power supplies Flashcards Preview

2015 Mark > power supplies > Flashcards

Flashcards in power supplies Deck (50):
1

Commercial power that feeds our power supplies and home are _______ or ________ VAC

120 or 240

2

Commercial power that feeds our power supplies is ______Hz

60

3

Commercial power that feeds our power supplies is a _________ wave

Sine

4

3 battery power supplies have a voltage of ______

36V

5

What changes the DC battery volts to VAC?

Power Supply Inverter

6

What changes the input VAC from 120V or 240V to 60V or 90V output?

Step Down Transformer

7

What device combines the PS voltage with the network RF signal?

LPI (Line Power Inserter)

8

SPI

Service Power Inserter

9

What devices are used to direct AC power?

Fuses or Shunts

10

This device has a low pass filter on each leg, this prevents RF leakage in the Power Supply

LPI (Line Power Inserter)

11

Powering architecture where there is only one power supply used to power the entire node and actives

Centralized powering

12

this power architecture is the most commonly used

distributed powering

13

Center Conductor Resistance + Sheath Resistance

DC Loop Resistance

14

Span current X Span resistance

Voltage drop

15

Voltage difference between batteries should be no more than:

0.3VDC

16

Battery terminals should be protected w/ corrosion inhibitor like NO-OX or NCP-2, True or False

True

17

Before disconnecting the batteries always turn off the _______ ________ first

Battery Breaker

18

Use a ________ to accurately measure power supply output VAC

True RMS Volt Meter

19

The most accurate & Reliable way to test batteries is to test them under _______ Conditions

Load

20

When testing with a load tester, batteries should or should not be disconnected

Should

21

Power supply batteries produce what gas when charging?

Hydrogen

22

Powering architecture where there is more than one power supply feeding the node and actives

Distributed power

23

Divide and conquer means

Cut the problem in half

24

The purpose of divide and conquer is to

Reduce Repair time

25

A frequency selective volt meter

SLM (Signal Level Meter)

26

two most commonly used pieces of test equipment

SLM & VOM (or DMM)

27

The majority of outages are _______ related

Power

28

TDR

Time Domain Reflectometer

29

In a terminated cable with no faults, the TDR energy is absorbed meaning there is _________ reflected energy

NO

30

Correct ________ is needed for correct TDR Measurements

VOP (Velocity of Propogation)

31

Resistance to AC is called

Impedance

32

two types of TDRs

Waveform & Digital

33

VOP

Velocity of Propogation

34

this is caused by the time lag needed for the TDR pulse to enter the cable

Dead Zone

35

use a ________ ________ to minimize the effect of a dead zone

Launch Jumper

36

The most accurate way to find a fault with a TDR is to

TDR from both ends and divide the difference in half

37

A TDR trace with the same polarity

Open

38

A TDR Reflection with the opposite polarity

Short

39

a properly terminated cable will _______ the TDR pulse energy

absorb

40

Locate colors-Power:Gas:Telecom:Water:

Redyelloworangeblue

41

Sending AC from two different power supplies to the same point

Bucking Power

42

A low resistance connection between two points in an electric circuit

Shunt

43

used to direct power in the CATV network

shunts & fuses

44

In the return path, the pads and EQs are insalled on the ________ side of the return amplifier to provide flat inputs to the next upstream amplifier

output

45

cumulative effect of the return path distortions

funnel effect

46

CPD beats fall _____ apart in the upstream

6MHz

47

In the forward path, CPD contributes to ______ distortions

CTB

48

Return path noise caused by arching electrical motors

Impulse Noise

49

Trenches greater than _______ feet must be shored to prevent cave ins

4ft

50

In coax, the attenuation of the reverse signals is _______ than that of the forward signals

Less