Need help identifying and sourcing parts

Discussion in 'General Electronics Chat' started by Dom Mancino, Dec 7, 2009.

  1. Dom Mancino

    Thread Starter New Member

    Dec 6, 2009
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    I am trying to repair an old Kenwood stereo control amplifier and need help in identifying the specs of these parts.

    Capacitor:

    [​IMG]
    [​IMG]

    I have found some 2200uF 35V 85° caps searching google and ebay but wasn't sure what the remaining markings stand for.

    IC:

    From what I can gather from google... its a Toshiba IC.

    [​IMG]

    I can only assume that sourcing original parts will be near impossible so I will also need to find a place to purchase something equivalent.

    Any help you guys could give is greatly appreciated.

    -Dom
     
  2. ELECTRONERD

    Senior Member

    May 26, 2009
    1,146
    16
    In regards to your capacitor, the voltage and capacitance ratings are the most important things to consider - which you noted. The capacitors you found online would work.

    As for your linear regulator, here is the datasheet:

    http://www.toshiba.com/taec/components2/Datasheet_Sync//265/5671.pdf

    You can find the part at the distributor Mouser Electronics and I'm sure you'd find it at Digi-Key as well.

    Austin
     
  3. hgmjr

    Moderator

    Jan 28, 2005
    9,030
    214
    The other labels on the capacitor are date code and probably package-type info.

    The three terminal device is a fixed 15 volt linear voltage regulator.

    hgmjr
     
  4. Dom Mancino

    Thread Starter New Member

    Dec 6, 2009
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    0
    You guys are awesome!

    In regards to the linear regulator... I just noticed that the second one I need to replace has a slightly different marking

    Instead of TA7815S, the second one reads TA7915S

    Is there a difference?
     
  5. ELECTRONERD

    Senior Member

    May 26, 2009
    1,146
    16
    It isn't very difficult to look up datasheets for those parts, or virtually any part for that matter. Just remember; google is your friend! ;) Another great resource is http://www.alldatasheet.com/

    For this regulator, the datasheet is: http://pdf1.alldatasheet.com/datasheet-pdf/view/31360/TOSHIBA/TA79005S.html

    Austin
     
  6. Dom Mancino

    Thread Starter New Member

    Dec 6, 2009
    14
    0
    Thank you for the resource Austin! that will definitely come in handy. I apologize for my lack of knowledge as I am no expert. I tried searching but all the different part numbers had my head spinning.
     
  7. ELECTRONERD

    Senior Member

    May 26, 2009
    1,146
    16
    No problem whatsoever! They also have some other good datasheet searching links posted in a sticky on this forum. Here you go:

    http://forum.allaboutcircuits.com/showthread.php?t=3246

    Austin
     
  8. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    The 7815 is a fixed positive 15v 1A regulator.
    The 7915 is a fixed negative 15v 1A regulator.
    You must not get them mixed up!

    I strongly suggest that you not buy replacement aluminum electrolytic capacitors via E-bay. You won't know how long they have been sitting on a shelf; and they do have a shelf life.

    Buy from an authorized high-volume distributor, like Digikey, Mouser, Newark, Allied, etc. You will be getting fresh stock from a reputable company. If they've been sitting in a warehouse for 10 years, they won't do you much good.
     
  9. Dom Mancino

    Thread Starter New Member

    Dec 6, 2009
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    0
    Still trying to get my head wrapped around all the different characteristics....

    After searching, I can only find 2 replacements (or so I think)

    Can you guys please take a look and tell me if these will work?

    For the TA7815S, I found this:

    http://www.mouser.com/ProductDetail/Fairchild-Semiconductor/KA7815ETU/?qs=4UZqDwmZbi8adq412dRTEA==

    However... there are some differences and I am not sure if they are significant. All other characteristics not listed are exactly the same for both.

    Operating Temp:
    TA7815S: -30 ~ 75°C
    KA7815ETU: 0 ~ +125°C

    Storage Temp:
    TA7815S: -55 ~ 150°C
    KA7815ETU: -65 ~ 150°C

    Thermal Resistance:
    TA7815S: Rth(j-c) 6.25 °C/W, Rth(j-a) 62.5 °C/W
    KA7815ETU: Rth(j-c) 5 °C/W, Rth(j-a) 65 °C/W

    Quiescent Current:
    TA7815S: Typ. 4.4, Max. 8.0 mA
    KA7815ETU: Typ. 5.2, Max. 8.0 mA

    Output Voltage Noise:
    TA7815S: Typ. 110 uVrms
    KA7815ETU: Typ. 90 uV/Vo

    Short Circuit Current Limit:
    TA7815S: Typ. 0.5 A
    KA7815ETU: Typ. 250 mA


    For the TA79015S, I found this:

    http://www.newark.com/nte-electronics/nte1973/voltage-regulator-ic/dp/31C3442

    Here are the differences in question:

    Power Dissipation:
    TA79015S: (Tc = 25°C) 20W
    NTE1973: (TC ≤ +70°C) 16W

    Storage Temp:
    TA79015S: -55 ~ 150°C
    NTE1973: -40 ~ 125°C

    Thermal Resistance:
    TA79015S: Rth(j-c) 6.25 °C/W, Rth(j-a) 62.5 °C/W
    NTE1973: Rth(j-c) 5 °C/W, Rth(j-a) 60 °C/W

    Output Voltage (really foggy as to why they're reversed)
    TA79015S: Min. -15.6, Typ. -15, Max. -14.4 V
    NTE1973: Min. -14.4, Typ. -15, Max. -15.6 V

    Quiescent Current:
    TA79015S: Typ. 4.4, Max. 8.0 mA
    NTE1973: Typ. 4.4, Max. 6.0 mA

    Load Regulation:
    TA79015S: (250mA ≤ IOUT ≤ 750mA) Typ. 25, Max. 150 mV
    NTE1973: (VIN = –23V, IO = 0.005 to 1.5A) Typ. 35, Max. 150 mV

    Line Regulation:
    TA79015S: (-26V ≤ VIN ≤ -20V) Typ. 14, Max. 150 mV
    NTE1973: (VIN = –17.5V to –30V, IO = 0.5A) Typ. 11, Max. 150 mV

    Ripple Rejection:
    TA79015S: Min. 53, Typ. 60 dB
    NTE1973: Min. 60, Typ. 70 dB

    Average Temp. Coefficient of Output Voltage:
    TA79015S: (IOUT = 5.0mA) Typ. 2.0 mV/°C
    NTE1973: (VIN = –23V, IO = 0.5A) Typ. -1.5 mV/°C

    To me these differences seem major... but again, I am new to this so please try not to rip me apart too much :)

    -DM
     
  10. Dom Mancino

    Thread Starter New Member

    Dec 6, 2009
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    0
    Am I over complicating things?
     
  11. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    I would agree. In general NTE parts are more costly than from other manufacturers.

    The choices in fixed regulators are endless. Back in the time when the original regulators were spec'ed, those 7815's and 7915's were good for about a one amp output. That is about all you need to be concerned about - plus perhaps using an isolation pad under the 7915, as the tab is connected to the input voltage, and needs to be isolated from the heat sink in most cases.

    In Mouser, ON semi part#MC7915CTG @ $.49 and the MC7815CTG @ $.49 would seem to be satisfactory replacements. Just add "863-" to the ON part number for the Mouser part number. They are both good for a one amp output with heat sinking.
     
  12. Dom Mancino

    Thread Starter New Member

    Dec 6, 2009
    14
    0
    Thank you!
     
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