Psion 5 Voltage Tolerances? - Scion

This is a discussion on Psion 5 Voltage Tolerances? - Scion ; Anyone happen to know what kind of voltage can be fed into a Psion 5? I see it has an external port indicating 6V, anybody try 7.2V? How about 3.6V through the internal AA bank? The reason I ask is ...

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Thread: Psion 5 Voltage Tolerances?

  1. Psion 5 Voltage Tolerances?


    Anyone happen to know what kind of voltage can be fed into a Psion 5?
    I see it has an external port indicating 6V, anybody try 7.2V? How about
    3.6V through the internal AA bank?
    The reason I ask is because I am looking to use NiMHs, which run at a slightly
    lower voltage than alkalaines, so odd combinations put their output slightly
    higher than "normal".
    With a pair of 2100 NiMH running at 2.4V total, what kind of run time can I
    expect with the backlight off?

    --
    Solar-powered Linux: Slackware 10.0, 2.6.11.7, Averatec 3250H1
    RLU#272755

  2. Re: Psion 5 Voltage Tolerances?

    Danno wrote:
    > Anyone happen to know what kind of voltage can be fed into a Psion 5?
    > I see it has an external port indicating 6V, anybody try 7.2V? How about
    > 3.6V through the internal AA bank?
    > The reason I ask is because I am looking to use NiMHs, which run at a slightly
    > lower voltage than alkalaines, so odd combinations put their output slightly
    > higher than "normal".
    > With a pair of 2100 NiMH running at 2.4V total, what kind of run time can I
    > expect with the backlight off?
    >

    Hi Danno,
    I am using 2 NiMHs (2.4V) in my 5mx. They are GP 2100, with capacity
    2050mAh. Normal runtime with them is from 18 to 24 hours without
    backlight. When the Psion shows empty batery status, the mAh counter is
    at around 1500mAh used.
    With your series 5 you can expect longer batery lifetime, because of
    lower power consumption.
    Petr

  3. Re: Psion 5 Voltage Tolerances?


    "Danno" wrote in message
    news:slrnd9g3gp.36s.TOOmuchSPAM@3250H1.danux.net.. .
    >
    > Anyone happen to know what kind of voltage can be fed into a Psion 5?
    > I see it has an external port indicating 6V, anybody try 7.2V? How about
    > 3.6V through the internal AA bank?
    > The reason I ask is because I am looking to use NiMHs, which run at a
    > slightly
    > lower voltage than alkalaines, so odd combinations put their output
    > slightly
    > higher than "normal".
    > With a pair of 2100 NiMH running at 2.4V total, what kind of run time can
    > I
    > expect with the backlight off?
    >
    > --
    > Solar-powered Linux: Slackware 10.0, 2.6.11.7, Averatec 3250H1
    > RLU#272755


    I used to get around 12 hours from similar rechargeables. Watch for them
    going low- the drop off is quicker than alkalines so you could more easily
    lose all of the information. backup regularly.



  4. Re: Psion 5 Voltage Tolerances?


    "Danno" wrote in message
    news:slrnd9g3gp.36s.TOOmuchSPAM@3250H1.danux.net.. .
    >
    > Anyone happen to know what kind of voltage can be fed into a Psion 5?
    > I see it has an external port indicating 6V, anybody try 7.2V? How about
    > 3.6V through the internal AA bank?
    > The reason I ask is because I am looking to use NiMHs, which run at a
    > slightly
    > lower voltage than alkalaines, so odd combinations put their output
    > slightly
    > higher than "normal".
    > With a pair of 2100 NiMH running at 2.4V total, what kind of run time can
    > I
    > expect with the backlight off?
    >
    > --
    > Solar-powered Linux: Slackware 10.0, 2.6.11.7, Averatec 3250H1
    > RLU#272755


    I've run my Psion off of rechargeable from time to time without any
    problems. I'm sure you are aware that rechargeable run at a more or less
    constant output till near the end whereas alkaline batteries drop off quite
    a bit in the early stages (due to an increase in internal resistance if I
    remember correctly) but then level off. As for running time, I guess it
    depends how often you use it.

    Martin



  5. Re: Psion 5 Voltage Tolerances?

    On 2005-05-28, Danno wrote:
    >


    OK, thanks everyone. Looks like I'll just stick with 2.4 and 6 volts.

    --
    Solar-powered Linux: Slackware 10.0, 2.6.11.7, Averatec 3250H1
    RLU#272755

  6. Re: Psion 5 Voltage Tolerances?

    On Saturday, in article

    TOOmuchSPAM@hotmail.com "Danno" wrote:

    > Anyone happen to know what kind of voltage can be fed into a Psion 5?
    > I see it has an external port indicating 6V, anybody try 7.2V? How about
    > 3.6V through the internal AA bank?
    > The reason I ask is because I am looking to use NiMHs, which run at a slightly
    > lower voltage than alkalaines, so odd combinations put their output slightly
    > higher than "normal".
    > With a pair of 2100 NiMH running at 2.4V total, what kind of run time can I
    > expect with the backlight off?


    Depends what you're doing. All my Psion's are broken and I can't afford
    to mend them right now, and I can't remember what operation times I was
    getting from them, but I was running them on NiMH fairly soon after
    buying the first one and didn't look back. Just don't expect to be able
    to recharge them in situ. You still need to carry a spare pair, as you
    would with dry cells, and recharge externally. You're battery level
    indicator will always show below optimum, but as NiMH have a relatively
    low internal resistance you'll get able to run to lower voltages than
    you could with dry cells. Only drawback is that if you use a CF card
    you'll reach a point where you can't write to it, but the machine
    continues to run for some time still on the same pair of cells. With dry
    cells once you reached the "battery voltage too low" warning when writing
    to the CF card it was a given that they were all but dead anyway.
    --
    Raj Rijhwani | This is the voice of the Mysterons...
    raj@rijhwani.org | ... We know that you can hear us Earthmen
    http://www.rijhwani.org/raj/ | "Lieutenant Green: Launch all Angels!"
    Permission to distribute this article as website content is expressly denied.


  7. Re: Psion 5 Voltage Tolerances?

    On 2005-05-30, Raj Rijhwani wrote:
    > On Saturday, in article


    > Only drawback is that if you use a CF card
    > you'll reach a point where you can't write to it, but the machine
    > continues to run for some time still on the same pair of cells. With dry
    > cells once you reached the "battery voltage too low" warning when writing
    > to the CF card it was a given that they were all but dead anyway.


    Ahh, this is good info to know. I had planned mostly to read from it, but
    figured on ocassionally writing/coding with it. Thanks for the info.

    --
    Solar-powered Linux: Slackware 10.0, 2.6.11.7, Averatec 3250H1
    RLU#272755

  8. Re: Psion 5 Voltage Tolerances?


    "Danno" wrote in message
    news:slrnd9lba0.2vt.TOOmuchSPAM@3250H1.danux.net.. .
    > On 2005-05-30, Raj Rijhwani wrote:
    >> On Saturday, in article

    >
    >> Only drawback is that if you use a CF card
    >> you'll reach a point where you can't write to it, but the machine
    >> continues to run for some time still on the same pair of cells. With dry
    >> cells once you reached the "battery voltage too low" warning when writing
    >> to the CF card it was a given that they were all but dead anyway.

    >
    > Ahh, this is good info to know. I had planned mostly to read from it, but
    > figured on ocassionally writing/coding with it. Thanks for the info.
    >
    > --
    > Solar-powered Linux: Slackware 10.0, 2.6.11.7, Averatec 3250H1
    > RLU#272755


    If you write when low check that the file has been written (and backup
    regularly)- the psion didn't always tell leading to corrupt files.

    I used a card reader on the PC to just copy the whole card, be careful with
    the pc checking utilities as they could change one bit of the card header
    info.



  9. Re: Psion 5 Voltage Tolerances?

    I can answer the question for the 5mx which is similar to the series 5.

    The DC input for the 5mx goes straight into a PQ20VZ51 device that is a
    voltage regulator set to about 4.5V output. The max input for this device
    is 24V however there is a 20V cap on the input so this would appear to be
    the max voltage. However, there is also a power dissipation max of about 5W
    (derated) for this device so one would need to be careful of that too. I
    think that 10V would be a sensible maximum (given that many 'power blocks'
    are unregulated and hence peak voltage can be high off load) but I would not
    suggest anyone try this!

    Paul

    "Danno" wrote in message
    news:slrnd9g3gp.36s.TOOmuchSPAM@3250H1.danux.net.. .
    >
    > Anyone happen to know what kind of voltage can be fed into a Psion 5?
    > I see it has an external port indicating 6V, anybody try 7.2V? How about
    > 3.6V through the internal AA bank?
    > The reason I ask is because I am looking to use NiMHs, which run at a

    slightly
    > lower voltage than alkalaines, so odd combinations put their output

    slightly
    > higher than "normal".
    > With a pair of 2100 NiMH running at 2.4V total, what kind of run time can

    I
    > expect with the backlight off?
    >
    > --
    > Solar-powered Linux: Slackware 10.0, 2.6.11.7, Averatec 3250H1
    > RLU#272755




  10. Re: Psion 5 Voltage Tolerances?

    Wrighty wrote:
    > However, there is also a power
    > dissipation max of about 5W (derated) for this device so one would
    > need to be careful of that too.


    Wouldn't the actual dissipation maximum also depend on the thermal
    characteristics of the mounting? (Unless it's such a tiny device that even
    free air circulation would not make any difference, but my guess is that 5W
    is too great for that.)

    Mike.
    --
    If reply address = connectfee, add an r because it is free not fee.



  11. Re: Psion 5 Voltage Tolerances?


    "Mike Coon" wrote in message
    news:d7kts4$mdi$1@news7.svr.pol.co.uk...
    > Wrighty wrote:
    >> However, there is also a power
    >> dissipation max of about 5W (derated) for this device so one would
    >> need to be careful of that too.

    >
    > Wouldn't the actual dissipation maximum also depend on the thermal
    > characteristics of the mounting? (Unless it's such a tiny device that even
    > free air circulation would not make any difference, but my guess is that
    > 5W is too great for that.)
    >
    > Mike.
    > --
    > If reply address = connectfee, add an r because it is free not fee.
    >


    Hearsay- The convertor had burned out on a Psion I used- the Voltage was
    only slighter higher than the Psion unit (~0.5V) and the (regulated) unit
    supplied up to 2A. And that's what the repairers (POS I think but may have
    been Psion) blamed without actually knowing that was used.



  12. Re: Psion 5 Voltage Tolerances?


    "Mike Coon" wrote in message
    news:d7kts4$mdi$1@news7.svr.pol.co.uk...
    > Wrighty wrote:
    > > However, there is also a power
    > > dissipation max of about 5W (derated) for this device so one would
    > > need to be careful of that too.

    >
    > Wouldn't the actual dissipation maximum also depend on the thermal
    > characteristics of the mounting? (Unless it's such a tiny device that even
    > free air circulation would not make any difference, but my guess is that

    5W
    > is too great for that.)
    >
    > Mike.


    Mike

    Obviously it would depend on the thermal design of the system. However, the
    design looks moderately good as it is conduction rather than convection
    cooled. Also, I was doing my usual 'military' derating on the figures. In
    reality, the Psion only draws about 100mA with the backlight on so if the
    input voltage were, say, 10V then the power dissipation in the device would
    only be 0.55W. Even with an input of 20V and assuming the Psion was drawing
    200mA there is only a 3.1W dissipation in the device. You are far more
    likely to blow up the 20V cap if you increase the voltage than over power
    the regulator!!

    Paul



  13. Re: Psion 5 Voltage Tolerances?

    On 2005-05-31, Wrighty wrote:
    > I can answer the question for the 5mx which is similar to the series 5.
    >
    > The DC input for the 5mx goes straight into a PQ20VZ51 device that is a
    > voltage regulator set to about 4.5V output. The max input for this device
    > is 24V however there is a 20V cap on the input so this would appear to be
    > the max voltage. However, there is also a power dissipation max of about 5W
    > (derated) for this device so one would need to be careful of that too. I
    > think that 10V would be a sensible maximum (given that many 'power blocks'
    > are unregulated and hence peak voltage can be high off load) but I would not
    > suggest anyone try this!
    >
    > Paul
    >


    Hey, thanks, that *is* good news. I feel far less uncertain about trying 7.2V
    now. Appreciate the response.

    --
    Solar-powered Linux: Slackware 10.0, 2.6.11.7, Averatec 3250H1
    RLU#272755

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