Ultra-Wide Range Input Power Supply with TOPswitch
I need to design an Ultra-Wide Range Input Power Supply with TOPswitch, in another words, with the following characteristics:
Input Voltage: from 22 to 240Vac/Vdc
Output 1: 5V x 500mA (2,5W)
Output 2: 12V x 350mA (4,2W)
Total: 6,7W power supply with ultra wide range input.
I ask if is it possible to reach these parameters with Topswitch line.
I´ve tried to test a TOP243PN (Under voltage lockout disabled) with voltages Near 20Vdc, and it worked, but can not start with load. The datasheet does not mention anything about minimum input for a TOPswitch line chip.
Could some expert help me with this design?
I would like to use TOPswitch because it not uses skip-pulse (when low load applyed) technique like current controlled switchers. Skip-pulse generates too RIPPLE and audible NOISE.
Thanks a lot!
Comments
I was hopping if there is someway, like design idea DI-152 from PI.
It seems that the low current linear power supply attached to a Tiny or Topswitch device could get away with the auxiliary winding, allowing working with low input voltages.
See the attached picture. Thanks a lot for any helping
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| 18-265V_3_W_Ultra-Wide_Range_Input_Power_Supply_for_Industrial_Controls_-_di152.png (80.45 KB) | 80.45 KB |
Easy Peasy
Do you have chematic for DC the booster?
No, but I could provide one ...
Hi thermtronic,
Do you have the schematic of your TOP243 design including the transformer inductance? You've mentioned that it can power up at 20Vac but cannot start-up with load. At what loading condition it cannot start-up? 1W, 2W, etc... Remember that TOPSwitch is also limited by duty cycle max.
Thanks,
Pi-SevenofNine
Do you have any idea on how to do it work better and with stability?
Nominal Primary Inductance of the transformer is 516uH.
The schematic is attached.
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| 5V_12V_12V_08W_NEE20.pdf.zip (177.65 KB) | 177.65 KB |
Hi thermtronic,
We will check the schematic and will get back to you. Thanks.
Best Regards,
PI-SevenofNine
Dear PI-SevenOfNine.
Theank you for the tip. Yes, the limitation was in the duty-cycle. I´m trying to use the TOP243 to do the work from 20Vdc to 240Vac. I´m doing tests with TNY also (I´m affraid TNY generates audible noise).
Hi thermtronic,
As for the TNY, this is an ON-OFF control. The controller can go to audible range of frequency only at lighter load where less energy is being stored in the transformer. If you are worried about the audible noise, you may try to varnish your transformer. Thanks.
Best Regards,
PI-SevenofNine
Dear PI-SevenOfNine,
Why PI Expert uses a so thick wire in the bias coil?
Thank you again!
Hi thermtronic,
Can you please attach the screenshot here, for us to check. Thanks.
Best Regards,
PI-SevenOfNine
Dear PI-SevenOfNine.
I´ve attached the screenshot of the transformer and schematic here. Note that bias coil has 2x25AWG.
Thank you!
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| TH212_Transformer_construction.png (177.88 KB) | 177.88 KB |
| TH212_schemactic.png (125.75 KB) | 125.75 KB |
Hi thermtronic,
Your design now is at 85Vac according to your schematic. Based from your initial inquiry it was at 20Vac, which might be difficult to design given the output power you specified. Thanks.
Best Regards,
PI-SevenofNine
Dear PI-SevenOfNine,
I would like ask you a suggestion of some PI device indicated to do this project. Is it possible to do that with a TOPswitch device?
I have tried to do it with PIXIs design, but it seems that the software can´t help me design a powersupply with TOPswitch family which the input voltage is lower than 50Vac, because the duty cycle gets over 78%. Is there some parameter that I may change for solving that?
Thank you a lot!
Hi, do you have the booster schematic you are talking about. I need to design as low as 19.2VAC using topswitch as well.
Thank you.
bong_mendoza, if you need a power of 3W or less, I posted an schemactic on post number #3.
Hello Therm_tronic, you request is a rare one, 22 to 240Vac, it might be an idea to design a booster ckt that operates from 22Vac to say 70Vac input to raise the DC bus to 130VDC say to allow a normal TOP-switch design to operate from.
If the AC input is above 70Vac the booster can be disabled, and you loose only a boost diode drop ( 0.9 V ) and the series impedance of the boost choke.
At your low input power - this would be a valid solution.
:o) EP.