Welders And Filters Flashcards
Resistors are divided into two (2) broad groups. What are they?
Fixed
Variable
What are the two most important ratings of a resistor?
Resistance
Power
A resistor has yellow, violet, red and gold colour bands. What is it’s resistance rating?
4700 ohms ~5%
A resistor has the marked rating of 4K7. What is it’s resistance?
4700 ohms
What are the three (3) most important ratings of a capacitor?
Voltage
Tolerance
Capacitance
What is the capacitance in uF of a ceramic capacitor with a capacitance code of 224?
0.22 x 10^-6
or
0.22uF
What are the two most important ratings of a coil?
Current
Inductance
Which of the following is often referred to as a choke?
a) a wire-wound resistor
b) an inductor
c) a tantalum capacitor
d) an electrolytic capacitor
b) an inductor
Define the term ripple:
Ripple is a variation in the magnitude of voltage.
What does a filter do?
Filters are used on the output of rectifiers to smooth DC
How should the capacitor be connected to the rectifier to filter output?
The capacitor should be connected in parallel with the output terminals of the rectifier.
Name the two (2) factors that affect the amount of ripple a load sees in a capacitor filter circuit.
Amount of capacitance of the capacitor
Resistance or impedance of the load
How should an inductor be connected to a rectifier to filter output?
The inductor should be connected in series with the output of the rectifier.
What are the two (2) factors that determine how well the choke filters the output?
Inductance of the choke
Amount of current
Why should a L-Section filter be connected as a choke input?
To reduce the possibility of voltage spikes at the load produced by the choke
GMAW welders weld with?
a) AC
b) DC
c) acetylene
d) oxygen
b) DC
You can change the heat settings on a welder by using which taps in the transformer?
Primary or Secondary
The diode current rating for the 120V centre tapped welding machine must be at least ______ _____ of the welder current.
One half
Trying to weld when one of the diodes for the 240V welding machine has failed an open circuit will cause the welder to supply ____ ______ of its setting.
One half
