This board is designed to build a voltage regulator with V out = 5V. The main component is regulator LM 317T. Values of R3 and R2 must be calculated. All calculations are made on the basis of voltage deviders theory and formula Vout= Vref *(1+R3/R2), where Vref=1.25 V
All calculations are on the photo below:
LIST OF COMPONENTS
N.B. Initially, calculations were done for the Red Led with voltage drop which differ from the Yellow LED. But I was supplied with Yellow LED to build the circuit board. As a result, voltage drop measured across the LED gives higher value than it must be.
Voltage drops at the bottom of the last photo describe how this voltage regulator works: 12v input signal comes through the half wave rectifier (D13) with voltage drop 0.699 what tells us that it works at the 'knee voltage'. Rectified signal is stabilized by Zener diode with Vd =10.93V and smoothed by C15. This 10.93V signal comes to the input of Regulator LM317T. The output of the Regulator is 5.13V. Voltage for the adjustment electrode of the Regulator is preset by R2 and R3 devider.D12 diode protects the LM317T regulator from the storage charge in the capacitors at the moments of switch- on or switch-off modes. The outcome signal is once again smoothed by C16 and provides voltage for the LED via limiting resistor R1. V drop across R1 is 1.217V.Voltage drop across Yellow LED is 3.9V.In practice, all these fluctuations are due to preliminary calculations for the RED LED as I mentioned above and also because of elements tolerance.
LM317 is one of the most common regulators which can be used to provide stable 5V signal for electronics devices. Calculation and implementation are simple and affordable.
A reflection would have been good to see what you have learnt or how you could in prove your board.
ReplyDeleteApart from that there is some good work