Yes, you are correct, L4970A can do the job, but again the transformer would be somewhere 100VA for a 18Vdc and 10Amp (I up the required output). This is like meeting the traditional power supply and the switching power supply half way.

Well, if I continue to have problem getting matching regulator IC versus the off the shelf planar supplied by Pulse Engineering or Technotrol company in Singapore, I may revert to L4970A.

Appreciate any kind soul could help.

 

I saw a SMPS for 13.8 V 40mps. He has packed the Ferrite tranformer using three ETD cores and combined them and wound over it. So a 150watt power supply would really need a ETD 34 size core.
Perhaps please see whether you can salvage a TV power supply and try to rewire the Ferrite transformer with suitable secondary winding. It would nearly meet your needs.

__________________
Regards,
Sarma.

 

Hi,
Attached the off the shelf planar transformer from Pulse Engineering.

Any kind soul could help match the regulator IC and circuit for these Planar models detailed in the attachments.

Attached Files

	SPM2007_52.pdf (255.5 KB, 27 views)
	SPM2007_53.pdf (217.3 KB, 19 views)

 

A 550W SMPs is nothing, I've seen datashseets for 5000W 48V SMPses before - we're thinking of buying one for a project at work.

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oops
I typed wrongly 150 watts -- it should have been 550 watts.
Neither a normal TV SMPS core would do for this.

Yes Hero999, I too worked with 5KW SMPSs in the Indian Telecom scenario. We used to stalk 3 of them, one across each phase (230V 50Hz) and thus balance the load on public mains for a 300Amp 50V DC power needs of telecom switches in villages.

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Sarma.

 

please see this product and I feel it is rather cheap . One can verywell manage with it unless one has to make it by himself.

12V 13.8V DC 12 Amp Regulated Switching Power Supply - eBay (item 350062751166 end time May-28-08 22:17:34 PDT)

__________________
Regards,
Sarma.

 

Hi Sarma,
I live in Singapore. I had some experience with China made switching power supply, which cost about S$100, US$77. It say adjustable 0 to 24Vdc and 10Amp. In reality, adjustable to 16Vdc and 4.5Amp.

Thank you for following this thread closely. Just want to be assured, did you know of anyone who had use this brand. Please let me know their experience.

Meanwhile, Hero base on the attached Planar information appreciate any circuit and IC recommendation.

 

Generally a psu with adjustable output will be costly. So if you need a fixed voltage, better go for fixed smps. As e-bay has quoted below 20 bucks, there is no need to pay more than 25$. i got the info only on net and never I used the device.

__________________
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Sarma.

 

My Idea Is To First Use A Hi Voltage Preregulator For 180v To Insure That The Power Will Not Go Away When It Dips And Bounce. Then Use Low Voltages Pwm To Get The Current

 

ok, this sound interesting. please post schematic of the circuit.

 

Off-line switched PSUs can be designed as "universal" - working in the 85V - 265V range. That would make the preregulator unnecessary.

 

every stage counts on your pocket and also on power efficiency. It is always better to work a one time solution. Unless one is going for a project, i still feel the site indicated by me sells a psu very cheap.

__________________
Regards,
Sarma.

 

even drawing 500W from 220VAC is only about 2.25A so a 5A bridge would be fine.

 

My suggestion was with specific reference to L4970A chip and the schematic there on provided by the OP. There after the OP wanted to use Planar transformers-- i was confused with low height CRGO core transformers --some of them I saw in light dimmers( Really sleek and wide.)

__________________
Regards,
Sarma.

 

Although he'd need to use some inrush current limiting to avoid destroying it.

__________________
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