Changes

This image from the book "Product Integrity and Reliability in Design" appears to be a schematic of the Model 250.<br />[[File:John W. Evans, Jillian Y. Evans, Dong-su Ryu (auth.), John W. Evans, Jillian Y. Evans (eds.) - Product Integrity and Reliability in Design-Springer-Verlag London (2001).jpg]]<br />---- ==Acid Etching Unit Pictures==<gallery mode="packed" heights="200">

</gallery>---- ==Control Unit Pictures==<gallery mode="packed" heights="200">File:BG Model 250 Controller Front.jpg|Front panel with LCD screen and 6 button keypad for loading programs and controlling various built-in maintenance features.File:BG Model 250 Controller Back.jpeg|Rear with DB9 and DB25 connections on the left. DB9 supports RS232 and DB25 is from the IO Board which connects to the Acid Etching unit to control all the valves and read values back. Fan, power switch and plug on the right.File:BG Model 250 Controller Control Panel PCB.jpeg|Rear of LCD PCB seen on the top, bottom is PCB used for reading buttons and signal conditioning for LCD.File:BG Model 250 Controller Internal 1.jpeg|Power supply on the right with EMI Suppression on the bottom. Control PCB's on the top with ribbon cable that plugs into front panel PCB.File:BG Model 250 Controller Internal 2.jpeg|Internal view from the other sideFile:BG Model 250 Controller Processor Board.jpeg|Processor board runs on a Motorola 6803 8-bit microcontroller at 4.9152 MHz with an external 8k RAM, 64k EEPROM and a 256k EPROM with version sticker on it.File:BG Model 250 Controller Processor Board Back.jpeg|Back of processor board, small jumper wire seen on the top right side. This is present on two different processor PCB's I have, not just a manufacturing defect with this board.File:BG Model 250 Controller IO Board Front.jpeg|IO Board used to drive valves in Acid Etching unit. a buzzer is on the bottom middle which is triggered when there are errors or user interaction needed in the process.File:BG Model 250 Controller IO Board IC.jpeg|Close up image of the IC's usedFile:BG Model 250 Controller IO Board Transistor2.jpeg|Close up image of the transistors on the left used to drive the valves, driven by the smaller ones on the right.File:BG Model 250 Controller IO Board Transistor.jpeg|Close up image of the transistors the Processor board drives which in turn drive the larger ones on the right that control the valves.File:BG Model 250 Controller Backplane Top.jpeg|Backplane PCB which the processor board and IO board plug into, the black connector at the top is where the power supply connects. A ground trace is run to the nut on the top left which mounts to the chassis. The paint on the chassis around this screw was removed to make a good connection.File:BG Model 250 Controller Backplane Bottom.jpeg|Botton of the backplane PCB, nuts are riveted to the PCB which mount to the bottom of the metal chassis.<br /gallery>