The practical use of LED light controllers within machine vision systems STEMMER IMAGING Technology Forum Munich, November 2013
Contents Why use an LED Light Controller General controller features Product range overview SafeSense and SafePower Wrap Up
Why use an LED Light Controller Use a lighting controller for: Very stable light output Pulsing lights Overdriving lights for extra brightness Dynamic changing of lighting configuration Sequencing lights Dynamic lighting calibration Complex functions
Why use an LED Light Controller - Stable Light Output LEDs are current driven devices Voltage gives very non-linear control of LEDs LED forward voltage changes by about 4% with temperature 10% voltage increase (250mV) doubles the output current The brightness varies linearly with current 1% voltage ripple = 10% brightness variation 1% current ripple = 1% brightness variation Courtesy of OSRAM
Why use an LED Light Controller - Pulsing Lights In pulsed mode the lighting is switched on only when required. Increases light lifetime Reduces lighting temperature The controller receives a trigger signal when a pulse is required. The delay from the trigger to the output pulse, the length of the pulse and the intensity of the pulse are all configurable. Use to freeze the image of moving objects.
Why use an LED Light Controller - Overdriving Lights Possible to obtain > 100% brightness of an LED by driving with more current rating for short pulses. Must use a current source, not a voltage source Overdriving with Gardasoft SafePower and SafeSense technology provides ease of use and complete confidence. The exceptions are long exposures and linescan applications.
Why use an LED Light Controller Complex Functions Advanced and Custom controller functions Custom features for some customers. Some standard complex functions For example the S15 feature outputs a different pulse intensity on each trigger Trigger Light 1 Light 2 Light 3 Light 4
Why use an LED Light Controller Dynamic changing of lighting configuration Change intensity for different production runs Gives fast change of production run Sequencing lights Switch different lights on for different images Multiple images can be taken at one point Saves cost and production time Dynamic lighting calibration Adjust output current to maintain lighting brightness Adjusts for ageing of lights More reliable systems over long term
Contents Why use an LED Light Controller General controller features Product range overview SafeSense and SafePower Wrap Up
Controllers Output Modes I t CONTINUOUS MODE Channel outputs a continuous current (no trigger required) I t PULSED MODE Channel provides a single pulse when a trigger pulse is received I t SWITCHED MODE Channel provides an output current when the trigger input is active I t SELECTED MODE Provides a switch between two different intensities
Configuring a Controller Front panel Pushbutton and three digit display Ethernet Webpage interface UDP or TCP packets from PC application or a PLC RS232 Configuration program Text commands from PC application or a PLC
Configuration - Web Browser The Ethernet based controllers have an internal web servers Enter the controller s IP address in a web browser to configure it
Contents Why use an LED Light Controller General controller features Product range overview SafeSense and SafePower Wrap Up
Gardasoft LED Controller Features Common Features 2 to 8 channels Patented SafeSense TM technology High stability, fast pulsing linear regulation PP Series Up to 48V input Pushbutton and Ethernet RT Series Can use 24V for any system SafePower TM technology Low heat dissipation and easy overdriving Pushbutton, RS-232 and Ethernet
CC320 Trigger Timing Controller CC320 Integrates encoders, cameras, lighting, proximity sensors and reject gates Ethernet communications Fast and accurate Faster scan time than PLCs - 100µsec Up to 200Khz encoder input Camera and reject trigger timing Discrete inputs and outputs
CC320 Typical Application Conveyor belt system Product sensor Cameras and lights to be triggered along the belt Reject mechanism (timed to original sensor trigger) Tracking multiple parts on belt (needs FIFO system) Encoder or timed operation
Gardasoft Lighting Products VTR traffic monitoring strobe lights IR or white IP66 enclosure Fast repetition for high frame rates VLX line lights Water and air cooled Profile correction 2Mlux focussed onto a 3mm wide line
Contents Why use an LED Light Controller General controller features Product range overview SafeSense and SafePower Wrap Up
SafeSense What is SafeSense Allows safe and accurate driving of LED lighting SafeSense works in four steps: Sensing when a light is connected Finding the current rating of the light Driving the light within safe limits Detecting faults SafeSense SafeSense
SafePower RT controllers only Reduces controller heat dissipation Allows 24V lights to be overdriven from a 24V supply Allows more flexible choice of power supply
Contents Why use an LED Light Controller General controller features Product range overview SafeSense and SafePower Wrap Up
Gardasoft History Early history Founded in 1999 as an engineering consulting, design and integration firm Designed first LED controllers in response to customer requests Offered LED controllers to machine vision market Gardasoft today world class LED control and lighting 25 employees New facility in Cambridge, UK Gardasoft LLC supports North America Worldwide technology leader in controllers High brightness strobe and line lights
More Information White Papers LED Controllers technical White Paper LED Strobe lighting for ITS White Paper Further Information Gardasoft Range Summary APP930 Overdriving LEDs APP936 SafeSense APP966 SafePower Technical Information APP916 RS232 Troubleshooting Guide APP921 Upgrading Firmware APP923 Ethernet Troubleshooting Guide APP926, APP939 PP500 Heat Dissipation APP944 Fast Pulse Shapes APP969 Using Japanese Lighting Another 60 application notes available www.gardasoft.com
Thank you Head office Gardasoft Vision Limited Buckingway Business Park Cambridge CB24 4UQ, UK Tel: +44 1954 234970 email: vision@gardasoft.com US office Gardasoft LLC Oak Ridge Road Weare NH 03281 Tel: +1-603-657-9026 email: visionusa@gardasoft.com www.gardasoft.com Gardasoft Vision 2013