012-02-08 | 深圳市合信达控制系统有限公司 | Flame ion current intensity detection and pulse ignition circuit |
| CN101883468B (en) * | 2009-05-04 | 2012-10-03 | 海洋王照明科技股份有限公司 | Control circuit of fluorescent lamp and control method |
| CN103104347A (en) * | 2013-02-18 | 2013-05-15 | 成都泛华航空仪表电器有限公司 | High energy solid state discharge igniting module |
| CN106383799A (en) * | 2016-09-12 | 2017-02-08 | 四川赛科安全技术有限公司 | Special integrated chip for peripheral interface of fire-fighting fire alarm system |
| CN109210568A (en) * | 2018-08-31 | 2019-01-15 | 广州爱孚圣电子科技有限公司 | A kind of Electronic match detection igniter |
| CN109578147A (en) * | 2018-10-31 | 2019-04-05 | 四川泛华航空仪表电器有限公司 | A kind of igniter being automatically repaired |
| CN112709658A (en) * | 2020-12-31 | 2021-04-27 | 陕西航天西诺美灵电气有限公司 | Novel ignition control device and method |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5255174A (en) * | 1991-10-18 | 1993-10-19 | Allied-Signal Inc. | Regulated bi-directional DC-to-DC voltage converter which maintains a continuous input current during step-up conversion |
| CN2760277Y (en) * | 2004-12-10 | 2006-02-22 | 齐和 | High-energy ignition control circuit |
| CN200958453Y (en) * | 2006-08-21 | 2007-10-10 | 重庆隆鑫工业（集团）有限公司 | Double-fuel high-energy ignitor of motorcycle |
| CN201237244Y (en) * | 2008-02-29 | 2009-05-13 | 徐州艾迪科技有限公司 | Intelligent high-energy igniting means |
-
2008
- 2008-02-29 CN CN2008100185962A patent/CN101235968B/en not_active Expired - Fee Related
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101883468B (en) * | 2009-05-04 | 2012-10-03 | 海洋王照明科技股份有限公司 | Control circuit of fluorescent lamp and control method |
| CN102345878A (en) * | 2010-08-03 | 2012-02-08 | 深圳市合信达控制系统有限公司 | Flame ion current intensity detection and pulse ignition circuit |
| CN102345878B (en) * | 2010-08-03 | 2014-03-26 | 深圳市合信达控制系统有限公司 | Flame ion current intensity detection and pulse ignition circuit |
| CN103104347A (en) * | 2013-02-18 | 2013-05-15 | 成都泛华航空仪表电器有限公司 | High energy solid state discharge igniting module |
| CN103104347B (en) * | 2013-02-18 | 2014-12-03 | 成都泛华航空仪表电器有限公司 | High energy solid state discharge igniting module |
| CN106383799A (en) * | 2016-09-12 | 2017-02-08 | 四川赛科安全技术有限公司 | Special integrated chip for peripheral interface of fire-fighting fire alarm system |
| CN109210568A (en) * | 2018-08-31 | 2019-01-15 | 广州爱孚圣电子科技有限公司 | A kind of Electronic match detection igniter |
| CN109578147A (en) * | 2018-10-31 | 2019-04-05 | 四川泛华航空仪表电器有限公司 | A kind of igniter being automatically repaired |
| CN109578147B (en) * | 2018-10-31 | 2022-01-11 | 四川泛华航空仪表电器有限公司 | Ignition device capable of automatically repairing |
| CN112709658A (en) * | 2020-12-31 | 2021-04-27 | 陕西航天西诺美灵电气有限公司 | Novel ignition control device and method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101235968B (en) | 2010-12-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101235968B (en) | Intelligent type high energy igniting means | |
| CN104952667B (en) | A kind of electromagnetic switch intelligent controlling device suitable for low voltage power supply system | |
| CN201237244Y (en) | Intelligent high-energy igniting means | |
| CN203775041U (en) | Alternating-current power source based on dual voltage rectifying and BOOST circuits | |
| CN110174579B (en) | Multifunctional modularized gas discharge tube test circuit and device | |
| CN109167515B (en) | Design method of intrinsically safe Buck converter | |
| CN109682076B (en) | Ignition and heat detection circuit based on Buck principle and gas wall-mounted furnace | |
| CN113315388B (en) | High-power-density long-life high-frequency pulse alternating-current power supply | |
| CN102794546B (en) | Control circuit for gas-shielded welding machine | |
| CN202411628U (en) | Anti-electric shock protective device of electric welding machine | |
| CN205129141U (en) | Take welding set of protection against electric shock | |
| CN204513450U (en) | A kind of firing circuit of ignition | |
| CN210431220U (en) | Capacitive energy release device | |
| CN205792277U (en) | A kind of mine direct current essential safety source circuit | |
| CN203502776U (en) | Application circuit for real-time fan current detection | |
| CN104254167B (en) | LED (light emitting diode) lighting circuit | |
| CN107528485B (en) | Large-current waveform generator | |
| CN206963128U (en) | A kind of low ripple high efficiency magnetron power source | |
| CN114459053B (en) | Electronic ignition and flame detection circuit | |
| CN2896786Y (en) | Electronic ballast for HID lamp | |
| CN203352888U (en) | LED lighting circuit | |
| CN109611213A (en) | A kind of ignition electric nozzle timing aging device | |
| CN204046409U (en) | AC input current surge suppressor | |
| Meng et al. | Calculation and analysis of residual energy storage in intrinsically safe buck converter | |
| CN2445820Y (en) | Electronic smoke purifier |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20101229 Termination date: 20170229 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |