Help ID'ing these devices?

D

DaveC

Guest
Inside a small regulated 12v dc "brick" supply, are 6 diodes, several caps,
and 3 semi's.

One semi is heatsinked to a large sink. It is a TO-220 device with "A1012" on
it. I first suspected it to be a 12v, 3-terminal regulator IC, but all the
information I find on-line about A1012's have to do with power transistors. A
series-pass transistor? Maybe one of the diodes is a 12v zener that drives
this?

Another is a TO-92 device with "C3202", which is clearly a 2SC 3202.

The third one is also a TO-92 device with these markings:
KIA
432
851

Can't find anything on this last one. Ideas?

Thanks,
--
DaveC
me@privacy.net
This is an invalid return address
Please reply in the news group
 
"DaveC" <me@privacy.net> wrote in message
news:0001HW.BC1DDBEE0000E2A7F0080600@news.individual.net...
Inside a small regulated 12v dc "brick" supply, are 6 diodes, several
caps,
and 3 semi's.

One semi is heatsinked to a large sink. It is a TO-220 device with "A1012"
on
it. I first suspected it to be a 12v, 3-terminal regulator IC, but all the
information I find on-line about A1012's have to do with power
transistors. A
series-pass transistor? Maybe one of the diodes is a 12v zener that drives
this?

Another is a TO-92 device with "C3202", which is clearly a 2SC 3202.

The third one is also a TO-92 device with these markings:
KIA
432
851
Click to expand...
KIA = Killed In Action?

Ok - sorry, its late in the evening and I couldn't resist :)

Cheers

Klaus
 
DaveC schrieb:

One semi is heatsinked to a large sink. It is a TO-220 device with "A1012" on
it.
Click to expand...
http://www.semicon.toshiba.co.jp/td/en/Transistors/Bipolar_Power_Transistors/en_20010628_2SA1012_datasheet.pdf


The third one is also a TO-92 device with these markings:
KIA
432
851
Click to expand...
Maybe KIA431?
http://databook.kec.co.kr/Data/PDF/KIA/ENG/KIA431_A_AF_B_BF_F.pdf


Regards,
Dieter
 
On Sun, 4 Jan 2004 15:04:14 -0800, the renowned DaveC <me@privacy.net>
wrote:

Inside a small regulated 12v dc "brick" supply, are 6 diodes, several caps,
and 3 semi's.

One semi is heatsinked to a large sink. It is a TO-220 device with "A1012" on
it. I first suspected it to be a 12v, 3-terminal regulator IC, but all the
information I find on-line about A1012's have to do with power transistors. A
series-pass transistor? Maybe one of the diodes is a 12v zener that drives
this?
Click to expand...
Maybe a 2SA1012 pass transistor.

Another is a TO-92 device with "C3202", which is clearly a 2SC 3202.

The third one is also a TO-92 device with these markings:
KIA
432
851

Can't find anything on this last one. Ideas?
Click to expand...
KIA is a transistor manufacturer, but they also have some low-end
jellybean linears.

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
 
Howdy!

"DaveC" <me@privacy.net> wrote in message
news:0001HW.BC1DDBEE0000E2A7F0080600@news.individual.net...
Inside a small regulated 12v dc "brick" supply, are 6 diodes, several
caps,
and 3 semi's.

One semi is heatsinked to a large sink. It is a TO-220 device with "A1012"
on
it. I first suspected it to be a 12v, 3-terminal regulator IC, but all the
information I find on-line about A1012's have to do with power
transistors. A
series-pass transistor? Maybe one of the diodes is a 12v zener that drives
this?

Another is a TO-92 device with "C3202", which is clearly a 2SC 3202.

The third one is also a TO-92 device with these markings:
KIA
432
851

Can't find anything on this last one. Ideas?
Click to expand...
If it were a KIA 431, I'd say it's an adjustable voltage reference -
usable as an "Adjustable Zener".

The KIA 432 isn't listed, and trying LM432 yields an 8 pin mini-dip.

But if it were a KIA 431, that would make sense. It regulates the
2SC3202, which does base drive for the 2SA1012 ...

RwP
 
On Sun, 4 Jan 2004 23:13:21 -0800, Ralph Wade Phillips wrote
(in message <btb309$5746t$8@ID-81734.news.uni-berlin.de>):

If it were a KIA 431, I'd say it's an adjustable voltage reference -
usable as an "Adjustable Zener".

The KIA 432 isn't listed, and trying LM432 yields an 8 pin mini-dip.

But if it were a KIA 431, that would make sense. It regulates the
2SC3202, which does base drive for the 2SA1012 ...
Click to expand...
Dang! Another typo! Perfection slips through my hands again.

http://databook.kec.co.kr/Data/PDF/KIA/ENG/KIA431_A_AF_B_BF_F.pdf
Click to expand...
Indeed it is a KIA 431. Printed on the PCB for the leads are A, K, R.

So, I should see a voltage reference at the anode terminal, less two
junctions (~ 10.8), yes?

Thanks,
--
DaveC
me@privacy.net
This is an invalid return address
Please reply in the news group
 
DaveC wrote:
On Sun, 4 Jan 2004 23:13:21 -0800, Ralph Wade Phillips wrote
(in message <btb309$5746t$8@ID-81734.news.uni-berlin.de>):

If it were a KIA 431, I'd say it's an adjustable voltage reference -
usable as an "Adjustable Zener".

The KIA 432 isn't listed, and trying LM432 yields an 8 pin mini-dip.

But if it were a KIA 431, that would make sense. It regulates the
2SC3202, which does base drive for the 2SA1012 ...

Dang! Another typo! Perfection slips through my hands again.

http://databook.kec.co.kr/Data/PDF/KIA/ENG/KIA431_A_AF_B_BF_F.pdf

Indeed it is a KIA 431. Printed on the PCB for the leads are A, K, R.

So, I should see a voltage reference at the anode terminal, less two
junctions (~ 10.8), yes?

Thanks,
--
DaveC
Click to expand...
It's a programmable zener - same as a TL431, so the
*cathode* voltage will vary depending on the voltage placed
on the ref pin by the circuit. The anode is tied to ground
for most uses. See the datasheet:
http://www.fairchildsemi.com/ds/TL/TL431A.pdf
It's clearer than the KIA datasheet.

As a shunt regulator, you place a voltage divider on the
reference pin - 2 resistors in series from Vcc to ground
with the junction of the resistors tied to the ref pin on
the 431. The voltage divider determines when (what voltage)
the zener conducts. For example, assume Vcc is 10 volts.
The junction of R1 R2 will be at 5 volts. That means the
voltage across R3 will be 5 volts. The formula for figuring
the voltage is Vout = Vref*(1 + R1/R2) (Vref is ~2.5)


Vcc
|
\
/ R3
\ 1K
/
|
+---------+----Vout
| |
/ R1 |
\ 2.2K |
/ |
\ --- Note: Since this is a Zener-like
| ^ device, the cathode goes to
+--------/ \ 431 + and the anode goes to gnd.
| --- The datasheet shows an exception
\ | when it is used as a constant
/ R2 | current source, but the anode is
\ 2.2K | still more negative than the
/ | cathode.
| |
+---------+
|
Gnd
 
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