Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

a 150W switchmode power supply with 555 timer

Status
Not open for further replies.

alphi

Advanced Member level 1
Joined
Dec 23, 2001
Messages
414
Helped
11
Reputation
24
Reaction score
10
Trophy points
1,298
Activity points
3,211
555 power supply

a 150W switchmode power supply with 555 timer:
it cheapest method to design such switch mode power supply.
 

Ante

Full Member level 3
Joined
May 1, 2004
Messages
169
Helped
17
Reputation
34
Reaction score
11
Trophy points
1,298
Activity points
1,321
555 smps

March 1977, you must be kidding. I it 2004 now, get real!

Ante :roll:
 

tryagain

Newbie level 1
Joined
Jun 14, 2002
Messages
0
Helped
2
Reputation
4
Reaction score
2
Trophy points
1,282
Activity points
797
ka3525 circuit

in 2004,we can advanced chip(like 3842,....),but 555 chip is cheapest!
 

goodboy_pl

Full Member level 5
Joined
Mar 12, 2002
Messages
253
Helped
16
Reputation
32
Reaction score
15
Trophy points
1,298
Activity points
3,119
homemade switching power supply

the fundamental behind the most of SMPSes are the same but the advances in technology provide lower cost, efficient and feature rich chips which integrate all of the power electronincs circuits in a single die or package (hybrids).
currently several manufacturers provide integrated switchers/regulators with this range of power or upper; BTW the circuit is useful as a home made DC to DC convertor.

BEST!
 

felix1200

Junior Member level 3
Joined
Dec 31, 1999
Messages
29
Helped
2
Reputation
4
Reaction score
2
Trophy points
1,283
Activity points
207
ka3525 application

This 'simple' step down converter is one of the most expensive I ever seen. (1977 it's ok, but today too expensive)
This regulator has a poor efficiency. I think the losses in the switching Darlington transistor are > 10W. So you are in need to cool it well with a very expensive and BIG heat sink !!! A mechanical disaster.

Modern concepts are much cheaper. They work with MOSFETs and do not need heatsinks to be cooled.

felix1200
 

rauol

Full Member level 6
Joined
Oct 2, 2002
Messages
325
Helped
16
Reputation
32
Reaction score
4
Trophy points
1,298
Location
India
Activity points
2,647
smps 555

8) i have used 555 timer in low power DC DC converter application, works fine but has many limitations. 1; have to add external referances 2: add external drive elements 3: limited sypply voltage range. 4:external components required for current limiting .

way back in 77 the price of SMPS controllers where high and people where experimenting using other available IC s.
but now the price of 555 , SG3524, TL494 or UC 3842 are almost equal. there is no point in designing using Timer IC.
 

Ante

Full Member level 3
Joined
May 1, 2004
Messages
169
Helped
17
Reputation
34
Reaction score
11
Trophy points
1,298
Activity points
1,321
555 switching power supply

The 555 is cool but not for this application! And look 8O at some of the other stuff, transistors, diodes, PUT and more. They are gonners in an app like this, maybe not even possible to get hold of.

Ante :roll:
 

batdin

Full Member level 3
Joined
Jun 3, 2004
Messages
182
Helped
5
Reputation
10
Reaction score
2
Trophy points
1,298
Location
Bulgaria
Activity points
1,928
555 timer power supply

It sounds to me like "Rocket-engine powered dragster using cart wheels".
Call me ultramodern but I prefer KA3525 ;)
 

alphi

Advanced Member level 1
Joined
Dec 23, 2001
Messages
414
Helped
11
Reputation
24
Reaction score
10
Trophy points
1,298
Activity points
3,211
lm555 with smps

Ka3525 for halfbridge,
I think Uc3843 for forward topology power supply is better.
 

metal

Full Member level 6
Joined
Dec 21, 2004
Messages
364
Helped
19
Reputation
38
Reaction score
6
Trophy points
1,298
Activity points
3,834
power supply 555

Hello Everybody

I don't know why people think its shame to use old or cheap stuff to acomplish a job, the guy just wanted to share a nice circuit, in deed, the UC3843 is not available in my country, so Such people like me will consider such circuit of great help.

Anyway,ITS UP TO THE CONSTRUCTOR whether to use new, old or even discontinued products. My self, I have used the µPC1225H to build an audio power amplifier of 60 watts output. Its performance was great, although its a continued one and really old one.

No hard feelings
Regards
 
  • Like
Reactions: exnol

    exnol

    Points: 2
    Helpful Answer Positive Rating

nand_gates

Advanced Member level 3
Joined
Jul 19, 2004
Messages
893
Helped
175
Reputation
350
Reaction score
51
Trophy points
1,308
Activity points
6,843
uc3843 power supply

Good one!!
We should think about improving this circuit by replacing switching transiotor
by power MOSFET!
 

cetc1525

Full Member level 3
Joined
Oct 8, 2004
Messages
174
Helped
5
Reputation
10
Reaction score
2
Trophy points
1,298
Activity points
1,396
ka3525 schematic

i think we should improve effcient.
 

metal

Full Member level 6
Joined
Dec 21, 2004
Messages
364
Helped
19
Reputation
38
Reaction score
6
Trophy points
1,298
Activity points
3,834
uc3843 power supply schematic

Hello

Concerning the MOSFET, I think there is no need to use it, as long as the switching frequency is not too high. So as not to raise the cost, for being cost effective.

Regards
 

leoneder

Newbie level 1
Joined
Jun 8, 2007
Messages
1
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,284
homemade switch mode power supply

Hi, friends
Anyone can please send me some SMPS schemmatic, I´m working in a project like these. Thanks!
 

DJ Exprice

Newbie level 1
Joined
Jun 21, 2007
Messages
1
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,284
ka3525 application note

I made an alternative link on my server.

Hope that helps! :wink:

**broken link removed**
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top