Greeetings:
I am trying to build a +5V regulator using a LM350K. I am using a 28V
5A transformer and a two diode (GI750) full wave rectifier. I get about 10.4V No Load voltage at the filter cap (10,000uf) I am using 120 Ohm resistor for R1 and a 180 Ohm resistor plus a 500 Ohm Pot. for R2. Those are the only components used in the regulator.I have noticed that the regulator handles variations on the input side of it well. However, the output voltage varies significantly according to the resistance of the load. If I adjust the regulator to provide ~5.25V at no load, the voltage will then drop to 4.66 when the load is a 1.4 Ohm resistor that results in 3.4 amps of output current.
The voltage drop apparently is inversely proportional in a virtually linear fashion to the output current. Here are links to a jpg's of the ciruit and performance:
Does anybody know how to stablize the output voltage with regard to output current?
BTW I thought this device might be malfunctioning so I substutited a LM150K and got the same results. So, I concluded this is just the way the devices functions in this circuit.
Additionally, the heat sink I am using is rated at 5.5 degrees per watt. So the thermal resistance of the whole assembly is about 8 degrees per watt.
Best Regards,
CV