Phaff 1221circuit board dead

J

JJW1221

New Member

• Jan 9, 2022

• #1

Hi i need help repairing this phaff 1221 circuit board. fuse has been removed.
the big capacitor tests dead, but i read on an older thread you can read it completely.
Found this hand drawn schematic on an older thread.
My issue is the 3 coiled transformer is blown up. Any ideas why and how to replace it? thanks.

 

rjenkinsgb

Well-Known Member

Most Helpful Member

• Jan 9, 2022

• #2

You should be able to use an OEP "PT6" pulse transformer. It may not be physically identical, but it has three windings and is suitable for thyristor triggering.

PT6 | OEP Through Hole Pulse Transformer 1:1 Turns Ratio, 3mH Prim. Inductance, 1.1Ω Prim. Resistance | RS

uk.rs-online.com

 

J

JJW1221

New Member

• Jan 11, 2022

• #3

I will see if i can find something similiar here in the US.
what could cause it to blown up? would some component also be bad upstream?

 

J

JJW1221

New Member

• Jan 11, 2022

• #4

And theres no specs on this transformer, What specs do I use to find a replacement?
Could you check out this site? https://www.digikey.com/ See if theres a replacement.

 

rjenkinsgb

Well-Known Member

Most Helpful Member

• Jan 11, 2022

• #5

Digikey do quite a lot that may be suitable:

Pulse Transformers | Electronic Components Distributor DigiKey

Pulse Transformers are in stock at DigiKey. Order Now! Transformers ship same day

www.digikey.com

Look for ones with probably somewhere in the region of 1 - 2mH inductance, at a guess.
This one may be OK?

77202C Murata Power Solutions Inc. | Transformers | DigiKey

Order today, ships today. 77202C – 1mH SCR and Triac Trigger (Encapsulated) Pulse Transformer 1:1:1 Through Hole from Murata Power Solutions Inc.. Pricing and Availability on millions of electronic components from Digi-Key Electronics.

www.digikey.com

Or this:

IL-10-0001 SCHURTER Inc. | Transformers | DigiKey

Order today, ships today. IL-10-0001 – 2.5mH SCR and Triac Trigger (Encapsulated) Pulse Transformer 1:1:1 Through Hole from SCHURTER Inc.. Pricing and Availability on millions of electronic components from Digi-Key Electronics.

www.digikey.com

etc.

78602/8C Murata Power Solutions Inc. | Transformers | DigiKey

Order today, ships today. 78602/8C – 1mH General Purpose Pulse Transformer 1:1:1 Through Hole from Murata Power Solutions Inc.. Pricing and Availability on millions of electronic components from Digi-Key Electronics.

www.digikey.com

 

J

JJW1221

New Member

• Jan 27, 2022

• #6

Hi i replaced this pulse transformer and immediately at power up,
it blew again without motor or anything else hooked up to board.
Any ideas? Capacitor tests ok.