E-3

THEORY OF OPERATION

E-3

 

 

TOC

TOC

 

 

 

 

FIGURE E.2 Power and Voltage Boards

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Section

Master

 

 

CONTACTOR CLOSURE (#2 AND #4)

 

 

 

 

 

 

 

 

 

 

 

 

 

TACH FEEDBACK (MOTOR RPM)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ARC VOLTS (SET & ACTUAL)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

REMOTE VOLTAGE CONTROL (A, B, C)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

to

to

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

WORK SENSING (#21)

 

 

 

 

 

 

1/2 AMP

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Return

Return

 

 

 

 

 

 

 

 

F501

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

115VAC

 

 

 

 

 

 

 

 

 

 

SET VOLTAGE

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ODE

SENSING (#67)

VOLTAGE

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R

 

 

 

 

BOARD

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

T

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

TACH

C

 

 

 

 

 

TRAVEL

 

 

 

 

 

 

 

 

 

 

 

 

 

E

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

L

 

D

 

 

 

 

 

RECEPTACLE

FLUX

 

 

 

 

 

 

 

 

 

 

 

 

E

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

C

 

 

 

 

 

 

 

 

RECEPTACLE

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

MOTOR

 

S

 

 

 

A

 

3

 

 

 

 

 

 

 

 

 

 

 

 

 

U

 

 

 

R

A

CR

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

C

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

P

 

 

 

 

N

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

P

 

 

 

V D

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

L

 

 

 

O

S

2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

L

 

 

 

 

 

 

 

 

 

 

 

 

A

 

 

 

 

Y

START

STOP

INCH

T

H

CR

 

 

 

 

 

 

 

 

 

 

 

 

V

 

V

 

 

A

U

 

 

 

 

 

 

 

 

 

 

 

 

 

R

F

 

V

SWITCH

 

DOWN

G T

 

 

 

 

 

 

 

 

 

 

 

 

 

M

O

O

 

SWITCH SWITCH

E

D

 

 

 

 

 

 

 

 

 

 

 

 

 

A

L

I

L

 

O

 

 

 

 

O

1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

W

 

 

 

 

 

 

 

 

 

 

 

 

T

T

E T

 

L

 

 

 

 

N

CR

 

 

 

 

 

 

 

 

 

 

 

 

U

A

L

A

 

T

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R

G

D

G

 

A

 

 

 

 

 

 

P

 

VOLTS

SPEED

OPTIONAL

 

 

 

 

 

 

 

E

E

 

E

 

G

 

 

 

 

 

 

 

START

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

START

 

 

 

INPUT

 

 

 

 

P

 

 

E

 

 

 

 

 

DC SUPPLY VOLTAGE

R

 

 

 

BOARD

TIMER

 

 

 

POWER

CIRCUIT

 

 

 

 

 

 

 

 

 

 

 

 

O B

STRIKE

 

 

 

 

 

SWITCH

BREAKER

 

R1(2 OHMS)

 

O F2

 

 

 

 

LOGIC

 

STRIKE/WELD PROCEDURE

 

 

OPTIONAL

CRATER

TOC

TOC

 

#31

 

 

 

 

W

 

 

 

 

 

 

 

C

O

 

 

CRATER

TIMER

CONTROL

 

 

 

 

 

 

 

 

 

 

ENABLE

 

 

BOARD

 

 

 

 

 

 

 

 

 

BOARD

 

 

 

 

CABLE

115

 

 

 

 

E

 

 

 

 

 

 

E A

 

 

 

 

RECEPTACLE

V A C

 

 

 

 

R

 

 

 

 

 

 

 

 

 

D

R

 

 

OPTIONAL

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

WELD

 

Section

Master

 

#32

 

 

F1

B

 

 

 

 

 

 

 

 

 

U D

WELD

TIMER

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R

 

 

 

 

 

 

 

 

 

O

FIELD

DIRECTION

SIGNAL

 

F

 

 

 

E

 

 

 

BURNBACK

 

 

 

 

 

 

 

A

 

 

 

 

 

VOLTS

SPEED

TIMER

 

 

 

 

 

 

 

 

 

 

 

 

E

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R

 

 

 

 

 

E

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

MOTOR

ARMATURE

E

 

 

WELD

 

 

 

 

 

 

to

to

 

 

 

 

 

 

D

 

 

 

 

G

N

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

A

A

 

CURRENT

 

 

 

 

 

 

 

 

 

T1

T2

 

 

 

 

 

 

REED SWITCH

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

T

B

 

 

 

 

 

 

Return

Return

 

 

 

 

 

 

 

 

 

 

 

E

L

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

S

E

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

I

 

 

 

 

 

 

 

 

 

 

 

 

 

 

115VAC

 

 

 

 

 

 

G

S

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

N

I

 

 

 

 

 

 

 

 

 

 

 

1

 

 

 

 

 

 

 

 

A

G

 

 

SET SPEED

 

 

 

 

 

 

 

 

 

36VAC (18+18VAC)

 

 

 

 

L

N

 

 

 

 

 

 

 

 

 

 

0

 

 

 

 

 

S

A

 

 

 

 

 

 

 

 

 

 

 

V

 

22VAC

 

 

 

 

 

 

 

L

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

A

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

C

 

 

 

 

 

 

 

 

 

 

 

 

10VDC REFERENCEVOLTAGE

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

DC VOLTAGE

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

VOLT

SPEED

WIRE FEED SPEED (SET & ACTUAL)

 

 

 

CONTROL

 

 

 

TACH FEEDBACK (MOTOR RPM)

 

 

 

 

METER

METER

 

 

 

 

 

 

 

 

BOARD

 

 

 

 

 

 

 

 

 

 

 

 

BOARD

BOARD

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

INCH

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

UP

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SWITCH

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

DIGITAL

DIGITAL

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

METER

METER

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

POWER AND VOLTAGE

 

TOC

TOC

BOARDS

 

 

 

Section

Master

The AC voltages that are received by

The voltage board also generates a low

 

 

 

 

the power board are rectified and regu-

DC voltage that is applied to the elec-

 

 

lated. These DC voltages are supplied

trode during the inch down mode.

to

to

to the motor, voltage board and control

When the electrode makes contact with

Return

Return

board. The two SCR-controlled

the work piece, this low voltage is

armature and field circuits.

cuitry to stop the wire feed motor. This

 

 

115VDC supplies power the motor

"loaded down", signaling the control cir-

 

 

The actual arc voltage is sensed at leads

feature allows the operator to utilize the

 

 

"work touch sensing" feature.

 

 

#67(electrode) and #21(work) which are

 

 

 

coupled to the voltage board. The pre-

If for any reason the actual welding arc

 

 

set voltage requirements are also sent to

voltage does not match the set weld

 

 

the voltage board. This information is

voltage

 

 

compared and processed on the voltage

(+/- 0.5Volts) the NA-5 will shutdown.

TOC

TOC

board and the resultant correction signal

This feature insures that the actual

is sent to the Lincoln CV power source

welding voltage is the same as the pre-

 

 

Section

Master

via the remote voltage leads (A,B,C).

set voltage during the welding cycle.

The preset and actual arc voltage infor-

This circuitry is incorporated on the volt-

 

 

 

 

mation is also sent to the voltage meter

age board.

to

to

board where it is processed and dis-

 

played on the digital meter.

 

Return

Return

 

NOTE: Unshaded areas of block logic diagrams are the subject of discussion.

 

 

 

 

NA-5

 

Page 50
Image 50
Lincoln Electric NA-5NF, NA-5SF service manual Power and Voltage, Boards

NA-5S, NA-5N, NA-5SF, NA-5NF specifications

The Lincoln Electric NA-5NF, NA-5SF, NA-5N, and NA-5S are advanced welding helmets that are pivotal in enhancing the safety and efficiency of welders in various applications. These models are designed to provide exceptional protection and visibility, making them indispensable tools in the welding industry.

One of the main features of the NA-5 series is the auto-darkening filter technology. This feature allows the helmet to automatically adjust its shade based on the intensity of the arc. As the welder strikes an arc, the lens darkens instantaneously, shielding the eyes from harmful rays generated during the welding process. This functionality not only ensures safety but also enhances productivity, as welders do not need to manually flip the helmet up and down.

The helmets are equipped with a wide viewing area that allows for better visibility and precision while working. With a large lens, welders can easily monitor their work and surrounding environment, minimizing the risk of accidents. Additionally, the lightweight design of the NA-5NF, NA-5SF, NA-5N, and NA-5S provides comfort during extended periods of use, reducing neck strain and fatigue.

The NA-5 series is also well-regarded for its durability. Constructed from impact-resistant materials, these helmets can withstand the rigors of demanding work environments. This durability extends the lifespan of the helmet, making it a cost-effective investment for both professional and hobbyist welders.

Another notable characteristic is the adjustable sensitivity and delay settings found in certain models. These settings allow the user to customize the helmet based on their specific welding conditions. For instance, a welder can increase sensitivity for low-amperage tasks or adjust the delay to allow for a smoother transition from dark to light after completing a weld.

Furthermore, the helmets come with a reliable battery life, ensuring that they can be used for long periods without interruption. Some models also feature solar assist functionality, which helps recharge the auto-darkening filter, enhancing their overall efficiency.

In summary, the Lincoln Electric NA-5NF, NA-5SF, NA-5N, and NA-5S welding helmets represent a significant advancement in personal protective equipment for welders. Their combination of auto-darkening technology, wide viewing area, lightweight design, durability, and customizable settings makes them an excellent choice for anyone engaged in welding tasks. With these helmets, users can achieve greater safety and efficiency in their work, enabling them to focus on their craft with peace of mind.