Help to identify these devices

  • Thread starter John Damm Sřrensen
  • Start date
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John Damm Sřrensen

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Recently the flouroscent lamp in my AGFA Snapscan scanner wore out.

I found on the Web, that the lamp is standard 8W daylight type, so I
bought an Osram L8W/950.

Now when I powered up the device the lamp did not turn as is used to do.

I then disssambled the scanner and found that there is a separate
inverter type supply that drives the lamp. This circuit is a separate
part of the power supply and it is fused with a 2A fuse and supplied
from the +12V.

The fuse had blown and replacing it did not change anything.

I suspect that one or both of the transistors in the inverting circuit
has shorted because if I apply external power the circuit more or less
acts like a short.
I cannot determine whether the transistors are normal bipolar
transistors or FET's of some kind.

I do not have a schematic, so I had to reconstruct it by tracing the
traces on the PCB. From that I can deduct that the pin out is ECB or
SDG. The package is 3 lead TO-251.

The printing on the devices reads D1802 and below to the left is an S
and below to the right is 6J.

Does anyone known what type of transistor its and is it right that I can
use the Osram lamp I bought. The original lamp was a Satellite F8T5D.

Cheers
John
 
find tansistor here:
http://www.chipdocs.com/pndecoder/datasheets/SANYO/2SD1802.html

"John Damm Sřrensen" <john-nospam@nomail.hovedpuden.dk> wrote in message
news:3f53a3de$0$20053$edfadb0f@dread11.news.tele.dk...
Recently the flouroscent lamp in my AGFA Snapscan scanner wore out.

I found on the Web, that the lamp is standard 8W daylight type, so I
bought an Osram L8W/950.

Now when I powered up the device the lamp did not turn as is used to do.

I then disssambled the scanner and found that there is a separate
inverter type supply that drives the lamp. This circuit is a separate
part of the power supply and it is fused with a 2A fuse and supplied
from the +12V.

The fuse had blown and replacing it did not change anything.

I suspect that one or both of the transistors in the inverting circuit
has shorted because if I apply external power the circuit more or less
acts like a short.
I cannot determine whether the transistors are normal bipolar
transistors or FET's of some kind.

I do not have a schematic, so I had to reconstruct it by tracing the
traces on the PCB. From that I can deduct that the pin out is ECB or
SDG. The package is 3 lead TO-251.

The printing on the devices reads D1802 and below to the left is an S
and below to the right is 6J.

Does anyone known what type of transistor its and is it right that I can
use the Osram lamp I bought. The original lamp was a Satellite F8T5D.

Cheers
John
Click to expand...
 
John Damm Sřrensen wrote:

Recently the flouroscent lamp in my AGFA Snapscan scanner wore out.

I found on the Web, that the lamp is standard 8W daylight type, so I
bought an Osram L8W/950.

Now when I powered up the device the lamp did not turn as is used to do.

I then disssambled the scanner and found that there is a separate
inverter type supply that drives the lamp. This circuit is a separate
part of the power supply and it is fused with a 2A fuse and supplied
from the +12V.

The fuse had blown and replacing it did not change anything.

I suspect that one or both of the transistors in the inverting circuit
has shorted because if I apply external power the circuit more or less
acts like a short.
I cannot determine whether the transistors are normal bipolar
transistors or FET's of some kind.

I do not have a schematic, so I had to reconstruct it by tracing the
traces on the PCB. From that I can deduct that the pin out is ECB or
SDG. The package is 3 lead TO-251.

The printing on the devices reads D1802 and below to the left is an S
and below to the right is 6J.

Does anyone known what type of transistor its and is it right that I can
use the Osram lamp I bought. The original lamp was a Satellite F8T5D.

Cheers
John

Well I found that one of the transistors is shorted.
Click to expand...
So now I just need to know what type it is.

/John
remove -nospam and nomail. from email to send e-mail to me directly.
 
Digi Man wrote:

find tansistor here:
http://www.chipdocs.com/pndecoder/datasheets/SANYO/2SD1802.html

"John Damm Sřrensen" <john-nospam@nomail.hovedpuden.dk> wrote in message
news:3f53a3de$0$20053$edfadb0f@dread11.news.tele.dk...

Recently the flouroscent lamp in my AGFA Snapscan scanner wore out.

I found on the Web, that the lamp is standard 8W daylight type, so I
bought an Osram L8W/950.

Now when I powered up the device the lamp did not turn as is used to do.

I then disssambled the scanner and found that there is a separate
inverter type supply that drives the lamp. This circuit is a separate
part of the power supply and it is fused with a 2A fuse and supplied
from the +12V.

The fuse had blown and replacing it did not change anything.

I suspect that one or both of the transistors in the inverting circuit
has shorted because if I apply external power the circuit more or less
acts like a short.
I cannot determine whether the transistors are normal bipolar
transistors or FET's of some kind.

I do not have a schematic, so I had to reconstruct it by tracing the
traces on the PCB. From that I can deduct that the pin out is ECB or
SDG. The package is 3 lead TO-251.

The printing on the devices reads D1802 and below to the left is an S
and below to the right is 6J.

Does anyone known what type of transistor its and is it right that I can
use the Osram lamp I bought. The original lamp was a Satellite F8T5D.

Cheers
John




Thanks. This seems to be correct type.
Click to expand...
I found an equivalent type BUP41 which is available here in Europe.

/John
 
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