Acer AL1717P Schematic

Acer AL1717

Service Guide

Service guide files and updates are available on the CSD web: for more information,

Please refer to http://csd.acer.com.tw/

- 1 -

Copyright © 2003 by Acer Incorporated. All rights reserved. No part of this publication may be reproduced, transmitted, transcribed, stored in a retrieval system, or translated into any language or computer language, in any form or by any means, electronic, mechanical, magnetic, optical, chemical, manual or otherwise, without the prior written permission of Acer Incorporated.

Disclaimer

The information in this guide is subject to change without notice. Acer Incorporated makes no representations or warranties, either expresses or implied, with respect to the contents hereof and specifically disclaims any warranties of merchantability or fitness for any particular purpose, Any Acer Incorporated software described in this manual is sold or licensed “as is ”. Should the programs prove defective following their purchase, the buyer (and not Acer Incorporated, its distributor, of its dealer) assumes the entire cost of all necessary servicing, repair, and any incidental or consequential damages resulting from any defect in the software.

Acer is a registered trademark of Acer Corporation. Intel is a registered trademark of Intel Corporation.

Pentium and Pentium II/III are trademarks of Intel Corporation.

Other brand and product names are trademarks and/or registered trademarks of their respective holders.

- 2 -

Conventions

The following conventions are used in this manual:

Screen messages	Denotes actual messages that appear on screen

Note	Gives bits and pieces of additional information related to the current topic.

Warning	Alerts you to any damage that might result from doing or not doing specific actions.

Caution	Gives precautionary measures to avoid possible hardware or software problems.

Important	Reminds you to do specific actions relevant to the accomplishment of procedures.

Preface

Before using this information and the product it supports, please read the following general information.

1.this Service Guide provides you with all technical information relating to the BASICCONFIGURATION decided for Acer’s “global” product offering. To better fit local market requirements and enhance product competitiveness, your regional office MAY have decided to extend the functionality of a machine (e.g. add-on card, modem, or extra memory capability). These LOCALIZED FEATURES will NOT be covered in this generic service guide. In such cases, please contact your regional offices or the responsible personnel/channel to provide you with further technical details.

2.please not WHEN ORDERING FRU PARTS, that you should check the most up-to-date information available on your regional web or channel. If, for whatever reason, a part number change is made, it will not be noted in the printed Service Guide, for ACER-AUTHORIZED SERVICE PROVIDERS, your Acer office may have a DIFFERENT part number code to those given in the FRU list of this printed Service Guide. You MUST use the list provided by your regional Acer office to order FRU parts for repair and Service of customer machines.

- 3 -

WARNING: (FOR FCC CERTIFIED MODELS)

NOTE: this equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses and can radiate radio frequency energy, and if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception,

Which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures:

1.Reorient or relocate the receiving antenna.

2.Increase the separation between the equipment and receiver.

3.Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.

4.Consult the dealer or an experienced radio/TV technician for help.

Warning

Use only shielded signal cables to connect I/O devices to this equipment. You are cautioned that changes or modifications not expressly approved by the party responsible for comliance could viold your authority to operate the equipment.

As an ENERGY STAR® Partner our company has determined that this product meets the ENERGY STAR® guidelines for energy efficiency.

WARNING:

To prevent fire or chock hazard, do not expose the monitor to rain or moisture. Dangerously high voltages are present inside the monitor. Do not open the cabinet. Refer servicing to qualified personnel only.

- 4 -

PRECAUTIONS

zDo not use the monitor near water, e.g. near a bathtub, washbowl, kitchen sink, laundry tub, Swimming pool or in a wet basement.

zDo not place the monitor on an unstable trolley, stand, or table. If the monitor falls, it can injure a person and cause serious damage to the appliance. Use only a trolley or stand recommended by the manufacture or sold with the monitor. If you mount the monitor on a wall or shelf, use a mounting kit approved by the manufacture and follow the kit instructions.

zSlots and openings in the back and bottom of the cabinet area provided for ventilation. To ensure reliable operation of the monitor and to protect it from overheating, be sure these openings are not blocked or covered. Do not place the monitor on a bed, sofa, rug or similar surface. Do not place the monitor near or over a radiator or heat register. Do not place the monitor in a bookcase or cabinet unless proper ventilation is provided.

zThe monitor should be operated only from the type of power source indicated on the label. If you are not sure of the type of power supplied to your home, consult your dealer or local power company.

zThe monitor is equipped with a three-pronged grounded plug, a plug with a third (grounding) pin. This plug will fit only into a grounded power outlet as a safety feature. If your outlet does not accommodate the three-wire plug, have an electrician install the correct outlet, or use an adapter to ground the appliance safely. Do not defeat the safety purpose of the grounded plug.

zUnplug the unit during a lightning storm or when it will not be used for long periods of time. This will protect the monitor from damage due to power surges.

zDo not overload power strips and extension cords. Overloading can result in fire or electric shock.

zNever push any object into the slot on the monitor cabinet. It could short circuit parts causing a fire or electric shock. Never spill liquids on the monitor.

zDo not attempt to service the monitor yourself; opening or removing covers can expose you to dangerous voltages and other hazards. Please refer all servicing to qualified service personnel.

zTo ensure satisfactory operation, use the monitor only with UL listed computers which have appropriate configured receptacles marked between 100-240V AC, Min. 3.5A.

zThe wall socket shall be installed near the equipment and shall be easily accessible.

- 5 -

SPECIAL NOTES ON LCD MONITORS

The following symptoms are normal with LCD monitor and do not indicate a problem.

NOTES

zDue to the nature of the fluorescent light, the screen may flicker during initial use. Turn off the Power Switch and then turn it on again to make sure the flicker disappears.

zYou may find slightly uneven brightness in the screen depending on the desktop pattern you use.

zThe LCD screen has effective pixels of 99.99% or more. It may include blemishes of 0.01% or less such as a missing pixel or a pixel lit all of the time.

zDue to the nature of the LCD screen, an afterimage of the previous screen may remain after switching the image, when the same image is displayed for hours. In this case, the screen is recovered slowly by changing the image or turning off the Power Switch for hours.

- 6 -

Table of contents

Chapter 1 Monitor Feature …………………………………………………………………...………..8 Chapter 2 Operating Instruction ………………………………………………..……………………..27

Chapter 3 Machine Disassembly and Replacement …………………………………..…………35

Chapter 4 Troubleshooting …………………………………………………………………………..48

Chapter 5 Connector Information …………………………………………………………………..52

Chapter 6 FRU List …………………………………………………………………………………… 53 Chapter 7 Schematic Diagram ….……………………………………………………………………..63

- 7 -

Chapter 1

Monitor Feature

INTRODUCTION

Scope

This specification defines the requirements for the 17” MICRO-PROCESSOR based Multi-mode supported high resolution color LCD monitor. This monitor can be directly connected to general 15 pin D-sub VGA connector and eliminates the requirement of optional special display card. It also supports VESA DPMS power management and plug & play function. There is a build-in stereo audio amplifier with volume control to drive a pair of speakers.

Description

The LCD monitor is designed with the latest LCD technology to provide a performance oriented product with no radiation. This will alleviate the growing health concerns. It is also a space saving design, allowing more desktop space, and comparing to the traditional CRT monitor, it consumes less power and gets less weight in addition MTBF target is 20k hours or more.

Comparison Chart of AA677

		AA677
		Normal 17” panel
	Panel	LG HT17E01-A5
		TOPPOLY TD170WGCB2

	Signal Interface	DSUB
	Sync Type for analog	Separate / compatible /
	input	Separate / compatible /
	input
	Color Temp user adjust	Support
	DDC	DDC2B
	Speaker	0.5W+0.5W
	Headphone Jack	NO
	Microphone Jack	No
	USB Hub	Not support
	Tilt / Swivel	Yes / No
	Height Adjust	Option

- 8 -

ELECTRICAL REQUIREMENTS

Standard Test Conditions

All tests shall be performed under the following conditions, unless otherwise specified.

Ambient light :	225 lux
Viewing distance :	50 cm in front of LCD panel
Warrn up time
All specifications :	30 minutes
Fully functional :	5 seconds
Measuring Equipment :	Chroma 2250 signal generator or equivalent, directly
	Connected to the monitor under test.
	Minolta CA100 photometer, or equivalent
Control settings
User brightness control :	Maximum (unless otherwise specified )
User contrast control:	Typical (unless otherwise specified )
User red/white balance,
Green/white balance and
Blue/white balance control :	In the center (unless otherwise specified )
Power input:	110Vac or 230Vac
Ambient temperature:	20 ± 5 ˚C ( 68 ± 9 ˚ F)
Analog input mode:	1280 x1024 /60 Hz

MEASUREMENT SYSTEMS

The units of measure stated in this document are listed below: 1 gamma = 1 nano tesla

1 tesla = 10,000 gauss cm = in x 2.54

lb = kg x 2.2

degrees F = [°C x 1.8] + 32 degrees C = [°F - 32]/1.8 u' = 4x/(-2x + 12y + 3)

v' = 9y/(-2x + 12y + 3)

x = (27u'/4)/[(9u'/2) - 12v' + 9] y = (3v')/[(9u'/2) - 12v' + 9] nits = cd/(m2) = Ft-L x 3.426 lux = foot-candle x 10.76

- 9 -

LCD monitor General specification

Panel Type:	17 “ active matrix color TFT LCD
	1). LG HT17E01-A05
	2). Toppoly TD1402
Display size:	37.92mm (H) × 270.34mm(V)
Display mode:	VGA		720 ×	400	(70 Hz)
	VGA		640 ×	480	(60/66/70/72/75 Hz)
	SVGA		800 ×	600	(60/70/72/75 Hz)
	XGA	1024 ×		768	(60/70/75 Hz)
	SXGA	1280 × 1024 (60/70/75 Hz) standard resolution
Pixel pitch:	0.264mm(H) × 0.264mm(V)
Display Dot:	1280 x (RGB) × 1024
Pixel Clock:	25.2 – 135.0MHz
Contrast ratio: θ = 0˚	LG 450 : 1 , TOPPOLY 450 :1
Brightness:	LG:250, TOPPOLY 260(typical)
Response time (Tr/Tf):	LG(16), TOPPOLY (12)
Display color:	16.2M(6 bit color+FRC)
Viewing angle:	LG	L / R 70 / 70 ( 140 degrees horizontal typical)
		U / D 60 / 60( 120 degrees vertical typical)
	TOPPOLY		L / R 75 / 75
			U / D 75 / 60
Luminance Uniformity:	> 75 % (typical)
Pc interface:	1).Video:		RGB analog 0.7V peak to peak
	Sync: TTL positive or negative
Signal connector:	15 pin Mini D type, (standard VGA video)
	3.5 mm stereo audio jack (Audio) (For AR577 only)
Audio power:	0.5Wrms + 0.5Wrms (300Hz – 10kHz (S.P.L. – 10 dB))(AA677 only)
Front control:	power on/off with LED select adjustment (+,-)
Interface frequency
Horizontal Frequency	24KHz --80KHz
Vertical Frequency	49Hz	------75Hz
Plug & play:	Support VESA DDC2B functions
Power Input voltage:	Single phase, 50/60HZ, 100 VAC to 240VAC ±10%
Total output power:	40 Watt max.

- 10 -

LCD Panel Specification

LCD Panel Model (LG LT17E01-A05)

•

Display Type	active matrix color TFT LCD
Resolution	1280x1024 pixels
Display Dot	1280x (RGB) x 1024
Display Area	337.92mm(H) x 270.34mm(V)
Pixel Pitch	0.264mm(H) x 0.264mm(V)
Display Color	16M (6 bite color+FRC)
Lamp Voltage	650 Vrms (typ)
Lamp Current	6.5 mArms (typ)
Weight	1890g (typ)
Optical Specifications

IL = 6.5mA (RMS)		Ta = 25 ± 2°C		VDD = 5V		FV = 60Hz	FDCLK = 54MHz

	ITEM		Symbol		Condition	MIN.	TYP.	MAX.	UNIT

	Contrast Ratio		CR
	(Center of screen)					350	430	-

	Response	Rising	TR			-	16	-	(total)
	Time at Ta	Falling	TF			-	16	-	msec
	Time at Ta	Falling	TF						msec

	Luminance of white		YL
	(Center of screen)				φ=0,	-	250	-	cd/m2
			RX		θ=0	0.611	0.641	0.671
		Red	RY		Normal	0.312	0.342	0.372
			GX		Viewing	0.262	0.292	0.322
	Color	Green			Angle
	Color	Green	GY		Angle	0.581	0.611	0.641
	Chromaticity		BX			0.117	0.147	0.177
	(CIE)	Blue	BY			0.038	0.068	0.098
			WX			0.283	0.313	0.343
		White	WY			0.299	0.329	0.359
			θL			-	70	-
	Viewing	Hori.	θR			-	70	-	Degrees
	Angle				CR≥10
	Angle		φH		CR≥10	-	60	-
		Vert.	φL			-	60	-
	Brightness Uniformity		BUNI			-	-	1.7

	Flicker		F			-	-	5	%

	Cross talk		CT			-	-	2.0	%

- 11 -

LCD Panel Model (ToppolyTD170WGCB2)

•	Display Type	active matrix color TFT LCD
•	Resolution	1280x1024 pixels
•	Display Dot	1280x (RGB) x 1024
•	Display Area	337.92mm(H) x 270.34mm(V)
•	Pixel Pitch	0.264mm(H) x 0.264mm(V)
•	Display Color	16M (6 bite color+FRC)
•	Lamp Voltage	655 Vrms (typ)
•	Lamp Current	7 mArms (typ)
•	Weight	1850g (typ)
•	Optical Specifications

IL = 7mA (RMS)		Ta = 25 ± 2°C		VDD = 5V		FV = 75Hz	FDCLK = 135MHz

	Item		Symbol		Condition	Min.	Typ.	Max.	Unit

		Hor.	θL			65	75	-

	Viewing Angle		θR		CR=10 At	65	75	-	degree
			θR		CR=10 At	65	75	-
					center point
		Ver.	θH			65	75	-
			θH			65	75	-

			θL			50	60	-
			θL			50	60	-

	Contrast Ratio		CR		θ = 0˚	300	450	-
	(Center point)		CR		θ = 0˚	300	450	-
	(Center point)

	Response time	Rising	TR			-	4	5	cd/m2

		Falling	TF			-	12	15
		Falling	TF			-	12	15

	Luminance of White		YL			200	260	-
	(Center point)		YL			200	260	-
	(Center point)

		White	Wx			0.622	0.652	0.682
					θ=0,
			Wy			0.303	0.333	0.363

					φ=0

			Rx			0.247	0.277	0.307
	Color	Red	Rx		Normal	0.247	0.277	0.307

			Ry			0.599	0.629	0.659
	Chromaticity		Ry		Viewing	0.599	0.629	0.659

			Gx			0.111	0.141	0.171
	(CIE1931)	Green	Gx		Angle	0.111	0.141	0.171

			Gy			0.024	0.054	0.084
			Gy			0.024	0.054	0.084

		Blue	Bx			0.28	0.31	0.34

			By			0.30	0.33	0.36
			By			0.30	0.33	0.36

	9 Points White Variation		δ L			0.7	0.8	-

	Cross Talk		CT			-	-	2.0	%

- 12 -

Note 1) Definition of Viewing Angle: Viewing angle range (10≤CR)

Note 2) Definition of Contrast Ratio (CR): Ratio of gray max(Gmax),gray min(Gmin) at the center point of panel.

Luminance with all pixels white (Gmax)

CR=

Luminance with all pixels black (Gmin)

Note 3) Definition of Response time: Sum of TR , TF

- 13 -

Note 4) After stabilizing and leaving the panel alone at a given temperature for 30 min, the measurement should be executed .Measurement should be executed n a stable, windless ,and dark room.30 min after lighting the back-light. This should be measured in the center of screen. Dual lamp current :13.0mA(6.5mA x2)(Refer to the note(1) in the page 14 for more information ).

Environment condition :Ta=25±2°C

Optical characteristics measurement setup

- 14 -

Notes 5) Definition of Luminance of White : measure the luminance of white at center point.

Notes 6)Definition of 5 points brightness uniformity (Measuring points: Refer to the Note 5)

Bmax

BUNI=

Bmin

Bmax: Maximum brightness

Bmin: Minimum brightness

Notes 7) Definition of Flicker level

Flicker Voltage pp

F = x 100 %

LMD Voltage dc

♦One maximum value of three estimated values.

♦For this test ,an LMD(Light Measurement Device)is needed with adequate response time to track any visible rate flicker component and with a voltage level output proportional

To luminance intensity.

♦Test Pattern: For dot inversion Driving(Gray levels of foreground dots on the test panel

Are G22,G32,and G45)

♦Test Point :Center point of the display area

- 15 -

Note 8) Definition of Crosstalk (Refer to the VESA STD)

The calculation for shadowing is made from the 2 luminance measurements Gbkg and Lsh, as follows:

	Lmax -Lmin
CT	= x100 %
	Lmin

Where Lmax is the larger value of Gbkg or Lsh , and Lmin is the smaller of the two.

♦ To determine background and foreground levels (colors),first set the background to any gray scale or color level suitable for shadowing determination.(Note that it may take several iterations of adjusting background level and box levels to determine the proper value for the background .Next display the box levels to determine the proper value for the background level. Look for shadowing in any direction from box E. Independently vary the gray level (or color) of the background and box E until the worst case shadowing is observed. This defines the background (Gbkg) and foreground (Gfg) levels to be maintained for the remainder of the test.

♦ One point only (the target) will be measured. To determine that point proceed as follows

Using the background and foreground gray levels of step1 (Gbkg and Gfg). Turn on each box at a time. Look for the case with the worst shadowing. The box causing the worst case is the shadowing source, or Bsrc. Use Bsrc and the box opposite from it that lies directly in the shadow path. That is the target box, or Btgt. Note that box Eight be either Bsrc or Btgt, depending on the shadowing conditions, but typically Bsrc and Btgt will be a pair of opposite boxes, A&C or B&D. Btgt will only be displayed for aligning the LMD. It will be turned off for the actual measurement.

♦ The target box point (Btgt) will be measured with the source box (Bsrc) turned on then off. (Btgt is for alignment purpose only) Display the background only at level Gbkg. Display Btgt determined in step 2 above. Using the correct distance, angle, and measurement aperture, align the LMD to the center of the Btgt. Turn off Btgt. With Gbkg set to its proper level, measure the luminance (or color). Next,turn on the source box Bsrc. Again measure at the center point of Btgt (without Btgt present.). In this case the LMD will be measuring the shadowing level, Lsh.

- 16 -

Panel Relative Humidity

JP777-E02

Input Signals

Video input

•

Type	Analog R, G, B.
Input Impedance	75 ohm +/- 2%
Polarity	Positive
Amplitude	0 - 0.7 +/- 0.05 Vp
Display Color	same as LCD panel

Sync input

•

Signal	separate horizontal and vertical sync, or composite sync
	which are TTL compatible
Polarity	positive and negative.

Interface frequency

The following frequency range is generalized by supported timing. If the entered mode does not match the supported timing the display optimization will not be assured.

•

Horizontal Frequency	24KHz --	80KHz
Vertical Frequency	49Hz -------	75Hz

- 17 -

Supported Timing

TIMING	FH(KHZ)	SYNC	TOTAL	ACTIVE	SYNC	FRONT	BACK	PIXEL
TIMING	FV(HZ)	POLARITY	(DOT/LINE	(DOT/LINE)	WIDTH	PORCH	PORCH	FOREQ.(MHZ
	FV(HZ)	POLARITY	(DOT/LINE	(DOT/LINE)	WIDTH	PORCH	PORCH	FOREQ.(MHZ
			)		(DOT/LINE)	(DOT/LINE)	(DOT/LINE)	)
					(DOT/LINE)	(DOT/LINE)	(DOT/LINE)
640x350	31.469	+	800	640	96	16	48	25.175
VGA-350	70.087	–	449	350	2	37	60
640x400	24.83	–	848	640	64	64	80	21.05
NEC PC9801	56.42	–	440	400	8	7	25
640x400	31.469	–	800	640	96	16	48	25.175
VGA-GRAPH	70.087	+	449	400	2	12	35
640x400	31.5	–	800	640	64	16	80	25.197
NEC PC9821	70.15	–	449	400	2	13	34
640X480	31.469	-	800	640	96	16	48	25.175
VESA-PAL	50.030	-	629	480	2	62	85
640x480	31.469	–	800	640	96	16	48	25.175
VGA-480	59.94	–	525	480	2	10	33
640x480	35.00	–	864	640	64	64	96	30.24
APPLE MAC-480	66.67	–	525	480	3	3	39
640x480	37.861	–	832	640	40	16	120	31.5
VESA-480-72Hz	72.809	–	520	480	3	1	20
640x480	37.5	–	840	640	64	16	120	31.5
VESA-480-75Hz	75	–	500	480	3	1	16
720x400	31.469	–	900	720	108	18	54	28.322
VGA-400-TEXT	70.087	+	449	400	2	12	35
832x624	49.725	–	1152	832	64	32	224	57.2832
APPLE MAC-800	74.55	–	667	624	3	1	39
800x600	35.156	+	1024	800	72	24	128	36
SVGA	56.25	+	625	600	2	1	22
800x600	37.879	+	1056	800	128	40	88	40
VESA-600-60Hz	60.317	+	628	600	4	1	23
800x600	48.077	+	1040	800	120	56	64	50
VESA-600-72Hz	72.188	+	666	600	6	37	23
800x600	46.875	+	1056	800	80	16	160	49.5
VESA-600-75Hz	75	+	625	600	3	1	21
1024x768	48.363	–	1344	1024	136	24	160	65
XGA	60.004	–	806	768	6	3	29
1024x768	53.964	+	1328	1024	176	16	112	71.664
COMPAQ-XGA	66.132	+	816	768	4	8	36
1024x768	56.476	–	1328	1024	136	24	144	75
VESA-768-70Hz	70.069	–	806	768	6	3	29
1024x768	60.023	+	1312	1024	96	16	176	78.75
VESA-768-75Hz	75.029	+	800	768	3	1	28
1024x768	60.24	–	1328	1024	96	32	176	80
APPLE MAC-768	75.02	–	803	768	3	3	29
1152x864	54.054	+	1480	1152	96	40	192	80
(60Hz)	59.270	+	912	864	3	13	32
1152x864	63.851	+	1480	1152	96	32	200	94.499
(70Hz)	70.012	+	912	864	3	1	44
1152x864	67.50	+	1600	1152	128	64	256	108.00
(75Hz)	75.00	+	900	864	2	2	32
1280x960	60.00	+	1800	1280	112	96	312	108.00
(60Hz)	60.00	+	1000	960	3	1	36
1280x960	70.00	+	1800	1280	112	96	312	126.00
(70Hz)	70.00	+	1000	960	3	1	36
1280x960	75.00	+	1800	1280	112	96	312	135.00
(75Hz)	75.00	+	1000	960	3	1	36
1280x1024	64	+	1688	1280	112	48	248	108
VESA-1024-60H	60	+	1066	1024	3	1	38
z
1280x1024	80	+	1688	1280	144	16	248	135
VESA-1024-75H	75	+	1066	1024	3	1	38
z

Note: Mode 640x350, 640x400 and 720x400 will locate on middle position but cannot be expanded to full screen on vertical direction

- 18 -

Support Modes

There will be 28 total support modes to accommodate the above mode and other video modes within the frequency range of the monitor.

85Hz refresh rate Support

Monitor should display 85Hz refresh rate mode as emergency mode.

Monitor should display “Out of Range” warning menu at this mode.

Video input Connector

Analog Video input Connector: 15pins mini D-Sub

Table 2.4.5. Pin assignment for D-sub connector

PIN NO.	Separate Sync

1	RED VIDEO

2	GREEN VIDEO

3	BLUE VIDEO

4	GROUND

5	GROUND

6	RED GROUND

7	GREEN GROUND

8	BLUE GROUND

9	PC5V (+5V DDC)

10	CABLE DETECTION

11	GROUND

12	SDA

13	H.SYNC

14	V.SYNC

15	SCL

		Color of plastic parts: Blue (PC99)

5	1
10	6
15	11

D-sub connector

- 19 -

Monitor Block Diagram

The LCD monitor will contain an main board, an inverter/ power board, key board and internal adapter which house the flat panel control logic, brightness control logic and DDC.

The inverter board will drive the backlight of panel and the DC-DC conversion.

Power board

(include: AC/DC,inverter)