ETX R.A. Drive Corrector Schematic

Dotted lines 1 to 4 are the links to the hand controller. I used a modular phone jack I picked up at the dollar store. A coulple of holes need to be drilled into the side of the ETX for the power supply selector switch (SW3) and for the phone jack. I couple of the lines in the original PC board in the ETX base must be cut, as well, new ones soldered in for SW3 and the 9V battery. I think is cost me less than $30 to put this together. Most of that cost is for the switches and the Radio Shack "project box" to put it all in. (I had most of the LED's, diodes and resistors in my junk drawer)

WARNING: attempt at own risk!! I will not take responsibility for any damage you may do to your ETX.

Parst List:
SW3 - DPDT switch - added to ETX circuit to determine which power source to use
SW4 - DPDT switch - on/off for drive controller power supply
PB1 - DPDT pushbutton - switch between new circuit and original circuit
PB2 - DPDT momentary pushbutton - TURBO bypass switch - super fast speed
(sorry - I just buy DPDT switches for everything, keeps the options open, eh!)
D1 - red LED - indicators, on/off, and ETX/new circuit - 2 req'd
D2 - silicon diodes - block back current - 2 req'd
R1 - 10K resistor - 2 req'd
R2 - 5K pot
R3 - 1K resistor
R4 - 1.3K resistor
Adjustable Power Regulator IC - LM317T - radio shack part # 276-1778

Created: Sept 17, 1998