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

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