Industrial fiber optics Ml 801 User manual

12 0113

Rules for Laser Safety

• Lasers produce a very intense beam of light. Treat them with respect.

Most educational lasers have an output of less than 3 milliwatts, and

will not harm the s in.

• Never loo into the laser aperture while the laser is turned on.

PERMANENT EYE DAMAGE COULD RESULT.

• Never stare into the oncoming beam. Never use magnifiers (such as

binoculars or telescopes) to loo at the beam as it travels — or when it

stri es a surface.

• Never point a laser at anyone's eyes or face, no matter how far away

they are.

• When using a laser in the classroom or laboratory, always use a beam

stop, or project the beam to areas which people won't enter or pass

through.

• Never leave a laser unattended while it is turned on — and always

unplug it when it's not actually being used.

• Remove all shiny objects from the area in which you will be wor ing.

This includes rings, watches, metal bands, tools, and glass. Reflections

from the beam can be nearly as intense as the beam itself.

• Never disassemble or try to adjust the laser's internal components.

Electric shoc could result.

ML 801 “Build a Laser” Kit

Instruction Manual

Model Nu ber:

ML 801

NDUSTRIAL

IBER

PTICS

by Industrial Fiber Optics Inc.

Rev. E

stored in any form or by any means without prior written consent, except by

reviewer, who may quote brief passages in a review, or provided for in the

Products and brand names mentioned in this document are trademar s of their respective

companies.

The structure of this manual and its content are based on a previous edition were written by

Herbert H. Gottlieb for Metrologic Inc. Much of the content has been rewritten for Industrial

Fiber Optics to reflect several upgrades and redesigns. But the sequence and form of the

assembly instructions have been maintained to provide continuity for teachers and instructors

already using Metrologic’s ML801 “Build a Laser” Kit (now supplied by Industrial Fiber Optics)

in their curriculums.

Figure 5 Inserting Laser in Case

- 27 -

44293

22 0023

42 0215

00-00155

22 0024

Table of Contents

Introduction................................................................................................1

Notes, Cautions and Warnings ......................................................1

Required Items Not Supplied with Kit ............................................2

Unpac ing and Chec ing Parts.................................................................3

Soldering ...................................................................................................7

Assembly Instructions ...............................................................................8

Mounting Diodes ..........................................................................8

Mounting Resistors ......................................................................9

Mounting Capacitors ..................................................................10

Mounting Transformer T1...........................................................11

Mounting Transistor Q1..............................................................11

Mounting the Laser Tube on the PC Board ...............................13

Connecting the Rear End Cap to the PC Board ........................14

Visual Inspection .....................................................................................15

Adjusting Laser Tube Current .................................................................17

Final Assembly........................................................................................19

Warranty-Shipping-Service .....................................................................21

Disclaimer................................................................................................23

List of Illustrations

Figure 1 Printed Circuit Board Assembly Diagram...............................24

Figure 2 ML801 Schematic diagram ....................................................25

Figure 3 Heat Sin Assembly...............................................................26

Figure 4 Laser Tube Mounting Diagram ..............................................26

Figure 5 Inserting Laser in Case ..........................................................27

- i -

Introduction

This boo let contains instructions for building an ML801 helium-neon laser

using parts supplied in the it. It is assumed that whoever is building the it

has had some experience in wiring electronic circuits and in soldering

components to printed circuit boards. It is also assumed that the person

building the it has adequate tools.

Because the electronic power supply generates high voltages and because

the concentrated light output from this low powered (typically 0.5 mW) laser

can be harmful to the eyes, following instructions in the sequence given in

this manual is especially important.

Notes, Cautions, and Warnings

While wor ing through this manual, there will be several paragraphs

headed NOTES, CAUTIONS and WARNINGS. Do not ignore them!

NOTE Gives additional bac ground information, hints, and

suggestions for building techniques that can save time,

trouble, and effort and result in a professionally built piece of

equipment that will give many years of service.

Caution Provides information that will help prevent damage to the

equipment. Cautions must always be ta en seriously and

should never be ignored.

Warning Given whenever there is the li elihood that injury to the it

builder or others can occur. The necessity of heeding all

warnings cannot be overemphasized.

- 1 -

22 0026

#6-

32 x ¼” Flat Head

Phillips Screw

(Thru Housing at

the

Bottom of Laser

Case)

#4-40 Hex Loc

Nut 21 0015

Shoulder

Nylon Washer

0040

#6-32 x ¼” Pan Head

Phillips Screw 22 0024

Printed Circuit Board

35105A

#6 Internal Loc

washer 23

0032

#4-40 x ½”

Pan Head Screw

22 0025

Beryllia Washer

00538

Transistor

24-24030

Thermal Compound

(On Surfaces Indicated)

0300

Printed Circuit Board

Foil Side Up

35105A

Kapton Tape Insulator

0115

Blac

Cathode Lead

55 0051

Red

Anode

Lead

Plastic

Stay Wrap

35 0126

REAR

FRONT

Figure 4 Laser Tube Mounting Diagram

Figure 3 Heat Sin Assembly

- 26 -

Cradle

Positions

30 30022

- 25 -

Required Ite s Not Supplied with Kit

All of the necessary circuit elements, connecting leads, fasteners and other

assembly parts are provided with the it, In addition, the following items

should be available.

Soldering iron A low power (25 to 30 watts) soldering iron to mount

circuit elements.

Long Nose Pliers A pair of long nose pliers to bend and dress wire leads.

Diagonal pliers Diagonal pliers, or a similar tool, to strip insulation and

to trim leads after soldering.

Screwdrivers One small Phillips head and one slotted.

Allen wrench 5/64

inch Allen wrench

Also, the following items, which are readily available in local

hardware stores.

• Roll of rosin core solder (.031 inch diameter or smaller)

• Tube of Dow Corning Clear Sealant (or bathtub caul ing)

• A roll of plastic electric tape

• A tube of DUCO (or similar fast drying cement)

• Spray point, Krylon crystal clear, No. 1302

Caution: Acid flux or acid core solder is corrosive and should

never be used for electronic circuits. The use of acid

solder voids all guarantees provided by the manufacturer.

- 2 -

Unpacking and Checking Parts

Before attempting to assemble the it, identify and chec off each part to be sure that

the it is complete.

Resistors

Symbol Resistance

(ohms)

Power

(watt)

Color bands on

Resistor

(see note below)

Part # Replace

Cost

R1 22 2. red, red, orange 15-15001 $.50

R2 22 2. red, red, orange 15-15001 $.50

R3 4.7 M 0.5 yellow, purple, green 13-13553 $.30

R4 4.7 M 0.5 yellow, purple, green 13-13553 $.30

R5 15 1 brown, green, orange 14-14507 $.35

R6 1.0 M 0.5 brown, blac , green 13-13533 $.20

R7 22 2 red, red, orange 15-15001 $.50

R8 22 ohms 0.5 red, red, blac 13-13542 $.35

R9 560 ohms 0.5 green, blue, brown 13-13537 $.20

R10 100 0.5 brown, blac , yellow 13-13552 $.20

R12 10 ohms 0.5 brown, blac , blac 14-14513 $3.35

R13 39 ohms 0.5 orange, white, blac 61 0515 $.20

R14 2.2 M 0.5 red, red, green 13-13558 $.20

Note: Gold banded resistors are +/- 5% tolerance

Silver banded resistors are +/- 10% tolerance

Capacitors

Symbol Capacitance Type/Mar ings Volts Part # Replace

Cost

C1 100 pF 100M 3 V 21-21047 $1.00

C2 100 pF 100M 3 V 21-21047 $1.00

C3 100 pF 100M 3 V 21-21047 $1.00

C4 100 pF 100M 3 V 21-21047 $1.00

C5 100 pF 100M 3 V 21-21047 $1.00

C6 .01 µ

µµ

µF 103M 3 V 21-21005 $.60

C7 .01 µ

µµ

µF 103M 3 V 21-21005 $.60

C8 .01 µ

µµ

µF 103M 3 V 21-21005 $.60

C9 100 pF 100M 3 V 21-21047 $1.00

C10 .001 µ

µµ

µF 102M 3 V 21-21138 $2.00

C11 .1 µ

µµ

µF Mylar/100 V, 104K 100 V 22-22030 $2.00

C12 .001 µ

µµ

µF .001M 1 V 64 0031 $2.00

C13 47 µ

µµ

µF Electrolytic 250 V 20-20037 $2.50

- 3 -

- 24 –

Disclai er

Industrial Fiber Optics, Inc. and the author or authors ma e no claims or

warranties with respect to the contents or accuracy of this publication, or the

product it describes, including any warranties of fitness or merchantability

for a particular purpose. Any stated or expressed warranties are in lieu of all

obligations or liability for any damages, whether special, indirect, or

consequential, arising out of or in connection with the use of this publication

or the product it describes. Furthermore, the right is reserved to ma e any

changes to this publication without obligation to notify any person of such

changes. Industrial Fiber Optics also reserves the right to ma e any

changes to the product described herein.

- 23 -

Diodes

Symbol Type Comments Part # Replace

Cost

D1-D6 3G3 Printed on each of these six

diodes is a band (formed of

alternating triangles) which

indicates the negative (-) end.

23-23021 $3.75

D7, D8 XG6 Similar to the 3G3 above, but

the XG6 diodes are larger

23-23030 $4.10

D9 1N5223B Tiny diode with numbers

5223B printed on it. The band

indicates negative (-) end.

23-23018 $0.60

D10-

D13

1N4007 The band around one end

indicates negative (-) end.

71 0016 $0.25

Transistors

Q1 TIP 49 Terminal at the center is the 24-24022 $2.25

Collector. Metal tab mount.

Transfor er

T1 2.0 mW The terminal that is closest to 40-40023 $24.55

115 V the groove in the base is

terminal No. 1

Laser tube

LT1 0.5 mW Hard seal, HeNe, with 76 0161 $145.00

output attached pre-aligned end

mirrors and connectors

- 4 -

Miscellaneous parts

Type Comments Part # Replace

Cost

Laser Case Cast aluminum, 2.7 x 2.7 x 11.0

inches Threaded tripod mount at

bottom

42 0215 $40.00

Laser Cradle Two strips of blac plastic each

about 1 inch long. Mounts laser

tube on circuit board

30-30022 $4.00

Cushion Tape Two lengths of ¼ inch x 11 inch

rubber. Used to cushion bottom of

laser case

00-00155 $3.00

Front End Cap

Asse bly

Aluminum plate with shutter

mounted in a threaded aperture

44-44293 $50.00

Printed circuit

Board

Phenolic. Laser tube and resistor

R1 mount on foil side and all other

parts mount on the reverse side

35-35105A $30.00

End Cap

Screws

Eight blac screws 4-40 x ½ inch

Secure end caps to laser case.

22 0023 $0.50

Stay Wraps Two plastic strips. Holds laser tube

on PC board

35 0126 $0.25

Cathode Lead One 4 inch blac wire 55 0050 $1.60

Anode Lead One 4 inch red wire 55 0051 $1.55

Insulators 2 inch x 2 inch Kapton insulating

tape (2 pieces) taped to the PC

board. Remove and store on a

clean surface before beginning

construction of the PC board.

14 0115 $1.85

- 5 -

any loss or damage during shipment as long as the buyer observed the

following rules:

• Refuse any pac age which is not in perfect condition. Once a pac age

has been accepted, the buyer must initiate and collect insurance claims.

• If damage is discovered during unpac ing, notify the carrier and the

distributor (or Industrial Fiber Optics if the item was purchased directly)

from whom the item was purchased immediately. The carrier must note

the damage and ma e a concealed damage report. Time is of essence

because damage claims submitted more than five days after the

delivery may not be honored by the carrier.

• Keep all pac ing material.

• In writing, describe the specific nature of the damage to the product.

• In cases of severe damage, do not attempt to use the product.

Return Policy

Industrial Fiber Optics will pay the return-to-customer shipping and

insurance charges for warranty repair deliveries made within the United

States by United Parcel Service or Parcel Post. Any other delivery means

must be paid by the customer. The cost of return shipments for out-of-

warranty items is paid by the customers.

- 22 -

Warranty – Shipping - Service

Li ited Warranty

This it was carefully inspected before leaving the factory. If any

components are missing, or (except for the laser tube) were damaged

during shipping, Industrial Fiber Optics will replace them at its discretion.

Since soldering and incorrect assembly can damage electrical components,

no warranty can be made after assembly has begun. If any parts become

damaged, replacements can be obtained from most radio/electronics supply

shops, or from Industrial Fiber Optics.

While Industrial Fiber Optics does not assume any responsibility for defects

that have been caused by the failure of a purchaser to follow the it building

instructions, it can assist in repairs of damage caused by the incorrect

assembly. In such instances, the entire it can be returned to Industrial

Fiber Optics for an evaluation and quote on the cost of these repairs. Send

the entire it to;

Industrial Fiber Optics

627 S. 48

St. Ste. 100

Tempe, AZ 85281

Be sure to include sufficient contact information so that Industrial Fiber

Optics can reply with results of the evaluation and a repair cost quote. Also,

include a return address for return shipping.

This warranty does not cover failure due to transistor and diode

breakdowns caused by failure to provide adequate heat sinking as

specified in the kit builder’s instructions.

It is assumed that the same reasonable care will be given to the laser as

one gives to any electronic device. Store in a dust-free atmosphere and

avoid extremes of temperature and humidity. However, the ML-801 is a

hard-seal laser and unli e previous lasers, continuous or periodic operation

is not required to ensure a long life.

Industrial Fiber Optics shall have no responsibility for the installation or

maintenance of the product or for any personal injury, property damage or

any special incidental, contingent or consequential damages or losses of

any ind resulting from defects of the product or failure of the product to

perform, or failure of the it builder to heed the warnings in this manual.

Da age or Loss in Ship ent

Standard rules govern loss and damage in shipping. As soon as the

pac age leaves the F.O.B. point, it becomes the customer’s property, even

lost or damaged in shipment. The carrier, however, will be responsible for

- 21 -

Heat Sink Subasse bly (Refer to Figure 3)

Type Comments Part # Replace

Cost

Heat Sink Aluminum U-bloc with drilled

holes

31-31141 $6.00

Screw 4-40 x .5” Mounts transistor on

heat sin

22 0025 $0.25

Washer White beryllia. Provides heat

conduction and electrical

isolation for transistor tab

00-00538 $4.00

Washer Nylon shoulder washer 23 0040 $0.20

Nut No. 4 hexagonal nut 21 0015 $0.20

Screw 6-32 x 3/16” Phillips head pan

screw

22 0026 $0.20

Screw 6-32 x ¼” Phillips flat head

screw

22 0024 $0.20

Washer No. 6 internal tooth 23 0032 $0.20

Ther al

Co pound

White paste pac ed in tin foil 32 0300 $0.50

Rear End

Asse bly

Plug in assembly. Contains

switch, pilot lamp, fuse and line

cord. Its 4” leads are soldered

directly to the PC board.

44-44103 $50.00

Fuse ¾ Amp fuse 00-00484 $1.50

Instruction

Manual 45-801

Complete instructions for

building Laser ML801

12 0113 $5.00

Operator’s

Manual

Hard-Seal Helium-Neon Laser

Installation and User’s Guide

12 0098 $5.00

- 6 -

Soldering

Although it is assumed that those building this laser it have experience in

wiring and soldering, a few reminders of good soldering techniques may be

helpful.

• Use a low-power (25 to 30 watts) soldering iron to mount circuit

elements. Excessive heat can damage the printed circuit board and

components. Never use a soldering gun to mount solid-state diodes or

transistors. The electromagnetic field surrounding the tip can

permanently damage these sensitive components.

• Use a spool of very thin (.031 inch diameter or smaller) rosin-core

solder. Solders with acid cores or those requiring acid flux are

corrosive and should never be used for electric circuits.

• Chec to ma e sure that the tip of your soldering iron is clean. If

necessary, remove any corrosion from the tip with emery cloth or steel

wool. Then ma e the tip shiny by applying a drop of melted solder and

wiping off the excess with a damp rag or sponge.

• Insert leads of a resistor or other component in the specified holes of

the circuit board. Before soldering, chec that the leads are in the

correct holes with the component close to, but not touching, the circuit

board.

• When the soldering iron is hot, hold its tip against the circuit board foil

and component leads to be soldered. Apply solder to the connection

until the solder melts. Melt the solder with the component lead and foil

– not the soldering iron. Carefully remove the soldering iron and with

the parts motionless for a few seconds, allow the solder to cool and

solidify. A good solder joint is clean, smooth, shiny and round. When

soldering many connections, eep the tip of the soldering iron shiny by

periodically applying solder directly to it, then wiping off the excess.

• Special care is needed to prevent overheating diodes and transistors.

Before applying the soldering iron to one of the leads, grasp the lead

near the base of the component with a pair of needle nose pliers. Hold

the pliers firmly on the lead while the connection is being heated with

the soldering iron. The pliers act as a heat sin , preventing heat

conduction into the body of the diode or transistor.

•

Never apply more solder than is absolutely necessary to join the

connection parts together. Large globs of solder can form solder

bridges between conductors on the circuit board and cause short

circuits when power is applied.

- 7 -

Shut off the power. Slide the printed circuit board out of the laser case

being very careful not to misalign the laser tube. Squeeze out of a liberal

quantity of Dow Corning Clear Sealant (or bathtub caul ing) and apply it

between the sides of the laser tube and the PC board near each laser

cradle. Do not disturb the laser until the cement has cured.

5. When the cement is firm, slide the PC board bac into its laser case.

Ma e sure that there is a liberal amount of heat sin compound at the

place where the heat sin contacts the laser case.

6. Insert the 6-32 x ¼ inch screw through the bottom of the laser case

into the threaded hole of the aluminum heat sin bloc .

7. Mount the rear end cap with the other four 4-40 x ½ inch screws.

8. Apply the foam tape to the grooves on the underside of the case.

This completes the assembly and alignment of the entire laser.

- 20 -

Final Asse bly

The final assembly consists of placing all of the electronic parts inside the

laser case and aligning the laser beam so it will emerge from the aperture in

the front end plate. During this phase, operating the laser with charged

electronic components partially exposed will be necessary, so again be very

careful when proceeding.

1. With the power off, slide the printed circuit board all of the way into

the laser case (Figure 5). Without touching the end mirrors of the

laser tube, slide the tube forward or bac ward on the PC board so

the front and rear end caps can be assembled without contacting

the ends of the laser tube. Also, the hole in the bottom of the case

should be aligned with the tapped hole in the aluminum heat sin

bloc .

2. With the laser aimed so it cannot stri e any reflecting objects or the

eyes of anyone in the vicinity, turn the power on. The pilot lamp

should light, a strong beam should come out of the front of the laser

and a much wea er beam should emerge from the rear.

3. Disconnect the power and mount the front end cap using four of the 4-

40 x ¼ inch screws. Point the laser at a wall, or other dull, non-

reflective surface and reapply power. Vary the position of the aperture

until you see the laser beam “spot” on the surface. When the spot is a

perfect circle, without any strea s or fringes surrounding it, it is passing

cleanly through the aperture.

Warning: Do not look into the aperture to see the laser bea . Observe

only the laser spot on the surface.

4. It may be necessary to remove the front end cap and use a non-metallic

object, such as a comb or a piece of wood to push the laser tube to a

central position inside the case to help line up the beam and the

aperture.

Warning: There are high voltages at the laser ter inals and the etallic

ends of the laser tube are also charged. Do not use your

fingers or any conducting object for aligning the laser bea .

If difficulty is experienced in getting the beam aligned with the front end

plate, chec for any irregularities or globs of solder under the laser cradles

that might be tilting the laser tube. If obstructions are found, the power

should be turned off and carefully removed.

Once the aperture and tube have been properly aligned, tighten the three

screws securing the aperture to the front end cap with a 5/64 inch allen

wrench.

- 19 -

Asse bly Instructions

The electronic components of the laser, including the laser tube, must all be

mounted on printed circuit board PC1. Although this engineering provision

is very handy when building, testing and troubleshooting the laser, always

be aware of the hazards of operating an electrical circuit without its

protective case securely mounted in place. Exposed terminals on the rear

end cap carry 110 volts from the AC power cord. Potentials high as 12,000

volts are available on the printed circuit board and at the terminals of the

laser tube. Also, when the laser is operating, ultra violet light is emitted

from the sides of the laser tube and a coherent laser beam radiates from

both ends.

Accidents can be prevented by following the advice of professionals: Never

apply power until all connections have been double checked and that

it is certain that the laser is pointed away fro the eyes of anyone in

the vicinity or fro reflecting objects. Resist the urge to apply power

and try the laser before the entire circuit has been completely wired and

adequate safety precautions have been ta en.

Mounting Diodes

Follow the instructions below to mount the 13 diodes (D1 through D13) on

the printed circuit board. Refer to the printed circuit assembly diagram

(Figure 1), for their correct positions.

1. With a pair of pliers, ma e a sharp right angle bend in each lead of

the diode so the diodes will exactly fit between the appropriate sets of

pre-punched holes on the circuit boards.

2. Insert the leads of each diode into the printed circuit board ma ing

sure that the body of each diode is as close as possible to the board

and that the negative (-) end of the diode is facing the correct

direction. If any of the diodes are mounted bac wards, the laser will

not operate and further damage can result in the electronic circuit.

3. Ma e certain that each diode is on the circuit board and is facing the

correct direction. Then apply a small amount of rosin core solder at

the base of each lead on the foil side of the PC board.

Caution: Diodes are heat sensitive. Never use a large soldering iron, a

high wattage solder gun, or apply heat longer than is necessary

to melt the solder and fuse the leads to the printed circuit board.

- 8 -

4. Using a pair of diagonal cutting pliers, snip off the excess lengths of

diode leads as close as possible to the printed circuit board and

discard them.

This completes the mounting of the diodes.

Mounting Resistors

There are 13 resistors to be mounted on the printed circuit board. Follow

the instructions below and refer to Figure 1 for the placement of the

resistors.

1. Resistors R12 and R1 are mounted on the PC board standing up

instead of lying down li e the other resistors. Insert one of the leads

of resistor R12 into the designated hole near the lower right corner of

the PC board and push it all the way into the hole until the end of the

resistor body touches the board. Holding it in this position, apply a

small amount of solder to the resistor lead at the foil side of the

board. When the solder has cooled, bend the other lead down, insert

it into its designated hole at the lower right corner of the board and

solder it in place.

2. Resistor R1 is the only resistor mounted on the foil side of the circuit

board. To mount this resistor, pass one of its leads through the hole

provided near the front of the circuit board. Then, on the component

side of the board, bend this lead and insert it into the solder hole that

is located near the bottom of resistor R7 (See figures 1 and 4).

Solder the lead and trim any excess of the lead that protrudes

through the solder hole. Do not connect the free end of the resistor

R1 at this time. Later it will be connected to the anode at the front of

the laser tube.

3. With a pair of pliers, ma e sharp, right angle bends in each of the

remaining resistor leads so the resistors will exactly fit between the

appropriate sets of pre-punched holes on the circuit board.

4. Insert the leads of resistors R2, R5 and R7 in the designated holes at

the left side of the board. Because these resistors become hot when

the circuit is operating, the body of each of these resistors should not

be mounted too close to the circuit board. Hold each resistor about a

quarter to a half inch above the circuit board and ma e sure the leads

are in the correct holes. Then apply a small amount of solder to the

resistor leads at the foil side of the circuit board.

- 9 -

Warning: Re e ber to turn off the power whenever touching the

laser or the eter as necessary.

8. Once the tube current has been chec ed and adjusted, turn off the

power, remove the meter and reconnect the blac cathode lead to

the laser tube terminal

This completes the laser tube current adjustment.

- 18 -

Adjusting Laser Tube Current

For optimal operation, the laser tube current should be between 3 and 3.5

milliamperes. Most lasers will operate properly with the correct tube current

when assembled according to the instructions given above. However,

because there are small differences in the electrical characteristics of

individual laser tubes, there is a small possibility that the tube current in your

laser does not fall within these specified limits. If the tube current is much

too low, the laser will produce pulsating bursts of light rather than a steady

beam. If the current is too high, the life of the tube may be shortened. To

adjust the tube current, proceed as follows:

1. Remove all power from the laser and move the switch on the rear

end cap to OFF.

2. Slip off the blac lead connected to the cathode terminal of the laser

tube.

3. Connect the negative (-) milliammeter lead to the blac cathode wire

and the positive (+) milliammeter lead to the cathode terminal of the

laser tube.

Warning: High voltage appears at the laser tube ter inals when it is

operating. Do not touch the illia eter, the laser tube,

or the printed circuit board while the laser is plugged into a

wall socket.

4. Ma e sure that the apparatus is positioned so that the meter can be

observed without touching it, insert the plug into a wall soc et and

turn the power switch ON.

5. If the milliammeter indicates between 3 and 3.5 mA, s ip the rest of

this procedure. The beam current is within specified limits and no

adjustment is necessary. In that case, turn off the power, remove

the ammeter, and reconnect the blac lead to the laser tube.

6. If the milliammeter indicated LESS THAN 3 mA, disconnect the

power, unsolder resistor R13 from the printed circuit board, and

replace it with a 36-ohm resistor. Reapply power. If the

milliammeter still indicates less than 3 mA, try replacing resistor R13

with a 27-ohm resistor. Always re e ber to re ove power

before touching the laser or the eter.

7. If the milliammeter indicates MORE THAN 3.5 mA, replace resistor

R13 with a 43-ohm, 47-ohm or 56-ohm resistor in turn until the tube

current falls within the 3 to 3.5 mA range.

- 17 -

NOTE: Unli e diodes, the direction that a resistor faces in a circuit is

unimportant. As long as a resistor is in the correct holes of the

circuit board, it will function correctly.

5. Insert the leads of the remaining eight resistors in the designated

holes of the circuit board. Ma e sure the bodies of these resistors are

as close as possible to the circuit board. Apply solder at the foil side

of the board.

6. Using a pair of diagonal cutting pliers, snip off the excess lengths of

resistor leads and discard them.

At this point all of the diodes and resistors ha e been mounted on the

circuit board.

Mounting Capacitors

Refer to the assembly diagram (Figure 1) and the instructions below to

mount the 13 capacitors on the printed circuit board.

1. Place the leads of capacitor C13 in the designated holes of the

printed circuit board ma ing sure that the negative (-) is toward

the top of the board and the positive (+) end is down. If there is

no + or – signs on the capacitor, loo for arrows running along its

length. The arrow head points to the negative (-) end.

Caution: Capacitor C13 is an electrolytic filter capacitor. If it is mounted

bac wards with the leads reversed, the capacitor and other

electronic components will be permanently damaged when

power is applied.

When capacitor C13 leads are all the way in the

correct holes; press the body of the capacitor against

the board, apply a small amount of solder to the leads

at the foil side and snip off excess lead lengths.

2. Mount capacitors C1 through C12 in the designated holes of the PC

board. Capacitors C1 through 10 are ceramic discs and capacitors

C11 and C12 are tubular Mylar types. Because these capacitors

are not polarized, it is not important that they face any particular

direction and the leads may be reversed without harm. Each of

these capacitors should be held as closely as possible to the

printed circuit board. Apply small amounts of solder to the leads at

the foil side of the board. Snip off excess lead lengths.

At this point all of the capacitors, diodes and resistors ha e been mounted.

- 10 -

Mounting Transfor er T1

Refer to Figure 1 and follow the instructions below to mount transformer T1

on the printed circuit board.

1. Hold transformer T1 so the base is down and the groove at the base

(which identifies terminal 1) is at the lower right.

2. Insert the transformer in the printed circuit board so that all 12

terminals at the transformer base are firmly seated in the

corresponding holes of the board.

3. Apply a small amount of solder to each of the transformer terminals

at the foil side of the board.

NOTE: When soldering the terminals, be especially careful to avoid

solder bridges between adjacent terminals. These can short out

electronic circuits when power is applied.

Mounting Transistor Q1

Transistor Q1 is perhaps the most difficult component to mount on

the printed circuit board. This is because it must not only be

mounted in the correct location but, additional heat sin ing

precautions must be ta en to avoid premature failure of this

sensitive part. Refer to the exploded view of transistor Q1 and its

heat sin mounting components in Figure 3.

1. Hold transistor Q1 so its metal mounting tab is facing the

aluminum heat sin as shown in Figure 3.

2. Mount the transistor to the heat sin with a screw and beryllia

washer using plenty of heat sin compound on both sides of the

berylia washer. The shoulder washer and nut go on the other side

of the heat sin as shown on Figure 3, the “nec ” of the shoulder

washer fits into the hole in the heat sin . Ma e the nut as tight as

possible without brea ing the screw.

NOTE: Because the metal tab on the transistor is internally connected

to the emitter, it must be electrically isolated from the heat

sin . The beryllia washer provides both electric isolation and

heat conduction.

- 11 -

10. Insert the Plug into a 3 conductor GROUNDED wall outlet,

105-120 volts AC, 60 Hz.

Warning: If the plug is inserted in an ungrounded outlet, dangerous

voltages could appear on the laser case.

11. Operate the power switch on the rear end cap to the ON position.

The pilot light in the rear end cap should go on. The inside of the

laser tube should glow blue orange-red. A strong laser beam

should come out of the front end of the laser tube and a wea er

beam should come out of the opposite end.

NOTE: If everything has been done correctly, the laser should be

wor ing properly. However, since individual laser tubes have

different operating characteristics the laser beam current can be

adjusted for optimum operation in the particular laser. This

optional procedure is described in the next section.

- 16 -

Visual Inspection

Before the laser is mounted in its outer case, ma e a thorough chec

of the electrical components of the laser as follows:

Caution: Do not connect power to the laser until all of the preliminary

chec s are made and specific instructions are given to do so.

The premature application of power can cause extensive

damage.

1. Chec that diodes, resistors, capacitors and other electrical parts

are mounted in the correct positions of the printed circuit board.

Refer to both the assembly diagram (Figure 1) and the schematic

diagram (Figure 2) while chec ing each part.

2. Wiggle each of the electrical components methodically while

watching the printed circuit board for any movement that would

indicate solder failure or a cold solder joint. If available, chec each

joint with a magnifying glass or eye loupe.

3. Scan the foil side of the printed circuit board loo ing for any solder

bridges between circuits that will cause shorts.

4. Search for and remove any deposits of solder around the outer

edge of the printed circuit board that might interfere with sliding the

board into the outer case of the laser.

5. Inspect the mounting of the transistor and its heat sin to be sure

that all of the mechanical connections are tight and there is a liberal

amount of heat sin compound on both sides of the beryllia washer.

6. Ma e sure that the stay wraps on the laser tube are tight and the

anode/cathode pin connectors are secure on the laser tube

terminals.

7. Open the fuse holder at the rear end cap to be sure that the correct

fuse (type 3AG, ¾ ampere) is inside.

8. Operate the power switch on the rear end cap to the OFF position.

9. Place some boo s or boxes on the table at the ends of the laser

tube to act as beam stoppers when the laser starts to operate.

- 15 -

3. Bend the transistor terminals so they fit into the three designated

holes in the PC board.

4. Secure the aluminum heat sin to the board with a No. 6 pan head

screw and loc washer. (Before beginning this step, read the note

below)

NOTE: When tightening the pan head screw at the bottom of the heat

sin , hold the aluminum U-bloc steady so it does not twist and

brea the leads of the transistor. It is imperative that the bottom of

the aluminum U-bloc contacts the PC board.

Caution: Failure to ma e a tight connection or failure to use heat sin

compound is li ely to result in extensive damage to the transistor

and several nearby diodes.

5. Apply a small amount of solder to the transistor leads at the foil

side of the PC board.

6. Chec to be sure that everything is sufficiently tight to provide heat

sin ing action when the circuit is operated.

NOTE: At this point we recommend an optional procedure to increase the

laser longevity. Spray two or three thin coats of Krylon crystal

clear No. 1302 on both sides of the PC board from the transformer

to the anode/cathode end.

This completes the mounting of all components on the printed circuit board

except the laser tube.

- 12 -

Mounting the Laser Tube on the PC Board

Laser tube LT-1 and resistor R1 are the only components mounted on the

foil side of the circuit board. Follow the instructions below and refer to

Figure 4.

1. With the foil side up, cement the flat side of a laser cradle to the PC

board between the holes located between diodes D3 and D4 using

a thin coat of Duco (or similar) cement.

NOTE: The laser cradles provide the right amount of elevation for aligning

the laser tube with the openings in the outer case. Chec to be sure

that there are no foreign materials or globs of solder on the foil side

of the PC board near the laser cradles.

2. Cement the flat side of the second laser cradle to the foil side of the

PC board between the holes near resistor R9 and capacitor C12.

3. Carefully lay the laser tube on the cradles and position the two

pieces of Kapton tape on the PC board, directly under the anode

and cathode of the tube. Ma e sure one edge of the tape is

pressed up against each of the cradles. Remove the tube and

apply pressure to the tape to securely adhere it to the board.

4. With the printed circuit board foil side up, insert the pointed end of a

plastic stay wrap through one of the large holes between diodes D3

and D4. The corrugated side of the stay wrap must face the middle

of the PC board and the smooth side must be closest to the edge of

the board. Now thread it bac through the other hole as shown in

Figure 4.

5. Repeat the above procedure and insert a second stay wrap through

the holes between resistor R9 and capacitor C12.

6. Carefully place the laser tube on the circuit board in the position

shown in Figure 4.

Caution: Be very careful in handling the laser tube. It is fragile and the pre-

aligned end mirrors can be damaged by dust or fingerprints. It

can also be damaged by very slight bumps.

7. Pass the pointed end of each stay wrap through its end loc as

shown in Figure 4. Draw the stay wraps tightly against the laser

tube and snip off the protruding ends of the wraps.

- 13 -

8. A 4-inch length of red wire, called the anode lead, is included in the

it. Attach one end of this wire to the metal clip mounted on the

front of the laser tube (Refer to Figure 4). Before connecting the

other end of the anode lead, measure the distance required for it to

reach resistor R1. Cut off and discard part of the red wire and

solder the remainder to the free end of resistor R1.

9. Solder one end of a blac 4-inch cathode wire to the metal

connector on the bac of the laser tube. Solder the other end of

this wire to the ground connector at the corner of the circuit board

(Refer to Figure 4).

This completes a temporary mounting of the laser tube on the PC board.

Connecting the Rear End Cap to the PC Board

Solder the three leads from the rear end cap assembly directly to the PC

board as shown in Figure 1).

This completes all of the electrical connections of the laser.

- 14 -

Mounting the Laser Tube on the PC Board

Laser tube LT-1 and resistor R1 are the only components mounted on the

foil side of the circuit board. Follow the instructions below and refer to

Figure 4.

1. With the foil side up, cement the flat side of a laser cradle to the PC

board between the holes located between diodes D3 and D4 using

a thin coat of Duco (or similar) cement.

NOTE: The laser cradles provide the right amount of elevation for aligning

the laser tube with the openings in the outer case. Chec to be sure

that there are no foreign materials or globs of solder on the foil side

of the PC board near the laser cradles.

2. Cement the flat side of the second laser cradle to the foil side of the

PC board between the holes near resistor R9 and capacitor C12.

3. Carefully lay the laser tube on the cradles and position the two

pieces of Kapton tape on the PC board, directly under the anode

and cathode of the tube. Ma e sure one edge of the tape is

pressed up against each of the cradles. Remove the tube and

apply pressure to the tape to securely adhere it to the board.

4. With the printed circuit board foil side up, insert the pointed end of a

plastic stay wrap through one of the large holes between diodes D3

and D4. The corrugated side of the stay wrap must face the middle

of the PC board and the smooth side must be closest to the edge of

the board. Now thread it bac through the other hole as shown in

Figure 4.

5. Repeat the above procedure and insert a second stay wrap through

the holes between resistor R9 and capacitor C12.

6. Carefully place the laser tube on the circuit board in the position

shown in Figure 4.

Caution: Be very careful in handling the laser tube. It is fragile and the pre-

aligned end mirrors can be damaged by dust or fingerprints. It

can also be damaged by very slight bumps.

7. Pass the pointed end of each stay wrap through its end loc as

shown in Figure 4. Draw the stay wraps tightly against the laser

tube and snip off the protruding ends of the wraps.

- 13 -

8. A 4-inch length of red wire, called the anode lead, is included in the

it. Attach one end of this wire to the metal clip mounted on the

front of the laser tube (Refer to Figure 4). Before connecting the

other end of the anode lead, measure the distance required for it to

reach resistor R1. Cut off and discard part of the red wire and

solder the remainder to the free end of resistor R1.

9. Solder one end of a blac 4-inch cathode wire to the metal

connector on the bac of the laser tube. Solder the other end of

this wire to the ground connector at the corner of the circuit board

(Refer to Figure 4).

This completes a temporary mounting of the laser tube on the PC board.

Connecting the Rear End Cap to the PC Board

Solder the three leads from the rear end cap assembly directly to the PC

board as shown in Figure 1).

This completes all of the electrical connections of the laser.

- 14 -

Visual Inspection

Before the laser is mounted in its outer case, ma e a thorough chec

of the electrical components of the laser as follows:

Caution: Do not connect power to the laser until all of the preliminary

chec s are made and specific instructions are given to do so.

The premature application of power can cause extensive

damage.

1. Chec that diodes, resistors, capacitors and other electrical parts

are mounted in the correct positions of the printed circuit board.

Refer to both the assembly diagram (Figure 1) and the schematic

diagram (Figure 2) while chec ing each part.

2. Wiggle each of the electrical components methodically while

watching the printed circuit board for any movement that would

indicate solder failure or a cold solder joint. If available, chec each

joint with a magnifying glass or eye loupe.

3. Scan the foil side of the printed circuit board loo ing for any solder

bridges between circuits that will cause shorts.

4. Search for and remove any deposits of solder around the outer

edge of the printed circuit board that might interfere with sliding the

board into the outer case of the laser.

5. Inspect the mounting of the transistor and its heat sin to be sure

that all of the mechanical connections are tight and there is a liberal

amount of heat sin compound on both sides of the beryllia washer.

6. Ma e sure that the stay wraps on the laser tube are tight and the

anode/cathode pin connectors are secure on the laser tube

terminals.

7. Open the fuse holder at the rear end cap to be sure that the correct

fuse (type 3AG, ¾ ampere) is inside.

8. Operate the power switch on the rear end cap to the OFF position.

9. Place some boo s or boxes on the table at the ends of the laser

tube to act as beam stoppers when the laser starts to operate.

- 15 -

3. Bend the transistor terminals so they fit into the three designated

holes in the PC board.

4. Secure the aluminum heat sin to the board with a No. 6 pan head

screw and loc washer. (Before beginning this step, read the note

below)

NOTE: When tightening the pan head screw at the bottom of the heat

sin , hold the aluminum U-bloc steady so it does not twist and

brea the leads of the transistor. It is imperative that the bottom of

the aluminum U-bloc contacts the PC board.

Caution: Failure to ma e a tight connection or failure to use heat sin

compound is li ely to result in extensive damage to the transistor

and several nearby diodes.

5. Apply a small amount of solder to the transistor leads at the foil

side of the PC board.

6. Chec to be sure that everything is sufficiently tight to provide heat

sin ing action when the circuit is operated.

NOTE: At this point we recommend an optional procedure to increase the

laser longevity. Spray two or three thin coats of Krylon crystal

clear No. 1302 on both sides of the PC board from the transformer

to the anode/cathode end.

This completes the mounting of all components on the printed circuit board

except the laser tube.

- 12 -

Mounting Transfor er T1

Refer to Figure 1 and follow the instructions below to mount transformer T1

on the printed circuit board.

1. Hold transformer T1 so the base is down and the groove at the base

(which identifies terminal 1) is at the lower right.

2. Insert the transformer in the printed circuit board so that all 12

terminals at the transformer base are firmly seated in the

corresponding holes of the board.

3. Apply a small amount of solder to each of the transformer terminals

at the foil side of the board.

NOTE: When soldering the terminals, be especially careful to avoid

solder bridges between adjacent terminals. These can short out

electronic circuits when power is applied.

Mounting Transistor Q1

Transistor Q1 is perhaps the most difficult component to mount on

the printed circuit board. This is because it must not only be

mounted in the correct location but, additional heat sin ing

precautions must be ta en to avoid premature failure of this

sensitive part. Refer to the exploded view of transistor Q1 and its

heat sin mounting components in Figure 3.

1. Hold transistor Q1 so its metal mounting tab is facing the

aluminum heat sin as shown in Figure 3.

2. Mount the transistor to the heat sin with a screw and beryllia

washer using plenty of heat sin compound on both sides of the

berylia washer. The shoulder washer and nut go on the other side

of the heat sin as shown on Figure 3, the “nec ” of the shoulder

washer fits into the hole in the heat sin . Ma e the nut as tight as

possible without brea ing the screw.

NOTE: Because the metal tab on the transistor is internally connected

to the emitter, it must be electrically isolated from the heat

sin . The beryllia washer provides both electric isolation and

heat conduction.

- 11 -

10. Insert the Plug into a 3 conductor GROUNDED wall outlet,

105-120 volts AC, 60 Hz.

Warning: If the plug is inserted in an ungrounded outlet, dangerous

voltages could appear on the laser case.

11. Operate the power switch on the rear end cap to the ON position.

The pilot light in the rear end cap should go on. The inside of the

laser tube should glow blue orange-red. A strong laser beam

should come out of the front end of the laser tube and a wea er

beam should come out of the opposite end.

NOTE: If everything has been done correctly, the laser should be

wor ing properly. However, since individual laser tubes have

different operating characteristics the laser beam current can be

adjusted for optimum operation in the particular laser. This

optional procedure is described in the next section.

- 16 -