Switch and diode

Nescafe

New Member

• May 20, 2014

• #1

Hi, can someone confirm that the schematic below will work safely?

Thank You.

 

Attachments

• Switch.jpg

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dougy83

Well-Known Member

Most Helpful Member

• May 20, 2014

• #2

Your simple diode-OR configuration looks fine to me. I assume the diode forward voltage drop won't affect the triggering of the relay driver C and that there is a pulldown on the relay drivers already (or that they don't require a pull-down).

 

Nescafe

New Member

• May 20, 2014

• #3

Thank You dougy83, the relay driver is ON Semi NUD3112 or NUD3105 and it have pull down R embedded, diode is 1N4004 and the drop voltage is low enough for driver VGS treshold. I'm worrying about current flow loop, maybe I'm paranoid

 

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dougy83

Well-Known Member

Most Helpful Member

• May 20, 2014

• #4

Nescafe said:

I'm worrying about current flow loop

Click to expand...

What (or where) is that?

 

Nescafe

New Member

• May 21, 2014

• #5

dougy83 said:

What (or where) is that?

Click to expand...

When both switch is on and one of the diode is not right (leakage current), do I need to worry about that?

 

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dougy83

Well-Known Member

Most Helpful Member

• May 21, 2014

• #6

When both switches are on, there is no leakage current to worry about.

 

Nescafe

New Member

• May 21, 2014

• #7

ahahaha......my bad, I mean when one switch is on....., do this circuit is safe as using "OR" logic gate?

 

alec_t

Well-Known Member

Most Helpful Member

• May 21, 2014

• #8

this circuit is safe as using "OR" logic gate?

Click to expand...

The 'safety' is probably similar. A diode failing open or short circuit would result in false operation; but so would failure of a logic gate.

 

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eTech

Well-Known Member

• May 21, 2014

• #9

Nescafe said:

Hi, can someone confirm that the schematic below will work safely?

Thank You.

Click to expand...

Hi

What do you mean by safely?

Is it going to control something that can potentially cause bodily harm if it fails?

eT

 

Nescafe

New Member

• May 21, 2014

• #10

Hi,
this is for audio device, so no body will harm, and by safe I mean is the possibility for the diode to fail compare to the logic considering the diode will directly connect to VCC (big current).

 

alec_t

Well-Known Member

Most Helpful Member

• May 21, 2014

• #11

But the logic circuit also "will directly connect to VCC (big current)". I don't understand your concern.

 

Nescafe

New Member

• May 21, 2014

• #12

Then the risk is the same whatever I use, so nevermind.
Thank You everybody.