Page 344 - Electrician -1st Year - TT

¥_õhPp @l¬dÏYu£ ÁhPo (Digital Frequency Meter)

úSôdLeLs: ClTôPj§u Ø¥®p ¿eLs ùT\ úYi¥V A±Ü §\uLs
• ¥_õhPp @l¬dÏYu£ ÁhP¬u úYûX ùNnÙm ®Rm ϱjÕ áßRp
• ¥_õhPp @l¬dÏYu£ ÁhP¬u block YûWTPjûR ®Y¬jRp.

GkR JÚ periodic AûX Y¥YjûRÙm (wave- ùNÛjRlTÓ¡\Õ. CÕ LÜuPÚdÏ
form) A[kÕ Lôh£TÓjÕm LÚ® ¥_õhPp L¥LôWUôL ùNVpTÓ¡\Õ.
A[dÏm LÚ®L[ôÏm. JÚ ¨oQ«dLlThP
ERôWQUôL úLh £L]Xõu úSWm N¬VôL JÚ
úSWj§p ùR¬VôR Cu×h £d]ûX
®Sô¥VôL CÚdÏm úTôÕ ùR¬VôR Cu×h
LÜiPÚdÏ Aàl© CVeÏYÕ CRu
£d]p 600Hz NÕW AûX (square wave)
RjÕYm BÏm.
Y¥YUôL CÚdÏm. JÚ ®Sô¥«u Ø¥®p
ùR¬VôR Cu×h £d]ûX LÜuPÚdÏ LÜuPo 600 YûW Gi¦ ®Óm. CÕ
N¬VôL JÚ ®Sô¥ gate ùNnÙm úTôÕ ùR¬VôR Cu×h £d]Xõu N¬Vô]
LÜiP¬p LÜuhL°u Gi¦dûL @l¬dÏYu£ BÏm. LÜuPûW '0' þ®p
AàU§dLlThPôp AÕ Cu×h £d]Xõu AûUdL t þp LÜiPÚdÏ ÑjRUô] Õ¥l×
0
@l¬dÏYu£VôÏm. AND ApXÕ OR úLh (pulses) TVuTÓjRlTÓ¡\Õ. AûX Y¥Ym
(gate) A[Ü ùR¬VôR Cu×h £d]ûX Fig 2þp LôhPlThÓs[Õ. t þdÏ Øu× GATE
1
LÜuPÚdÏ AàU§lTRôp gated Gu\ TRm ENABLE £d]p Ïû\YôL CÚdÏm. AR]ôp
(term) YkRÕ. (Fig 1) AND gate þu AÜh×h Ïû\YôL CÚlTRôp
LÜuPo GiQôÕ. GATE ENABLE t t t
1 0 2
þ®XõÚkÕ CkR úSW CûPùY°«p
t = (t - t ) A[Ü ùR¬VôR Cu×h £d]p
2 1
Õ¥l× AND gate Y¯VôL ùNpYRôp AND gate
LÜuPWôp GiQlTÓ¡\Õ.

t dÏ ©\Ï AND gate þu AÜh×h §ÚmTÜm
2
Ïû\kÕ LÜuPo GiÔYûR ¨ßj§
®Ó¡\Õ. CR]ôp 't'CûPùY°«p HtTÓm

Õ¥l×Lû[ GATE ENABLE £d]ûX GiQ
úYiÓm. Ø¥®p Cu×h £d]Xõp
@l¬dÏYu£ûV úSW¥VôL A[d¡\Õ.
Block YûWTPjûR ®Y¬jRp (Discription of
block diagram): @l¬dÏYu£ LÜuP¬u block
YûWTPm RWlThÓs[Õ. (Fig 1). C§p JÚ
LÜuPo display/decoder ªuÑtß, L¥LôW
B£úXhPo JÚ ¥ûYPo Utßm JÚ AND
úLh (gate) B¡VûYLs Es[]. ùTôÕYôL
LÜuPo Cascaded Binary Coded Decimal (BCD)
LÜuPoL[ôp ùNnVlThÓs[Õ. Decoder unit
BCD AÜh×hûP ùP£ùUp display þVôL
Uôtß¡\Õ.

AND úLh¥u JÚ legþ«p JÚ GATE ENABLE
£d]p ùNÛjRlTÓ¡\Õ. JÚ ùR¬VôR
£d]p AND úLh¥u Utù\ôÚ legdÏ

324 TYo : GXdh¬μVu (NSQF - Revised 2022) R.T. Ex.No. 1.10.85 & 86