HELP! project abt DC power supply.

[majorabak]

erm ... wad if i add the 7905 under the C6 capacitor? Is that correct? ;D

 

[majorabak]

TIMOTHY OI! U HONG TUAN RITE AHAHAHAH... I Kenneth seh... haiz tis stuff is making go nuts... help ???

 

[majorabak]

hey loveheb3 ? do i noe u? i also from tp... hmm ... lks like the ept stuff very stress

 

[majorabak]

aniwae why do i add my extra capacitors to my 5V regulator? and also ... are C5 and C6 electrolytic capacitors too? sorry i blur sia... plz reply back ty very much...

 

[infinity.o3]

omg, all from tp. "-.-
wat if teacher found out tt our cct is the same. haha.
do ur guy noe how to write the report? who ur teacher ar?

 

[thefinalaeon]

me frm class 24 lol

 

[infinity.o3]

die sia. tis coming monday i ned to hand up tis project. n i hv nt the report. hv ur do?
i onli noe tt our class is the last class to enrol to tp. LOL.

 

[majorabak]

hey all frm etcm rite? haiz ept SO SIANZ :'(

 

[infinity.o3]

when is ur date line?

i nt from etcm.
last wk term test. math ur noe how to do?

 

[infinity.o3]

hey, can i replace LM719 to LM7805?? plz reply. thx. =))

 

[thefinalaeon]

maths can pass la... so easy paper but no time... sian... antes, can we replace 7905 with 7805 and 7915 to 7815? please reply thanks alot

 

[timothy1]

Hi everyone!Base on what the teacher had teached,the 78series is for positive volt.For example 7815 is positive 15 volt.Therefore,79 series is for negative volt.For example 7905 is negative 5 volt.So you have to change the voltage regulator.Then i thinking that the Zener diode can be remove since it is to prevent getting inverse voltage.Er...anybody has a better idea?

 

[majorabak]

heyz manz... i dun tink need zener diode... but i tink muz connect the gnd pin of teh -5V regulator to the 0V wire and the input of teh -5V regulator to the output of the -15V regulator... tat is what i tink lah but i may be wrong... the nthe output of ur -5V regulator is ur -5V output supply lorz... i still dunno where to c0onnect extra capacitors for the -5V regulator... ai yah i not sure lah... n also r the c5 n c6 capacitors electrolytic capacitors too?
WAH SUPER STRESS LIAOZ SOMEONE HELP PLZ

 

[SM2GXN]

Hi!

You guys should have started a bit earlier with your EPT project  :

 

[Luffy1]

The function of the diode is to provide only 1 pave for current flow. Since the voltage after a step down from the transformer is AC, the diode is essential to change this AC voltage to DC voltage.

To have a better idea
The graph of the output voltage after step down is actually a sine curve. After passing through the diode, the resultant graph will be a sine curve w/o the negative/positive (depends on direction of diode) part of the curve. So it is necessary to have the present of diode to convert AC voltage to pusalting DC voltage

Aids your research
To get better idea of the concept of a triple output power supply, i suggest that you break up the research into different part.

We noe that a power supply needs
- Transformer to step down AC voltage from the power unit to the required amount
- Retifier to convert AC voltage to pulsating DC voltage
- Filter to convert this pulsating voltage to pure DC voltage
- Voltage regulator to direct the desire output voltage

So it is better that you guyz search through the net to get ideas of these sector. After understanding the function of

 

[infinity.o3]

it ez. but i did nt complete my test. "-.-
i nv even touch on the last question.  :'(

whr is all the pro ppl ar?
y left sg ppl here?

 

[POOH]

hey all..finished wif ur projects?i'm still very confused...so wad if we need capacitor but how do we  how much farad or volt to use...can dun use transformer...ahhh.......stress....

 

[sianz]

hey do u have any idea on where is the -5v position?pretty blurred....

 

[BabyPrince]

helloo...
Cn any1 juz summarise the whole ting..?

 

[howly]

wah...sianz...so many parts..see liao oso blur. if not for that 10%(EPT)....