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2008-03-20 by M F
hi friends
have u ever worked at any switching circuits? i want
to design a DC power supply.may i use 555 Ic's??
is there any sites to help me.your ideas could help
me.
let me know if u have designed a switching power
supply
thank u
have a nice spring holidays
Shervin
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Never miss a thing. Make Yahoo your home page.
http://www.yahoo.com/r/hs2008-03-21 by Zack Widup
I've designed quite a few. What are your power requirements? What voltages in and out? What maximum current out? There are far better ways to do it than with a 555. But that will work if you only need small currents. Zack
On Wed, 19 Mar 2008, M F wrote: > hi friends > have u ever worked at any switching circuits? i want > to design a DC power supply.may i use 555 Ic's?? > is there any sites to help me.your ideas could help > me. > let me know if u have designed a switching power > supply > > thank u > have a nice spring holidays > > Shervin > > > ____________________________________________________________________________________ > Never miss a thing. Make Yahoo your home page. > http://www.yahoo.com/r/hs >
2008-03-21 by LEON HELLER
M F <ektenad@yahoo.com> wrote: hi friends have u ever worked at any switching circuits? i want to design a DC power supply.may i use 555 Ic's?? is there any sites to help me.your ideas could help me. let me know if u have designed a switching power supply I have, I used an AT90S2313. Leon [Non-text portions of this message have been removed]
2008-03-21 by Dennis Clark
Maybe I've lost the spirit of discovery, but I see no reason to design a new power supply when there are dedicated switching controllers out there for a song (low cost). Is there a reason you want to do this the hard way? DLC > hi friends > have u ever worked at any switching circuits? i want > to design a DC power supply.may i use 555 Ic's?? > is there any sites to help me.your ideas could help > me. > let me know if u have designed a switching power > supply > > thank u > have a nice spring holidays > > Shervin > > > ____________________________________________________________________________________ > Never miss a thing. Make Yahoo your home page. > http://www.yahoo.com/r/hs > > ------------------------------------ > > Yahoo! Groups Links > > > > -- Dennis Clark TTT Enterprises
2008-03-21 by James Wagner
Shervin - Yes, you probably could, but the 555 only represents a small part of what would go into a switch-mode power supply. Further, the 555 is really designed to vary its duty cycle or pulse width based on external resistors and not voltages. This makes it harder to use for this kind of application than one would really like. IF you REALLY want to experiment and learn what the challenges are for making a SMPS, then charge on. However, since you are posting on an AVR list, I would assume that your goal is to power an AVR or peripheral circuits. If that is the case, then you will be spending a LOT of time on something that really is secondary to your end goal. I can understand, if you are in a part of the world where electronic components are hard to get and you may only have access to 555s and 741 op amps and such. There are some switcher "cores" that have been around for a LONG time and are very low cost and widely available. Unfortunately, I can't find any references to what I remember, but I do know that they are out there. Unfortunately, if your problem is finding modern components, you will also have problems getting Schottky diodes and power inductors you really need for such a supply. Jim Wagner On Mar 21, 2008, at 9:03 AM, Dennis Clark wrote: > Maybe I've lost the spirit of discovery, but I see no reason to > design a > new power supply when there are dedicated switching controllers out > there for a song (low cost). > > Is there a reason you want to do this the hard way? > > DLC > > > hi friends > > have u ever worked at any switching circuits? i want > > to design a DC power supply.may i use 555 Ic's?? > > is there any sites to help me.your ideas could help > > me. > > let me know if u have designed a switching power > > supply > > > > thank u > > have a nice spring holidays > > > > Shervin > > > > > > __________________________________________________________ > > Never miss a thing. Make Yahoo your home page. > > http://www.yahoo.com/r/hs > > > > ------------------------------------ > > > > Yahoo! Groups Links > > > > > > > > > > -- > Dennis Clark > TTT Enterprises > > > [Non-text portions of this message have been removed]
2008-03-21 by Roy E. Burrage
Try an MC34063A, UA3843A, or an LM3425A will all do what you want and do it very economically. The first two come in an 8 pin DIP and the last one is a 16 pin DIP. All are easy to use, which to use depends upon the application. REB James Wagner wrote: > Shervin - > > Yes, you probably could, but the 555 only represents a small part of > what would go into a switch-mode power supply. Further, the 555 is > really designed to vary its duty cycle or pulse width based on > external resistors and not voltages. This makes it harder to use for > this kind of application than one would really like. IF you REALLY > want to experiment and learn what the challenges are for making a > SMPS, then charge on. However, since you are posting on an AVR list, I > would assume that your goal is to power an AVR or peripheral circuits. > If that is the case, then you will be spending a LOT of time on > something that really is secondary to your end goal. > > I can understand, if you are in a part of the world where electronic > components are hard to get and you may only have access to 555s and > 741 op amps and such. There are some switcher "cores" that have been > around for a LONG time and are very low cost and widely available. > Unfortunately, I can't find any references to what I remember, but I > do know that they are out there. Unfortunately, if your problem is > finding modern components, you will also have problems getting > Schottky diodes and power inductors you really need for such a supply. > > Jim Wagner > > On Mar 21, 2008, at 9:03 AM, Dennis Clark wrote: > > >> Maybe I've lost the spirit of discovery, but I see no reason to >> design a >> new power supply when there are dedicated switching controllers out >> there for a song (low cost). >> >> Is there a reason you want to do this the hard way? >> >> DLC >> >> >>> hi friends >>> have u ever worked at any switching circuits? i want >>> to design a DC power supply.may i use 555 Ic's?? >>> is there any sites to help me.your ideas could help >>> me. >>> let me know if u have designed a switching power >>> supply >>> >>> thank u >>> have a nice spring holidays >>> >>> Shervin >>> >>> >>> __________________________________________________________ >>> Never miss a thing. Make Yahoo your home page. >>> http://www.yahoo.com/r/hs >>> >>> ------------------------------------ >>> >>> Yahoo! Groups Links >>> >>> >>> >>> >>> >> -- >> Dennis Clark >> TTT Enterprises >> >> >> >> > > > > [Non-text portions of this message have been removed] > > > ------------------------------------ > > Yahoo! Groups Links > > > > > [Non-text portions of this message have been removed]
2008-03-21 by James Wagner
The MC34063A was what I was remembering. Thanks, Roy. Jim \ On Mar 21, 2008, at 12:11 PM, Roy E. Burrage wrote: > Try an MC34063A, UA3843A, or an LM3425A will all do what you want > and do > it very economically. The first two come in an 8 pin DIP and the last > one is a 16 pin DIP. All are easy to use, which to use depends upon > the > application. > > REB > > James Wagner wrote: > > Shervin - > > > > Yes, you probably could, but the 555 only represents a small part of > > what would go into a switch-mode power supply. Further, the 555 is > > really designed to vary its duty cycle or pulse width based on > > external resistors and not voltages. This makes it harder to use for > > this kind of application than one would really like. IF you REALLY > > want to experiment and learn what the challenges are for making a > > SMPS, then charge on. However, since you are posting on an AVR > list, I > > would assume that your goal is to power an AVR or peripheral > circuits. > > If that is the case, then you will be spending a LOT of time on > > something that really is secondary to your end goal. > > > > I can understand, if you are in a part of the world where electronic > > components are hard to get and you may only have access to 555s and > > 741 op amps and such. There are some switcher "cores" that have been > > around for a LONG time and are very low cost and widely available. > > Unfortunately, I can't find any references to what I remember, but I > > do know that they are out there. Unfortunately, if your problem is > > finding modern components, you will also have problems getting > > Schottky diodes and power inductors you really need for such a > supply. > > > > Jim Wagner > > > > On Mar 21, 2008, at 9:03 AM, Dennis Clark wrote: > > > > > >> Maybe I've lost the spirit of discovery, but I see no reason to > >> design a > >> new power supply when there are dedicated switching controllers out > >> there for a song (low cost). > >> > >> Is there a reason you want to do this the hard way? > >> > >> DLC > >> > >> > >>> hi friends > >>> have u ever worked at any switching circuits? i want > >>> to design a DC power supply.may i use 555 Ic's?? > >>> is there any sites to help me.your ideas could help > >>> me. > >>> let me know if u have designed a switching power > >>> supply > >>> > >>> thank u > >>> have a nice spring holidays > >>> > >>> Shervin > >>> > >>> > >>> __________________________________________________________ > >>> Never miss a thing. Make Yahoo your home page. > >>> http://www.yahoo.com/r/hs > >>> > >>> ------------------------------------ > >>> > >>> Yahoo! Groups Links > >>> > >>> > >>> > >>> > >>> > >> -- > >> Dennis Clark > >> TTT Enterprises > >> > >> > >> > >> > > > > > > > > [Non-text portions of this message have been removed] > > > > > > ------------------------------------ > > > > Yahoo! Groups Links > > > > > > > > > > > > [Non-text portions of this message have been removed] > > > [Non-text portions of this message have been removed]