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sutekh

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About sutekh

  • Birthday March 28

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  • Gender
    Male
  • Location
    Utah
  • Interests
    Computers, Cars, Airplanes

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    IT Director

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  1. sutekh

    Basket Case PowerBook 180c

    Whoops! I forgot all about it TBH. Glad you identified the culprit!
  2. sutekh

    PB 1[4-8][0,5]c? Li-ion Battery

    Yes! I'm using an LT1494 to that end (see above schematic). Issue is that in order to keep the voltage drop low across the sense resistor, I've reduced it to .01ohm, at which point I have to push a fair amount of current through R3 for the opamp to detect it. As originally conceived, that parasitic drain is continuous. In what is becoming the most ridiculously overwrought thing I've built in a while, tonight I replaced R3 with an itty bitty microcontroller board running a bit of PIC assembly I cobbled to wait 10s, then ground a 1Kohm resistor for 100ms, on permanent repeat. It means it can take up to 10s to detect the power cord has been plugged in and start charging, but that's NBD. That little board (gray leads were for programming and then removed) is situated top right in the pic below and the new ideal diode is the little board with the heat sink. Pack voltage is now up over a volt to 7.2vdc, and all is well and good for a one off, but overall I'm left feeling it's needlessly complex and too hard to build. I'd like to come up with something more repeatable and accessible to others. At a minimum, I may design a single board with SMD components to replace the 3 separate steering, ideal diode, and now microcontroller PCBs, which will also get rid of a bunch of interconnect wiring.
  3. sutekh

    PB 1[4-8][0,5]c? Li-ion Battery

    Another week on with a bit more experience using the pack under my belt, I'm not quite satisfied. The voltage drop across the diode and R1 has the notebook complaining about low power. Apple's published figures for "charged voltage" are just wrong. I think they must have meant nominal. I've replaced D1 with an ideal diode, but the relationship between R1 and R3 isn't optimal. If I decrease the resistance of R1, the op-amp doesn't detect the nominal current flowing through R3 unless I decrease its resistance to the point that I'm wasting a material amount of energy at all times. I'd hoped to keep this mostly analog, but I'm going to try replacing R3 with a Microchip PIC10f200 microcontroller flashed with a few lines of assembly to sleep for 15s, drive a 1Kohm resistive load across R1 for 100ms, and repeat indefinitely. That'll run for years on 3500mAh, and coupled with the ideal diode, should get the charged pack voltage up to around 7vdc. If that works, I'll probably CAD up a little PCB, as it's getting too cramped in there to keep using large, through-hole components...
  4. sutekh

    PB180 preventative maintenance?

    I hear ya! I went from zero, to 1, to 3 PowerBooks in a hurry myself. The 180, even with it's screen issue, is usable and is currently my wifi modem hack test mule. Much as I'd like to keep both 180cs in working order though, I'll likely part one and combine them into a single, very nice example + spares to keep it running. As for the inserts, clearances are tight around the drives, but the logic board standoffs are less cramped. The plastics are ABS, so cement could work, but I don't know how well it'll grab the metal inserts. In addition to JB Weld, my adhesive of choice if a thick slurry of ABS scraps (mostly just 3D printing filament and castoffs) + Acetone I keep in a paint can. Correct, the counter-sunk screws shown on the back of the lid grab unused thread at the base of the existing inserts. The inserts don't have a closed end, so you can send a drill-bit all the way through and out the other side for a pilot hole.
  5. sutekh

    PB180 preventative maintenance?

    Purchase the "VCN" variety with vertical mount tabs that will allow you to solder the wires on further away from the cell.
  6. sutekh

    PB180 preventative maintenance?

    Whoops, that PRAM batt is the one I built for my Duo. PB just solders in
  7. sutekh

    PB180 preventative maintenance?

    I believe you've covered the major bullet points. I'd also consider a SCSI2SD, as even a working original is a likely failure point. The vast amount a storage is nice too! A suitable PRAM replacement can be fashioned from a pair of VL-2330s and a bit of heat-shrink. In addition to the much maligned plastic behind the hinges, check the mount points on the base into which the drive and logic board brass inserts are molded. All 3 of my PowerBooks had cracking & crumbling there as well. As for the hinge plastic, there are a number of good solutions presented here on the forum, including a 3D printed reinforcement, but any of them should be coupled with a thorough cleaning and re-lubrication of the metal portion. For my part, I've had good luck with a) first roughing up the adjacent plastic, then b) JB welding the inserts back in place, and c) drilling through the other side and pinning the whole assembly together with qty-4 2.5x7mm flat-head screws countersunk into the lid. Good luck with your 180! Mine has the dreaded LCD vignetting unfortunately. Someday I may try the oven technique...
  8. sutekh

    Duo Li-ion Battery

    Alright, I promised an update... The ideal diodes arrived and they work nicely! Under full load, I'm only seeing a ~.2v drop, but (because of course there's a but) I'm still getting low-power alerts from the OS throughout much of the discharge cycle. The OE pack contains 10 NiMH cells in series, which should measure from ~1.5vdc per cell charged to 900mv discharged (15v - 9v overall), and I'd surmised that a Li-Ion replacement outputting 12.6v - 10.5v should fall nicely within that range. I think the problem lies in the fact that NiMH cells spend most of their discharge cycle at ~1.2v, and only drop off rapidly toward .9v at the very end of their useful life. Even with the ideal diodes, under load my Li-Ion pack is measuring in the elevens throughout much of its discharge cycle, which the power manager is interpreting as a mostly discharged battery. That "but" notwithstanding though, the pack works quite well! E.g., I ran the 280c for a few hours this afternoon with the added draw of an Etherdock and my wifi-module. I'm not really interested in trying to boost the output voltage with more internal electronics since it'd just waste energy, but I wonder if there might be a potential software solution? I suspect the acceptable voltage ranges are flashed onto the ROM or Power Manager (can anyone confirm?), and this passage from the Power Manager Developer Note is particularly interesting: Reading the Status of the Battery and the Battery Charger 6: The Power Manager monitors the voltage level of the internal battery and warns the user when the voltage drops below a threshold value stored in parameter RAM. If the voltage continues to drop and falls below another, lower value stored in parameter RAM, the Power Manager puts the computer into the sleep state. The Power Manager provides a function that allows you to read the state of charge of the battery and the status of the battery charger. Infuriatingly, neither that Developer Note, nor the Duo's, indicate WHAT those values are, or WHERE they originate from, but I'd bet an extension could override them. There is, for instance, an existing "Type III Battery" extension for Duo type III NiMH packs that ostensibly does something similar to make the OS / Power Manager play nicely with those higher-capacity batteries. I pulled that extension into ResEdit and HEX dumped it, but haven't made heads or tails of the instructions yet. I'd welcome assistance from someone with more experience in that arena than I have. I think all this hypothetical extension would need to do is update the value of "batteryLow" in PRAM to a slightly lower value. Anyway, that annoying but mostly cosmetic wrinkle aside, here's an updated, accurate circuit diagram and BOM. I've also attached the STLs for any who want to 3D print the enclosure I designed. I printed mine using ABS (Octave's Gray) on my MakerBot 2X with 2 shells at 20% infill. Duo 280c Battery Top.stl Duo 280c Battery Bottom.stl
  9. sutekh

    Powerbook 160 LCD woes

    This is the behavior that drives me bonkers. People don't check completed listings before posting to see what actual market value is. They see one example of what they're selling listed for an absurd price (that's been sitting there forever unsold) and immediately assume they too own a goldmine.
  10. sutekh

    Using SCSI2SD v5.5 in a Powerbook

    Sure, but per the attached picture, the connector is already different than the one included on the v5.5 (not 90deg). I'm just suggesting that if a different part is being used, a DB25F is more suitable for a device targeted at PowerBooks or other mobiles since most either a) have an HDI-30, b) ports concealed behind doors or overhangs, or c) don't have external SCSI at all, making direct attachment impractical / impossible and prioritizing compatibility with a cable makes more sense.
  11. With all of last week's posting issues resolved, let me try this again... Not sure if this is most appropriately posted in this forum or over in Hacks, but I think it's more likely to reach the target audience here As a follow up to my recent Duo Li-Ion battery project, I've been working on a suitable Li-Ion battery replacement for the M5417, M5463, and M5464 NiCd packs used in the PowerBook 140 - 180c. I'd foolishly surmised that, due to the nicely compatible voltage ranges, this would be a walk in the park compared to the Duo project. When will I learn... The trick here is packing a Lithium-suitable CC/CV charger inside the pack, but only powering it when plugged into A/C power and preventing it from back feeding off of the pack itself the rest of the time. Severely complicating matters is the fact that the charge and discharge ports are the battery's same two + / - contacts. There are any number of "power path" ICs designed to solve this charge / discharge switcheroo, but they assume the load output and the charge input are separate paths. This didn't manifest as a problem when designing a pack for the Duo because its charger sends ~20vdc to the battery (which is intended to get pulled down by the NiMh once inserted). The battery-pack-internal Li-Ion 3S CC/CV charger I used requires ~13.5vdc to engage, so when AC is disconnected, it can't back feed off of 3S 18650 cell network that, at most, outputs 12.6vdc. Had I tried the same approach here, the first problem would be a 2S Li-Ion charger needs at least 8.4vdc to function (vs. the PowerBook's 7.5vdc wall adapter output). Once fronted by a boost converter, the second problem would be that, due to the common charge / discharge path, there's no way to prevent the following: Li-Ion cells -> boost converter -> charger -> cells.... in a vicious, parasitic drain cycle that would have the BMS kicking in at low-voltage cutoff in no time. A more sophisticated, current direction sensing approach is needed that works properly in all of the following scenarios: Pack installed and providing power (discharge) Pack installed and charging from AC (charge) Pack removed from unit. No charge or discharge (idle) Pack installed and charging, then toggled to discharge (e.g., AC power removed) Pack installed and discharging (or idle), then toggled to charge (e.g., AC power connected) Those last 2 may seem obvious or unnecessary, but some of the circuits designs I devised seemingly worked fine for scenarios 1-3, but wouldn't disengage the charger in the case of situation #4 for instance. Anyway, here's what I've come up with: The sensing / steering is managed by an Analog Devices LT1494 precision OpAmp, and the following is a brief description of what's happening in each of the 5 scenarios outlined above: Current flows out of the pack through D1. The gate of N-channel MOSFET Q1 is pulled low by R2 (10K Ω) and remains disengaged by LT1494 due to current flow from - to + across R1. Charger is off. Current flows across R1 from + to - causing LT1494 to pull Q1's gate high, thereby allowing current to flow from Source to Drain. Charger is on. Similar to #1. No flow across R1 so LT1494's output & Q1's gate remain low via R2. Charger is off. Once current stops flowing from + to - across R1, R2 pulls Q1's gate low. Takes about 1s with a 10K resistor at R2. This one was a bit of a puzzle. Even with power applied, D1 prevents current from flowing into the battery (as it should since only the CC/CV charger has any business charging the cells) and with Q1 off, there's no current flow across R1 for the LT1494 to sense and turn Q1 on (Catch 22). Enter R3 at 100K Ω. Once plugged into AC, a nominal current flows from battery + to battery - through R3 and across R1, thereby inducing LT1494 to energize Q1's gate and turn on the charger. Unfortunately, R3 remains when not plugged in and with the pack removed, so there's permanent, small parasitic drain. Left long enough, it'll eventually drain the cells to the point that the BMS intervenes and shuts down so if someone has a better idea, I'd love to hear it! That said, it'll take nearly 5 years to drain with a 100K Ω R3, so perhaps not a material concern Here's a shot of the circuit above on a breadboard doing what it's supposed to do. And last but not least, here's the finished article with the steering circuit crammed onto a small perf-board between the charger / boost converter sandwich (left) and BMS (right)... The battery my 180c had in it when received was an aftermarket pack that just screwed together, which was really quite convenient! I'm using 8 x 800mAh 14500 3.7vdc Li-Ion cells (2 serial banks of 4 cells), which are a perfect lengthwise replacement for the OE NiCds, but leave a bit of space on top (hence the strips of rubber tape to keep things from rattling). If someone made a 16500 (16mm diameter vs. 14mm) cell with a bit more oomph, that would be just the thing! I suppose at 3.2Ah (800mAh *4) though, I shouldn't complain. I've been running the pack as pictured for a couple of weeks now with no issues. Happy to post a BOM if anyone is interested
  12. sutekh

    Using SCSI2SD v5.5 in a Powerbook

    Very nice! Good to know about Artmix's shenanigans. Long time OSS / GPL proponent, so they'll get none of my business. Only thing I like about their unit, however, is the included metal frame with horizontal threaded holes so no 3D printed or other custom mount is necessary. Also, I'm probably missing something obvious, but wouldn't a DB25F make it easier to connect externally? Every DB25 SCSI cable I've ever seen ends in a DB25M unless you're imagining these be installed directly against the Mac sans-cable?
  13. sutekh

    Using SCSI2SD v5.5 in a Powerbook

    Thanks for the update (I was just about to pull the trigger on an ARTMix) and sorry for piling on. Happy to keep waiting knowing something is in the works.
  14. sutekh

    Basket Case PowerBook 180c

    It's buttoned up at the moment, but I'll be opening it up in coming days to 1) send 5v (probably from the ADB since it's right there and fused) into pin-5 of the SCSI HID-30 connector for term power and b) to yank the Global Village modem and install a ribbon cable in its place so I can start testing the wifi modem replacement board I have a thread about over in the Hacks forum. I'll meter the power traces when I do and let you know... BTW, interested to hear how your hinges hold up. I tried JB-Weld at first, but it eventually gave way. Ended up dismantling and cleaning the hinges, then re-lubricating to relieve tension (helped somewhat) and also drilled pilot holes through all 4 knurled brass inserts out the back of the clamshell and sent some 2.5mm x 6mm screws in from the other side to pin everything together. They're obviously visible, but after counter-sinking the holes, I think they look just fine. There's plenty of remaining unused thread within the inserts for them to grab onto. Quite solid now.
  15. sutekh

    PowerBook 1xx Wireless Modem

    It'd be interesting to try. To get that actually working, I've wondered if I'd need to implement some of the modem-specific functions like DCD, Modem.Busy, etc. that I'd planned to omit. Not sure what the driver expects... Yeah, my initial mockup had and SMA connector there, but I decided on an RJ11 as mentioned above for a couple of reasons: The port door on the back would interfere with it for one. More importantly though, I want a way to connect an FTDI cable to the device in situ for re-programming, updating, etc. that doesn't require pulling the PowerBook apart. With their fragile plastics, the less often that happens the better! I don't believe a helper PC should be necessary with the ESP8266 running ESP_SLIP_Router (https://github.com/martin-ger/esp_slip_router). You should just need to serial into the device via a terminal to setup the SSID, PW, etc., then use MacSLIP (or similar). Indeed this is a problem. I've really no idea what that internal port is real-world capable of without more testing. I think the fact that Apple moved to an SPI approach leveraging multiple data paths for the "Express" modems beginning with 14.4 suggests it's pretty underwhelming though. The way I'm looking at it, anything these machines can do online is "quite slow" regardless, and even modem speed should suffice for IRC, SSH, Lynx browsing, etc. It's a limitation I'm probably willing to accept for internal, modular wifi. If it's just unacceptably slow, I've pondered remixing something like Saybur's scuznet to include an ESP2866. An all-in-one SCSI bus connected hard-drive replacement that provided SD storage and wifi would be pretty neat!
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