Answer / siva kumar

UPS is a uninterrupted power supply, where as VFD is a variable frequency drive. VFD is used for controlling speed of the motors according to the below mentioned formula

speed(N)= 120f/p

f= frequency, p= no.of poles

poles are fixed at the design stage of the machine later we can't be modified so speed control is possible only controlling the frequency of the machine.

Answer / houssem

UPS converting incoming AC to DC through a rectifier and converts it back with an inverter with the same frequency

VFD converting incoming AC to DC through a rectifier and converts it back with an inverter with variable frequency according to operating point (Tm= V/F) of a motor

74Ls244 is _____?

0 Answers  

---

Why gold is added to the p-n junction?

0 Answers  

---

what are advantages of dc over ac supply?

5 Answers   Ecil, TCS,

---

WHAT IS THE DIFFERENCE BETWEEN ABSOLUTE ENCODER AND INCREMENTAL ENCODER.

2 Answers  

---

what is the difference between delegation and containership?

0 Answers   KIIT,

---

i m i n3rd ye of btech EC branch and have been placed in sftware company..wat sghd i do to improve my skills in 4th yr..i have a gd academic background.

0 Answers   ABB,

---

what is need of modulation & de-modulation in communication?

6 Answers  

---

the maximum spectral response of the germanium and silicon is in the ?

3 Answers   BSNL, HCL,

---

By which meter we can measure of the VSAT angle, like Ellivation and Azimuth??????

2 Answers   Hughes,

---

For a 1φ voltage controller, feeding a resistive load, draw the waveforms of source voltage, gating signals, output voltage and voltage across the scr. Describe the working with reference to waveforms drawn?

0 Answers  

---

what are the advantage of pmmc?

2 Answers  

---

what is the difference b/w gsm and cdma

1 Answers  

---