I'm trying to use a LM317 to provide power to a Sparkfun Serial GLCD (which needs 6-7 volts). I have it circuited so that R1 across the Vout and Adj is 100 ohm and R2 connected to Adj and GND is a 1K trimmer set to about 430 ohm. By the LM317 calculator is should get 6.6 volts on Vout with a 12 volt supply. I check with my meter and I am getting 6.6 volts with no load.
The problem is when I connect the GLCD (which draws 80mA) to the regulator, the voltage drops to roughly 4.25 volts and the display doesn't work well. The only thing I can think of is that the 100 ohm resistor (R1) is causing the issue... the recommended R1 is 220 or 240 ohm. I don't have a 220 or 240 on hand to test this but I was wondering if anybody else had this problem?