how to purify DC totally without AC?

[johncsl82]

lm7805c

hi...

well I mearsure the 4 x 1.5V AA everday super heavy battery with digital multimeter:

1. when I switch it to DCV 200 mode it show 05.8

2. when I switch it to ACV 200 mode it show 12.2

3. sorry I don't have oscillator therefore i don't know the frequency

I need 1000uf capacitor or other alternative?

Thanks

 

[Borber]

What do you want at all. It seems that you are not familliar with basics.

 

[johncsl82]

just pure DC without the AC in it....

Thanks

 

[Borber]

Batteries have pure DC. If your load current have high AC component some AC voltage can appear on batteries voltage because of it's internal Resistance. Place 1mF across batteries to lower AC voltage on batteries.

If you want to measure AC voltage on batteries place appropriate capacitor in series with your multimeter and use AC voltage range. Multimeter without a capacitor in series on AC range allso measure DC and your measurement is wrong.

If you are measuring voltage on batteries without a load it is pure DC.

 

[johncsl82]

The reason I'm asking about getting pure DC is cause my PIC microcontroller get heat very fast and hot, moreover I fried few of those PIC already...........


Thanks

 

[Borber]

You are probably looking at the wrong side.

 

[hermin]

well, if your pic is getting hot fast, try to check on how you connect your pic, inputs, outputs, things like that. Because AC alone does not heat your pic, but the current entering your pic, either ac or dc. If there are any objections, feel free to correct my opinion.

 

[VSMVDD]

Hi

the problem you have is pic needs 5v only !!!
6 v is no good most cells produce 1.75 or more
so 4x 1.75 = 5.75
too high and will make the chip run hot
better to look for a pc power supply AT style
then has a power switch
also gives exact 5v

only use red and black wire

i did this to my pc

in the square where there is a badge i place a cigar lighter socket from a car

also i placed a power socket onto the front
i protected the 5v socket with 2 amp fuse
the 12v i just take 2 amps also so a 2 amp fuse

problem for small projects now is solved for you

and forget your batteries

reason is ac is same as dc *1.404 to deal with sine wave peeks

so ac and dc meter will read this differance
as dc is still a voltage so ac meter will still read
meter is stupid buy a cheep digital meter
or if you have money n expensive one

hey ,,, even build one with your pic...mcu

 

[johncsl82]

lastest update:

ok, this time I put 5V DC regulator(LM7805C - V) when i switch on the PIC microcontroller, the regulator heat up as if can cook an egg then later come the PIC microcontroller turn to heat up......

link to my schematic : **broken link removed**

Thanks

 

[johncsl82]

Project fixed and issue resolved

VDD -> (+)

VSS -> (-)



Thank to all who help me solve the problem

Thank you very much

P.S: Mod please close the post, thank you very much