There is a switching power supply on the Ferroli boiler (attached pics).
The transformer failed to produce appropriate voltage on the secondary sides.
I have no idea about the specifications of the transformer.
How can I replace this part with an appropriate one?
I appreciate any help or tips about this problem.
Thank you in advance for spending your valuable time for solving the problem.
Mohamad Sayadi Hope the following attachments will solve your problem.
https://wcmagnetics.com/wp-content/uploads/2015/02/appnote11.28.10.pdf
https://www.ti.com/lit/ml/slup126/slup126.pdf
@ Mohamad Sayadi, are You sure it is the transformer,
this is a component which almost never fails.
(Unless it is really burned or shorted)
First check the green resistor (It's used as a fuse) if it is interrupted, replace it together with this Viper chip.
This would be a much more common way of failing.
If this equipment is very old, it might also be wise to replace the electrolytic capacitors.
Mohamad Sayadi as a suggestion, could you look into the datasheet for the PMIC controller, it looks to be the 8-DIP IC in the picture.
Please see this link: https://www.st.com/resource/en/application_note/cd00005177.pdf
You may attempt to backtrack the design process of the SMPS by noting the values of the components used in the design you do know. ie. the SMD resistors and capacitors that might define the switching frequency and output voltage specifications.
Finding the primary:secondary ratio and inductance will land you close to a replacement part. Note: Parameters such as current and maximum voltage should also be considered when selecting the transformer, using the parameters stated in the IC datasheet as your baseline. This could land you close to a replacement part, but a reference design with part numbers was included in the link above which may be similar to your design.
Thank you for all the scientists who dedicated their valuable time and responded to this topic.
Dear professor @Brenden Bradshaw I rechecked the whole switching module. It will produces three voltage supplies for different parts of the card.
First: a low voltage for driving the Viper22a about 14V,
Second: a medium voltage about 24V for driving the MCU and relays
Third: high voltage for ignition system (sparking in boiler). A 400V/1uF Cap used for smoothing this part.
I can create first and second voltage by a separate PSU but I have no idea how to generate the high voltage for ignition system. furthermore, I do not know how much it is.
I have also re-engineered a part of the circuit and attached to this reply.
The switching circuit also use PKC136 diode in primary winding.
I would be really grateful for any recommendation to solve this challenge.
As previously mentioned, the transformer is seldom the problem. Reverse engineering a custom power transformer is usually difficult it the design was optimized for high-volume production, with winding spacing, direction, layer order, core gaps, etc. all having significant effect on the resultant device. If you goal is to repair your system, the best chance of success is to locate a replacement board, either from the manufacturer (try https://www.ferroli.co.uk/spares/ ) or on the used/repair market using Google searches for part names/numbers on the main PC board.
Alternative suggestions mentioned above may also be successful, with replacement of all electrolytic caps being the highest chance of success. If any of the caps have leaked onto the the board, vigorous cleaning will be needed as part of the repair.
Check the high-voltage igniter area for open/shorted diodes and burn marks on the PC board. Most igniter systems have flame detection by either thermocouple or flame condictivity (rectification) methods, which may need to be repaired after the initial functionality is obtained.
Good luck!
