This happens owing to the fact that the mosfet tends to conduct and ground the output voltage whenever the voltage across its drain/source tries to rise above the set value which may be 165V as assumed here. The LEDs thus stay safeguarded from all possible high voltage and surge current hazards. Once set, this voltage gets clamped and never exceeds even under worse conditions. If 50 LEDs are connected in series at the output the above preset must be selected to produce precisely a voltage of around 50 x 3.3 = 165V The preset is appropriately set such that the the output matches the total forward drop of the connected LEDs. This high DC is applied across the crowbar network comprising the zener, MOSFET and the preset in the stage. The bridge rectifier in conjunction with the 1uF/400V rectifies the AC into a 330V DC. The input capacitor which is a high voltage metalized polyester 2uF/400V rated capacitor drops the mains 220v to desirable limits and feeds the connected the bridge rectifier stage.
#Smd circuit design software driver
The proposed 5630 SMD LED driver or compact tube light circuit may be understood with the help of the following discussion: Circuit Operation The present design is based on my previous variable transformerless power supply design, which enjoys a novel crowbar network concept for safeguarding the involved sophisticated devices.
Power dissipation: 0.5 watts approximate.Īlthough it is recommended to operate any LED via a current controlled SMPS, for simplicity sake the following compact transformerless power supply may be tried and could prove as good as it's other counterparts. The LED model shown below is the 5630 type surface mount LED from Samsung which has the following typical voltage and current specifications: I am a very big fan of your website and it has been much helpful to me in my college projects i wanted to design a driver to drive 1 to LE and input voltage 110 to 235 v, forward voltage of LED is 3.3v and i need a very efficient circuit i.e all LED should be maximum brigh would u please help us with this circuitlooking forward to your reply soon
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