I'm using the following voltage regulator from National, the LM338:
http://www.national.com/ds/LM/LM138.pdf
Now I'm trying to get get an output of about 11V-12V from this regulator. My input voltage coming from bridge rectifier is 11V. Now following the formula listed in the datasheet, I get completely wierd numbers for my resistance values. I haven't included any caps in my circuit yet, and I've been playing with potentiomers to adjust the voltage and still no luck
However, I've been thinking if I even need the voltage regulator. I'm running a small DC motor and I intend to control it using PWM. If I'm planning to run it from anywhere to 6V to 11V, is there even a need for a voltage regulator(Since I'm getting 11V out of my bridge rectifier)? Can I just throw in a couple of caps after my bridge rectifier circuit to smooth out the voltage and run it straight to the motor, or is a regulator required no matter what?
http://www.national.com/ds/LM/LM138.pdf
Now I'm trying to get get an output of about 11V-12V from this regulator. My input voltage coming from bridge rectifier is 11V. Now following the formula listed in the datasheet, I get completely wierd numbers for my resistance values. I haven't included any caps in my circuit yet, and I've been playing with potentiomers to adjust the voltage and still no luck
However, I've been thinking if I even need the voltage regulator. I'm running a small DC motor and I intend to control it using PWM. If I'm planning to run it from anywhere to 6V to 11V, is there even a need for a voltage regulator(Since I'm getting 11V out of my bridge rectifier)? Can I just throw in a couple of caps after my bridge rectifier circuit to smooth out the voltage and run it straight to the motor, or is a regulator required no matter what?
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