Brymen BM857

Brymen BM857

Status	planned
Counts	50000, 500000(DCV), 999999(Hz)
IEC 61010-1	CAT III (600V)
Connectivity	Infrared RS232
Measurements	voltage, frequency, diode, resistance, continuity, capacitance, current
Features	autorange, data hold, crest, backlight, true-rms, AC+DC
Website	brymen.com

The Brymen BM857 is a 50000 counts (500000 DC), CAT III handheld digital multimeter with infrared connectivity.

Hardware

Multimeter:

• Multimeter IC: TBD
• Precision +2.5V Voltage reference: Analog Devices REF43
• True RMS-to-DC converter: Analog Devices AD737
• EEPROM(?): Chip marked S24C0.
• Unidentified: Several 062-JRC chips. These appear to be JFET opamps.
• Unidentified: Two QFP64 chips.
• TODO

Cable:

• TODO

See User_talk:Mrnuke#BM857_PC_Interface_cable

Photos

Multimeter:

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  Box

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  Mughsot

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  Device, back

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  Package contents

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  Probe cable storage clips

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  Holster removed, front

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  Holster removed, back

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  Case opened

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  Rear cover

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  Front cover

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  Rear cover, PCB removed

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  Upper PCB, top

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  Upper PCB, bottom

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  Main PCB, top

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  Main PCB, bottom

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  High voltage isolation slots.

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  High voltage isolation walls, designed to fit in the isolation slots.

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  Input circuit near the V jack

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  Microcontroller (right), and LCD controller (left)

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  Microcontroller (right), and LCD controller (left)

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  LCD controller and connector

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  ICs on the main PCB

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  More ICs

Cable:

We don't have a cable (BC-85Xa) for this device. Currently, mrnuke is working on an improvised USB-to-infrared converter for development purposes. If you have a BC-85Xa you'd like to donate, contact mrnuke on #sigrok. See User_talk:Mrnuke#BM857_PC_interface_cable for more details.

Protocol

TODO

Resources

TODO