Author Topic: Prisma elevator door controller, damaged psu, need identify components  (Read 2558 times)

0 Members and 1 Guest are viewing this topic.

Offline Harry_22

  • Frequent Contributor
  • **
  • Posts: 603
  • Country: 00
Re: Prisma elevator door controller, damaged psu, need identify components
« Reply #25 on: December 08, 2024, 02:00:15 pm »
Zeners can be 13 volts. This is enough to start the controller (Vcc=9V max).
The main thing is that after start-up Vcc voltage rises slightly (up to 10-11 volts) and turns off Q32.
 

Offline timeandfrequency

  • Regular Contributor
  • *
  • Posts: 246
  • Country: fr
Re: Prisma elevator door controller, damaged psu, need identify components
« Reply #26 on: December 08, 2024, 08:56:32 pm »
Buy also a replacement for R114 (100 k).
10 k seems pretty low (lead to a start current of  I = 31 mA)
If the controller does not start with 100 k, you can still try 10 k in a second attempt.
« Last Edit: December 08, 2024, 08:58:49 pm by timeandfrequency »
 

Offline Harry_22

  • Frequent Contributor
  • **
  • Posts: 603
  • Country: 00
Re: Prisma elevator door controller, damaged psu, need identify components
« Reply #27 on: December 08, 2024, 09:48:04 pm »
100k resistor will not burn out as much as 10k in case of Q32 short.
 

Offline timeandfrequency

  • Regular Contributor
  • *
  • Posts: 246
  • Country: fr
Re: Prisma elevator door controller, damaged psu, need identify components
« Reply #28 on: December 08, 2024, 10:09:32 pm »
100k resistor will not burn out as much as 10k in case of Q32 short.
I already noticed your explanation above.
Let me just allow to have different opinion than yours.
« Last Edit: December 08, 2024, 10:11:50 pm by timeandfrequency »
 
The following users thanked this post: Harry_22

Offline Poroit

  • Regular Contributor
  • *
  • Posts: 198
  • Country: au
Re: Prisma elevator door controller, damaged psu, need identify components
« Reply #29 on: December 09, 2024, 05:40:24 am »
G'day All,

I am not sure if the attached is a help or a hinderance but it contains similar components to the damaged PSU.

I have seen similar damaged components in these as well.

I do not have a schematic.
 

Offline Harry_22

  • Frequent Contributor
  • **
  • Posts: 603
  • Country: 00
Re: Prisma elevator door controller, damaged psu, need identify components
« Reply #30 on: December 09, 2024, 10:42:54 am »
G'day All,

I am not sure if the attached is a help or a hinderance but it contains similar components to the damaged PSU.

I have seen similar damaged components in these as well.

I do not have a schematic.

Hi Poroit!

Yes, yours PSU is mostly similar.
PFC provides its own Vcc supply. That is why low power start-up UCx845 is used there.
Also 50% duty cycle is usually used with the high power transformer.
 

Offline timeandfrequency

  • Regular Contributor
  • *
  • Posts: 246
  • Country: fr
Re: Prisma elevator door controller, damaged psu, need identify components
« Reply #31 on: December 09, 2024, 09:20:45 pm »
Hello Poroit,

G'day All,

I am not sure if the attached is a help or a hinderance but it contains similar components to the damaged PSU.

I have seen similar damaged components in these as well.

I do not have a schematic.

Can you confirm that the document you provided shows an elevator door controller from Prisma ?
 

Offline timeandfrequency

  • Regular Contributor
  • *
  • Posts: 246
  • Country: fr
Re: Prisma elevator door controller, damaged psu, need identify components
« Reply #32 on: December 09, 2024, 09:34:29 pm »
About Z14  (Vz = 11 V in the latest schematic)
@PiotrMisiuna Any marking on the zeners ?


Minimum PWM controller startup voltage depends on IC reference :
UC3842 &  UC3844 : 16 VDC   :  Z14 value is underrated, PWM controller will not start
UC3843  &  UC3845  : 8,4 VDC  : Z14  value is OK


Interesting sentence in chapter '7.3.5 Undervoltage Lockout' of the datasheet :

During normal circuit operation, VCC is developed from auxiliary winding NA with DBIAS
and CVCC. At start-up, however, CVCC must be charged to 16 V (*) through RSTART. With a start-up current of 1 mA,
RSTART can be as large as 100 kΩ and still charge CVCC when VAC = 90 V RMS (low line). Power dissipation in
RSTART is then be less than 350 mW even under high line (VAC= 130 V RMS) conditions.



(*) Actual minimal startup voltage depends on IC model, see above.

Reminder : as PiotrMisiuna is located in Europe, VAC = 240 V RMS @ 50Hz (hence DC rail voltage = 339 VDC)
« Last Edit: December 10, 2024, 09:39:38 am by timeandfrequency »
 

Offline Poroit

  • Regular Contributor
  • *
  • Posts: 198
  • Country: au
Re: Prisma elevator door controller, damaged psu, need identify components
« Reply #33 on: December 10, 2024, 05:36:16 am »
G'day timeandfrequency,

Unfortunately not.

It is an SMPS from a 25 year old Air Data Test Set.
 
The following users thanked this post: timeandfrequency

Offline timeandfrequency

  • Regular Contributor
  • *
  • Posts: 246
  • Country: fr
Re: Prisma elevator door controller, damaged psu, need identify components
« Reply #34 on: December 10, 2024, 09:47:25 am »
Unfortunately not.
It is an SMPS from a 25 year old Air Data Test Set.
Thanks Poroit for this information.
These UCx84x switchers have numerous applications and were used in many different designs.
This thread is about the repair of a 'Prisma elevator door controller'.
Unfortunately, the board you showed can not really be used as reference to identify the fried parts we have on that elevator controller.
« Last Edit: December 10, 2024, 01:01:41 pm by timeandfrequency »
 
The following users thanked this post: Poroit

Offline PiotrMisiunaTopic starter

  • Contributor
  • Posts: 32
  • Country: cy
Re: Prisma elevator door controller, damaged psu, need identify components
« Reply #35 on: January 18, 2025, 08:42:28 pm »
I believe the repair is successful. Powered up on the workbench effected in one of  LED lights going red and some relays going click.  Now I will pass it and wait for feedback from the elevator technician.  :)
 
The following users thanked this post: timeandfrequency, Poroit

Offline timeandfrequency

  • Regular Contributor
  • *
  • Posts: 246
  • Country: fr
That's good news.
Keep us updated.
If possible, post again the latest version of the schematics, with the actual parts values/references you used to repair the board.
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf