Sony XM604M Marine 4/3-Channel Amplifier List Price:$199.95 Sale Price: $169.95 You save: $30.00 (15%) Eligible for free shipping! Availability: Usually ships in 24 hours
1993 Honda Accord Ex Where to amendment radio? Well i have a 1993 honda union that i just get about a afternoon ago and i checked the radio today and theirs some code you have to input contained by and the original owner never told me the code so very soon i wanna change my...
1994 Cadilac Eldorado? I just have a Alpine CDA-9884 CD Receiver installed contained by my 94 Eldorado and as soon as i it got installed here was static beside the AM, FM, CD player, and everything else. The static get worse when my car starts to move. Does anyone...
1994 Nissan Maxima stereo? My radio just only just went out within my car (see sub. line). The stereo is a Bose video deck/CD combo, stock with the vehicle. The display will show the radio frequency, but act close to the station doesn't exist (doesn't show ST in display)....
1994 Thunderbird speaker install? How do you remove the inside door panels on a 1994 Thunderbird to replace the speakers? Also, how do you replace the support speakers? Not the rear deck ones, but the ones surrounded by the side by the backseat window arm rests
1994 Toyota Camry flipside deck speakers? I am going to replace my rear deck speakers on my camry, and I know that I enjoy factory 6x9" speakers in the hindmost. However, on sites such as www.crutchfield.com , they say that 6X9" replacement speakers will not fit surrounded by my car. What do i...
1995 camry... I am looking for a hole within the fire wall?!?!? I am trying to install an amplifier so I need somewhere to run the wiring through. i enjoy been looking but I havent found anything. I would like to run it on the drivers side though becuase i.e. the side the battery is on. Any ideas...
1995 Ford Escort: Need Speaker Wiring Diagram? I am hooking up speakers in a 95 Escort. If anyone here works at an audio install place or have one of those nifty manuals that tell you each motor and make of what respectively wire is....I really inevitability to know the colors for the...
1995 GMC Jimmy, Should I catch a subwoofer? Hey I own a 1995 GMC Jimmy, I just put contained by a new pioneer headunit (http://www.pioneerelectronics.com/pna/v3... and speakers (http://www.pioneerelectronics.com/pna/v3... and it sounds angelic, but I want to get the most out of my headunit on the final of it, it has...
1996 Corsica cassette player problems? I just bought one of those tape player output things so I can play my ipod over my cars radio. I've used these past with no problems in other cars as resourcefully as this one, but this new tape seem to have problems. Both...
1996 Jeep Grand Cherokee Laredo, 4x4 -6? Has anybody had to replace the antenna on this model. It looks resembling a detailed job contained by having to budge thru the wheel all right and then removing inside side panel. I tried to replace the antenna flagstaff but no improved results. The radio picks...
1996 Oldsmobile Aurora motor stereo? I am trying to put the original stereo vertebrae into the car and I can't numeral it out. The wires in the vehicle are green, yellow, blue, red, white near black stripe, grey, and black. The wires on the back of the stereo are...
1997 Camaro electrical problems...? I have a 1997 V6 camaro next to a 1 year old cd player installed within it. About 10 months after I installed the cd player it started shutting off disconnectedly. I checked all connections and could not fine any fouled wires. I...
1997 ford explorer stereo electric wiring diagram? i have the 2 things that come from the motor into the radio. So one is long and the other is kind of square. i get the long one hooked up. The other has 16 wires coming out of it. adjectives of them of different colors....
1997 Pathfinder Grounding through antenna? Putting an aftermarket radio in a 1997 pathfinder (non bose) The ground chain is gray, I do not get ground until antenna is plugged contained by (with nissan adapter) I did a test near the factory radio, and it also does not work until the antenna...
1997 union preamps? i just bought a 1997 honda harmony and i am planning on putting in a cd player. and i be woundering if the speakers had preamps? because i know if they do the cd player wont work...i believe explicitly correct..any help please and thank you
1998 chevy S10 mobile go limp very soon radio locked up, how can i receive it unlocked,? not sure but when i bought the truck ,i might of punched in a financial guarantee code or something,cant remember for sure,but if that`s the case how can i resolve this so my radio will work again.
1998 Ford Escort ZX2 factory stereo? I just bought the Escort, and it has a cassette deck. I wanna put a C.D. player in it, but don't like how it would look beside an after market stereo with the paraphernalia. Is there anywhere I can buy the factory c.d. player for my...
1998 Honda Civic EX Front Speakers Installation? I bought a pair of front side door speakers to install within my car. But earlier i put them in my self I merely wanted to know if it is straightforward as taking out the old set and simply pluging the current ones in?
1999 Buick Regal installing door and backside speakers? i have a 1999 buick colonial and i want to put kappa perfect 5.1 speakers surrounded by it but the kappa comes with 2 speakers and 2 tweeters and 2 crossovers right? but the majestic has 6 speakers and it basically gets complicated for me unwell...
1999 Dodge Durango, upgrade electrical Big 3? Hello all. I have a 1999 Dodge Durango that I've be upgrading the sound system on. What I have going are 4 untried speakers (*MB Quart RVF 216* and *Polk MMC5600*) running off a *kicker zx650.4* 4 channel amp, for 120 watts rms x...
1999 dodge intrepid stereo electrical system? in the doors of the 1999 dodge intrepid the speaker wires are FL green/purple FL green/black FR blue/red FR blue/black BL brown/blue BL brown/yellow BR blue/orange BR blue/white this is not at the radio i am talking within the door and in the back ...
1999 Ford Expedition Speakers? What size speakers will fit my vehical? I've already tried 6.5, im thinking either 6.8 or 6.9. Will any one of those fit? Knowlegable answers singular its a really big vehical so im gonna need 3 sets of speakers anyway.
1999 Ford Expedition Stero System? Would this CD player fit my 1999 Ford Expedition (Eddie Bauer)... http://www.fingerhut.com/ProductGroup.as...
1999 Silverado ...Speaker Problem? In the front passenger door I can see through the Grill/Cage that holds the speakers that a speaker is just hanging here and bouncing around. **What is the correct way to take out the "Grill/Cage" to procure to the speaker to...
1999 yukon? what type of stuff do i need to carry in command for me to install an battery surrounded by back of my yukon for my 2 12 aubaian speakers and is it frozen to install one
1ohm electrical system please minister to !!? wen i put the speaker wire to the subwoofer to fashion a 1ohm load, do i put the positive & distrustful speaker wire to respectively voice coil? or ONLY put positive speaker wires to the positive voice coils and negative speaker wires to the denial voice...
2 (12)Kicker comp C12 v.s. 2 (12) sony xplod? so i have a friends that has 2 12' sony xplod, the model number XSL120b5d he brought them from circuitcity, but he said i.e. sony xplod will distroy my 2 kicker comp. his speaker are rated 2000w max and mine are rated 600w max. so that...
2 10' or 2 12' subwoofers that will equal 2000 rms put together lower than 350$ respectively? Ones that hit good for both high and lows
2 12 mtx 9500 or 1 15" mtx 9500? Which would be louder? 12s being powerd by 750w respectively or the 15" being powerd by 1500w?
Washburn N4 Coil tap tones - Peacemaker Die - Extreme
4 Channel Amp Connection Diagram Questions
High Brightness LEDs Require High-Speed Production Testing
HBLED testing involves different types of test sequences at various stages of production, such as during design research and development, on-wafer measurements during production, and final tests of packaged parts. Testing "recipes" often include a multitude of steps, but this article focuses on the basic "ingredients" for these recipes—essential tests that illustrate how to probe for LED characteristics and examples of test setups. The emphasis is on electrical device characterization, but includes light measurement techniques where appropriate. Moreover, according to Keithley Instruments, http://www.keithley.com/ , by applying new test technologies, test times and costs can be reduced.
Basic electrical tests involve current-voltage (I-V) measurements to get a picture of an LED's operating characteristics. The resulting I-V curves look pretty much like those of a conventional diode. A complete test could include a multitude of voltage values versus current operating points, but a limited sample of points is generally sufficient to probe for an LED's figures of merit.
Some tests require the application of a dc current source to the LED, and then measuring the resulting voltage; other tests require the application of a dc power supply and measuring the current through the LED. A source-measure unit (SMU or SourceMeter® instrument) is ideal for these types of test, because it combines a precision power supply with high accuracy measurements similar to those that can be achieved with a precision digital multimeter (DMM). Simply put, these instruments can function as a dc power source to supply voltages or currents, and also measure each of these signal types.
Forward Voltage (VF) Test and Optical Tests. The VF test verifies the forward operating voltage of an LED. A VF test is performed by sourcing a known current and measuring the resulting voltage drop across the diode. When the forward current is applied to the diode, it begins to conduct. During the initial low current source values, the voltage drop across the diode increases rapidly, but the slope begins to level off as drive current increases. The diode normally operates in this region of relatively constant voltage, which is why it is useful to test the diode under these conditions. Typical test currents range from tens of milliamps to amps, while the resulting voltage measurements are typically in the range of few volts. The results of this test are typically used by manufacturers for binning purposes as the forward voltage is directly related to the chromaticity (color characteristic) of the LED.
Forward current biasing is also used for optical tests because electrical current flow is closely related to the amount of light emitted. Optical power measurements can be made by using an integrating sphere or placing a photodiode close to the LED under test to capture the emitted photons. This light is then converted to a current, which can be measured by an ammeter or one channel of a SourceMeter instrument.
In many test applications, the voltage and light output of the diode can be measured simultaneously using a fixed source current value. In addition, details such as spectral output can be obtained by using the same drive current value and a spectrometer.
Reverse Breakdown Voltage (VR) and Leakage Current (IL) Tests. Applying a negative bias current to the LED will allow probing for the so-called Reverse Breakdown Voltage (VR). The test current should be set to a level where the measured voltage value no longer increases significantly when the current is increased slightly more. At levels higher than this voltage, large increases in reverse bias current result in insignificant changes in reverse voltage. The specification for this parameter is usually a minimum value. The test is performed by sourcing a low-level reverse bias current for a specified time, then measuring the voltage drop across the LED. The measurement result is typically in the range of tens of volts.
Normally, moderate voltage levels (volts to tens of volts) are used to measure a Leakage Current (IL). The IL test measures the low-level current that leaks across the LED when a reverse voltage less than breakdown is applied. It is a common practice for leakage measurements, and more generally for isolation measurements, to make sure a certain threshold is not exceeded in production. There are two reasons for this. First, low current measurements require longer settling times, so they take longer to complete. Second, environmental interference and electrical noise in the test environment exert greater influence on low level signals, so extra care in shielding is required. This extra shielding complicates the test fixture and may interfere with automated component handlers.
Single LED Test System. An automated single LED test station would typically consist of a PC, component handler and dual-channel SourceMeter instrument, such as a Keithley Model 2602A. If the tests are being done at the wafer stage of production, then a wafer probe station would also be involved.
In such a test system, the main purpose of the PC is to store measurement data in a database for documentation. A secondary purpose is to reconfigure the test sequence on the SourceMeter instrument for different parts. However, a Keithley Model 2602A can actually operate independently from the PC controller. It has a Test Script Processor (TSP) that supports writing a complete test plan to operate on the instrument itself. In other words, a user can write a complete PASS/ FAIL test sequence script and run it from the front panel of the unit without instrument reprogramming.
In a more production-oriented setting, the component handler would transport individual LEDs to the test fixture where electrical contact to the SourceMeter is established. The fixture is shielded from ambient light and houses a photo detector for light measurements. In this setup, a single Dual-Channel SourceMeter can be used for both source and measure connections. Channel A can supply the test signal to the LED and measure its electrical response, while Channel B monitors the photo detector during optical measurements.
The test sequence can be programmed to begin using a digital signal line from the component handler, which provides a "start of test" (SOT) signal. When the SourceMeter instrument detects the SOT signal, the characterization tests for the LED begin. After all electrical and optical tests are completed, a digital line from the SourceMeter instrument sends a "measurement complete" signal to the component handler. In addition, the SourceMeter instrument's built-in intelligence can perform all pass/fail operations and send a command through its digital I/O port to the component handler instructing it to bin the LED based on pass/fail criteria. Usually, two subsequent actions take place synchronously: data transfer to the PC for statistical process control (SPC), and mechanical placement of a new LED in the test fixture.
LED Test System for Multiple Devices/Arrays. Large scale production testing of multiple LEDs and LED arrays may involve a burn-in process. In these tests, multiple parts are measured over a specified time period. A continuous current flow is usually mandatory to drive the LEDs, but multiple light detectors might be multiplexed to a current meter by a switch system. The appropriate instrument and switching system and will be dictated by the dynamic range of electrical currents used in the tests, and the number of devices being tested in each sequence.
For example, Keithley's Model 3706 System Switch/Multimeter offers six switch card slots, which can handle up to 576 multiplexed channels or 2688 switch matrix cross-points. It also has TSP capabilities, making it a good companion to the company's SourceMeter instruments. Their TSP-Link® feature allows both instruments to be quickly and easily integrated for tight synchronization of operations, and both can be operated from a single test script to maximize test throughput.
Programming Tests for Speed Using TSP. With many instruments, the PC has to control all aspects of the test. If so, in each element of a test sequence the instruments must be configured for each test, then perform the desired action, and subsequently return data to the controlling PC. The controlling PC must then evaluate the pass/fail criteria and perform the appropriate action for LED binning. Each command sent and executed consumes precious production time and lowers throughput.
Obviously, a large percentage of this test sequence time is consumed by communicating information to and from the PC. Instruments with TSP capabilities dramatically decrease the amount of traffic over the communications bus, and thereby increase system throughput for complicated test sequences
With TSP, the majority of the test sequence is embedded in the instrument. TSP is a full-featured test sequence engine that allows control of the test sequence, with internal pass/fail criteria, math, calculations, and control of digital I/O. TSP can store a user-defined test sequence in memory and execute it on command. This limits the set-up and configuration time for each step in the test sequence and increases throughput by lessening the amount of communications to and from the instrument and PC
Using TSP involves a simple 3-step process:
1) Create the script.
2) Download the script to the instrument.
3) Call the script to run.
The test script can be written with Test Script Builder software provided with each SourceMeter instrument, or it can be downloaded to the instrument using another program, such as Visual Basic or LabVIEW.
More details on HBLED testing, including test system diagrams, sample TSP scripts, and tips on avoiding measurement errors are available in an application note, "High Speed Testing of High Brightness LEDs", available for free download at
www.keithley.com/data?asset=50328.
About the Author
Charles Cimino has been with <a href="http://www.keithley.com/">Keithley Instruments</a> in Cleveland, OH for more than 20 years in various product and business development roles. Currently he is a Business Manager responsible for the company's Precision DMM and Signal Switching products. He has an undergraduate electrical engineering degree and an MBA degree from Case Western Reserve University's Weatherhead School of Management. He can be reached at ccimino @keithley.com, or at 440-248-0400.
Eligible for free shipping!
Leave a Comment