I am trying to test a simple servo controller with a 555 timer and transistor. I've read every page I can find and I still can't make it work right. I have a variable resistor between R1 and R2 and (both R1 and R2 are 4.7k) and while I can change the pot, the servo continually jitters and moves in small increments, sometimes CW and sometimes CCW. The power indicating LED (5v regulated through LM2940CT) flickers as well and the regulator really heats up. Something is obviously not right. Please help.