diodes

[jin29_neci]

:lol:
Hello guys!

I want to make a power supply.

But the questin in my head is this- what diode will i use because i want the diode to directly rectifier the ac line, no more transformer to step up or step down the voltage. I want to direct a bridge rectifier diode in a ac line.

What value of a diode for frequencuy 60hz and 220 volts.

Thanks!

Sorry for this question.

 

[Someone Electro]

This is dengerus to do!!!

 

[Morgen]

You are looking at over 300 volts direct current, with no isolation from the mains power source. EXTREMELY dangerous. What do you need with a power supply like that?!? It is definitely not newbie territory.
FYI, diodes aren't normally frequency dependent, unless you are switching very high frequencies.

 

[jin29_neci]

thanks! guys.........

Im just thinking if this is possible.......

as you can see may television sets are using highly frequency diodes, so it came up into my mind if i can make a power supply like that using a high frequency diode, then a filter capacitor,then a power regulator......


sorry if this is not possible

thanks anyway!

 

[Nigel Goodwin]

thanks! guys.........

Im just thinking if this is possible.......

as you can see may television sets are using highly frequency diodes, so it came up into my mind if i can make a power supply like that using a high frequency diode, then a filter capacitor,then a power regulator......


sorry if this is not possible

thanks anyway!

You still haven't mentioned what you are trying to do?, TV sets commonly use switchmode PSU's, where you have normal low speed rectifiers producing a DC voltage (around 330V in Europe!). This is then 'chopped' at a high frequency and fed through a transformer, using high speed rectifiers on the output to produce the DC supplies. By adding feedback from secondary to primary the entire supply is regulated.

 

[jin29_neci]

:?
nIGEL gOODWIN

thanks for the post!!!

so is this possible(I HOPE SO)!
i want suggestions to you guys regarding this PWS or Switch mode power supply. Do you think i can make a god one.........

 

[ljcox]

You could extract one from a failed TV or VCR, etc.

Len

 

[samcheetah]

:?
nIGEL gOODWIN

thanks for the post!!!

so is this possible(I HOPE SO)!
i want suggestions to you guys regarding this PWS or Switch mode power supply. Do you think i can make a god one.........

yes you can make a good switchmode power supply. i would recommend that you go to national's website. they have plenty of ICs that will make your work really easy. and in addition to that you should buy the book "Switching power supply design" by Abraham I. Pressman

i hope that helps

 

[Nigel Goodwin]

so is this possible(I HOPE SO)!
i want suggestions to you guys regarding this PWS or Switch mode power supply. Do you think i can make a god one.........

You still haven't mentioned what you want it to do?, the output voltage and current (and the intended application) are obviously important to know.

Do you really need a switchmode supply?, they are FAR more complicated (and prone to 'blowing up') than conventional ones.