Need to understand how optocoupler work

[Test]

I am trying figure out how an optocoupler
(http://pdf1.alldatasheet.com/datasheet-pdf/view/2847/MOTOROLA/4N29.html) works.

Is optocoupler similar to a solid state relay?

What should happen if I apply current going thru pins 1->2? Should resistance
drop to zero between 5 and 4?

My goal is to use LPT port to switch stuff on and off. I have a couple ways to
achive this but I want try what works. I want to learn new stuff.

 

[Jasen Betts]

On 2008-09-25, Test <test@> wrote:

I am trying figure out how an optocoupler
(http://pdf1.alldatasheet.com/datasheet-pdf/view/2847/MOTOROLA/4N29.html) works.

Is optocoupler similar to a solid state relay?

yes, but they operate at much lower output-side power than typical
solid-state relays.

What should happen if I apply current going thru pins 1->2? Should resistance
drop to zero between 5 and 4?

close to zero, for small currents.

My goal is to use LPT port to switch stuff on and off.
I have a couple ways to
achive this but I want try what works. I want to learn new stuff.

depending on the stuff an optocoupler may be suitable.

Bye.
Jasen

 

[John Fields]

On Thu, 25 Sep 2008 11:35:06 +0300, Test <test@.nil.invalid.com> wrote:

I am trying figure out how an optocoupler
(http://pdf1.alldatasheet.com/datasheet-pdf/view/2847/MOTOROLA/4N29.html) works.

Is optocoupler similar to a solid state relay?

---
Similar, but not the same.
---

What should happen if I apply current going thru pins 1->2? Should resistance
drop to zero between 5 and 4?

---
The resistance will decrease, but it'll never get to zero.

Take a look at Figure 6 on:

http://www.fairchildsemi.com/ds/4N/4N29M.pdf
---

My goal is to use LPT port to switch stuff on and off. I have a couple ways to
achive this but I want try what works. I want to learn new stuff.

---
Commendable.

JF

 

[Eeyore]

John Fields wrote:

On Thu, 25 Sep 2008 11:35:06 +0300, Test <test@.nil.invalid.com> wrote:

I am trying figure out how an optocoupler
(http://pdf1.alldatasheet.com/datasheet-pdf/view/2847/MOTOROLA/4N29.html) works.

Is optocoupler similar to a solid state relay?

---
Similar, but not the same.
---

What should happen if I apply current going thru pins 1->2? Should resistance
drop to zero between 5 and 4?

---
The resistance will decrease, but it'll never get to zero.

Take a look at Figure 6 on:

http://www.fairchildsemi.com/ds/4N/4N29M.pdf
---

Perhaps worth mentioing that you can also get optocouplers with triac, resisitve, fet
and logic outputs.

Graham

 

[John Fields]

On Thu, 25 Sep 2008 17:58:31 +0100, Eeyore
<rabbitsfriendsandrelations@hotmail.com> wrote:

John Fields wrote:

On Thu, 25 Sep 2008 11:35:06 +0300, Test <test@.nil.invalid.com> wrote:

I am trying figure out how an optocoupler
(http://pdf1.alldatasheet.com/datasheet-pdf/view/2847/MOTOROLA/4N29.html) works.

Is optocoupler similar to a solid state relay?

---
Similar, but not the same.
---

What should happen if I apply current going thru pins 1->2? Should resistance
drop to zero between 5 and 4?

---
The resistance will decrease, but it'll never get to zero.

Take a look at Figure 6 on:

http://www.fairchildsemi.com/ds/4N/4N29M.pdf
---

Perhaps worth mentioing that you can also get optocouplers with triac, resisitve, fet
and logic outputs.

---
Why confuse him with too much information?

He asked a specific question and got a specific answer.

End of story.

JF

 

[Eeyore]

John Fields wrote:

Eeyore wrote:
John Fields wrote:

On Thu, 25 Sep 2008 11:35:06 +0300, Test <test@.nil.invalid.com> wrote:

I am trying figure out how an optocoupler
(http://pdf1.alldatasheet.com/datasheet-pdf/view/2847/MOTOROLA/4N29.html) works.

Is optocoupler similar to a solid state relay?

---
Similar, but not the same.
---

What should happen if I apply current going thru pins 1->2? Should resistance
drop to zero between 5 and 4?

---
The resistance will decrease, but it'll never get to zero.

Take a look at Figure 6 on:

http://www.fairchildsemi.com/ds/4N/4N29M.pdf
---

Perhaps worth mentioing that you can also get optocouplers with triac, resisitve, fet
and logic outputs.

---
Why confuse him with too much information?

That wasn't the intention but since he was talking of the output *resistance* I thought it
valid to mention resistive output and fet types (and the others for good measure).

Graham

 

[John Fields]

On Fri, 26 Sep 2008 02:58:05 +0100, Eeyore
<rabbitsfriendsandrelations@hotmail.com> wrote:

John Fields wrote:

Eeyore wrote:
John Fields wrote:

On Thu, 25 Sep 2008 11:35:06 +0300, Test <test@.nil.invalid.com> wrote:

I am trying figure out how an optocoupler
(http://pdf1.alldatasheet.com/datasheet-pdf/view/2847/MOTOROLA/4N29.html) works.

Is optocoupler similar to a solid state relay?

---
Similar, but not the same.
---

What should happen if I apply current going thru pins 1->2? Should resistance
drop to zero between 5 and 4?

---
The resistance will decrease, but it'll never get to zero.

Take a look at Figure 6 on:

http://www.fairchildsemi.com/ds/4N/4N29M.pdf
---

Perhaps worth mentioing that you can also get optocouplers with triac, resisitve, fet
and logic outputs.

---
Why confuse him with too much information?

That wasn't the intention but since he was talking of the output *resistance* I thought it
valid to mention resistive output and fet types (and the others for good measure).

---
What a crock of shit.

All you were really interested in was, as usual, posting irrelevance for
the purpose of attracting attention.

JF