need help designing DC-DC Converter

Status
Not open for further replies.
S

sangel

New Member
I found only this one on the net, and this is not extrlay what I need

Electronics Experiments: Simple DC-DC Converter

I have to convert DC 220V to about 5-10V (i'm not shure extly what I need there, I will know only after my device will work)


Curent I do not care, device need very low curent , about 100mA, But it has to be as light as possible, so I cannot use usual transformer chemm ( It cannot be under 70g weight, and I prefere total weight under 50g).

So I prefere any scheme that I can use here.

p.s. I cannot use schemes without the transformer (like tiristor based) besouse of the safety.


thank u for all your unswers.
 
WHere are you getting 220V DC coming from?Transformers do not work with DC.
 
Last edited:
Given those requirements I think you are pretty much out of luck. Good luck finding a solution.
 
offline switcher. mind you, you might have trouble finding the transformer. the manufacturers are not likely to sell singles for less than $20-$30 since most are custom.

you would be better off just buying a small switcher supply for $10. I can explain why the price disparity but I do not want to bore you.
 

Ttransformer I beleave it is not a problem, I have a nice stock of them, from about 7g to 40g, That I beleave I can use.

And small switcher is a problem, they always 5V or 12V , and i'm not shure what exactly I need.
 
sangel said:
Ttransformer I beleave it is not a problem, I have a nice stock of them, from about 7g to 40g, That I beleave I can use.

And small switcher is a problem, they always 5V or 12V , and i'm not shure what exactly I need.
Click to expand...
That would be very unusual, switching transformers are a bit picky.

https://www.electro-tech-online.com/custompdfs/2008/12/tnypk_family_datasheet.pdf will work, assuming that you have an appropriate transformer. It also makes a difference if you are going for safety regs isolation or not. There are a lot of transformers out there that are only for 24-48V in or that only have 500V isolation instead of the 3-5KV that is required. (250VAC CE medical isolation is 5KV)

Dan
 
dknguyen said:
WHere are you getting 220V DC coming from?Transformers do not work with DC.
Click to expand...

Its probably 180 VDC. When 220-240 VAC is rectified it yields about 180 VDC. This is a very common voltage conversion in industrial plants. Most of the smaller industrial DC motors use either the 180 volt field or the 90 volt field. When 110-120 is rectified it yields 90 VDC. From what Sangel is describing I would say that the DC voltage is coming from something similar to a DC motor controller.

Sangel, here is a link to Dart Controls. See if this would help you.
Dart Controls - Your motor speed control solutions provider!
 



it is not it. It is regular trasformer scheme, with a bulky low frequency transformer.
 
sangel said:
it is not it. It is regular trasformer scheme, with a bulky low frequency transformer.
Click to expand...
I am missing something here...your origional post said you could not use a bulky 60Hz power transformer so I posted an economical switcher chip to which you reply it is using a low frequency transformer.

It makes me wonder if you have a clue what you are talking about.
 
Status
Not open for further replies.

Similar threads

AC/DC Transformer with 240V output
2 3 4
Replies
63
Views
7K
ThomsCircuit
P
  • Question
HOW CAN I MAINTAIN HIGH CURRENT IN NEGATIVE DC TO DC REGULATOR?
2
Replies
20
Views
2K
Reloadron
C
  • Question
DC Motor Drive L293D
Replies
7
Views
1K
tepalia02
T
  • Question
Using PIC16F1939 and designing a circuit around it.
Replies
1
Views
143
Diver300
D
P
  • Question
DC and AC Motor Confusion
Replies
8
Views
1K
Nigel Goodwin
Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…