Can anyone please confirm this is valid?

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bigal_scorpio

Active Member

• Nov 14, 2008

• #1

Hi to all,

I was just hoping someone could verify this circuit.

It is designed to output PWM on pin 3, but having built it 3 times I am beginning to wonder if its OK, as I said I have made it 3 times on Veroboard all to no avail.

Thanks for looking............Al

 

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Last edited: Nov 14, 2008

picasm

Member

• Nov 14, 2008

• #2

It looks like there is no means of discharging the capacitor in that circuit.

Try one of these designs - they use pin3 to charge/discharge the capacitor.

Pulse Width Modulation 2

**broken link removed**

 

K

kchriste

New Member

Forum Supporter

• Nov 14, 2008

• #3

There is a mistake in the schematic. Here is the fixed version:

 

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bigal_scorpio

Active Member

• Nov 15, 2008

• #4

Sorted!

Hi to both of you,

Thanks guys, thats got it cracked!

Now I can get on with the PWM project for She who must be obeyed!

Thanks again..........Al

 

P

picbits

Well-Known Member

• Nov 15, 2008

• #5

You're making your wife a PWM controller for her Iron for her Christmas Present ?

 

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bigal_scorpio

Active Member

• Nov 17, 2008

• #6

picbits said:

You're making your wife a PWM controller for her Iron for her Christmas Present ?

Click to expand...

Hi Picbits,

Hehehe, now thats an idea!

But seriously she wanted some LED lighting in a glass fronted cabinet and couldn't make up her mind what colour she wanted, so I just made her an adjustable RGB one. Three pots and she can now have any colour she likes!

Now I can get back to my projects without that funny whining noise. hehehe

Al