3. The word ‘inverter’ in the context of power-
electronics denotes a class of power conversion (or
power conditioning) circuits that operates from a
dc voltage source or a dc current source and
converts it into ac voltage or current. The
‘inverter’ does reverse of what ac-to-dc ‘converter’
does (refer to ac to dc converters). Even though
input to an inverter circuit is a dc source, it is not
uncommon to have this dc derived from an ac
source such as utility ac supply. Thus, for
example, the primary source of input power may
be utility ac voltage supply that is ‘converted’ to
dc by an ac to dc converter and then ‘inverted’
back to ac using an inverter. Here, the final ac
output may be of a different frequency and
magnitude than the input ac of the utility supply.
10. Here is a simple low-power inverter that
converts 12V DC into 230-250V AC. It can be
used to power very light loads like window
chargers and night lamps, or simply give shock
to keep the intruders away. The circuit is built
around just two ICs, namely, IC CD4047 and IC
ULN2004.
IC CD4047 (IC1) is a monostable/astable
multivibrator. It is wired in astable mode and
produces symmetrical pulses of 50 to 400 Hz,
which are given to IC2 via resistors R1 and R2.
11. IC ULN2004 (IC2) is a popular 7-channel
Darlington array IC. Here, the three Darlington
stages are paralleled to amplify the frequencies
received from IC1. The output of IC2 is fed to
transformer X1 via resistors R3 and R4.
Transformer X1 (9V-0-9V, 500mA secondary) is
an ordinary step-down transformer that is used
here for the reverse function, i.e., step up. That
means it produces a high voltage. Resistors R3
and R4 are used to limit the output current from
the ULN to safe values. The 230-250V AC output
is available across the high-impedance winding
of the transformer’s primary windings.
12. 1) It provides quality power output.
2) It is lighter and smaller in size, and hence can
be easily transported.
3) It’s noise-free in functioning when compared
to traditional generators.
4) Requires less maintenance.
5) Higher efficiencies as each panel/pair of
panels is managed individually.
13. 1) There are no large capacity generators in the
markets.
2) The Inverter can power a few appliances for a
short period.
3) More individual hardware pieces that can fail
14. 1) DC power source utilization.
2) Uninterruptible power supplies.
3) Electroshock weapons.
4) HVDC power transmission.
5) Inverters can be very helpful during power
cuts.