A. Kelvin-Varley. Voltage Divider. Instruction Manual. P/N mm (8) In the event of failure of a product covered by this warranty, John Fluke Mfg. Co., . The Fluke A Kelvin-Varley Voltage Divider generates V and 11W of power. A models provide an absolute linearity of ppm, a temperature. Find great deals for Fluke A Kelvin Varley Voltage Divider Shop with confidence on eBay!.
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Fluke 720A Kelvin-Varley Voltage Divider
Bridge balance pot and trimmers accessible from front panel. The switches used have gold plated solid silver alloy contacts for long life, minimum contact resistance, and no tarnishing. Function switch Take a look on decades more closely. Faulty Decade A switch Well, our quest with Decade A does not end so quick with only bad wiring, as even after reassembly of wiring properly, divider does circuit does not work as expected.
Bottom PCB have long array of low-resistance wire-wound resistors, few variable 1-turn potentiometers and multi-turn trimpots.
Oy East Trade Promotion Ltd – Fluke A Kelvin-Varley Voltage Divider
Fluke A page AN In no event shall the author, xDevs. Resistors R, 720z and R are checked and well within expected range, so no problem there. The front panel is clearly labeled showing step size for each decade. Inside from top side. And as expected, after decade switch replacement unit came back to life.
ffluke There are no any active thermal regulation inside A, so Fluke engineers went other way around thermal stability and performance. The single turn pots are wire wound, manufactured by CTS. If you would like to support us by making a donation please click the Paypal button: Wiring around decade B Image If you willing to contribute or add your experience regarding any instruments repairs or provide extra information, you can do so following these simple instructions.
Later ones are accessible from front panel to implement calibration functionality for decades A and B. Troubleshooting and repair Incorrect wiring on Decade A switch Continuity measurements revealed lack of connection from Input terminals to the beginning of Decade A resistor network. Bridge power and detector terminals are used for calibration and linearity testing.
All information posted here is hosted just for education purposes and provided Fluks IS. Incorrect wiring on decade switch. Markings on rotary switch and resistors. On sub-ppm performance levels there are no insignificant details, so great care was taken to guarantee design targets.
If anyone knows details about this, please share. Little board with beautiful Fluke-made teal resistors mounted just above the oil tank from the top side. Also connection to input and output binding posts has got my attention, as soldering does not look very good.
There is also little 5K KVD -pot with co-axis fine and coarse adjustment for balancing bridge. They are mounted to the case on special Kel-F washers to insure low leakage.
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Continuity measurements revealed lack of connection from Input terminals to the beginning of Decade A resistor network. Additional service and repairs Plastic shafts used to rotate decade switches were replaced as well.
Few extra photos of wiring and routing around rotary decades.
High quality gold plated tellurium-copper binding posts serve to minimize the thermal emf effects which would flke reflect a change in dc resistance measurements. None of this would happen without great volt-nut community all over the globe. Temperature coefficient of linearity is 0.
Sticker on the unit. The most significant decade is sealed in an oil bath to minimize temperature coefficient effects. ToddlowimpedanceDr.
But instead we had no connection there:.
To achieve this ratio, calibrated HP A multimeter will be used. The KVD has a resolution of 0. Gold also allows the use with low level signals.
This instrument is… Image 7: