Old Philips Fluke 97 / 96B (maybe others?)

[Scottjd]

I finally died after 29570 seconds or 8.26 hours.  At 584mA, 4821mAh.  Seems the pack does meet their claimed 4500mAh but I just don't know how you would go about charging it with the scopemeter.

I wouldn't use any of the built in charging for the Ni-MH pack. I was thinking about this idea I had. Feel free to add to the idea or give feed back about it.
For charging a Ni-MH lack in the meter I was thinking about the following idea.

I would add a female micro/mini USB port that I can splice into the positive battery cage tab. Then using a power supply to supply power to a Ni-MH charging boar I can put it inline between the power supply and before the male USB plug. Maybe I can 3D print a bigger housing for the power supply and put the charge board inside this housing with a plastic wall for separation between the power supply and charging board.
Maybe start off with something like this one, or use one of the cheap chargers I don't trust that came with some LED flashlights and mod them?
http://www.ebay.com/itm/Ni-MH-Charger-Auto-Stop-Circuit-board-1-to-10-cell-800mA-MJE2955T-12-16VDC/140353600313?_trksid=p2045573.c100033.m2042&_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D38530%26meid%3D302ca39224134343948c276a38f87bf0%26pid%3D100033%26rk%3D2%26rkt%3D8%26sd%3D401046168634

I would wire it so when the USB port is plugged in it will disconnects the positive line from the battery packs to the meter preventing the meter from running off the battery when it's charging. Then provide the positive line from the charging board to the battery positive terminal, not the charging tab. I would disconnect the wire from the onboard charger to the battery cage. This way you can also plug in the stock power supply to run the meter at the same time it's charging the battery from the USB port. This will also allow standard Ni-MH C cells to be used without a need for a charging tab and could charge them from the USB port. Also running standard C cells will be easier to check the individual cell voltage and replace a bad cell if one dies.
Interference from the charging board should be minimal since the charging circuit will be external and away from the meter with at least 3 feet of wire or longer.

The charging board would have an adjustable charge current controlled by a resistor pod. I can use a in line USB power monitor for adjusting the current so I won't need to put a display on the charging board. My USB power monitors from YZXStudio runs from 4V to 14V with little burden voltage and little power consumption.

My concerns would be the charge rate and the heat generated on the cells as they increase to full charge capacity in that little battery compartment that is sealed with an O ring. I can use the USB data lines to a K style thermostat or thermistor that I can hot glue the sensor inside the battery compartment. Then include a temperature cut off monitor on the charging board when it reaches a set temperature. I did read about a Ni-MH charging method that was based off the temperature only. The charger turns off when it hits a set temperature despite the voltage levels.  This charging style is new to me so I would need to research it but it makes sense. I would also want voltage monitoring as a backup cutoff.

If the pack doesn't get too hot when charging then I can set the charge board to put out  1A or maybe higher for a faster charge. NI-MH batteries are designed to charge with higher current and they could over charge with low current like from the built in Ni-CD charger. The built in charger won't be able to detect when the cells are full when it's doing a trickle charge that would over charge the NI-MH cells.

I will probably just disable any trickle charging on the Ni-MH board so it might drop the total capacity when it's done charging the pack, but not much loss difference in capacity. It will still have plenty of capacity for long run times and shorten the charging time a little. This way the Ni-MH pack would charge faster with temp cut off as the cell fills up to near full capacity as they reach near full charge.

TIP:
I soldered a pin to the end of an old probe (or you can solder it to the wire with a male bandanna on the other end) and poked little holes in my pack so I can check the individual cell voltages without unwrapping the pack.  I wouldn't recommend using this pin probe for LiPo packs since they are easier to puncture.

So far mine seem fairly balanced, well within spec for what I would expect from a Ni-MH pack without balancing capabilities. A little trick I used to do with RC packs to check for a bad cell without having to unwrap the pack. I used to charge the packs at max current. Heck the old Ni-Cd packs we used to charge them in a ziplock bag then put into an ice cooler so they would take the max capacity and have a longer run time. It killed the packs faster as expected, but it was racing so competition brings out inventive ways to win within the rules.
I know my charger is a delta charger, so I can set the mV for the trickle to top it off or leave it on automatic. This was an idea to top off all the cells to the same level. Not sure if or how it really works. I just kept it on automatic. I changed over to LiPo packs shortly after this and stepped into the next class of races.

Thank you,
Scott

[joeqsmith]

I have not looked to see how they connect in the scope.  Assumed it was 3 wire + com -.  Normally when I need a scope like this, it's for under an hour so 7+ hours is more than enough.  I did contact Fluke about trying to get parts for them (holster, gaskets, etc) and they have no parts available.   

It will be interesting to see what you come up with.  Maybe you could strip the entire power supply section, use the connector that is on the unit and start clean rather than trying to work with what it there. 

[Scottjd]

I have not looked to see how they connect in the scope.  Assumed it was 3 wire + com -.  Normally when I need a scope like this, it's for under an hour so 7+ hours is more than enough.  I did contact Fluke about trying to get parts for them (holster, gaskets, etc) and they have no parts available.   

It will be interesting to see what you come up with.  Maybe you could strip the entire power supply section, use the connector that is on the unit and start clean rather than trying to work with what it there.

I did think about stripping the whole power supply section and starting clean, but I also like the fact that it current will run off of 12VDC to 20VDC on the current DC input. This give a lot of options for powering it and handy for automotive, just jump to the battery and it's on. I'm not sure if your 97 is set up the same way?
The other concern with starting fresh was inadvertently causing interference with what you are probing. This is why I was wanting to put the charging board at the power plug and not inside the unit, and also disconnecting it from the unit while it's charging the battery to prevent any interference while it's still being powered from the DC barrel 12-20V input.

I think I may have a dual power supply in the box of power supplies, I'll have to see how good the separation is on it and scope the signals. I may be able to use a dual and just split the wires so one is the USB for charging and the other is the DC barrel. So only one thing to plug into the wall, and since it takes a wide range of power input with 12-20V this opens up options for finding a good dual power supply.

I don't have an immediate rush or even have a daily need to use this scope, so it may be a back burner project but something I still think would be fun to do. I'll keep the thread updated, I'll probably have to come back to the thread to see my own notes an idea any way 

[joeqsmith]

Seems like starting over, rolling a complete new design from scratch you could really improve it.   

Looking at the manual now.  I have not read any of the documents yet besides a few parts of the service manual.  The claim it can read up to 5MHz frequency.  mVDC has a 5KHz low-pass.  The state the inputs are protected against surges up to 4KV. 

NiCad was about 4 hours run time.   16 hours of charge time (scope not running). They show the input voltage range of 8 to 20 volts, 5W. 

[Scottjd]

Seems like starting over, rolling a complete new design from scratch you could really improve it.   

Looking at the manual now.  I have not read any of the documents yet besides a few parts of the service manual.  The claim it can read up to 5MHz frequency.  mVDC has a 5KHz low-pass.  The state the inputs are protected against surges up to 4KV. 

NiCad was about 4 hours run time.   16 hours of charge time (scope not running). They show the input voltage range of 8 to 20 volts, 5W.

Ah yea, that's what it was. 8 to 20V in because I was debating if I could convert it to LiIon cells since the make the Chargers chips for LiIon so small these days.  But I figured it would need three cells, and to fit three LiIon  cells in the battery cage would be low capacity sizes. So it wasn't worth thinking that direction anymore.

[joeqsmith]

I am not sure how well the 97Vs power input is protected.  They don't provide a lot of details and I did not get the lighter adapter which may have added some level of protection.  Many times I have needed a scope, I did not have a power source I could plug into and had to run extension cords to power my old analog scope.  For the car, I would run a converter to get the 120 to power it.  Imagine having an analog scope sitting in the passenger seat.       A little harder to strap it to the bike! 
 
You could print a whole new back cover for it and put what ever you want for batteries in there.  No reason to lock yourself into what's there.

[stj]

cant you get a few 18650's in there side-by-side?

[Scottjd]

cant you get a few 18650's in there side-by-side?

Nope, defiantly not 18650's. I might be able to fit two, but that give me the nomanal voltage of 7.4V, minimum of 6V and max of 8.4V. To high for the battery powered rail, not high enough for the minimum sustained voltage of 8V if I spliced it into the DC power input jack.
So three cells would be needed, but three 18650's won't fit. Maybe three 14500 but then the capacity is low.
It would also need room for protection on each cell so if one fails it won't have a thermal runaway into another cell, and then the balancing added parts as well.

[joeqsmith]

I heard back from Fluke's legal department today and they have agreed to allow me to publish the training video for the 97.     I hope to have it listing in the next day or so.   

BIG THANKS TO FLUKE!!!!

[Scottjd]

I heard back from Fluke's legal department today and they have agreed to allow me to publish the training video for the 97.     I hope to have it listing in the next day or so.   

BIG THANKS TO FLUKE!!!!

That's great, I just saw the video online. For this that have not seen it or are not subscribed to Joes YouTube channel and notified of new video, this is the link.

https://youtu.be/0KZfjxGCi84

[mahi]

Here's another model from the 90 Series: The Fluke 98 Automotive ScopeMeter Series II. This model was aimed specifically towards automotive applications and operators without electronics background. Instead of manually using cursors and measurements, you select what you want to measure in advance: An oxygen sensor, ignition signal,... The ScopeMeter will then automatically set the most appropriate measurement mode and readings. The device can be used as a plain oscilloscope, but the feature set is extremely limited and the lack of dedicated oscilloscope buttons makes operation convoluted. Like all other ScopeMeters the Fluke 98 can also be used as a digital multimeter but the large size, weight and, again, user interface, make a simple digital multimeter a much better option. Nevertheless it's a great tool to diagnose older cars.

The Fluke 98 comes in a nice Fluke hard case with an assortment of leads and probes for automotive applications. Just like Fraser's PM97 ScopeMeter, a tiny demoboard is included to get the user familiar with the meter's features and operation. The Fluke 98 was also rebranded as the Bosch PMS 100, Opel TECH 31 and possibly others.

The main difference between the Fluke 98 and the rest of the ScopeMeter series is the software. The hardware is mostly identical although the bandwidth is much lower: 5 MHz instead of 60/100 MHz. The rest of the specs are pretty much identical.

Two major revisions exist: The original 98 and the 98 Series II. The most obvious difference between the two being the display. The original had the green display with weak backlight as seen in joeqsmith's pictures of his 97 ScopeMeter. The latter came with the high-contrast black-and-white display with permanent backlight as seen in the pictures of Scottjd's 96B ScopeMeter. I was unable to find a manual or even spec sheet of the original 98, so I have no details about other differences between both revisions, but some accessories like the DIS 90 work only with the 98 Series II.

The Fluke 98 Automotive ScopeMeter Series II owner's manual is available on the Fluke website (download link). Sadly, no service manual is publicly available.

[mahi]

The internals:











Full resolution pictures available on request.

[Scottjd]

The big difference in hardware besides the keypad is the one top plug in board on mine. I couldn't even find the wholes for were the plugs would have been. Oh, and yours has a neat little car with a  jack by the DC power input.
I guess that indicates this is the mechanic model?

[mahi]

I would have thought that the keypad would be built onto the main board with it being newer.

No, it's using exactly the same keypad foil as Scottjd's 96B and your 97 (with a different layout obviously). By the time my Fluke 98 was manufactured (1998) it was already an end-of-life product so I don't think Fluke would have bothered with hardware changes. The newer 120 series ScopeMeters had already been introduced a couple of years before and the faster 190 series was about to be released. By the way, both 120 and 190 series use a similar keypad foil so clearly Fluke thought it was a good idea. Guess what fails over time in these meters...

The big difference in hardware besides the keypad is the one top plug in board on mine. I couldn't even find the wholes for were the plugs would have been.

Any idea what purpose the tiny board serves?

Oh, and yours has a neat little car with a  jack by the DC power input. I guess that indicates this is the mechanic model?

A similar styled car is etched on the automotive demo board that came with the Fluke 98 so, yes, I'd say that indicates it's the automotive model.

[mahi]

The Fluke 97 is the only 90 series ScopeMeter of which some versions (I presume the earliest) have the keypad on the main PCB. All others use the keypad foil.

With the foil deteriorating over time, some have made replacement PCBs for the foil: See for example this eBay listing: Fluke 92 96 97 99 105 Scopemeter Keypad Contact Board (Replaces Foil). Note that it states that not all 97 have the foil.

[joeqsmith]

I really don't know the history of the two 97s I have.  The newer one has the keypad integrated with the main board.   The I/O board on this one is also newer.   The older scope may have been up graded at Fluke but the owner did not mention it ever being sent in for repairs. 

[Scottjd]

The big difference in hardware besides the keypad is the one top plug in board on mine. I couldn't even find the wholes for were the plugs would have been.

Any idea what purpose the tiny board serves?

Oh, and yours has a neat little car with a  jack by the DC power input. I guess that indicates this is the mechanic model?

A similar styled car is etched on the automotive demo board that came with the Fluke 98 so, yes, I'd say that indicates it's the automotive model.

Not a clue what thag little board is doing. I didn't find the schematic in the service manual and I looked it over twice. Maybe I missed it twice? It may have something to do with the recordinging and capturing of the data, this is just an edjicated guess after looking up some of the data sheets for the IC mounted on the board.

[Scottjd]

I really don't know the history of the two 97s I have.  The newer one has the keypad integrated with the main board.   The I/O board on this one is also newer.   The older scope may have been up graded at Fluke but the owner did not mention it ever being sent in for repairs.

My foil still seems to be working good, I guess mine didn't see a lot of use. But it's good to know I can get a PCB board replacement if I need it.

[Jamos205]

Hi sorry to bring up old post, i have a Bosch PMS100 scopemeter seen this post and thought someone might be able to shine some light on this for me. The unit work fine on c batteries but wont charge the nicd battery, think someone has shorted it out.

I have seen this pic earlier on this page was wondering if anyone knows what component 520 is in the pic, i have 19v at one side but 0v at oppisite , is this a fuse type component?

[PA0PBZ]

It looks like a filter, coils & cap. Hard to tell from the pic but it looks like it should conduct from right to left bottom and top.

[Fraser]

+1

EMC ferrite bead filter with Capacitor across the mid point.

Continuity should be present horizontally in the provided  picture, but not vertically (parallel to capacitor)

Fraser

[Jamos205]

+1

EMC ferrite bead filter with Capacitor across the mid point.

Continuity should be present horizontally in the provided  picture, but not vertically (parallel to capacitor)

Fraser

Ah ok thanks fraser, yeah no continuity horizontily, are these components available to purchase and replace.
Any idea where i can buy them from in the uk?

[Fraser]

I am surprised that this component is open circuit.

It can be replaced with bypass links if you are not worried about its official EMC compliance

Please do some carefull checks on the component though. The ones I have worked with are literally 0.8mm wires with a pair of ferrite beads on the wire and ent into a bridge shape. Yours has a capacitor added at the mid point of the wire 'bridge'. I have not seen any with a fusible link so I am unsure how it became open circuit. A 0.8mm wire would not fail easily and lots of heat damage would be evident.

Something does not seem right here.

Fraser

[Fraser]

Ok, I just looked at the underside of the PCB in the provided pictures.

My thoughts.....

1. The power connector is clearly connected to the filter on two of its pins
2. The filter has 6 pins !
3. I can see a nice thick power track coming off of one of the filter output pins.
4. There is a thin track coming off the other pin of the filter and this is unlikely a power track. More likely a sense line.
5. There are two additional pins at the mid point of the filter. One of these could be the second power rail output.
6. The filter contains only 3 ferrite cores instead of the usual 4. This may be the reason for the non standard footprint connections.

I suggest you carry out continuity checks on all 6 pins of this filter component. I do not expect it to be the cause of your problem. There should be at least two pairs of pins showing Zerp Ohms continuity and possibly an additional pin showing continuity with the positive rail as a sense line.

Fraser

[mahi]

Jamos205: The filter is a Murata BNX002-01 (datasheet). Just like Fraser I think it's rather unlikely it died. The filter is rated for 50 V / 10 A. The original Fluke PM 8907 power supply is only 15 V / 300 mA...