Which fuse, from attached figure, will blow first?

• Feb 13, 2005

• #1

E

E=MC2

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current flow

i have a question about the figure i have attatched

consider that the power is turned on simultaneously on both the circuits of Fig 1 and Fig 2. which fuse will blow first??

i think that both the fuses will blow at the same time. am i right?

 

• Feb 13, 2005

• #2

I

IanP

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Re: current flow

You are right ..
As far as current is concerned both circuits are identical ..

 

• Feb 13, 2005

• #3

P

platonas

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Re: current flow

Yes, always yes since current living the one side of the source is entering the other side. The same is for AC supply.

 

• Feb 13, 2005

• #4

B

bader

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Re: current flow

it dos not matter where you put the fuse because current flow in closed loop

 

• Feb 13, 2005

• #5

flatulent

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Re: current flow

In a real world circuit some portion of the circuit will be connected to the cabinet or other item the user can touch. It is always desirable to place the fuse in the power lead that is not so connected. That way when the fuse blows the absent minded human (who thinks that a blown fuse removes the power from the circuitry) can touch the circuitry without becoming part of the circuit.

Never make this assumption about disconnected power. Remove the primary power source by the line cord being removed from the wall outlet before opening the cabinet and touching the parts.

 

• Feb 14, 2005

• #6

C

cesare

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Re: current flow

As they are designed the two circuits are fully isolated (the two returns are isolated). In this situation which fuse blows first is a matter of tolarances.

It will blow first the fuse that has the higher internal resistance and higher power dissipation

 

• Feb 16, 2005

• #7

K

kukitron

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Re: current flow

All depends on the characteristics of each fuse,

Some has a smaller reacting time, and of course a higher price,

1 AMp does not tell much,

 

• Feb 16, 2005

• #8

T

trigger74

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current flow

yeap. The time is depended on the fuse properties.

Also, typical application circuit will put fuses on the positive voltage side or Live for AC voltages.

It is because to prevent another current path flow and prevent electric shock for AC voltages.

 

• Feb 19, 2005

• #9

H_u_n_t_e_r

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current flow

fuse should be on positive side because system can get its ground from earth so ground leg will be bypassed then circuit will be damage!

 

• Feb 19, 2005

• #10

A

aster

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Re: current flow

As the figur uses DC power source and
as the current direction is from positive to negative side, the fuse must be on the positive side. Regarding safety both in AC and DC sources fuse must be placed at the
first outlet point.

 

• Feb 20, 2005

• #11

E

electron_boy

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Re: current flow

if both the fuses are identical they are likely to fail simultaneously

 

• Feb 20, 2005

• #12

S

sabari

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current flow

both fuses glow at same time because it is a ac supply it doesnt matter fuse on what side it is

 

• Feb 20, 2005

• #13

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lsrama

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current flow

yes you are right.because as current is concern both circuits are same

 

• Feb 25, 2005

• #14

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komi

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Re: current flow

Im suggesting you that always use(learn first) some of not so complex technic for analysis ... Ist and IInd Kirhof rules ... its big step for begining but...

Most of simple cases have some trick, but in this case, only important thing:current it have same value in both cases... result its that both of fuses will be blow in same time ...