Why different rectifier diode voltage ratings?
 

Another question resulting from too much time on my hands. Why do we
have rectifier diodes (e.g. 1N4xxx, 1N54xx) with different voltage
ratings? Other than the voltage rating I don't see any differences on
the data sheets I've looked at. Why not just make and use 1kv diodes
alone?

73,
Mike, KK6GM

Lower voltage rectifiers are easier to make and therefore cheaper. Further,
they have lower forward drop and are faster. No point in using too high a
rating if these other factors are worth considering.

Lower voltage rectifiers are easier to make and therefore cheaper. Further,
they have lower forward drop and are faster. No point in using too high a
rating if these other factors are worth considering.

the funnie this is that the $$$ diference is not seen at the costumers end.

do you realy care the the diode is 3 Cents more (making a 100$ project)from
the low votalge one.......(some stores some cases)

73's


--
http://www.qsl.net/sv1hao
"Bob" wrote in message
...
Lower voltage rectifiers are easier to make and therefore cheaper.
Further,
they have lower forward drop and are faster. No point in using too high a
rating if these other factors are worth considering.

the funnie this is that the $$$ diference is not seen at the costumers end.

do you realy care the the diode is 3 Cents more (making a 100$ project)from
the low votalge one.......(some stores some cases)

73's


--
http://www.qsl.net/sv1hao
"Bob" wrote in message
...
Lower voltage rectifiers are easier to make and therefore cheaper.
Further,
they have lower forward drop and are faster. No point in using too high a
rating if these other factors are worth considering.

the funnie this is that the $$$ diference is not seen at the costumers end.

do you realy care the the diode is 3 Cents more (making a 100$ project)from
the low votalge one.......(some stores some cases)

You might be surprised.

In fact, cost reduction is a *big* issue in the manufacture of many
(most?) consumer electronic products.

Look at it this way: if you save three cents on a single part, of
which only one is used in a $100 device... and you manufacture a
million of these devices per year... then you've saved $30,000 per
year. That's not chump-change.

If you can save $.03 per part, and you use ten of these parts per
device, and you manufacture a million units per year - then you've
just saved $300,000, which will cover the cost (salary and overhead)
of at least one good engineer.

Yes, my friend, big electronics companies _do_ care - a lot - about
shaving the pennies out of the bill-of-materials cost of the devices
they manufacture.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

the funnie this is that the $$$ diference is not seen at the costumers end.

do you realy care the the diode is 3 Cents more (making a 100$ project)from
the low votalge one.......(some stores some cases)

You might be surprised.

In fact, cost reduction is a *big* issue in the manufacture of many
(most?) consumer electronic products.

Look at it this way: if you save three cents on a single part, of
which only one is used in a $100 device... and you manufacture a
million of these devices per year... then you've saved $30,000 per
year. That's not chump-change.

If you can save $.03 per part, and you use ten of these parts per
device, and you manufacture a million units per year - then you've
just saved $300,000, which will cover the cost (salary and overhead)
of at least one good engineer.

Yes, my friend, big electronics companies _do_ care - a lot - about
shaving the pennies out of the bill-of-materials cost of the devices
they manufacture.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

Deos wrote:
the PROBLEM it that none of us own a big Company.
so it's better to stock up the shack with the best

Except that there's no one diode that is "the best" for everything,
and so you need more than one type of diode in your junk box.

--
Mike Andrews

Tired old sysadmin since 1964

Deos wrote:
the PROBLEM it that none of us own a big Company.
so it's better to stock up the shack with the best

Except that there's no one diode that is "the best" for everything,
and so you need more than one type of diode in your junk box.

--
Mike Andrews

Tired old sysadmin since 1964

the PROBLEM it that none of us own a big Company.
so it's better to stock up the shack with the best

I hate to be the one to break the news to you but the diode mfg
doesn't really care much about the 10 diodes you are going to buy -)
They are going to mfg what the big company wants to buy.

the PROBLEM it that none of us own a big Company.
so it's better to stock up the shack with the best

I hate to be the one to break the news to you but the diode mfg
doesn't really care much about the 10 diodes you are going to buy -)
They are going to mfg what the big company wants to buy.

On Wed, 3 Sep 2003 10:39:33 -0700, "Bob"
wrote:

Lower voltage rectifiers are easier to make and therefore cheaper. Further,
they have lower forward drop and are faster. No point in using too high a
rating if these other factors are worth considering.

While the 1 kV 1N4007 is definitely a different creature (with some
PIN diode characteristics) compared to the lower voltage 1N4001-1N4006
rectifiers, I very much doubt that they make separate wafers for
1N4001, 1N4002 etc. but instead try to make, say a 500 V rectifier.

My guess is that they just measure the reverse leakage voltage at
various voltages and print a different label, based on these
measurements. Those passing only the 50 V test will be labelled 1N4001
and sold at a slightly lower price and so on.

If there is a huge order for 1N4001 and there is not enough 50 V units
produced, some units tested OK for 100-500 V are labelled 1N4001 to
full fill the large order. Thus, some selected 1N4001 parts may work
even above 100 V.

Paul OH3LWR

On Wed, 3 Sep 2003 10:39:33 -0700, "Bob"
wrote:

Lower voltage rectifiers are easier to make and therefore cheaper. Further,
they have lower forward drop and are faster. No point in using too high a
rating if these other factors are worth considering.

While the 1 kV 1N4007 is definitely a different creature (with some
PIN diode characteristics) compared to the lower voltage 1N4001-1N4006
rectifiers, I very much doubt that they make separate wafers for
1N4001, 1N4002 etc. but instead try to make, say a 500 V rectifier.

My guess is that they just measure the reverse leakage voltage at
various voltages and print a different label, based on these
measurements. Those passing only the 50 V test will be labelled 1N4001
and sold at a slightly lower price and so on.

If there is a huge order for 1N4001 and there is not enough 50 V units
produced, some units tested OK for 100-500 V are labelled 1N4001 to
full fill the large order. Thus, some selected 1N4001 parts may work
even above 100 V.

Paul OH3LWR

Dick Carroll; wrote:

W7TI wrote:

On 3 Sep 2003 10:13:00 -0700, (Mike Silva) wrote:

Another question resulting from too much time on my hands. Why do we
have rectifier diodes (e.g. 1N4xxx, 1N54xx) with different voltage
ratings? Other than the voltage rating I don't see any differences on
the data sheets I've looked at. Why not just make and use 1kv diodes
alone?

73,
Mike, KK6GM

__________________________________________________ _______

$$$

--
Bill, W7TI

Yep. And I'd wager if one did breakdown tests on a variety of diodes many would show the
same specs regardless of their different markings.

Another pet peeve-
Several times I've seen failure of low voltage capacitors which were run too close to
their ratings for comfort, IMO. Like 16 vdc rated on a 13.8 DC line in mobile gear.
Spikes are sure to take 'em out eventually, it would seem. Why designers do that I've
never understood, and I never replace them as rated, but use 25 or 30 volt caps. Never had
a problem from doing that, and no repeats.
I remember years ago troubleshooting a dead board in an Atlas 210 transciever that had a
shorted - leaky 16 volt rated electrolytic across a 13.8 dc line on the board. But it
still had enough internal resistance that it didn't smoke anything, just killed the
operation of the board.

I cussed the (unknown) designer of that thing for awhile! /:-D))

Dick,

Electrolytics should be run near their rated voltage to "form" properly.
The spikes should be taken out by a parallel 100nF cap, or clipped by a
zener.

Rob

Dick Carroll; wrote:

W7TI wrote:

On 3 Sep 2003 10:13:00 -0700, (Mike Silva) wrote:

Another question resulting from too much time on my hands. Why do we
have rectifier diodes (e.g. 1N4xxx, 1N54xx) with different voltage
ratings? Other than the voltage rating I don't see any differences on
the data sheets I've looked at. Why not just make and use 1kv diodes
alone?

73,
Mike, KK6GM

__________________________________________________ _______

$$$

--
Bill, W7TI

Yep. And I'd wager if one did breakdown tests on a variety of diodes many would show the
same specs regardless of their different markings.

Another pet peeve-
Several times I've seen failure of low voltage capacitors which were run too close to
their ratings for comfort, IMO. Like 16 vdc rated on a 13.8 DC line in mobile gear.
Spikes are sure to take 'em out eventually, it would seem. Why designers do that I've
never understood, and I never replace them as rated, but use 25 or 30 volt caps. Never had
a problem from doing that, and no repeats.
I remember years ago troubleshooting a dead board in an Atlas 210 transciever that had a
shorted - leaky 16 volt rated electrolytic across a 13.8 dc line on the board. But it
still had enough internal resistance that it didn't smoke anything, just killed the
operation of the board.

I cussed the (unknown) designer of that thing for awhile! /:-D))

Dick,

Electrolytics should be run near their rated voltage to "form" properly.
The spikes should be taken out by a parallel 100nF cap, or clipped by a
zener.

Rob

Other than the voltage rating I don't see any differences on
the data sheets I've looked at. Why not just make and use 1kv diodes
alone?

=================================

Because somebody like you would complain about no 2kv diodes being
available.

Other than the voltage rating I don't see any differences on
the data sheets I've looked at. Why not just make and use 1kv diodes
alone?

=================================

Because somebody like you would complain about no 2kv diodes being
available.

"Reg Edwards" wrote in message ...
Other than the voltage rating I don't see any differences on
the data sheets I've looked at. Why not just make and use 1kv diodes
alone?

=================================

Because somebody like you would complain about no 2kv diodes being
available.

Like me in what way? Curious? Uninformed? Ignorant? Whipped with
extension cords as a child? Raised by circus performers? Eats
mayonnaise out of the jar when depressed?

Come to think of it, why the heck *aren't* there any 2kv diodes
available?!

And how come I can't buy air-variables for a buck down at the corner
electronics store?!

73,
Mike, KK6GM

"Reg Edwards" wrote in message ...
Other than the voltage rating I don't see any differences on
the data sheets I've looked at. Why not just make and use 1kv diodes
alone?

=================================

Because somebody like you would complain about no 2kv diodes being
available.

Like me in what way? Curious? Uninformed? Ignorant? Whipped with
extension cords as a child? Raised by circus performers? Eats
mayonnaise out of the jar when depressed?

Come to think of it, why the heck *aren't* there any 2kv diodes
available?!

And how come I can't buy air-variables for a buck down at the corner
electronics store?!

73,
Mike, KK6GM

Like me in what way? Curious? Uninformed? Ignorant? Whipped with
extension cords as a child? Raised by circus performers? Eats
mayonnaise out of the jar when depressed?

=====================================
Mike, you and I have much in common. I really do sympathise. Pleased to
make your acquaintance.
---
Reg, G4FGQ

Like me in what way? Curious? Uninformed? Ignorant? Whipped with
extension cords as a child? Raised by circus performers? Eats
mayonnaise out of the jar when depressed?

=====================================
Mike, you and I have much in common. I really do sympathise. Pleased to
make your acquaintance.
---
Reg, G4FGQ