-
Fairchild AN-7511 - page 1
©2002 Fairch ild Semicond uctor Corpo ration Application No te 7511 Rev. A1 Insulated-Gate Transistors Sim plify AC-Motor Speed Control An IGT’ s f e w input requirements and low On-state resistance simplify driv e circuitry and increase po wer efficie ncy in mo tor- control applications . The v oltage-controlled, MOSFET -like input and transf e ...
-
Fairchild AN-7511 - page 2
©2002 Fairch ild Semicond uctor C orpo ration Application N ote 7511 Rev. A1 F or optically isolated “rela y-action” s witching, it makes sense to replace the phototransis tor optocoupler with an H11L1 Schmitt-trigger optocoupler (Figure 2B).) For applica tions requiring e xtremely high is olat ion, you c an use an optic al f iber to provide t ...
-
Fairchild AN-7511 - page 3
©2002 Fairch ild Semicond uctor C orpo ration Application N ote 7511 Rev. A1 FI GUR E 5 A. Y IELDING 4-kV ISOLA TI ON, A P IEZOELECTRIC COUPLER P RO VIDES TRANSFO RMER-LIKE PE RFORMANCE AND AN ISOLA TED PO WER SU PPL Y . FIGURE 5B. THIS CIRCUIT PROVIDE S THE DRIVE FOR THIS ARTICLE’S MOTOR-CONTROL CIRCUIT. CONTROL INP UT ON OFF GFOE1A1 EMITTER (D ...
-
Fairchild AN-7511 - page 4
©2002 Fairch ild Semicond uctor C orpo ration Application N ote 7511 Rev. A1 A piez oelectric c oupler op erationa lly simila r to a puls e-train dri ve transfor mer, b ut po tent ially less cos tly in hi gh volu me is a sm all, effi cien t device with iso lati on c apabi lit y rang ing to 4kV . What’s more, unlike opto coupl ers, t hey re quir ...
-
Fairchild AN-7511 - page 5
©2002 Fairch ild Semicond uctor C orpo ration Application N ote 7511 Rev. A1 Piezoelec tric Coupler s Pr ovide 4-kV Isolation Using a high-frequen cy oscil lator f or pulse-train driv e Figure 6B yields unlimite d on-time capa bility . Howe ver , the scheme requires an os cillator that can b e turned on a nd off by th e control lo gic. A diode or ...
-
Fairchild AN-7511 - page 6
©2002 Fairch ild Semicond uctor C orpo ration Application N ote 7511 Rev. A1 P o lyphase motors, controlled by solid-state, adjustable-fre- quency ac drives, are used e xtensively in pumps, conv ey ors, mills, machine tools and robotics applications. The specific con- trol method co uld be either 6-step o r pulse-width modu lation. This section de ...
-
Fairchild AN-7511 - page 7
©2002 Fairch ild Semicond uctor C orpo ration Application N ote 7511 Rev. A1 It’ s impr actical, ho wev er , to rate an in ve rter based on lock ed- rotor curren t. Y ou can a vo id this neces sity by a djusting th e s witchi ng regula tor’ s o utput v oltage and b y provi ding a fi xe d outp ut-cu rre nt li mit s ligh tly h igh er t han t he ...
-
Fairchild AN-7511 - page 8
©2002 Fairch ild Semicond uctor C orpo ration Application N ote 7511 Rev. A1 Use 6-Step Drive F or Speed-I n variant Tor que Figur e 10A shows th e inver ter c irc uit co nfig ured for th is example. Di odes D 1 thro ugh D 6 ca rry the sam e p eak cur r ent as the IGTs; con sequentl y , they’ re rated to hand le peak cur- rents of a t least 8.7 ...
-
Fairchild AN-7511 - page 9
©2002 Fairch ild Semicond uctor C orpo ration Application N ote 7511 Rev. A1 . FIGURE 13A. MOTOR CURRENT AND VOLTAGE ARE SHOWN HERE, FOR LIGHT LOADS FIGURE 13B. MOTOR CURRENT AND VOLTAGE ARE SHOWN HERE, FOR HEAVY LOADS. T o complet e the design of the 6-step moto r drive, it’s necess ary to consider protection circu itry for the ou tput IGT s. T ...
-
Fairchild AN-7511 - page 10
©2002 Fairch ild Semicond uctor C orpo ration Application N ote 7511 Rev. A1 FIGURE 15A. THIS ALL-ENCOMPASSING PROTECTI ON SYSTEM PROVIDES THREE I NDEPENDENT SHUTDOWN FUNCTONS - ONE EACH FOR THE UPPER AND LOWER IGTS AND THE HIGH -VOLTAGE SUPPLY. FIGURE 15B. THIS CIRCUIT P ROVIDES CHOPPER DRI VE FOR THE COPPER-WIRE SENSOR IN FIGURE 15A. FIGU RE 15C ...
-
Fairchild AN-7511 - page 11
©2002 Fairch ild Semicond uctor C orpo ration Application N ote 7511 Rev. A1 Latch-Up: Hints, Kinks and Caveats The IGT is a rugged device , requiring no snubber network when operating w ithin its publishe d safe-oper ating-area (SOA) r atings. Within the SO A, the gate emitter voltage controls the collector current. In f act, the IGT can conduct ...
-
Fairchild AN-7511 - page 12
©2002 Fairch ild Semicond uctor C orpo ration Application N ote 7511 Rev. A1 FIGURE 17. USE THIS LATCHING-CURRENT TESTE R TO TEST IGTS NONDESTRUCTIVELY. Q 1 ’S BASE-DRIV E PULSE WIDTH IS GREAT- ER THAN THAT OF THE IGT’S GATE DRIVE, SO THE IGT UNDER TEST IS S WITCHED THROUGH Q 1 WHEN REVERSE-BIAS LATCH-UP OCCURS. PULSE GENERA TO R PULSE GENERA ...
-
Fairchild AN-7511 - page 13
DISCLAIMER FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO A NY PRODUCTS HEREIN TO IMPROVE RELIABILITY , FUNCTION OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICA TION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS P A TENT RIGHTS, NOR ...
¿Tienes una pregunta acerca de Fairchild AN-7511?
Utiliza el formulario que se encuentra abajo
Si con la ayuda del manual de instrucciones encontrado no has podido solucionar tu problema con Fairchild AN-7511, haz una pregunta utilizando el formulario que se encuentra abajo. Si alguno de los usuarios ha tenido un problema parecido con Fairchild AN-7511 probablemente compartirá una forma de solucionarlo.