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T.O 33D5-14-52-1

OPERATION / MAINTENANCE MANUAL

AMPTEC RESEARCH MODEL 620A-4

FAILSAFE DIGITAL OHMMETER/

IGNITER CIRCUIT TESTER

NSN 6625-01-460-1499AQ

DISCLOSURE NOTICE: This Information Is furnished upon the condition that It will not be released to
another nation without the specific authority of the Department of the Air Force of the United States, that it
will be used for military purposes only, that individual or corporate rights originating In the information,
whether patented or not, will be respected, that the recipient will report promptly to the United States, any
known or suspected compromise, and that the Information will be provided substantially the same degree
of security afforded it by the Department of Defense of the United States. Also, regardless of any other
markings on the document, It will not be downgraded or declassified without written approval of the
originating United States agency.

DISTRIBUTION STATEMENT: Distribution authorized to U.S. Government agencies only, administrative or
operational use, 18 August 1992.. Other requests for this document shall be referred to O0-AI.C/TIED, Hill
AFB, Utah 84056-5820.

WARNING: This document contains technical data whose export Is registered by the Arms Export Control
Act (Title 22, U.S.C., Sec 2751 et seq) of the Export Administration Act of 1979, as amended (Title SO, U.S.C.,
App 24O1 et seq). Violations of these export laws are subject to severe criminal penalties. Disseminate In
accordance with provisions of AFI 61-204.

HANDLING AND DESTRUCTION NOTICE: Comply with the distribution statement and destroy by any
method that will prevent disclosure of contents or reconstruction of the document.

Published under authority of the Secretary of the Air Force

18 JULY 2000

ORIGINAL

Содержание 620A SERIES

Страница 1: ...any other markings on the document It will not be downgraded or declassified without written approval of the originating United States agency DISTRIBUTION STATEMENT Distribution authorized to U S Gov...

Страница 2: ...Digital Ohmmeter 10900 Research Blvd PMB1 Suite 160 C AUSTIN TX 78759 USA CAGE CODE 1CRL2 Phone 1 800 350 5105 from the USA FAX 1 800 430 5440 from the USA or 512 447 7455 website http www amptec com...

Страница 3: ..._________________ AMPTEC s permission and a return authorization RMA number must be obtained directly from our customer service department via phone FAX or email for repairs warranty or otherwise We m...

Страница 4: ...B 2 Specifications C 1 Available Accessories and Options C 2 Test Lead and Probe Sets D 1 General D 2 Front Panel D 3 Rear Panel D 4 4 Wire Resistance Measurement D 5 Connections D 6 Failsafe Operatio...

Страница 5: ...onverter E 5 1 Constant Current Source E 5 2 Constant Current Circuit Operation E 6 Failsafe Design E 7 Ultra Safe Power Supply Scheme F 1 General F 2 Required Test Equipment F 3 Calibration Procedure...

Страница 6: ...for any addendums that may apply to any differences between the newer rev D version 620A 4s and older rev C 620A 4 Igniter Testers with serial numbers less than 620A4 800 i e 620A4 525 Should the rec...

Страница 7: ...s Recharge time is typically twice the Power On time An Overnight charge usually restores the 620A 4 to a Fully Charged ready to use state If you turn on the 620A 4 and the display does not come on it...

Страница 8: ...s batteries charged for 12 to 24 hours it is ready for use The 620A 4 only draws a little electrical power internal battery based and generates virtually no heat Consequently it may be used in any are...

Страница 9: ...g normal 8mA worst case when faulty 20 000 count 4 digit Super Bright Light Emitting Diodes LED or select next higher range 620A Display flashes Approximately 300ms 250VDC or AC without damage clamped...

Страница 10: ...ntity four 4 Option 100 Carrying Case Option 100 is a hardshell impact resistant plastic shock absorbing foam lined meter and accessory carrying case for the 620A Ohmmeter with extra room for test lea...

Страница 11: ...medium size up to diameter conductors The dual banana plugs terminations connect directly to the 620A s front panel input terminals see Option 290 for a photo of the banana plug ends Option 305 Banana...

Страница 12: ...0 connector out to the resistance under test just as the 4000ITS Ohmmeter or Alinco 101 series Igniter Testers would perform For the most recent information regarding this adapter related probes and a...

Страница 13: ...witch is placed in the ON position the battery pack is disconnected isolated from the rear panel charging jack The possibility of a voltage between the device under test and AC Power ground is therefo...

Страница 14: ...ers a precise constant current The internal high impedance DVM senses the voltage drop across the load There is negligible contact and lead resistance error created by the voltage measurement because...

Страница 15: ...A Series Igniter Tester Ohmmeter incorporate a proprietary current source design that renders them incapable of delivering excessive voltage or current to the device under test The typical fail safe c...

Страница 16: ...as possible before trying to pin the problem down to a specific component Certain questions should be asked such as Does the problem occur on all ranges or on a specific range only The power supplies...

Страница 17: ...llowing descriptions references to integrated circuits are given in the form IC201 1 which refers to Integrated Circuit 201 pin 1 E 4 Analog to Digital Converter The A to D conversion is done with a I...

Страница 18: ......

Страница 19: ...D During the Deintegrate phase switch 5 is closed and a voltage which is V REF more positive than during Auto Zero is impressed on the BUFFER INPUT Thus the referance capacitor stores the equivalent v...

Страница 20: ...ill be reached when the output of 1C201 is equal to the non inverting input of 1C202 Again this condition occurs when the voltage drops across R212 and R222 are equal to the voltage drops across R213...

Страница 21: ...C2 The 5 VA is developed by the DC to DC convertor circuitry composed of Q103 Q104 T102 D103 D104 IC102 for the negative polarity For the positive polarity 5V the supply circuit is composed of Q101 Q1...

Страница 22: ...Figure E 5 LED Display Pin Functions...

Страница 23: ...red to calibrate the AMPTEC 620A 4 Calibration of versions other than the AMPTEC 620A 4 use the same basic procedure however different standard resistor values may apply for different resistance range...

Страница 24: ...e cover and feet screws taking care not to pinch any wires Low Battery Indicator The variable potentiometer trimpot RV3 is factory adjusted to have the low battery indicator come on at 4 50 VDC To mak...

Страница 25: ...SECTION G COMPONENT PARTS LISTS ___________________________________________________ The following parts lists are included in this manual 620 400 2 pages 620A Main Board Components List Rev D...

Страница 26: ...e line See Above line See Above line See Above line R10 1 9 0 05 50ppm C Wire Wound R223 1 100 0 025 50ppm C 1 4W Wire Wound R224 1 900 0 025 50ppm C 1 4W Wire Wound R225 1 9K 0 025 50ppm C 1 4W Wire...

Страница 27: ...hru Q104 4 NPN Transistor T092 2N4401 Q201 1 N Channel JFET 01899E or PN4392 or J111 Q202 1 NPN Transistor T0220 MJE3439 1 Zener reference 6 3V 20ppm C 5 1N825 1 Single LED Red Small Hewlett Packard H...

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