What model multimeter to measure the LED lamp beads good and bad good use
Pointer multimeter, rotate to resistance 10K file, with red and black pens were measured LED lamp beads, positive and negative cross-measurement, when measured to the parallel group of two lamp beads at the same time fluorescent light, the pointer action, if the countermeasurement of neither bright, the meter pointer also does not move, so that you can also know at once the positive and negative phases of the LED lights, the red end of the pen for the negative, if you give the LED lamp beads on the DC power, with the measurement of the 10K file when the pen Just the opposite, the red pen end is positive.
With the pointer multimeter to measure the LED light its advantages can be through the pointer action, the lamp bead shining straight, I think not worse than other table efficacy, you can also try!
10k resistance file using a 9 to 15V battery, when connected in series with a large resistor, make sure the pointer back to zero, you can measure more than 10k resistance.
Because the LED bead lights up with just a few milliamps of current, when it's measuring resistance, the small current creates a loop to the LED, doing work and emitting a pale light.
Here by the way to share a small production: because the multimeter equipped with a battery is not durable, I looked for two cell phone batteries in series for 8v, so that the voltage is not enough, the pointer can not go back to zero, I will change the resistor from a large number of resistors in the selection of a positive combination of resistors, change is also very good, use a year after the discovery of the 10k file pointer can not go back to zero, indicating that the battery should be recharged, it's very convenient to save time.
Digital multimeter can generally be measured very quickly, before I posted a multimeter to measure the LED lamp beads good or bad method, with the multimeter diode file can be, now the digital multimeter almost every model has this gear, so that no matter which multimeter, can be measured relatively quickly (only for the digital, pointer did not use much).
Series connection
This detection method is also very simple, the first to be tested to open the LED lampshade to the LED lamp beads, bare leakage out of the LED lamp beads, generally inside the LED lamp beads are connected in series, so the selection of diode gear can be powered by the LED lamp beads, if the polarity is not connected to the reverse, for normal LED lamp beads will be bright, bad LED lamp beads will not be bright, because we choose the diode gear, so in the display Because we choose the diode gear, so in the display can also be very obvious to show the bad LED light bead and good LED light bead display content is different.
Parallel connection
For more than one LED lamp beads in parallel in this case, there may be a diode file and not be able to drive so many LED lamp beads, so you can try to use a 5V power supply in the middle of the series of a 330Ω resistor, the electrode is connected to both ends of the LED lamp beads, if you see more than one LED lamp bead is bright, the individual LED lamp beads do not light up, then basically you can be sure not to light up the beads of the lamp beads are bad.
As most pointer multimeter is the use of two 1.5V batteries as R × 1-R × 1K resistance gear power supply, in the R × 10K block using 9V accumulator batteries, measuring the LED beads are good or bad can not be made to light up normally.
To measure the LED lamp beads to make it light, you must use more than 4.5V power supply multimeter.
I looked for the hand used several kinds of multimeter to do experiments to compare, and finally only a multimeter can be competent, it is the use of 12V miniature battery-powered small portable multimeter, the volume is very small, the function is relatively full, the measurement of the LED's good and bad is very intuitive and convenient.
The gear will be dialed to the "on-off" measurement gear, but also diode measurement block, the red pen connected to the LED "+" pole, the black pen connected to the "-", can make it light, online measurement is also a good way to measure the LED. Can make it light, online measurement can also be, without influence. Light is good, not light is bad, very intuitive.
