Fabricate

Printed Circuit Boards

for

Laser Pointer Audio Modulator - Laser Beam Detector/Demodulator

This page has etching masks which can be used to make printed circuit boards for the Laser Pointer Audio Modulator and Laser Beam Detector/Demodulator. The format is "bigfoot", a large 3" x 6" (8cm x 16cm), single-sided, standard DIP, no-holes (no drilling required), surface mount footprint - easy to make at home. Mirror images are included in case your fabrication process requires that format. Also shown are the parts placement masks (silkscreens) and Gerber files for automated commercial board fabrication.

Links to the mask files are shown below. Your browser will almost certainly NOT print these files correctly. You'll need an image viewer/manipulator to print these files. If you have Photoshop, you're home free. If not, Irfanview is a versatile image viewer and manipulator that comes absolutely free and highly recommended. Get Irfanview here.

Instructions for saving and printing the files begin below the image links.


Audio Modulator


Modulator - Top Copper - 6.42" W x 3.10" H (16.30cm x 7.87cm)

Click here for high-resolution printable image

Click here for Gerber file





Modulator - Top Copper - Mirror Image - 6.42" W x 3.10" H (16.30cm x 7.87cm)

Click here for high-resolution printable image





Modulator - Parts Placement Guide - 6.42" W x 3.10" H (16.30cm x 7.87cm)

Click here for high-resolution printable image

Click here for Gerber file

Parts list/designation chart appears below.






Detector/Demodulator


Detector/Demodulator - Top Copper - 6.20" W x 3.30" H (15.74cm x 8.38cm)

Click here for high-resolution printable image

Click here for Gerber file





Detector/Demodulator - Top Copper - Mirror Image - 6.20" W x 3.30" H (15.74cm x 8.38cm)

Click here for high-resolution printable image





Detector/Demodulator - Parts Placement Guide - 6.20" W x 3.30" H (15.74cm x 8.38cm)

Click here for high-resolution printable image

Click here for Gerber file

Parts list/designation chart appears below.






Combined

Modulator and Detector/Demodulator masks in a single image.


Combined Mod and Det/Demod - Top Copper - 6.42" W x 6.60" H (16.30cm x 16.76cm)

Click here for high-resolution printable image





Combined Mod and Det/Demod - Top Copper - Mirror Image - 6.42" W x 6.60" H (16.30cm x 16.76cm)

Click here for high-resolution printable image




Instructions for Saving the Image Files

  1. Click on the desired printable image link (not the Gerber) above; a new browser window will open and display the image.
  2. Right-click the image; a dialog box will appear.
  3. Click save picture as or save image as.
  4. Save the image (remember the location).


Instructions for Printing - Photoshop

  1. Open the saved file with Photoshop.
  2. Click File; click Print Options.
  3. In the Scaled Print Size box type the Height and Width information (enter the exact values shown with the links above, either in inches or cm).
  4. Click Print.


Instructions for Printing - Irfanview

  1. Open the saved file with Irfanview.
  2. Click File; click Print.
  3. In the Print size box click the Original size button.
  4. Click Print.


The Gerber Files

A Gerber file is a text file. Download and save. Gerber files can be viewed with Notepad (or Wordpad).

Some older browsers and/or operating systems may display the Gerber file as a web page. The file must be saved as a text file and then renamed as filetype .GRB. Click the desired Gerber file above. If (instead of downloading) the text is displayed in a new browser window, proceed as follows:

  1. Click File; click Save as.
  2. In the Save as type drop-down menu, select Text File (.txt)
  3. Save the file (remember the location).
  4. Open the saved file with a plain-text editor such as Wordpad. (Notepad probably will default to Wordpad.)
  5. Click File and Save as
  6. In the Save as type drop-down menu, select All Files (*.*).
  7. Type the file extension .GRB at the end of the file name (don't forget the dot).
  8. Save the file




Laser Pointer Audio Modulator Parts List and Component Designation Chart

Print this chart

Component Designator

Number of same value

 Value
C1,C2,C3

3

 .1uF (ceramic)
C4,C7

2

 4.7uF (25v electrolytic)
C5

1

 270pF (mica or metallized film)
C6,C10,C12

3

 1uF (35v tantalum)
C8

1

 .001uF (metallized film)
C11

1

 .01uF (metallized film)
C9,C13

2

 10uF (25v electrolytic)
C14

1

 100uF (16v electrolytic)
     
D1,D2

2

 1N5817 (Schottky rectifier)
D3

1

 Laser diode (Cheap laser pointer)
D4

1

 1N914
     
R1,R2,R8,R10,R14

5

 10k (all resistors 5% 1/4 watt)
R6

1

 1M
R3,R9

2

 270k
R4,R5,R7,R13

4

 100k
R11,R12,R15,R16

0

 not used
R17

1

 2.2k
R18

1

 33k
R19

1

 560 Ohm
R20

1

 240 Ohm
R21

1

 2 Ohm
     
U1

1

 LF347 (Quad JFET opamp)
U2

1

 CD4069 (Hex CMOS inverter)
U3

1

 CD4013 (Dual CMOS D flip-flop)
U4

1

 TC1411 (HS driver)(Digikey TC1411CPA-nd)
U5

1

 LM317 (Voltage regulator)
     
VR1 (Frequency)

1

 100k (trimpot)
VR2 (Linearity)

1

 10k (trimpot)
VR3 (Line Mod.)

1

 10k (trimpot)
VR4 (Mic. Mod.)

1

 10k (trimpot)
VR5 (Laser Current)

1

 500 Ohm (trimpot)

(Note: Diode D4 is installed on the board in parallel with resistor R14.)


Laser Modulator Board Jumper List

Print jumper lists.

The modulator board requires 4 wire jumpers.  These are added to the top of the board.  Use insulated wire.
Connect to
VDD (U2-14) VDD
U2-6 VR1-3
R9-1 U1-7
U1-14 U1-9




Laser Detector/Demodulator Parts List and Component Designation Chart

Print this chart

Component Designator Number of same value Value
C1,C3,C7,C9,C19

5

 .1uF (ceramic)
C2

1

 100uF (16v electrolytic)
C4,C8

0

 not used
C5

1

 220pF (mica or metallized film)
C6

1

 2200pF (mica or metallized film)
C10

1

 .001uF (2% polypropylene)
C12,C13

2

 .01uF (metallized film)
C14,C15

2

 .001uF (metallized film)
C17

1

 .05uF (ceramic)
C18

1

 270uF (16v electrolytic)
C11,C16,C20

3

 1uF (35v tantalum)
C21

1

 10pF (ceramic)
     
D1 (photodiode)

1

 API PDB-C142 (Digikey PDB-C142-nd)
D2

1

 1N914
J1 (jack)

1

 1/8" Stereo phone jack
L1

1

 4.7 mH (molded choke)
Q1

1

 2N2222
     
R1,R12

2

 1k (resistors 5% 1/4-watt except where indicated)
R2

1

 470 Ohm
R3

0

 not used
R4

1

 2.2k
R5

1

 820k
R6,R10

2

 33k
R7,R8,R15,R16

4

 100k
R9

1

 9.53k (1% 1/4-watt)
R11,R13,R14,R19,R20

5

 10k 
R17

1

 39k
R18

1

 10 Ohm
Rsquelch

1

 1M
     
U1

1

 LF347 (Quad JFET opamp)
U2

1

 CD4069 (Hex CMOS inverter)
U3

1

 CD4013 (Dual CMOS D flip-flop)
U4

1

 LM386-4 (Audio amp.)
     
VR1 (Volume)

1

 10k (audio taper)


Detector/Demodulator Board Jumper List

Print jumper lists.

The demodulator board requires 4 wire jumpers.  These are added to the top of the board.  Use insulated wire.
Connect to
A (V+) A (U1 pin 4)
A (U1 pin 4) A (U2 pin 14)
A (U2 pin 14) A (U4 pin 6)
B (R13) B (R12)



Combined Modulator/Demodulator Parts List

(Shopping List)

Print shopping list

Quantity - Value or part number

1 - 220pF (mica or metallized film) 
1 - 270pF (mica or metallized film)
1 - 2200pF (mica or metallized film)
3 - .001uF (metallized film)
1 - .001uF (2% polypropylene)
3 - .01uF (metallized film)
1 - .05uF (ceramic)
8 - .1uF (ceramic)
7 - 1uF (35v tantalum)
2 - 4.7uF (25v electrolytic)
2 - 10uF (25v electrolytic)
2 - 100uF (16v electrolytic)
1 - 270uF (16v electrolytic)
1 - 10pF (ceramic)

1 - API PDB-C142 (Digikey PDB-C142-nd) Photodiode 

1 - 1/8 inch stereo phone jack

2 - 1N914 (1N4148) diode 
2 - 1N5817 (Schottky rectifier)

1 - 4.7mH (molded choke)

1 - 2N2222 transistor

1 - Laser diode (Cheap laser pointer)

(all resistors are 5% 1/4 watt except where noted) 

1 - 2 Ohm
1 - 10 Ohm
1 - 240 Ohm
1 - 470 Ohm
1 - 560 Ohm
2 - 1k 
2 - 2.2k
1 - 9.53k (1% 1/4-Watt)
10 - 10k 
3 - 33k
8 - 100k
2 - 270k
1 - 820k
2 - 1M

1 - 500 Ohm (trimpot)
3 - 10k (trimpot)
1 - 100k (trimpot)
1 - 10k (Audio taper pot - chassis mount)

2 - LF347 (Quad JFET opamp)
2 - CD4069 (Hex CMOS inverter)
2 - CD4013 (Dual CMOS D flip-flop)
1 - LM386-4 (Audio amp.)
1 - TC1411 (HS driver) (Digikey TC1411CPA-nd)
1 - LM317 (Voltage regulator)

1 - modulator printed circuit board
1 - detector/demodulator printed circuit board

2 - male/female circuit bd power supply connectors (if used)* (user selected)
1 - male/female laser diode connector (if used)* (user selected)
1 - male/female detector diode connector and cable (if used)* (user selected)

*The power, laser and photodiode connections can be made by directly soldering to the circuit boards, without connectors, if you like.

2 - cases (if used) (user selected)

Also - a few feet of small, stranded, insulated wire

Closing notes:

  • Remember that the "bigfoot" format is a surface mount layout - no holes. The copper traces are etched on the top side of the board.
  • The traces should be etched on double-sided copper-clad blank PC board material, with the lower side masked off with masking tape or electrical tape and left un-etched. The lower side copper should be connected to the grounded, negative power rail (the lower side copper acts as a shield).
  • A common way to make printed circuit boards at home is the iron-on toner transfer process. That process requires the mirror image versions of the PCB trace images above. More information on the iron-on process can be found by Googling "iron on pcb".
  • All of the components are installed on the top side. The components are all standard axial- or radial-leaded devices. (The format is very forgiving of variations in component size and style.) The integrated circuits are all standard DIP-package devices.  Bend the DIP pins outward before soldering to the board.


Here's what it's supposed to look like:

PCB layouts courtesy John West, KB0ONB, kb0onb@yahoo.com (kay bee zero oh en bee)

Laser Pointer Audio Modulator and Laser Beam Detector/Demodulator
Click Here for Schematics and Circuit Discriptions

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laser beam concentrator (schematic)
laser shotgun
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