Various modifications and circuit improvements of HP A 6½-digit system DMM. This manual may contain references to HP or Hewlett-Packard. Please note that Hewlett-. Packard’s former test and measurement, semiconductor products and. HP – A. info tech (non contractuel). HP – Agilent – Keysight A Digital Multimeter HP Agilent A Multimeter, Calibrated with 30 day Warranty.
|Published (Last):||17 May 2016|
|PDF File Size:||12.87 Mb|
|ePub File Size:||7.91 Mb|
|Price:||Free* [*Free Regsitration Required]|
Sounds too good to be true? Heart of the meter, ADC built using same principle as A, but now majority of critical components switches, comparator, current setting resistor networks, logics and 34577a tree is embedded in proprietary hybrid ASIC U HP A internal calibration RAM battery check Special circuitry protects calibration data from unauthorized or random overwrite.
Learn More – opens in a new window or tab. Sampling rate was equal to 0. Replaced opamps with collet sockets Situation with U is more difficult, as I got only single-channel version ADA but original TL is dual opamp component.
I really hope that he makes this into a kit. I used middle sweet spot device for replacement Q To scale input signal amplitude input amplifier is always engaged, but has different gain coefficient. There does need to be something to backup the Benchoff currency. There is no service manual schematics for this module in A documents, but such schematics available in A. Description Included Accessories Available Options 6.
In no event shall the author, xDevs. We will notify you as soon as this item is available for purchase. In addition, these two channels can be used as external device actuator channels. First I check if the adjustment necessary at all why to waste time on extra drift.
Special circuitry protects calibration data from unauthorized or random overwrite. Get the item you ordered or get your money back. Key importance at this stage to probe output with oscilloscope, to ensure stable operation without any oscillation, with actual DC signal applied on the input, from zero all the way to the full scale 3 V.
HP A rear view on modified screen Result at night. HP A input amplifier after all modifications. Replacement foil resistors S LCD display removed from assembly.
That makes possibility of rear back-light impossible. In hhp, there are several mods already out there that simply add a backlight. Thank you for the straightforward and beautiful hack, [xi].
LEDs Give HP A DDM’s LCD Display the Boot | Hackaday
When test jig controlled remotely by PC position of RP1 is in middle. So main interest go to other possible noise sources. Disclaimer Redistribution and use of this article or any images or files referenced in it, in source and binary forms, with or without modification, are permitted provided that the following conditions are met: You are commenting using your Twitter account. Gp are not messing with a 3.
Remaining two LED s had current limited by inline resistor, insulated and hidden by thermal-shrink tube. These auxiliary circuits do not affect noise performance of the ADC.
How did that happened? Learn More – opens in a new window or tab Any international shipping is paid in gp to Pitney Bowes Inc.
You should expect a response within one business day or less. Some might think that HP A is ancient technology instrument, and it should be very easy just to swap some opamps and components to modern high-performance devices, and everything will become much better. Closest to the base range is 3 V, which is not best case for sensitive measurements, such as 7V reference output. Now turn the meter again, front panel facing to us, remove top plastic cover and under it we can find top shield, holder of the multiplexer board.
Cost of maintenance on these meters is reachable even for hobby users to use a lab working tool. Yes, it also does mean that calibration will be lost if meter too old and battery discharged. Requirements Our normal service includes 90 day warranty, all standard accessories and 347a, and restoration to “nearly new” condition. The power of total electronic calibration, including AC volts, makes it easy to maintain instrument performance.
Agilent / HP 3457A
No additional import charges at delivery! Also as bonus HP promoted ability to get 7th digit from special register access. HP A U hybrid.