Tuesday, March 29, 2011
voltage regulator save the bad transformerr.. 5% losses only... and did it when supply had bad rectifiers and small filtering... the rectified voltage losses were enormous in the voltage regulator input..from 55V dropped to 40 V (around 28%) when loaded with something around 2.5A.... output voltage previously adjusted in 35 volts, had a 1.6 volts drop (-5%).....so.... input had 15 volts losses... output, regulator job, resulted in 1.6Volts losses..... this is good to be used when your transformer is bad.... or when you need to reduce voltage from some supply you have.... regulator needs around 7 volts from colector to emitter, in the series pass transistor, to work fine... better regulation increasing the error amplifier transistor gain... zener voltage use to be 1/3 of your selected output voltage (adjustable).... The lower the output voltage adjusted, the better the regulation...but the higher is the powr over the series pass transistor...the heat will be big.... in this case.... 2.5 amperes and 6.3 volts from colector to emitter..heat is 15.75 Watts... aluminium blade... 17 by 17 centimeters will be good to this symetrical series pass regulator...you can bend the aluminium to any shape you want, or you can use conventional, standard heatsinks..the ones uses fins.
http://www.youtube.com/watch?v=5rDSMxwcugI&hl=en
