Adjustment question - Fluke 8600A (fixed)

[Postal666]

To clarify: It won't work without the batteries, but it won't damage anything to try to turn it on with the batteries disconnected.

Gotcha. Glad I'm finally on the same page wih everyone else. haha

[wiss]

Some flukes (8050) might get damaged (the lcd) by running without NiCds, they are the only regulation of the primary supply.

[edavid]

Some flukes (8050) might get damaged (the lcd) by running without NiCds, they are the only regulation of the primary supply.

No!  Fluke's designers were not that stupid.

[wiss]

Some flukes (8050) might get damaged (the lcd) by running without NiCds, they are the only regulation of the primary supply.

No!  Fluke's designers were not that stupid.

Are you sure? The supply goes up from 5 to 7 V (or so) when the NiCds are removed on the 8050, the 8000 seems to be ok without them.

[edavid]

Some flukes (8050) might get damaged (the lcd) by running without NiCds, they are the only regulation of the primary supply.

No!  Fluke's designers were not that stupid.

Are you sure? The supply goes up from 5 to 7 V (or so) when the NiCds are removed on the 8050, the 8000 seems to be ok without them.

Yes, I am sure.  All of the Fluke meters that use NiCds, use them as shunt regulators.  None of them will be damaged if you try to power them up without the NiCds.

[pipe]

Resurrecting a somewhat old thread here, but I ripped all the cells and charging crap out of my 8600A and replaced it with the 5V regulation from the schematics. The 8600A also comes in a non-battery version, and that version is using a standard transformer, rectifier and a 7805. I kept their primitive switched +/-15V card. If you rip the batteries out, there's a footprint on the PCB for adding the normal linear regulator.

[Postal666]

Hey pipe!  Gonna follow your lead and dig this thread back up...haha.  So, I've been using mine as is, but two of the batteries are totally shot now, thus the thing won't even turn on.  Let me ask you just so I'm clear: You used the existing xfmr and built the +5V regulation of CR102, U102, C104 (from the line supply version) and fed that +5V into the original +/-15V board? 

[edavid]

Hey pipe!  Gonna follow your lead and dig this thread back up...haha.  So, I've been using mine as is, but two of the batteries are totally shot now, thus the thing won't even turn on.  Let me ask you just so I'm clear: You used the existing xfmr and built the +5V regulation of CR102, U102, C104 (from the line supply version) and fed that +5V into the original +/-15V board?

I found that the DC-DC converter needs 5.5V input to produce an output of 15V, and it is also quieter at that voltage than 5.0V.  So, I suggest using an LM317 and a trimpot so you can tweak the output voltage where you want it.

Also, the power switch is in the wrong place in the circuit.  If you care about that, there is an unused set of contacts on it that you can use to switch the AC input.