Spehro Pefhany wrote 01:22 2003-09-17 enligt nedan:
>>The main culprit is: is it really a standard type thyristor?
>
>
>FWIW, it's listed as an obsolete "rectifier diode" in Toshiba's Japanese
>language web pages, as you can see quite clearly here:
>
>http://www.semicon.toshiba.co.jp/prd/common/discab/discab_list_05_3-7.html

I found that page, but tell me, how can you tell it is a rectifier?
Do you know japaneese?

I did find this document, listing it amongst diodes
http://www.semicon.toshiba.co.jp/prd/diode/doc/db11_doc/11356D1AE/pdf/10.pdf

I still did not react as i thought "controlled rectifier"...

>>The pin names make me a little scared: K1, A, K2
>>That make it look like a double diode, but "K2" is a smaller pin and go to
>>what looks like a trig section on the PCB... so it must be some transistor
>>cousin...
>
>Maybe just two connections to the cathode, and anode. In which case, it's
>okay.

AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAHHhhhhhhhh!!!!!!!

You are probably right.  The wire from the extra cathode seem not to go to a=
 trigger output but to somewhere close.

I thought it was burnt short between K1 and K2.

**&%$#!=BD=A7=A7!!

Now i spent most of yesterday searching and ordered two expensive spare=
 parts for no use and I probably still havn=B4t found the problem!  Shit.

A recieved spare part from FANUC has the same short, and identical exterior,=
 except it is marked Hitachi DSM20A6 (which of course is not to be found on=
 Hitachi semiconductor site...).  And this pins are marked T1, T2, G, with=
 the short between G and T1.  Definitely wrong marking, but tested=
 electrically the same.

Now i have analyzed the design as far as i can tell it most probably IS a=
 plain simple vanilla rectifier diode.  Doh!

Power cirquit analysis:=20
There is an input 3phase rectifier feeding a semi large cap, and this diode=
 feeds from there to a large cap, which feeds the motor H-bridge.  When=
 there is a pushing load on the motor the H-bridge charges the large cap,=
 and i think the diode is there to protect the input bridge rectifier from=
 too high voltage.  (but why did they not use a better bridge??)  And if too=
 high voltage over the large cap there is a power NPN and huge wire wound R=
 to take the breaking power.
Most of the control electronics is cast in custom hybrid modules :(

Error:=20
It outputs sqarewave to the motor, and on every other "forward" half cycle=
 there is a double voltage spike.  This in a condition where the motor=
 should sit still.  I stil have not figured out how i can get such weird=
 output voltage.  There is no error indication from the onboard error LEDs,=
 "only" indication is a burnt motor...

Now first i must find a way to make sure it is not the controlling device=
 that sends wrong control signals...  Must set up the unit to run in my lab.

Somebody have a schematic on FANUC A06B-6047-H002 DC PWM Drive with brake,=
 single axis, tachofeedback driver unit?

A new from FANUC cost about 3000US and have delivery time.
I have found FANUC repair sites on the net and found it for half that, which=
 is still plenty if it really is no problem in this unit but elswhere.
I found Schematic unavailable, Manual =A380.

Begin to set it up for test...

/Morgan
--
Morgan Olsson, Kivik, Sweden

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