Good afternoon, dear viewers and readers. Today I want to show you a laser projector with electronic control. Otherwise it can be called a laser spirograph.
This laser spirograph was taken from the original article of radio magazine 2008, the first issue.
Once I tried to repeat and assemble this device, but for some reason I put it on the back burner. But recently I had the idea to do everything anew with a small modification of the printed circuit board.
Step 1: What a Laser Spirograph Is and How It Works.
The laser spirograph has two DC collector motors installed parallel to each other and a laser diode module or laser pointer. A mirror is mounted on the shaft of each motor at a slight angle.
Thus, the laser beam will fall to the center of the first mirror, and the beam reflected from the center of the first mirror will fall to the center of the second mirror. Each mirror will create an elliptical scan when rotated.
By overlapping two elliptical scans, we will be able to observe different figures depending on the frequency of rotation of the mirrors, similar to the Lissajous figures.
Step 2: Links to Radio Components
- Folder with laser spirograph files link 1: http://tiny.cc/vhd35y
- Archive with laser spirograph files link 2: http://tiny.cc/nqd35y
- Project on the EasyEDA page: http://tiny.cc/8td35y
- Radio parts store: http://ali.pub/3a5caa
- Header & Socket connectors 2.54 mm: http://ali.pub/39z71g
- Dupont connectors 2.54 mm: http://ali.pub/39z77v
- Microchip CD4049BE: http://ali.pub/39zbub
- Microchip CD4049BE: http://ali.pub/39zd40
- Microchip LM358: http://ali.pub/39zdfo
- Microchip LM324: http://ali.pub/39zdo1
- Microchip CD4017BE: http://ali.pub/39zdzi
- Multi-colored wire: http://ali.pub/39zepy
- Laser: http://ali.pub/39zev0
- Mirror: http://ali.pub/39zfak
- Buttons: http://ali.pub/39zfge
- Plastic pulley: http://ali.pub/39zfnl
- Microphone: http://ali.pub/39zfxp
- Motor RC300 6000RPM DC 1.5-9V: http://ali.pub/39zg6u
- Mounting racks: http://ali.pub/39zgib
Step 3: Circuit Design and PCB Layout
I have redrawn and slightly changed the basic scheme in the online environment for developing printed circuit boards EasyEDA.
The laser spirograph circuit contains such components as: a microphone amplifier, a pulse generator, an electric motor shaft speed regulator, an electronic mode switch for the projector, a sawtooth voltage generator.
Based on the principle diagram, a double-sided control circuit board was obtained, as well as separate printed circuit boards of buttons and brackets for motors and a laser consisting of several parts.
Step 4: Installation of Radio Components on the PCB
Let’s proceed to the installation of radio components on the control circuit board. Next let’s proceed to the installation of the printed circuit board of buttons.
After installation and soldering all the major radio components, we get such a great control circuit board.
Step 5: Installation of Brackets for Motors and a Laser
Let’s proceed to the installation of brackets for motors and a laser. Before you start connecting the printed circuit boards to each other, you need to thoroughly tin the places of their joints.
Soldering joints is done both outside and inside. For additional rigidity of the brackets, brass mounting racks 12 mm long are installed inside.
Step 6: Installation of Brackets on the Control PCB
Ready-made brackets are installed on the control circuit board using M3 screws and five-millimeter brass mounting racks.
Put a small plastic pulley with a glued mirror made of organic glass on the shaft of each motor.
Step 7: Wire Preparation for Connection
Then, prepare the wires for further connection of external indicators, buttons and switches.
Before soldering, remove all excess insulation and tin the wires.
Isolate each separate wire with a heat shrink tube to avoid short circuits.
Crimp the remaining wires with terminals and insert them into the appropriate connectors.
Twist the wires together with a screwdriver, giving them a more aesthetic look.
Step 8: Plastic Case Preparation for All Electronics
For installation all the electronics, we will use a ready-made plastic polystyrene case with removable panels. The dimensions of this case are 200 mm wide, 180 mm long and 70 mm high.
Drill holes in the lower part of the case for the mounting racks for the control circuit board, then bevel from the inside and outside.
Drill and cut holes for buttons, switches and LED indicators on the back of the removable panel, and make a hole with a diameter of 30 mm on the front panel for the beam of the laser module.
Step 9: Installation of All Electronics Inside the Plastic Case
Next, proceed to the final installation of all printed circuit boards and wire connections.
Step 10: Laser Spirograph Control
After the work done, the laser spirograph is ready for use. Before proceeding to the demonstration, let’s talk a little about control.
On the back of the case there are four buttons, two toggle switches, a microphone and operation mode indicators. The black button means the change of modes, the white button modulates the laser, the red and green buttons are responsible for the rotation speed of the motor and the volume of the microphone. The top toggle switch is used to reverse the motor, the bottom one for microphone gain.
Step 11: The Work of the Laser Spirograph
It is better to observe figures drawn with a laser spirograph in a darkened room.
You can easily create greater color saturation with a smoke generator, and then the laser beams become more spectacular.
The laser spirograph can be used in entertainment events – discos, concerts, club and home parties.
Remember, laser radiation is dangerous for the eyes. While making and operating a laser spirograph it is forbidden to light it in the eyes.
Step 12: End of Instruction
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