can Zenner 5 V1 to replace 4.3 V diodes????

[Mylinux]

http://main.linuxfocus.org/English/May2002/article236.shtml

see the component list.

I do not have 4.3 V but 5V1.

help, please.

 

[Ken Taylor]

You have the zener diode in back-to-front.

Ken

"Mylinux" <myLinux@My.com> wrote in message
news:bjn1ct$mee1@imsp212.netvigator.com...

Robert Lacoste <rlacoste@alciom.com> wrote in message
news:3f5ef306$0$20946$7a628cd7@news.club-internet.fr...
No, it won't work (the power supply is 5V and the zener is there to
detect
a
lower voltage...). My guess is that anything between 3.9 and 4.3V will
work,
but not 5.1...
Robert


I measure the 5V1( becuase it is marked ) via a digital multimeter is
0.636
V. Is there something wrong with this component?

however

I have four other diodes
a. 0.659 V
b. 0.658 V
c. 0641 V
d. 0.659 V

I may guess they are the same group.


which side is positive in circuit and actual component?

my guess is
on circuit
+ve is non -"twisted" bar side
on component
+ve is non flat-bar side




"Mylinux" <myLinux@My.com> a écrit dans le message de
news:bjmokb$e3710@imsp212.netvigator.com...
http://main.linuxfocus.org/English/May2002/article236.shtml

see the component list.

I do not have 4.3 V but 5V1.

help, please.

 

[Robert Lacoste]

No, it won't work (the power supply is 5V and the zener is there to detect a
lower voltage...). My guess is that anything between 3.9 and 4.3V will work,
but not 5.1...
Robert

"Mylinux" <myLinux@My.com> a écrit dans le message de
news:bjmokb$e3710@imsp212.netvigator.com...

http://main.linuxfocus.org/English/May2002/article236.shtml

see the component list.

I do not have 4.3 V but 5V1.

help, please.

 

[Mylinux]

Robert Lacoste <rlacoste@alciom.com> wrote in message
news:3f5ef306$0$20946$7a628cd7@news.club-internet.fr...

No, it won't work (the power supply is 5V and the zener is there to detect
a
lower voltage...). My guess is that anything between 3.9 and 4.3V will
work,
but not 5.1...
Robert

I measure the 5V1( becuase it is marked ) via a digital multimeter is 0.636
V. Is there something wrong with this component?

however

I have four other diodes
a. 0.659 V
b. 0.658 V
c. 0641 V
d. 0.659 V

I may guess they are the same group.


which side is positive in circuit and actual component?

my guess is
on circuit
+ve is non -"twisted" bar side
on component
+ve is non flat-bar side

"Mylinux" <myLinux@My.com> a écrit dans le message de
news:bjmokb$e3710@imsp212.netvigator.com...
http://main.linuxfocus.org/English/May2002/article236.shtml

see the component list.

I do not have 4.3 V but 5V1.

help, please.

 

[Mylinux]

Ken Taylor <ken@co.nz> wrote in message
news:bjn281$9l5$1@perki.connect.com.au...

You have the zener diode in back-to-front.

I mixed up the "back to front" , the multimeter will not show a voltage.

Ken

"Mylinux" <myLinux@My.com> wrote in message
news:bjn1ct$mee1@imsp212.netvigator.com...

Robert Lacoste <rlacoste@alciom.com> wrote in message
news:3f5ef306$0$20946$7a628cd7@news.club-internet.fr...
No, it won't work (the power supply is 5V and the zener is there to
detect
a
lower voltage...). My guess is that anything between 3.9 and 4.3V will
work,
but not 5.1...
Robert


I measure the 5V1( becuase it is marked ) via a digital multimeter is
0.636
V. Is there something wrong with this component?

however

I have four other diodes
a. 0.659 V
b. 0.658 V
c. 0641 V
d. 0.659 V

I may guess they are the same group.


which side is positive in circuit and actual component?

my guess is
on circuit
+ve is non -"twisted" bar side
on component
+ve is non flat-bar side




"Mylinux" <myLinux@My.com> a écrit dans le message de
news:bjmokb$e3710@imsp212.netvigator.com...
http://main.linuxfocus.org/English/May2002/article236.shtml

see the component list.

I do not have 4.3 V but 5V1.

help, please.

 

[CWatters]

I could only see that zenner in the brown-out circuit. A brown out circuit
is used to detect very brief partial power failures (eg where the supply
voltage falls from 5V to say 4.5V rather than all the way to 0V). Most
applications don't bother to detect this kind of brief power failure and
they use a simpler RC circuit on the Reset pin. Perhaps you don't need such
high reliability either? If not check the data sheet for the AT90S4433P and
see what circuit they recommend for the Reset pin.

Or..

If you had a lot of small signal diodes (like the 1N4148 or 1N4149) you
could use a lot in series instead of one zenner. eg 6 would give approx 6 x
0.65 = 4V which is close enough. Remember though that ordinary diodes would
need to be used the other way round eg "pointing down" rather than "pointing
up".

Colin

"Mylinux" <myLinux@My.com> wrote in message
news:bjmokb$e3710@imsp212.netvigator.com...

http://main.linuxfocus.org/English/May2002/article236.shtml

see the component list.

I do not have 4.3 V but 5V1.

help, please.

 

[Mylinux]

CWatters <colin.watters@pandora.be> wrote in message
news:TIE7b.12238$Js7.434294@phobos.telenet-ops.be...

I could only see that zenner in the brown-out circuit. A brown out circuit
is used to detect very brief partial power failures (eg where the supply
voltage falls from 5V to say 4.5V rather than all the way to 0V). Most
applications don't bother to detect this kind of brief power failure and
they use a simpler RC circuit on the Reset pin. Perhaps you don't need
such
high reliability either? If not check the data sheet for the AT90S4433P
and
see what circuit they recommend for the Reset pin.

Or..

If you had a lot of small signal diodes (like the 1N4148 or 1N4149) you
could use a lot in series instead of one zenner. eg 6 would give approx 6
x
0.65 = 4V which is close enough. Remember though that ordinary diodes
would
need to be used the other way round eg "pointing down" rather than
"pointing
up".

Colin

http://members.tripod.com/RoBoJRR/basics.htm


I always prefer this url epecially for diodes, my class mate told me zenner
diodes are just opposite direction for cathode and anode.

"Mylinux" <myLinux@My.com> wrote in message
news:bjmokb$e3710@imsp212.netvigator.com...
http://main.linuxfocus.org/English/May2002/article236.shtml

see the component list.

I do not have 4.3 V but 5V1.

help, please.

 

[Harry Bloomfield]

In article <bjn1ct$mee1@imsp212.netvigator.com>, myLinux@My.com says...
| I measure the 5V1( becuase it is marked ) via a digital multimeter is 0.636
| V. Is there something wrong with this component?
|
| however
|
| I have four other diodes
| a. 0.659 V
| b. 0.658 V
| c. 0641 V
| d. 0.659 V
|
|

You are measuring them the wrong way and you can't check the zenor
point just with a multi meter... You need to set it up in a circuit
with (for instance) a

12 v supply -1k resistor- zenor - ground
Then measure the DC voltage across the zenor diode.
--
Regards,
Harry (M1BYT)...

Remove the 'NOSPAM' in my email address to reply.

Free Amateur Radio Courses:-
http://www.ukradioamateur.org

 

[Harry Bloomfield]

In article <bjmokb$e3710@imsp212.netvigator.com>, myLinux@My.com
says...
| see the component list.
|
| I do not have 4.3 V but 5V1.
|
| help, please.
|
|

A 5v1 zenor will not work. 4v3 is about the ideal voltage (4.3 + 0.6
for the transistor junction = 4v9), just a touch lower than the 5v
supply, so it will detect the first droop of the 5v from a power loss.


--
Regards,
Harry (M1BYT)...

Remove the 'NOSPAM' in my email address to reply.

Free Amateur Radio Courses:-
http://www.ukradioamateur.org

 

[JeffM]

diodes are just opposite direction for cathode and
anode.
Mylinux

What you should have said is that
a zener is used in the reverse-bias mode.
Its avalanche knee voltage is much greater
than its 0.6V forward-bias knee.
| /
| /
| /
| /
-----==========-----
/ |+0.6V
/ |
/ -5V |
/ |

http://images.google.com/images?hl=en&lr=lang_en&ie=UTF-8&oe=UTF-8&q=diode+curve+northpark&btnG=Google+Search
(1st figure. Cached; original link is 404)