vendredi 25 octobre 2013

My stencil CNC cutter

My stencil CNC cutter
Part one : Laser driver

Regulate current: 

The current supplied by the battery is rather stable, but in most cases, is too much to drive a laser diode. For instance, a DVD-burner laser diode would need about 200-250mA of power at about 2.5-3 volts(for any long life span to actually be expected of the diode). Laser diodes are, unfortunately, a very light load when wired directly to a battery, and an alkaline battery would easily put out about 500mA or more, and lithiums put out 2 or 3 times that much! This too is an instant death situation for our beloved laser diode. Although very simplistic, it is not that common to find a flashlight with the right current regulation, and most of us would like to be able to control the current supply by using a potentiometer.

Current regulation is the tricky part of this circuit. The chip that I like most for current regulation is the LM317. The chip can be used as a voltage regulator and as a current regulator. This guide will use a capacitor as a voltage regulator since the battery's voltage is, for the most part, already regulated and stable, while all we need to do is limit the current that we let flow into the diode.

Laser diod:
What you will find in different drives:
- In a DVD-RW there are 2 burning diodes: Red for DVD and infraref for CD.
- Weak red lasers 1mW from DVD-ROM (read-only drives) are suitable only for a small laser pointer or poor laser show, they won't burn anything.
- V combos CD-RW/DVD-ROM (burning CD and read a hangover), there's a burning infrared dide and weak red diode (as in DVD-ROM)
- And finally, the lasers from CD-ROM are absolutely useless. I mention this list so I avoid stupid questions whether the diode from a CD-ROM will burn.
Warning! Laser diodes from DVD-RW drive are emitting visible and invisible laser radiation and they are extremely dangerous! Their light can permanently damage the eyes. You must never look into the working diode even without the lens or point it on a reflective surface. Laser beam can cause burns or fire. This is usually a Class IIIb laser. Everything you do at your own risk.

Schematic of current power supply for double laser from DVD-RW burner drive with switch for selecting operation mode (RED - INFRARED - BOTH). The resistor determines the output current to the laser diodes using the formula I = 1.25 / R. LM317 needs a heatsink. The voltage drop of infrared laser diode is 2.15 V and the voltage drop of red one is 2.5 V. 

                                                                 250mW open can laser diode be continued

jeudi 24 octobre 2013

Electronic components free sample

This list is currently being updated it will include "straight" suppliers as well as those that do have samples of their products available.
as the companies listed here do change their policies , some may no longer have samples available

Marktech | | Led and related
TI | | Semiconductor
Maxim | | Semiconductor
Analog Devices | | Semiconductor
Avago Technologies:
Microchip | | Semiconductor
Atmel | | Microcontroller
Intersil | | Semiconductor
Agilent Technologies:
Fairchild | | Semiconductor
Infenion | | Semiconductor
Microsemi | Semiconductor
Ramton | | Memory
Exar Corporation:
Laird Technologies:
On Semiconductor | | Semiconductor
Supertex | | Power Devices
IXYS Semiconductor:
Zilog | | Semiconductor
Coilcraft | | Inductor
Hittie | | Microwave
FTDIchips | | USB
AllegroMicro | | Sensors
Linear Technology | | Semiconductor
CML Micro | | Wireless communication
Holtek | | Semiconductor Need to be contacted
System General | | Semiconductor
Bivar | PCB Packaging and LED Assemblies
SunLED | | LED and Displays
AboveBoard Electronics | | Tools
MillMax | | Interconnects and IC sockets
Meritekusa | | Passive Components
Murata Manufacturing:
Molex | | Connectors
Kycon | | Connectors
Azmicrotek | | Logic Translator
Astrorep | | Supplier
FMG Elecronics | | Supplier
Electec | | Supplier
Avnet | | Supplier
Promor | | Supplier
Central Semiconductors | | Semiconductor
LittleFuse | | Power Devices and Fuses
Foxonline | | Crystals and Oscillators
Semtech | | Power Devices
OKW | | Enclosures and Knobs
SMD INC. | | Supplier
Heyco | | Grips and holders
Teknational | | Thermal Insulation and hardware
FCI Connect | | Connectors
Bridge Port | | Fittings
Pericom | | Semiconductor
Elesta | | Relays
Pacentec | | Enclosures
Sensitron | | Arrays, Semiconductors, LEDs
Bergquist | | Thermal related products
Cooperet | | Magnetics and protection
NorthWest Components | | Passive and Diodes
EM Microelectronics | | RFID
ERG | | Display related
ON Shore | | Terminal Blocks and connectors
AAVID Thermal Alloy | | Sample Kits
Epcos | | Passive Components
Fordata | | LCD
NJR | | Semiconductor
Wurth Elektronix | | PCB, EMI, EMC, Connectors
Spectra Symbol | | Flex Sensors
Cirrus Logic | | Digital chips, D/A converters, Ethernet controllers, audio/video decoders…
FreeScale | | Semiconductor
TE Connectivity:
ITW/Fastex | | Connectors and Clips
Micrometals | | Toroids
Marktech | | Led and related
New Age Enclosures | | Enclosures
STMicroelectronics | | Integrated Circuits
Manncorp | | SMT Solder Paste
Screenkeys | | LCD Screen Switches
Keystone | | Hardware and Accessories

samedi 19 octobre 2013


DSB HQ-230 description :
TheDSB HQ-230 is a high quality, low cost A4 Photo Laminator with an internationally patented folded tray design, and carrying handle that is perfect for Small or Home Office use, and for transporting to wherever the job may require it.
This hot or cold lamination system can laminate at a speed of 300 mm per minute any document up to A4 in size up to a total thickness of 250 microns (2x125mic) plus the document being laminated up to 0.4mm.
Features for theHQ-230include a paper support for the laminated document, and a handy release switch that can be used to release any jams that might occur. The HQ 230 has 2 Rollers and a Temperature Control Dial to setup required temp (0°C, 80°C, 100°C and 125°C).
For use in PCB transfer method the 125°C is not sufficient to drop toner to fusion point witch is 180°C.

1      -      Disassembling the unite and get the PCB
2      -      With your soldering iron remove the resistor 2.7K (as shown in photo) and replace it with 1K.

Voila your laminator is ready. When Control Dial is in 125°C you get a 178°C.

My first circuit (PICKIT2)!!!

vendredi 18 octobre 2013

  1. 1
    Design your circuit board. Use PCB computer-aided design (CAD) software to draw your circuit board. You can also use a perforated board that has pre-drilled holes in it to help you see how your circuit board's components would be placed and work in reality.
  2. 2
    Buy a plain board that is coated with a fine layer of copper on one side from a retailer.
  3. 3
    Scrub the board with a scouring pad and water to make sure the copper is clean. Let the board dry.
  4. 4
    Print your circuit board's design onto the dull side of a sheet of blue transfer paper. Make sure the design is oriented correctly for transfer.
  5. 5
    Place the blue transfer paper on the board with the circuit board's printed design against the copper.
  6. 6
    Lay a sheet of ordinary white paper over the blue paper. Following the transfer paper's instructions, iron over the white and blue paper to transfer the design onto the copper board. Iron every design detail that appears near an edge or corner of the board with the tip of the iron.
  7. 7
    Let the board and blue paper cool. Peel the blue paper slowly away from the board to see the transferred design.
  8. 8
    Examine the transfer paper to check for any black toner from the printed design that failed to transfer to the copper board. Make sure the board's design is oriented correctly.
  9. 9
    Replace any missing toner on the board with ink from a black permanent marker. Allow the ink to dry for a few hours.
  10. 10
    Remove exposed parts of the copper from the board using ferric chloride in a process called etching.
    • Put on old clothes, gloves and safety goggles.
    • Warm the ferric chloride, stored in a non-corrosive jar and sealed with a non-corrosive lid, in a bucket of warm water. Do not heat it above 115 F (46 C) to prevent toxic fumes from being released.
    • Pour only enough ferric chloride to fill a plastic tray that has plastic risers in it to rest the circuit board on. Be sure to do this in a well-ventilated space.
    • Use plastic tongs to lay the circuit board face down on the risers in the tray. Allow 5 to 20 minutes, depending on the size of your circuit board, for the exposed copper to drop off the board as it etches away. Use the plastic tongs to agitate the board and tray to allow for faster etching if necessary.
  11. 11
    Wash all the etching equipment and the circuit board thoroughly with plenty of running water.
  12. 12
    Drill 0.03 inch (0.8 mm) lead component holes into your circuit board with high-speed steel or carbide drill bits. Wear safety goggles and a protective mask to protect your eyes and lungs while you drill.
  13. 13
    Scrub the board clean with a scouring pad and running water. Add your board's electrical components and solder them into place.