All posts by Linda

smd 5050 led

smd 5050 led
The name 5050patch led module comes from it’s size, because of his size was 5mm*5mm*1.6mm,this work voltage is same than normal led as 3.2~3.4V . and current 60mA. in the parameter above we know that the 5050 led module had extremely tiny body.. so The hand welding method is hard . if the hand welding is necessary . the temperature were kept down to just 250 degree. It is commonly used to Energy saving lamp, car dashboard, LED lamp belt, mobile phone backlight and keypad, instrument backlight …those product requires the led module having small size.

What the impact for human when using blue light led.

What the impact for human when using blue light led.
What the impact for human when using blue light led. uv led(uv led strip) or blue light led is still a hot topic and the contestation concerning discussion have never stopped Since blue light led has appeared, in fact, the blue light is an integral part to visible light, Which doesn’t blue light led that scary, With the in-depth research, people’s knowledge about visible light had increased gradually, these misconceptions will also be reduced.
Do it like this ,the visible light can better played its own advantages to meet the needs of different projects,

Typical constant circuit for LED

The hardware scheme use supper bright high power LED and 1W of constant circuit which supply constant output current

1W constant circuit

The sensor resistor is externally connected, which realize output current programmable(R1 is sampling resistance)
Peak current = 500mV/R1

 

 

LED flicker

LED flicker

Many factories using “no radiation, no flicker, high brightness” to advertising the LED production.
Just for now, the LED work in pure DC and flicker-free, eliminating the visual fatigue by traditional strobe light. but there are alternatives to power supply for LED . the way is AC power supply. The LED is vulnerable to be influenced by interferences and noises caused by AC alternating ripple .
Now , given an example to showing the LED flicker in everyday life.
the ambulance also has a red light on top to warn people that it is coming. the signal frequency is about 8~10Hz. which people are not comfortable with. the frequency(cause alarm in people) . fluorescent lights flickered when digital cameras shoots the images. The same is true for noises caused by AC alternating ripple . the different point that they have different frequency .

Rated current of LED

Rated current of LED
Different types of led offer different the rated current . The user should not push the system beyond its maximum current rating. You should be familiar with normal unit as well .
Led type                                                       Rated current
The indicator LED light                     5MA
0.5W LED                                                  150MA
1W                                                                  350MA
3W                                                                  700MA

Simply boost circuit for DIY led

Simply boost circuit for DIY led
It presents designs of boost circuit, The power board consists of LED , Triode , resistance ,hand-wound ferrite toroid.
First attaché pic is circuit for DIY led
DIY led (boost)
Now we started we did DIY led.
DIY LED 1(boost )
DIY LED 1(boost 1)
DIY LED 1(boost 2)
DIY LED 1(boost 3)
ok , finish!
DIY LED 1(boost 4)

Solution of led supply by battery

Solution of led supply by battery

The led supply is diversified and stable, which includes the support for battery . the application is so wide such as: signal lights, emergency lights, headlights, uv led strip , flashlights and solar street lights , which has been successfully applied in Lighting field .LED gradually took over from Incandescent lamp, fluorescent lamp, xenon lamp.
Now more drive the LED by constant current source method. but today we share that a way of drive led by LM317, please see circuit pic as follows:
LM317 drive circuit

LED gold thread

LED gold thread
The LED gold thread is the core of LED. LED usually use LED gold thread, LED cord and Bracket as raw material to produce. the led cord was hinged to Bracket through LED gold thread, then Stick them on using a small amount of glue .it has a slender diameter. the gold thread blew for an electric current across LED. so double led gold thread that can bear more loads(current) .
LED gold thread

The mono-dimensional dynamic changes of LED

The mono-dimensional dynamic changes of LED
We base this  wire length and diameter given graph of the reactance-distance . Before that, Let’s explore that the equivalent impedance. increased the resistance when the sizes of them increase . The main effects on power output performance . manifested on its measurement of the output power and loader voltage are not accurate . the voltage must not be greater than 0.5V。
Attention: use thicker cable, If this bound is exceeded,

Wire diameter                   Impedance  mΩ/M(at 20oC)
0.5mm2                                         52.8
0.75mm2                                        33.5
1.0mm2                                         20.96
1.5mm2                                         13.19
2.5mm2                                         8.30
4mm2                                          5.22
6mm2                                          3.277

What can you do to distinguish constant-voltage source and constant-current source by parameter?

What can you do to distinguish constant-voltage source and constant-current source by parameter?
If you just got a led power supply . How was I to know that it’s constant-voltage source or constant-current source . first you should be find voltage Parameter from production nameplate .
The type, power and speed of the machine are seen on the nameplate. we usually go straight into analysis mode:
The specified nominal values of voltage is fix value, it is constant-voltage source an orientation position,eedle Tle along a scale.
The voltage moves a needle along a scale. it is constant-current source .