V Match the clauses together to make sentences.

A

1 The unfiltered dc provides power to operate lightsand relays for

2 Diode CR1 is a Zener diode that develops aconstant dc voltage

3 If the dc inputvoltage at the top of R1 increases, CR1 will conductharder

4 If thevoltage decreases, CR1 conducts less;

5 If no current flows through R2, the same potentialpresent

6 If thecombined resistance values of R3 and R4 are the sameas

7 Naval aircraft have backup (emergency) electricalpower if

8 The various ways of supplying this emergency power are

B

a aircraft storage batteries, auxiliary power units, and hydraulic motor driven

generators.

b if primary sources of electrical power fail.

c the resistance of R2, the potential of the outputvoltage and the anode of CR1 are

the same

d at the input of amplifier A1 and on the anode ofCR1 is the same.

e less voltagedrops across R1

f the excess voltage drops across R1.

g at the input of amplifier A1,regardless of input voltage fluctuations.

h internal operation of the system and feedsa filter network.

VISkim the text to discuss the following questions with a partner.

1 What types of secondary power sources do you know?

2 Can you describe the construction of secondary power sources?

3 Can you describe the characteristics of secondary power sources?

4 Can you describe the operating principles of secondarypower sources?