Experimenting means there will be casualties :-)

A

AK

Guest
This is part of a previous post. Thought I would start a new thread.

"https://blog.prayogindia.in/make-laser-light-security-alarm/"

The directions are poor as hell as is his pictures.

His schematic shows a 6.8 K resistor, but no where is it mentioned in his assembly directions. (I think the author should be drawn and quartered.)

When I hooked it up the first time using a 100 ohm resistor, the bc 547 started smoking.

The alarm and led did light up for a short time. :)

I hooked it up a different way using the 330 ohm resistor.

It did not smoke but also did not work.

I am glad I ordered multiple quantities of parts.

I am waiting on parts for another design that uses a 555 timer IC.

"https://makezine.com/projects/laser-tripwire-alarm/"

Andy
 
On 5/4/2019 2:22 PM, AK wrote:
This is part of a previous post. Thought I would start a new thread.

"https://blog.prayogindia.in/make-laser-light-security-alarm/"

The directions are poor as hell as is his pictures.

His schematic shows a 6.8 K resistor, but no where is it mentioned in his assembly directions. (I think the author should be drawn and quartered.)

When I hooked it up the first time using a 100 ohm resistor, the bc 547 started smoking.

The alarm and led did light up for a short time. :)

I hooked it up a different way using the 330 ohm resistor.

It did not smoke but also did not work.

I am glad I ordered multiple quantities of parts.

I am waiting on parts for another design that uses a 555 timer IC.

"https://makezine.com/projects/laser-tripwire-alarm/"

Andy

I don't understand that circuit.
He talks about a BC547 and then shows 2N7000 in the schematic.
He goes on to do a poor job of showing the connections to the laser.
It should be two separate circuits.
The first one is your laser, a resistor and the battery.
The second would look something like the circuits here.
> https://www.google.com/search?client=firefox-b-1-d&q=LDR+on+base+of+transistor

I suggest you build one of these, the first one should be fine.
Shown here,
https://www.build-electronic-circuits.com/ldr-circuit-diagram/
Replace the LED with your buzzer.

Mikek
 
On Sat, 4 May 2019 12:22:43 -0700 (PDT), AK <scientist77017@gmail.com>
wrote:

This is part of a previous post. Thought I would start a new thread.

"https://blog.prayogindia.in/make-laser-light-security-alarm/"

The directions are poor as hell as is his pictures.

His schematic shows a 6.8 K resistor, but no where is it mentioned in his assembly directions. (I think the author should be drawn and quartered.)

When I hooked it up the first time using a 100 ohm resistor, the bc 547 started smoking.

The alarm and led did light up for a short time. :)

I hooked it up a different way using the 330 ohm resistor.

It did not smoke but also did not work.

I am glad I ordered multiple quantities of parts.

I am waiting on parts for another design that uses a 555 timer IC.

"https://makezine.com/projects/laser-tripwire-alarm/"

Andy

Can you show a picture of what you've connected?

What are you using for a supply voltage?

The 2N7000 is a N channel field effect transistor and the BC547 is a
bipolar transistor (if I understand it). Those aren't exactly
interchangeable parts.

Bipolar transistors start conducting with a specific current in the
base to emitter junction and a voltage of ~.6 volts. (Point six
volts) Mosfets will start conducting at ~2-4 volts with no current
flow to speak of. Different animals...

Don't get discouraged, it takes a degree of patience and perseverance
to learn electronics by building things. You will fail, but if you
learn from the failures they aren't really failures. Book-learning
can help.
 
On Friday, May 10, 2019 at 12:35:09 PM UTC-5, default wrote:
On Sat, 4 May 2019 12:22:43 -0700 (PDT), AK <scientist77017@gmail.com
wrote:

This is part of a previous post. Thought I would start a new thread.

"https://blog.prayogindia.in/make-laser-light-security-alarm/"

The directions are poor as hell as is his pictures.

His schematic shows a 6.8 K resistor, but no where is it mentioned in his assembly directions. (I think the author should be drawn and quartered.)

When I hooked it up the first time using a 100 ohm resistor, the bc 547 started smoking.

The alarm and led did light up for a short time. :)

I hooked it up a different way using the 330 ohm resistor.

It did not smoke but also did not work.

I am glad I ordered multiple quantities of parts.

I am waiting on parts for another design that uses a 555 timer IC.

"https://makezine.com/projects/laser-tripwire-alarm/"

Andy

Can you show a picture of what you've connected?

What are you using for a supply voltage?

The 2N7000 is a N channel field effect transistor and the BC547 is a
bipolar transistor (if I understand it). Those aren't exactly
interchangeable parts.

Bipolar transistors start conducting with a specific current in the
base to emitter junction and a voltage of ~.6 volts. (Point six
volts) Mosfets will start conducting at ~2-4 volts with no current
flow to speak of. Different animals...

Don't get discouraged, it takes a degree of patience and perseverance
to learn electronics by building things. You will fail, but if you
learn from the failures they aren't really failures. Book-learning
can help.

I found a better documented project.

https://makezine.com/projects/laser-tripwire-alarm/
 
Mistakes enlarge your knowledge.
Successes enlarge only your pride.

AK a Êcrit le 04/05/2019 à 21:22 :
This is part of a previous post. Thought I would start a new thread.

"https://blog.prayogindia.in/make-laser-light-security-alarm/"

The directions are poor as hell as is his pictures.

His schematic shows a 6.8 K resistor, but no where is it mentioned in his assembly directions. (I think the author should be drawn and quartered.)

When I hooked it up the first time using a 100 ohm resistor, the bc 547 started smoking.

The alarm and led did light up for a short time. :)

I hooked it up a different way using the 330 ohm resistor.

It did not smoke but also did not work.

I am glad I ordered multiple quantities of parts.

I am waiting on parts for another design that uses a 555 timer IC.

"https://makezine.com/projects/laser-tripwire-alarm/"

Andy
 
On 5/10/2019 12:52 PM, AK wrote:
On Friday, May 10, 2019 at 12:35:09 PM UTC-5, default wrote:
On Sat, 4 May 2019 12:22:43 -0700 (PDT), AK <scientist77017@gmail.com
wrote:

This is part of a previous post. Thought I would start a new thread.

"https://blog.prayogindia.in/make-laser-light-security-alarm/"

The directions are poor as hell as is his pictures.

His schematic shows a 6.8 K resistor, but no where is it mentioned in his assembly directions. (I think the author should be drawn and quartered.)

When I hooked it up the first time using a 100 ohm resistor, the bc 547 started smoking.

The alarm and led did light up for a short time. :)

I hooked it up a different way using the 330 ohm resistor.

It did not smoke but also did not work.

I am glad I ordered multiple quantities of parts.

I am waiting on parts for another design that uses a 555 timer IC.

"https://makezine.com/projects/laser-tripwire-alarm/"

Andy

Can you show a picture of what you've connected?

What are you using for a supply voltage?

The 2N7000 is a N channel field effect transistor and the BC547 is a
bipolar transistor (if I understand it). Those aren't exactly
interchangeable parts.

Bipolar transistors start conducting with a specific current in the
base to emitter junction and a voltage of ~.6 volts. (Point six
volts) Mosfets will start conducting at ~2-4 volts with no current
flow to speak of. Different animals...

Don't get discouraged, it takes a degree of patience and perseverance
to learn electronics by building things. You will fail, but if you
learn from the failures they aren't really failures. Book-learning
can help.

I found a better documented project.

https://makezine.com/projects/laser-tripwire-alarm/
But you already have the parts for the circuits I posted.
Why not put it together.
Mikek
 
On Friday, May 10, 2019 at 2:52:09 PM UTC-5, amdx wrote:
On 5/10/2019 12:52 PM, AK wrote:
On Friday, May 10, 2019 at 12:35:09 PM UTC-5, default wrote:
On Sat, 4 May 2019 12:22:43 -0700 (PDT), AK <scientist77017@gmail.com
wrote:

This is part of a previous post. Thought I would start a new thread.

"https://blog.prayogindia.in/make-laser-light-security-alarm/"

The directions are poor as hell as is his pictures.

His schematic shows a 6.8 K resistor, but no where is it mentioned in his assembly directions. (I think the author should be drawn and quartered.)

When I hooked it up the first time using a 100 ohm resistor, the bc 547 started smoking.

The alarm and led did light up for a short time. :)

I hooked it up a different way using the 330 ohm resistor.

It did not smoke but also did not work.

I am glad I ordered multiple quantities of parts.

I am waiting on parts for another design that uses a 555 timer IC.

"https://makezine.com/projects/laser-tripwire-alarm/"

Andy

Can you show a picture of what you've connected?

What are you using for a supply voltage?

The 2N7000 is a N channel field effect transistor and the BC547 is a
bipolar transistor (if I understand it). Those aren't exactly
interchangeable parts.

Bipolar transistors start conducting with a specific current in the
base to emitter junction and a voltage of ~.6 volts. (Point six
volts) Mosfets will start conducting at ~2-4 volts with no current
flow to speak of. Different animals...

Don't get discouraged, it takes a degree of patience and perseverance
to learn electronics by building things. You will fail, but if you
learn from the failures they aren't really failures. Book-learning
can help.

I found a better documented project.

https://makezine.com/projects/laser-tripwire-alarm/

But you already have the parts for the circuits I posted.
Why not put it together.
Mikek

I do not have a potentiometer.

Andy
 
On 5/10/2019 3:44 PM, AK wrote:
On Friday, May 10, 2019 at 2:52:09 PM UTC-5, amdx wrote:
On 5/10/2019 12:52 PM, AK wrote:
On Friday, May 10, 2019 at 12:35:09 PM UTC-5, default wrote:
On Sat, 4 May 2019 12:22:43 -0700 (PDT), AK <scientist77017@gmail.com
wrote:

This is part of a previous post. Thought I would start a new thread.

"https://blog.prayogindia.in/make-laser-light-security-alarm/"

The directions are poor as hell as is his pictures.

His schematic shows a 6.8 K resistor, but no where is it mentioned in his assembly directions. (I think the author should be drawn and quartered.)

When I hooked it up the first time using a 100 ohm resistor, the bc 547 started smoking.

The alarm and led did light up for a short time. :)

I hooked it up a different way using the 330 ohm resistor.

It did not smoke but also did not work.

I am glad I ordered multiple quantities of parts.

I am waiting on parts for another design that uses a 555 timer IC.

"https://makezine.com/projects/laser-tripwire-alarm/"

Andy

Can you show a picture of what you've connected?

What are you using for a supply voltage?

The 2N7000 is a N channel field effect transistor and the BC547 is a
bipolar transistor (if I understand it). Those aren't exactly
interchangeable parts.

Bipolar transistors start conducting with a specific current in the
base to emitter junction and a voltage of ~.6 volts. (Point six
volts) Mosfets will start conducting at ~2-4 volts with no current
flow to speak of. Different animals...

Don't get discouraged, it takes a degree of patience and perseverance
to learn electronics by building things. You will fail, but if you
learn from the failures they aren't really failures. Book-learning
can help.

I found a better documented project.

https://makezine.com/projects/laser-tripwire-alarm/

But you already have the parts for the circuits I posted.
Why not put it together.
Mikek

I do not have a potentiometer.

Andy
You can substitute a resistor for the potentiometer.
But I note the circuit is probably backwards from what you want.
https://www.build-electronic-circuits.com/ldr-circuit-diagram/
This circuit will turn on the buzzer when light hits the LDR.
I suspect you want the Buzzer to turn on when the laser beam is broken.
So, reverse the positions of potentiometer and the LDR.
For clearity we will label the resistor R1.
Now, when there is no light on the LDR it has a high resistance, this
means there is less voltage drop across R1. Because there is less
voltage drop, the voltage on the base of the transistor is high and it
conducts causing you buzzer to buzz.
With light on the LDR it has a low resistance, lots of current flows
through R1 and it has a high voltage drop. So much that the transistor
is off and the buzzer does not buzz.
Remember this is with the R1 and the potentiometer reversed.

If you build it and it doesn't work, give me the base voltage with and
without light on the LDR. You might even give me the voltage, dark, with
ambient light and with the laser shining on the LDR.
Mikek
 
On Friday, May 10, 2019 at 4:44:15 PM UTC-4, AK wrote:
On Friday, May 10, 2019 at 2:52:09 PM UTC-5, amdx wrote:
On 5/10/2019 12:52 PM, AK wrote:
On Friday, May 10, 2019 at 12:35:09 PM UTC-5, default wrote:
On Sat, 4 May 2019 12:22:43 -0700 (PDT), AK <scientist77017@gmail.com
wrote:

This is part of a previous post. Thought I would start a new thread.

"https://blog.prayogindia.in/make-laser-light-security-alarm/"

The directions are poor as hell as is his pictures.

His schematic shows a 6.8 K resistor, but no where is it mentioned in his assembly directions. (I think the author should be drawn and quartered.)

When I hooked it up the first time using a 100 ohm resistor, the bc 547 started smoking.

The alarm and led did light up for a short time. :)

I hooked it up a different way using the 330 ohm resistor.

It did not smoke but also did not work.

I am glad I ordered multiple quantities of parts.

I am waiting on parts for another design that uses a 555 timer IC.

"https://makezine.com/projects/laser-tripwire-alarm/"

Andy

Can you show a picture of what you've connected?

What are you using for a supply voltage?

The 2N7000 is a N channel field effect transistor and the BC547 is a
bipolar transistor (if I understand it). Those aren't exactly
interchangeable parts.

Bipolar transistors start conducting with a specific current in the
base to emitter junction and a voltage of ~.6 volts. (Point six
volts) Mosfets will start conducting at ~2-4 volts with no current
flow to speak of. Different animals...

Don't get discouraged, it takes a degree of patience and perseverance
to learn electronics by building things. You will fail, but if you
learn from the failures they aren't really failures. Book-learning
can help.

I found a better documented project.

https://makezine.com/projects/laser-tripwire-alarm/

But you already have the parts for the circuits I posted.
Why not put it together.
Mikek

I do not have a potentiometer.

Andy

Do you have any electronics books? For a beginner I'm
going to suggest "Practical Electronics for Inventors"
If you don't buy the latest edition, it's only $5-10.
With lotsa good stuff.

George H.
 
On Sat, 11 May 2019 03:09:04 -0700 (PDT), Andy
<andrewkennedy775@gmail.com> wrote:

>Thanks, i will look for it.

It is available for download as a bit torrent file too. (if you use
torrents)

The magnet link:

magnet:?xt=urn:btih:7912823298f185188593ec36404b15e73fde50db&dn=Practical+Electronics+for+Inventors+provides+step-by-step+instru&tr=udp%3A%2F%2Ftracker.leechers-paradise.org%3A6969&tr=udp%3A%2F%2Ftracker.openbittorrent.com%3A80&tr=udp%3A%2F%2Fopen.demonii.com%3A1337&tr=udp%3A%2F%2Ftracker.coppersurfer.tk%3A6969&tr=udp%3A%2F%2Fexodus.desync.com%3A6969
 
On Saturday, May 11, 2019 at 7:29:34 AM UTC-5, default wrote:
On Sat, 11 May 2019 03:09:04 -0700 (PDT), Andy
andrewkennedy775@gmail.com> wrote:

Thanks, i will look for it.

It is available for download as a bit torrent file too. (if you use
torrents)

The magnet link:

magnet:?xt=urn:btih:7912823298f185188593ec36404b15e73fde50db&dn=Practical+Electronics+for+Inventors+provides+step-by-step+instru&tr=udp%3A%2F%2Ftracker.leechers-paradise.org%3A6969&tr=udp%3A%2F%2Ftracker.openbittorrent.com%3A80&tr=udp%3A%2F%2Fopen.demonii.com%3A1337&tr=udp%3A%2F%2Ftracker.coppersurfer.tk%3A6969&tr=udp%3A%2F%2Fexodus.desync.com%3A6969

Thanks a lot. I am reading it now.

Andy
 
On Fri, 10 May 2019 13:35:04 -0400, default wrote:

The 2N7000 is a N channel field effect transistor and the BC547 is a
bipolar transistor (if I understand it). Those aren't exactly
interchangeable parts.

Not even *remotely* interchangeable!!




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On 04/05/2019 20:22, AK wrote:
This is part of a previous post. Thought I would start a new thread.

"https://blog.prayogindia.in/make-laser-light-security-alarm/"

The directions are poor as hell as is his pictures.

Hi Andy,

Firstly, please continue to ask questions, and surf around finding
interesting websites of projects.

Be slightly aware though, that a lot of websites (especially from the
less IT switched on parts of the world) are mostly set up to make their
operators money, or get them recognised as "employable" by their peers.

The information shared is often junk regurgitated from content other
folks that have shared.

A very worthwhile source of tutorials

http://www.fcctests.com/neets/Neets.htm

or google "Getting Started in Electronics by Forrest M. Mims III"

Seriously, I'd buy a copy. If I had the last book as a kid, I would
have been a very different kid.

( Apologies if you are not a kid.)

--
Adrian C
 
On Sunday, May 12, 2019 at 3:49:00 PM UTC-5, Adrian Caspersz wrote:
On 04/05/2019 20:22, AK wrote:
This is part of a previous post. Thought I would start a new thread.

"https://blog.prayogindia.in/make-laser-light-security-alarm/"

The directions are poor as hell as is his pictures.


Hi Andy,

Firstly, please continue to ask questions, and surf around finding
interesting websites of projects.

Be slightly aware though, that a lot of websites (especially from the
less IT switched on parts of the world) are mostly set up to make their
operators money, or get them recognised as "employable" by their peers.

The information shared is often junk regurgitated from content other
folks that have shared.

A very worthwhile source of tutorials

http://www.fcctests.com/neets/Neets.htm

or google "Getting Started in Electronics by Forrest M. Mims III"

Seriously, I'd buy a copy. If I had the last book as a kid, I would
have been a very different kid.

( Apologies if you are not a kid.)

--
Adrian C


Thanks.

I am a kid in an adult body. :)

Andy
 
On 12/05/2019 23:02, AK wrote:
On Sunday, May 12, 2019 at 3:49:00 PM UTC-5, Adrian Caspersz wrote:

or google "Getting Started in Electronics by Forrest M. Mims III"

Seriously, I'd buy a copy. If I had the last book as a kid, I would
have been a very different kid.

( Apologies if you are not a kid.)

--
Adrian C

Thanks.

I am a kid in an adult body. :)


Ain't we all :)

--
Adrian C
 

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