ACU-RITE D200 DRO

ACU-RITE 2x Mill D200

Overview

Glass scale based digital read out (DRO). It uses a vacuum fluorescent display (VFD) rather than a more modern LED displays.

2X MILL D200  DOM
PN: 2001003
SN: 99050879 Rev: B

Photos

Taken from eBay seller lovedabeach's eBay Item #122087858728.

Replacement Parts

Power Entry Module

  TE Connectivity Corcom Filters PS0SXS000

Transformer

ENSIGN CORPORATION
2001-900 B
172.9911

172 is the manufacturer code (Acu-Rite or Ensign?) 9911 is the date code, November 1999. B is the revision level.

Specs:

  • Input Power: 115/230VAC ± 20% @ 50/60Hz
  • Output #1: 7V minimum ripple valley @ 1.4ADC / 47000uF (± 20%) capacitor with 80% nominal input (92VAC instead of 115VAC), 15V ripple peak @ 450mA with 120% (138VAC instead of 115VAC) input.
  • Output #2: 34V minimum @ 115mA DC / 1000uF (± 20%) capacitor with 80% nominal input, no maximum specified.
  • typical forward diode drop is expected to be 1V
  • thermal fuse on each secondary, if it blows it's permanent.
  • external fusing, 0.5A slow blow for 115V operation, 0.25A slow blow for 230V operation.

Transformer pinout:

The bobbin manufacturer and Acu-Rite use different pin mappings. On the bobbin, pin #1 is marked by a notch in the plastic, that pin is also closer to it's adjacent pin than the rest. The bobbin pin numbers are numbered 1-6 then 7-12 clockwise (TODO: from above or below?). In other words, bobbin pins 6 and 7 are across from each other at the same end of the transformer.

Bobbin Pin Acu-Rite Pin Function
1 [NC] [NC]
2 1 Primary #1 A
3 2 Primary #1 B
4 3 Primary #2 A
5 4 Primary #2 B
6 [NC] [NC]
7 5 >34V out
8 6 >34V out
9 [NC] [NC]
10 [NC] [NC]
11 7 7-15V out
12 8 7-15V out
  • For 115V operation, jumper Primary #1A to Primary #2A as well as Primary #1B to Primary #2B. This puts the primaries in parallel.
  • For 230V operation, jumper Primary #1B to Primary #2A. This puts the primaries in series.

2x Logic Board

Name Markings
U1 Allegro UCN5818EPF
U2 Fairchild 74VHC138
U3 AMD Am188 EM-20KC
U4 Microchip 93AA66/SN
U5 Fairchild 74VHCT573
U6 ISSI IS62C256-70U
U7 National Semiconductor 74VHCT74
U8 AMI 9851NTF ACU-RITE 387577-702 REV-B
U9, U10 Motorola VHC574
U11 unknown, sticker reads "DRO 1.1.2" (ROM?)
U12 Fairchild 74VHC123A

VFDs

Top

Noritake CH1573G

8-digit 14-segment display with periods. The last (right-most) segment has a dot in the center of the top "circle" in the 8. There are also words above each digit to indicate modes.

Bottom

Noritake CH1572G

8-digit 7-segment display with periods and split center segments. The last (right-most) segment has a dot in the center of the top "circle" in the 8.

Online Resources

Acu-Rite DRO 200M Brochure

Acu-Rite DRO 200M Reference Manual

Manuals & Flyers – ACU-RITE

Technical Support – ACU-RITE

Service: Helpline - HEIDENHAIN

ACU-RITE DRO 200M | Digital Readout Systems

Acu-rite Digital Readout Repair Page