Diode Question

[Neil Thier]

Hi,

I've looked around online and couldn't find answers to these questions.
(if anyone has a really good online electronics resource please
point me there)

Does the capacity of a circuit affect the type of diode to be used?
I've got a small circuit (3V, 400mA) and found the limited information
on the diode packaging at the store to be confusing. I bought one that
says '100.0V, 1W"'. Is this to large for my circuit?

Also, is it possible to blow a diode?

Thanks,
Neil

 

[Dan Hollands]

The 100V is the max reverse voltage the diode can stand, The 1W is the max
power it can dissipate when conducting

You can blow out a diode with either excessive reverse voltage or to much
forward current.

100V 1W should be ok for the application you describe.

Dan


--
Dan Hollands
1104 State Road
Webster NY 14580
585-703-2963
QuickScore@USSailing.net
www.QuickScoreRace.com
"Neil Thier" <pleasespamme@aol.com> wrote in message
news:vUbXa.144863$hV.9431079@twister.austin.rr.com...

Hi,

I've looked around online and couldn't find answers to these questions.
(if anyone has a really good online electronics resource please
point me there)

Does the capacity of a circuit affect the type of diode to be used?
I've got a small circuit (3V, 400mA) and found the limited information
on the diode packaging at the store to be confusing. I bought one that
says '100.0V, 1W"'. Is this to large for my circuit?

Also, is it possible to blow a diode?

Thanks,
Neil

 

[scada]

"Neil Thier" <pleasespamme@aol.com> wrote in message
news:vUbXa.144863$hV.9431079@twister.austin.rr.com...

Hi,

I've looked around online and couldn't find answers to these questions.
(if anyone has a really good online electronics resource please
point me there)

Does the capacity of a circuit affect the type of diode to be used?
I've got a small circuit (3V, 400mA) and found the limited information
on the diode packaging at the store to be confusing. I bought one that
says '100.0V, 1W"'. Is this to large for my circuit?

Also, is it possible to blow a diode?

Thanks,
Neil

It sounds as if you bought a Zener Diode! Zeners are rated in Voltage and
Power. They are used to regulate voltage, not to Rectify. You need a
Rectifier Diode, that will be rated in PIV(Peak Inverse Voltage) and
current! Buy one of the IN4000 series diodes. 1N4001 will work for you (50V
@ 1A). The Diode voltage and current rating should be higher than the rating
of your circuit (3V @ 400ma).

 

[Brian Lund]

Does the capacity of a circuit affect the type of diode to be used?
I've got a small circuit (3V, 400mA) and found the limited information
on the diode packaging at the store to be confusing. I bought one that
says '100.0V, 1W"'. Is this to large for my circuit?

If it is a regular diode, no it is not to large, and it can not be too
large!

Also, is it possible to blow a diode?

Yes, actually if this diode you bought is a regular diode it might very well
blow!
Your circuit uses 3V * 0,4A = 1,2W which is a little more than the diode is
rated at.

Alternatively you can try and look for a number on the diode and either
search google or post the number here, maybe we can tell you if it is a
regular or some other sort of diode.


Brian Lund

 

[Eric Immel]

Brian Lund wrote:

Neil Thier wrote:
Does the capacity of a circuit affect the type of diode to be
I've got a small circuit (3V, 400mA) and found the limited information
on the diode packaging at the store to be confusing. I bought one that
says '100.0V, 1W"'. Is this to large for my circuit?

Generally speaking (especially with power supplies), bigger is better,
or at least not worse. Some components, a fuse for example, must be
replaced with the exact specified value.

Also, is it possible to blow a diode?

Any component will fail if it is subjected to conditions beyond its
rated capacity.

Your circuit uses 3V * 0,4A = 1,2W
[Excellent suggestion excised]
Brian Lund

The power dissipated by the *load* is 1.2W. The diode will dissipate
0.7V*0.4A=0.28W. The diode will be quite happy. You should solder it in
so that it sits off of the board a little bit to allow air to flow
underneath it. With even moderate airflow, it will probably run pretty cool.

EI

 

[Brian Lund]

Your circuit uses 3V * 0,4A = 1,2W
[Excellent suggestion excised]
Brian Lund

The power dissipated by the *load* is 1.2W. The diode will dissipate
0.7V*0.4A=0.28W. The diode will be quite happy. You should solder it in
so that it sits off of the board a little bit to allow air to flow
underneath it. With even moderate airflow, it will probably run pretty
cool.

Oh yeah... I must have been sleepy


Brian Lund