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0.47 vs 0.5 ohm resistor

Cesari0

Cesari0

Active Member
Hi everyone.
I have been looking around for the answer to this question, but for some reason I haven't found it.

So here it goes, I won't make it long.
I'm working on a project.
The emitter resistors are 0.47ohm 5w.
I would like to know if I could get away with using 0.5ohm 5w resistors.

So it's 0.47 vs 0.5 ohm.

Any input will be greatly appreciated.
 
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Yes. Adjust the bias after, it may be a smidge off. .47 to .5 isn't much of a difference.

Next question is, are the .5 ohm resistors the same type as the 4.7 ohm?

Rob
 
Robisme said:
Yes. Adjust the bias after, it may be a smidge off. .47 to .5 isn't much of a difference.

Next question is, are the .5 ohm resistors the same type as the 4.7 ohm?

Rob
Click to expand...
Thanks for the informative reply.
Yeah I'm planning to get 5w non-inductive resistors.
The reason why I asked was cause it appears to me that 0.5 Ohm 5w non-inductive resistors are more common.

Much appreciated.
 
Even at 1% tolerance, your 0.47 resistor would be in the range of 0.423 - 0.517.

It's possible your new 0.5 could measure closer to 0.47 than your old 0.47.

It will be fine.
 
50 Green said:
But what type are you replacing? If it's a plate resistor (commonly used for emitter resistors), 5W, 0.47 ohm are readily available.
Click to expand...

I have seen the plate resistors, unfortunately the space is pretty tight, crowded board on both sides.
The emitter resistors needs to be elevated off the board, for spatial and air circulation purpose.
 
Cesari0 said:
I have seen the plate resistors, unfortunately the space is pretty tight, crowded board on both sides.
The emitter resistors needs to be elevated off the board, for spatial and air circulation purpose.
Click to expand...
You haven't answered the question: What type of resistor are you replacing??
Can you post a picture? Or is this project something you're building from scratch?

If it's something you're building and it calls for 0.47 ohm emitter resistors, it is most likely calling for plate resistors. They do not take up a lot of board room because they stand off the board, perpendicular to it, and are usually stood off a quarter to half an inch, for cooling.

This is the resistor I would use (and have used.) Ignore the image on the listing. It's an oddly proportioned cutaway view and does not show how the resistor actually looks.

This is how they actually look. (This one is 0.1 ohm, but 0.47 looks similar. Pins can be straight or bent.)
3542688-40.jpg
 
Last edited:
willyrover said:
Even at 1% tolerance, your 0.47 resistor would be in the range of 0.423 - 0.517.

It's possible your new 0.5 could measure closer to 0.47 than your old 0.47.

It will be fine.
Click to expand...
I think that 1 % of 0.47 ohms is 0.047 ohms, so plus and minus 1% takes you from 0.4653 to 0.4747 ohms. You did your calculation using 10%. But I agree, it should not make any difference in the circuit.
 
Only trick here, if your setup has you set the bias by measuring voltage across the emitter resistor, make sure you re-calculate that for the different resistor value.
 
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