Chip with simple program for Toy

On 10/07/2011 07:13 AM, Dave wrote:
"Phil Hobbs"<pcdhSpamMeSenseless@electrooptical.net> wrote in message
news:4E8EDB7A.3060309@electrooptical.net...
On 10/07/2011 06:36 AM, Dave wrote:
As per my post in SEB, I am trying to use a photo resistor and sunlight
to
turn off a transistor that would otherwise be conducting like crazy, but
can't quite make the leap of comprehension as to how to actually do this.
Please see attached schematic parts that show more or less what I am
trying
to do this with. No part number for the photoresistor, sorry. It drops
from multi-megohms in the dark to single-digit Ohms in the light and
seems
perfectly capable of carrying the 30 to 50 mA current I am working with
at
the voltages indicated. Would really appreciate it if someone could
offer a
hint as to how I should proceed with as few components as possible (small
circuit board.) I hope that my method of posting the schematic portion
of
what I a working with is not too obtuse. Couldn't figure out any other
way
to do it...

Many thanks...

Dave




You're wasting a gross amount of current in that bias network. How about
a nice MOSFET?

Say a 2N7002, source to V-, drain to series resistor+LED, LDR plus pot to
set turn-on level:

(V+)----*----------------*
| |
| R
| R
| R
| R
*---* |
| | ---
| R \ / -----
*-> R ----- -----
R |
R | | D
| | |---*
| | |<--; 2N7000
*----------J |---*
| | | S
| |
L |
D |
R |
| |
| |
(V-)----*----------------*





Oh, man. Something to WORK with. THANK YOU! Much appreciated...

Dave
Click to expand...
De nada. If you're planning to use that circuit for real, you might
want an 0.1 uF cap from gate to source. That'll make it less twitchy
and less vulnerable to electrostatic discharge.

Cheers

Phil Hobbs


--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510
845-480-2058

hobbs at electrooptical dot net
http://electrooptical.net
 
"Phil Hobbs" <pcdhSpamMeSenseless@electrooptical.net> wrote in message
news:4E8EE1CA.10306@electrooptical.net...
On 10/07/2011 07:13 AM, Dave wrote:
"Phil Hobbs"<pcdhSpamMeSenseless@electrooptical.net> wrote in message
news:4E8EDB7A.3060309@electrooptical.net...
On 10/07/2011 06:36 AM, Dave wrote:
As per my post in SEB, I am trying to use a photo resistor and sunlight
to
turn off a transistor that would otherwise be conducting like crazy,
but
can't quite make the leap of comprehension as to how to actually do
this.
Please see attached schematic parts that show more or less what I am
trying
to do this with. No part number for the photoresistor, sorry. It
drops
from multi-megohms in the dark to single-digit Ohms in the light and
seems
perfectly capable of carrying the 30 to 50 mA current I am working with
at
the voltages indicated. Would really appreciate it if someone could
offer a
hint as to how I should proceed with as few components as possible
(small
circuit board.) I hope that my method of posting the schematic portion
of
what I a working with is not too obtuse. Couldn't figure out any other
way
to do it...

Many thanks...

Dave




You're wasting a gross amount of current in that bias network. How
about
a nice MOSFET?

Say a 2N7002, source to V-, drain to series resistor+LED, LDR plus pot
to
set turn-on level:

(V+)----*----------------*
| |
| R
| R
| R
| R
*---* |
| | ---
| R \ / -----
*-> R ----- -----
R |
R | | D
| | |---*
| | |<--; 2N7000
*----------J |---*
| | | S
| |
L |
D |
R |
| |
| |
(V-)----*----------------*





Oh, man. Something to WORK with. THANK YOU! Much appreciated...

Dave



De nada. If you're planning to use that circuit for real, you might
want an 0.1 uF cap from gate to source. That'll make it less twitchy and
less vulnerable to electrostatic discharge.

Cheers

Phil Hobbs


--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510
845-480-2058

hobbs at electrooptical dot net
http://electrooptical.net
Click to expand...
Gotcha. Thanks again.

D
 
On Fri, 07 Oct 2011 07:26:02 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

On 10/07/2011 07:13 AM, Dave wrote:
"Phil Hobbs"<pcdhSpamMeSenseless@electrooptical.net> wrote in message
news:4E8EDB7A.3060309@electrooptical.net...
On 10/07/2011 06:36 AM, Dave wrote:
As per my post in SEB, I am trying to use a photo resistor and sunlight
to
turn off a transistor that would otherwise be conducting like crazy, but
can't quite make the leap of comprehension as to how to actually do this.
Please see attached schematic parts that show more or less what I am
trying
to do this with. No part number for the photoresistor, sorry. It drops
from multi-megohms in the dark to single-digit Ohms in the light and
seems
perfectly capable of carrying the 30 to 50 mA current I am working with
at
the voltages indicated. Would really appreciate it if someone could
offer a
hint as to how I should proceed with as few components as possible (small
circuit board.) I hope that my method of posting the schematic portion
of
what I a working with is not too obtuse. Couldn't figure out any other
way
to do it...

Many thanks...

Dave




You're wasting a gross amount of current in that bias network. How about
a nice MOSFET?

Say a 2N7002, source to V-, drain to series resistor+LED, LDR plus pot to
set turn-on level:

(V+)----*----------------*
| |
| R
| R
| R
| R
*---* |
| | ---
| R \ / -----
*-> R ----- -----
R |
R | | D
| | |---*
| | |<--; 2N7000
*----------J |---*
| | | S
| |
L |
D |
R |
| |
| |
(V-)----*----------------*





Oh, man. Something to WORK with. THANK YOU! Much appreciated...

Dave



De nada. If you're planning to use that circuit for real, you might
want an 0.1 uF cap from gate to source. That'll make it less twitchy
and less vulnerable to electrostatic discharge.
Click to expand...

Phil has already answered the hard part but for the posting schematics
part, try either AACircuit or LTSpice.

AACircuit is available over at <http://www.tech-chat.de/aacircuit.html>
A rendering of your right-hand snippet would look like (view with a
fixed-pitch font):

2N3904
V- o-------o--------- ----------.
| ^ / |
| --- |
| | .-.
.-. | | |
| | | | | 160
120 | | | '-'
'-' | |
| | |
| | |
o----------' |
| |
| |
| |
.-. -
| | ^ ->
680 | | |
'-' | NTE 30045
| |
| |
V+ o-------o----------------------'
(created by AACircuit v1.28.6 beta 04/19/05 www.tech-chat.de)

Stylized but understandable -- and easier than trying to do it in a text
editor or Usenet client's window.


LTSpice is one of several free apps provided by Linear Technology
<http://www.linear.com/designtools/software/> It is a full Spice
simulator but it's also used around here to pass the schematics as ASCII
netlists.

AACircuit is typically best for small snippets, and nice since they are
directly viewable. LTSpice for the larger layouts.

Version 4
SHEET 1 880 680
WIRE 128 -32 -16 -32
WIRE 208 -32 128 -32
WIRE 384 -32 304 -32
WIRE 128 48 128 -32
WIRE 384 48 384 -32
WIRE 128 160 128 128
WIRE 256 160 256 32
WIRE 256 160 128 160
WIRE 128 192 128 160
WIRE 384 208 384 128
WIRE 128 336 128 272
WIRE 128 336 -16 336
WIRE 384 336 384 272
WIRE 384 336 128 336
SYMBOL res 112 32 R0
SYMATTR InstName R1
SYMATTR Value 120
SYMBOL res 112 176 R0
SYMATTR InstName R2
SYMATTR Value 680
SYMBOL res 368 32 R0
SYMATTR InstName R3
SYMATTR Value 160
SYMBOL npn 304 32 M270
SYMATTR InstName Q1
SYMATTR Value 2N3904
SYMBOL LED 400 272 R180
WINDOW 0 24 64 Left 2
WINDOW 3 24 0 Left 2
SYMATTR InstName D1
TEXT -56 -32 Left 2 ;V-
TEXT -64 336 Left 2 ;V+

--
Rich Webb Norfolk, VA
 
On Fri, 07 Oct 2011 06:59:06 -0400, Phil Hobbs wrote:

On 10/07/2011 06:36 AM, Dave wrote:
As per my post in SEB, I am trying to use a photo resistor and sunlight
to turn off a transistor that would otherwise be conducting like crazy,
but can't quite make the leap of comprehension as to how to actually do
this. Please see attached schematic parts that show more or less what I
am trying to do this with. No part number for the photoresistor,
sorry. It drops from multi-megohms in the dark to single-digit Ohms in
the light and seems perfectly capable of carrying the 30 to 50 mA
current I am working with at the voltages indicated. Would really
appreciate it if someone could offer a hint as to how I should proceed
with as few components as possible (small circuit board.) I hope that
my method of posting the schematic portion of what I a working with is
not too obtuse. Couldn't figure out any other way to do it...

Many thanks...

Dave




You're wasting a gross amount of current in that bias network. How
about a nice MOSFET?

Say a 2N7002, source to V-, drain to series resistor+LED, LDR plus pot
to set turn-on level:

(V+)----*----------------*
| |
| R
| R
| R
| R
*---* |
| | ---
| R \ / -----
*-> R ----- -----
R |
R | | D
| | |---*
| | |<--; 2N7000
*----------J |---*
| | | S
| |
L |
D |
R |
| |
| |
(V-)----*----------------*
Click to expand...
I couldn't find the original post, but if you're driving 20mA to an LED
you should only need a mA (at most!) into the base of a BJT. So you
could almost use Dr Hobbs's circuit above with an NPN, or use something
like



V+ o----------------o------------.
| |
| |
.-. .-.
| | R2 | | R5
| | | |
'-' '-'
| |
| |
.---------o |
| | |
| | V ->
| .-. -
| | | R3 | D1
| | | |
| '-' |
| | |
| | |/
| o----------| Q1
| | |>
| | |
.-. .-. |
~> | | R1 | | R4 |
~> | | | | |
'-' '-' |
| | |
| | |
| | |
V- o -----o---------o------------'
(created by AACircuit v1.28.6 beta 04/19/05 www.tech-chat.de)

Set up R2 and R3 to bias the transistor on, with R4 to lend a bit of
authority pulling the base down. When R1 starts to conduct the junction
of R2 and R3 doesn't have to get all the way down to 0.6V in order to
turn Q1 off fully.

Come to think of it, you could do this all with a jelly-bean comparator,
and add some hysteresis to boot. Then D1 would snap on and off, instead
of shivering on and shivering off as the light changes.

--
www.wescottdesign.com
 
On Fri, 07 Oct 2011 07:26:02 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

On 10/07/2011 07:13 AM, Dave wrote:
"Phil Hobbs"<pcdhSpamMeSenseless@electrooptical.net> wrote in message
news:4E8EDB7A.3060309@electrooptical.net...
On 10/07/2011 06:36 AM, Dave wrote:
As per my post in SEB, I am trying to use a photo resistor and sunlight
to
turn off a transistor that would otherwise be conducting like crazy, but
can't quite make the leap of comprehension as to how to actually do this.
Please see attached schematic parts that show more or less what I am
trying
to do this with. No part number for the photoresistor, sorry. It drops
from multi-megohms in the dark to single-digit Ohms in the light and
seems
perfectly capable of carrying the 30 to 50 mA current I am working with
at
the voltages indicated. Would really appreciate it if someone could
offer a
hint as to how I should proceed with as few components as possible (small
circuit board.) I hope that my method of posting the schematic portion
of
what I a working with is not too obtuse. Couldn't figure out any other
way
to do it...

Many thanks...

Dave




You're wasting a gross amount of current in that bias network. How about
a nice MOSFET?
Click to expand...
I've seen LDRs fry from too much light+current. I humbly suggest


Say a 2N7002, source to V-, drain to series resistor+LED, LDR plus pot to
set turn-on level:

(V+)----*----------------*
| |
R R
R R
R R
| R
*---* |
| | ---
| R \ / -----
*-> R ----- -----
R |
R | | D
| | |---*
| | |<--; 2N7000
*----------J |---*
| | | S
| |
L |
D |
R |
| |
| |
(V-)----*----------------*
Click to expand...
John
 
On 10/08/2011 06:06 PM, John Larkin wrote:
On Fri, 07 Oct 2011 07:26:02 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 10/07/2011 07:13 AM, Dave wrote:
"Phil Hobbs"<pcdhSpamMeSenseless@electrooptical.net> wrote in message
news:4E8EDB7A.3060309@electrooptical.net...
On 10/07/2011 06:36 AM, Dave wrote:
As per my post in SEB, I am trying to use a photo resistor and sunlight
to
turn off a transistor that would otherwise be conducting like crazy, but
can't quite make the leap of comprehension as to how to actually do this.
Please see attached schematic parts that show more or less what I am
trying
to do this with. No part number for the photoresistor, sorry. It drops
from multi-megohms in the dark to single-digit Ohms in the light and
seems
perfectly capable of carrying the 30 to 50 mA current I am working with
at
the voltages indicated. Would really appreciate it if someone could
offer a
hint as to how I should proceed with as few components as possible (small
circuit board.) I hope that my method of posting the schematic portion
of
what I a working with is not too obtuse. Couldn't figure out any other
way
to do it...

Many thanks...

Dave




You're wasting a gross amount of current in that bias network. How about
a nice MOSFET?


I've seen LDRs fry from too much light+current. I humbly suggest


Say a 2N7002, source to V-, drain to series resistor+LED, LDR plus pot to
set turn-on level:

(V+)----*----------------*
| |
R R
R R
R R
| R
*---* |
| | ---
| R \ / -----
*-> R ----- -----
R |
R | | D
| | |---*
| | |<--; 2N7000
*----------J |---*
| | | S
| |
L |
D |
R |
| |
| |
(V-)----*----------------*




John
Click to expand...
I haven't seen one fry itself on a 5V supply, but I suppose it's
possible. The extra resistor is good insurance, for sure.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510
845-480-2058

hobbs at electrooptical dot net
http://electrooptical.net
 
On Sat, 08 Oct 2011 15:06:56 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

I've seen LDRs fry from too much light+current. I humbly suggest
Click to expand...
I've done that... cobbled together a circuit with zero calculating
and it worked like a champ- until summer came then direct sunlight was
enough to lower the resistance and raise the ambient and poof no more
LDR.
 
<default> wrote in message
news:0h4397ljcuo6b42glbasa32v10qudh2qfi@4ax.com...
On Sat, 08 Oct 2011 15:06:56 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

I've seen LDRs fry from too much light+current. I humbly suggest

I've done that... cobbled together a circuit with zero calculating
and it worked like a champ- until summer came then direct sunlight was
enough to lower the resistance and raise the ambient and poof no more
LDR.
Click to expand...
Your LDR turned into a poof?!
 
On 6 oct, 21:40, JeffM <jef...@email.com> wrote:

At this rate, you might even open a closed mind.  :cool:
Click to expand...
:-D
There quite a work behind all that. A few months ago, someone very
kind checked very carefully the french manual and corrected a lot of
typos. Another person analyzed the code and helped a lot to fix a very
tricky bug. Others are working on the libraries of symbols. BTW, the
German and Spanish translations of the user interface should be
checked and revised, so if someone is interested... :)
Animating on a open source software is a very interesting human
adventure.

Randall is a treasure. I hope he lives forever.
Click to expand...
http://www.xkcd.com/730/

So, you've already given some thought to the issue.
Click to expand...
Of course I did :)

"Niche" would be my word.
If ones' needs fit the niche, the app is instantly useful.
Click to expand...
In some sort, FidoCadJ is a niche application, and part of this niche
is inherited from its ancestor speaking only in Italian. Now it is
much easier to share a picture in a newsletter message or a forum
post, but drawing quickly this picture can still be a problem. This
explains the enthusiasm gathered when FidoCadJ has been adopted in
2010 by the community of one of the portals I cited above. I have to
say that this enthusiasm was rather unexpected for me!
So I think FidoCadJ is still useful. I personally use it in my
professional activity to draw schematics in documents and books. The
library of symbols is sufficiently complete for my needs and this
makes FidoCadJ better for that purpose than a generic vector-based
editor. Much more powerful EDA softwares are not written for doing
that and the graphic rendering (for example a screen capture) is often
unsatisfactory. If what it can be done with FidoCadJ is not enough, I
export to SVN and I know I can complete the drawings with Inkscape or
some other vector graphic editor. Often I use FidoCadJ coupled with
the PGF/TikZ packet in LaTeX.

Community / installed base will be the issue for many;
I'm sure you've heard that before.
Click to expand...
Of course! Discussions exist about how FidoCadJ should evolve. Some
would like to have a complete open source EDA tool, like Kicad or
gEDA. This is not very useful in my point of view: instead of
developing another software to do the same thing, it would be better
to help improving Kicad and gEDA. FidoCadJ should be a different tool;
it may for example improve the typographic rendering of schematics and
allow to obtain easily graphically nice results. All with a very
simple tool, robust and the most reliable and open as possible.
BTW a new standard library for schematic symbols is being discussed
right now on Sourceforge:

https://sourceforge.net/projects/fidocadj/forums/forum/997486/topic/4714615

Regards,

D.
 
On 2011-10-09, Darwin <davbucci@tiscali.it> wrote:

Of course! Discussions exist about how FidoCadJ should evolve. Some
would like to have a complete open source EDA tool, like Kicad or
gEDA. This is not very useful in my point of view: instead of
developing another software to do the same thing, it would be better
to help improving Kicad and gEDA. FidoCadJ should be a different tool;
it may for example improve the typographic rendering of schematics and
allow to obtain easily graphically nice results. All with a very
simple tool, robust and the most reliable and open as possible.
BTW a new standard library for schematic symbols is being discussed
right now on Sourceforge:
Click to expand...
It seems to occupy a niche between kicad and xfig, (Is there a native windows
equivalent of xfig?) xfig already does truetype fonts, truecolour,
1000 layers, 1200/inch positioning resolution etc...




--
⚂⚃ 100% natural

--- Posted via news://freenews.netfront.net/ - Complaints to news@netfront.net ---
 
On 10 Ott, 14:33, Jasen Betts <ja...@xnet.co.nz> wrote:

It seems to occupy a niche between kicad and xfig,
Click to expand...
Very nice definition! I agree completely with that.

(Is there a native windows
equivalent of xfig?) xfig already does truetype fonts, truecolour,
1000 layers, 1200/inch positioning resolution etc...
Click to expand...
About xfig on Win, back in my Windows days, I remember I was able to
run XFree86 thanks to Cygwin and some X11 programs appeared inside
ordinary windows. Maybe someone compiled and/or adapted an xfig
version for Windows using something similar. I think you must have X11
for xfig, but I did not check, so I might be wrong if something has
changed since then.
It is relatively easy to add an export facility towards other vector
graphic formats in FidoCadJ. Well, one needs to study the details of
the file format, but then it is "just" the implementation of a Java
interface.
Would people using Linux appreciate or need export towards the fig
format?
 
"Phil Hobbs" <pcdhSpamMeSenseless@electrooptical.net> wrote in message
news:4E8EDB7A.3060309@electrooptical.net...
On 10/07/2011 06:36 AM, Dave wrote:
As per my post in SEB, I am trying to use a photo resistor and sunlight
to
turn off a transistor that would otherwise be conducting like crazy, but
can't quite make the leap of comprehension as to how to actually do this.
Please see attached schematic parts that show more or less what I am
trying
to do this with. No part number for the photoresistor, sorry. It drops
from multi-megohms in the dark to single-digit Ohms in the light and
seems
perfectly capable of carrying the 30 to 50 mA current I am working with
at
the voltages indicated. Would really appreciate it if someone could
offer a
hint as to how I should proceed with as few components as possible (small
circuit board.) I hope that my method of posting the schematic portion
of
what I a working with is not too obtuse. Couldn't figure out any other
way
to do it...

Many thanks...

Dave




You're wasting a gross amount of current in that bias network. How about
a nice MOSFET?

Say a 2N7002, source to V-, drain to series resistor+LED, LDR plus pot to
set turn-on level:

(V+)----*----------------*
| |
| R
| R
| R
| R
*---* |
| | ---
| R \ / -----
*-> R ----- -----
R |
R | | D
| | |---*
| | |<--; 2N7000
*----------J |---*
| | | S
| |
L |
D |
R |
| |
| |
(V-)----*----------------*














--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510
845-480-2058

hobbs at electrooptical dot net
http://electrooptical.net
Click to expand...
Man that was easy. Just had to get the MOSFET. Thank you, Phil Hobbs.

I spent so much time wrestling with that other configuration, and this just
flew together. And damn, but it works nice. Much appreciated. The whole
thing goes into a mushroom lawn ornament, with the LED inside the mushroom
cap to shine down on the fairy sitting underneath at night. Gonna look nice
between the sage and Mexican Mint Merigold, which is a weed down in Mexico,
but grows great in Texas and tastes just like Tarragon (which absolutely
will not grow in Texas.)

Dave
 
On Mon, 17 Oct 2011 17:53:01 -0500, "Dave" <db5151@hotmail.com> wrote:

"Phil Hobbs" <pcdhSpamMeSenseless@electrooptical.net> wrote in message
news:4E8EDB7A.3060309@electrooptical.net...
On 10/07/2011 06:36 AM, Dave wrote:
As per my post in SEB, I am trying to use a photo resistor and sunlight
to
turn off a transistor that would otherwise be conducting like crazy, but
can't quite make the leap of comprehension as to how to actually do this.
Please see attached schematic parts that show more or less what I am
trying
to do this with. No part number for the photoresistor, sorry. It drops
from multi-megohms in the dark to single-digit Ohms in the light and
seems
perfectly capable of carrying the 30 to 50 mA current I am working with
at
the voltages indicated. Would really appreciate it if someone could
offer a
hint as to how I should proceed with as few components as possible (small
circuit board.) I hope that my method of posting the schematic portion
of
what I a working with is not too obtuse. Couldn't figure out any other
way
to do it...

Many thanks...

Dave




You're wasting a gross amount of current in that bias network. How about
a nice MOSFET?

Say a 2N7002, source to V-, drain to series resistor+LED, LDR plus pot to
set turn-on level:

(V+)----*----------------*
| |
| R
| R
| R
| R
*---* |
| | ---
| R \ / -----
*-> R ----- -----
R |
R | | D
| | |---*
| | |<--; 2N7000
*----------J |---*
| | | S
| |
L |
D |
R |
| |
| |
(V-)----*----------------*














--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510
845-480-2058

hobbs at electrooptical dot net
http://electrooptical.net

Man that was easy. Just had to get the MOSFET. Thank you, Phil Hobbs.

I spent so much time wrestling with that other configuration, and this just
flew together. And damn, but it works nice. Much appreciated. The whole
thing goes into a mushroom lawn ornament, with the LED inside the mushroom
cap to shine down on the fairy sitting underneath at night. Gonna look nice
between the sage and Mexican Mint Merigold, which is a weed down in Mexico,
but grows great in Texas and tastes just like Tarragon (which absolutely
will not grow in Texas.)

Dave
Click to expand...
A likely story ;-)

...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.
 
On 10/17/2011 06:53 PM, Dave wrote:
"Phil Hobbs"<pcdhSpamMeSenseless@electrooptical.net> wrote in message
news:4E8EDB7A.3060309@electrooptical.net...
On 10/07/2011 06:36 AM, Dave wrote:
As per my post in SEB, I am trying to use a photo resistor and sunlight
to
turn off a transistor that would otherwise be conducting like crazy, but
can't quite make the leap of comprehension as to how to actually do this.
Please see attached schematic parts that show more or less what I am
trying
to do this with. No part number for the photoresistor, sorry. It drops
from multi-megohms in the dark to single-digit Ohms in the light and
seems
perfectly capable of carrying the 30 to 50 mA current I am working with
at
the voltages indicated. Would really appreciate it if someone could
offer a
hint as to how I should proceed with as few components as possible (small
circuit board.) I hope that my method of posting the schematic portion
of
what I a working with is not too obtuse. Couldn't figure out any other
way
to do it...

Many thanks...

Dave




You're wasting a gross amount of current in that bias network. How about
a nice MOSFET?

Say a 2N7002, source to V-, drain to series resistor+LED, LDR plus pot to
set turn-on level:

(V+)----*----------------*
| |
| R
| R
| R
| R
*---* |
| | ---
| R \ / -----
*-> R ----- -----
R |
R | | D
| | |---*
| | |<--; 2N7000
*----------J |---*
| | | S
| |
L |
D |
R |
| |
| |
(V-)----*----------------*




Man that was easy. Just had to get the MOSFET. Thank you, Phil Hobbs.

I spent so much time wrestling with that other configuration, and this just
flew together. And damn, but it works nice. Much appreciated. The whole
thing goes into a mushroom lawn ornament, with the LED inside the mushroom
cap to shine down on the fairy sitting underneath at night. Gonna look nice
between the sage and Mexican Mint Merigold, which is a weed down in Mexico,
but grows great in Texas and tastes just like Tarragon (which absolutely
will not grow in Texas.)

Dave


You're welcome. As the wise man said about beer, 2N7000s are "Good for
Click to expand...
what ails ya, and if nothing ails ya, it's good for that too."

Cheers

Phil Hobbs


--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510
845-480-2058

hobbs at electrooptical dot net
http://electrooptical.net
 
"Phil Hobbs" <pcdhSpamMeSenseless@electrooptical.net> wrote in message
news:4E9CC414.9000401@electrooptical.net...
On 10/17/2011 06:53 PM, Dave wrote:
"Phil Hobbs"<pcdhSpamMeSenseless@electrooptical.net> wrote in message
news:4E8EDB7A.3060309@electrooptical.net...
On 10/07/2011 06:36 AM, Dave wrote:
As per my post in SEB, I am trying to use a photo resistor and sunlight
to
turn off a transistor that would otherwise be conducting like crazy,
but
can't quite make the leap of comprehension as to how to actually do
this.
Please see attached schematic parts that show more or less what I am
trying
to do this with. No part number for the photoresistor, sorry. It
drops
from multi-megohms in the dark to single-digit Ohms in the light and
seems
perfectly capable of carrying the 30 to 50 mA current I am working with
at
the voltages indicated. Would really appreciate it if someone could
offer a
hint as to how I should proceed with as few components as possible
(small
circuit board.) I hope that my method of posting the schematic portion
of
what I a working with is not too obtuse. Couldn't figure out any other
way
to do it...

Many thanks...

Dave




You're wasting a gross amount of current in that bias network. How
about
a nice MOSFET?

Say a 2N7002, source to V-, drain to series resistor+LED, LDR plus pot
to
set turn-on level:

(V+)----*----------------*
| |
| R
| R
| R
| R
*---* |
| | ---
| R \ / -----
*-> R ----- -----
R |
R | | D
| | |---*
| | |<--; 2N7000
*----------J |---*
| | | S
| |
L |
D |
R |
| |
| |
(V-)----*----------------*




Man that was easy. Just had to get the MOSFET. Thank you, Phil Hobbs.

I spent so much time wrestling with that other configuration, and this
just
flew together. And damn, but it works nice. Much appreciated. The
whole
thing goes into a mushroom lawn ornament, with the LED inside the
mushroom
cap to shine down on the fairy sitting underneath at night. Gonna look
nice
between the sage and Mexican Mint Merigold, which is a weed down in
Mexico,
but grows great in Texas and tastes just like Tarragon (which absolutely
will not grow in Texas.)

Dave


You're welcome. As the wise man said about beer, 2N7000s are "Good for
what ails ya, and if nothing ails ya, it's good for that too."

Cheers

Phil Hobbs
Click to expand...
LOL! And thank you for that belly laugh. <shaking head> Cheers to you,
sir!

D

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510
845-480-2058

hobbs at electrooptical dot net
http://electrooptical.net
Click to expand...
 
On Mon, 17 Oct 2011 20:41:06 -0500, "Dave" <db5151@hotmail.com> wrote:

"Phil Hobbs" <pcdhSpamMeSenseless@electrooptical.net> wrote in message
news:4E9CC414.9000401@electrooptical.net...
On 10/17/2011 06:53 PM, Dave wrote:
"Phil Hobbs"<pcdhSpamMeSenseless@electrooptical.net> wrote in message
news:4E8EDB7A.3060309@electrooptical.net...
On 10/07/2011 06:36 AM, Dave wrote:
As per my post in SEB, I am trying to use a photo resistor and sunlight
to
turn off a transistor that would otherwise be conducting like crazy,
but
can't quite make the leap of comprehension as to how to actually do
this.
Please see attached schematic parts that show more or less what I am
trying
to do this with. No part number for the photoresistor, sorry. It
drops
from multi-megohms in the dark to single-digit Ohms in the light and
seems
perfectly capable of carrying the 30 to 50 mA current I am working with
at
the voltages indicated. Would really appreciate it if someone could
offer a
hint as to how I should proceed with as few components as possible
(small
circuit board.) I hope that my method of posting the schematic portion
of
what I a working with is not too obtuse. Couldn't figure out any other
way
to do it...

Many thanks...

Dave




You're wasting a gross amount of current in that bias network. How
about
a nice MOSFET?

Say a 2N7002, source to V-, drain to series resistor+LED, LDR plus pot
to
set turn-on level:

(V+)----*----------------*
| |
| R
| R
| R
| R
*---* |
| | ---
| R \ / -----
*-> R ----- -----
R |
R | | D
| | |---*
| | |<--; 2N7000
*----------J |---*
| | | S
| |
L |
D |
R |
| |
| |
(V-)----*----------------*




Man that was easy. Just had to get the MOSFET. Thank you, Phil Hobbs.

I spent so much time wrestling with that other configuration, and this
just
flew together. And damn, but it works nice. Much appreciated.
Click to expand...
---
Geez, I feel kind of miffed since my (Jan's) solution would allow you
to rid yourself of the LDR and its associated circuitry.

With that in mind, why would you find Doctor Phil's circuit, which is
wasteful of power and money by having it drive an unnecessary LDR,
superior to mine?

--
JF
 
"John Fields" <jfields@austininstruments.com> wrote in message
news:ft8s975344d866mo12ucjjef15hlsuce33@4ax.com...
On Mon, 17 Oct 2011 20:41:06 -0500, "Dave" <db5151@hotmail.com> wrote:


"Phil Hobbs" <pcdhSpamMeSenseless@electrooptical.net> wrote in message
news:4E9CC414.9000401@electrooptical.net...
On 10/17/2011 06:53 PM, Dave wrote:
"Phil Hobbs"<pcdhSpamMeSenseless@electrooptical.net> wrote in message
news:4E8EDB7A.3060309@electrooptical.net...
On 10/07/2011 06:36 AM, Dave wrote:
As per my post in SEB, I am trying to use a photo resistor and
sunlight
to
turn off a transistor that would otherwise be conducting like crazy,
but
can't quite make the leap of comprehension as to how to actually do
this.
Please see attached schematic parts that show more or less what I am
trying
to do this with. No part number for the photoresistor, sorry. It
drops
from multi-megohms in the dark to single-digit Ohms in the light and
seems
perfectly capable of carrying the 30 to 50 mA current I am working
with
at
the voltages indicated. Would really appreciate it if someone could
offer a
hint as to how I should proceed with as few components as possible
(small
circuit board.) I hope that my method of posting the schematic
portion
of
what I a working with is not too obtuse. Couldn't figure out any
other
way
to do it...

Many thanks...

Dave




You're wasting a gross amount of current in that bias network. How
about
a nice MOSFET?

Say a 2N7002, source to V-, drain to series resistor+LED, LDR plus pot
to
set turn-on level:

(V+)----*----------------*
| |
| R
| R
| R
| R
*---* |
| | ---
| R \ / -----
*-> R ----- -----
R |
R | | D
| | |---*
| | |<--; 2N7000
*----------J |---*
| | | S
| |
L |
D |
R |
| |
| |
(V-)----*----------------*




Man that was easy. Just had to get the MOSFET. Thank you, Phil Hobbs.

I spent so much time wrestling with that other configuration, and this
just
flew together. And damn, but it works nice. Much appreciated.

---
Geez, I feel kind of miffed since my (Jan's) solution would allow you
to rid yourself of the LDR and its associated circuitry.

With that in mind, why would you find Doctor Phil's circuit, which is
wasteful of power and money by having it drive an unnecessary LDR,
superior to mine?

--
JF
Click to expand...
Hey John. No offense intended, believe me. Your ASCII description
translated into a schematic where my tiny photocell (I'm guessing that's
what V3 was) was set up as 4 VDC, rather than .4 VDC, which is what it
actually put out. And even then, when I set it all up, it looked like it
ought to work, but it didn't. No idea why, other than that there is
something about the tiny photocell that I don't know. Finally gave up on
using that component. When my Digikey parts came in I put them together and
they took off. That version worked, so I used it. Now I'm trying to find a
6V solar cell smaller than the 6"X6" behemoth I currenty have in place.
Will probably go with one from Amazon that is 4"X3" and flexible.

Take it easy...

Dave
 
On Wed, 19 Oct 2011 13:05:27 -0500, "Dave" <db5151@hotmail.com> wrote:

"John Fields" <jfields@austininstruments.com> wrote in message
news:ft8s975344d866mo12ucjjef15hlsuce33@4ax.com...
On Mon, 17 Oct 2011 20:41:06 -0500, "Dave" <db5151@hotmail.com> wrote:


"Phil Hobbs" <pcdhSpamMeSenseless@electrooptical.net> wrote in message
news:4E9CC414.9000401@electrooptical.net...
On 10/17/2011 06:53 PM, Dave wrote:
"Phil Hobbs"<pcdhSpamMeSenseless@electrooptical.net> wrote in message
news:4E8EDB7A.3060309@electrooptical.net...
On 10/07/2011 06:36 AM, Dave wrote:
As per my post in SEB, I am trying to use a photo resistor and
sunlight
to
turn off a transistor that would otherwise be conducting like crazy,
but
can't quite make the leap of comprehension as to how to actually do
this.
Please see attached schematic parts that show more or less what I am
trying
to do this with. No part number for the photoresistor, sorry. It
drops
from multi-megohms in the dark to single-digit Ohms in the light and
seems
perfectly capable of carrying the 30 to 50 mA current I am working
with
at
the voltages indicated. Would really appreciate it if someone could
offer a
hint as to how I should proceed with as few components as possible
(small
circuit board.) I hope that my method of posting the schematic
portion
of
what I a working with is not too obtuse. Couldn't figure out any
other
way
to do it...

Many thanks...

Dave




You're wasting a gross amount of current in that bias network. How
about
a nice MOSFET?

Say a 2N7002, source to V-, drain to series resistor+LED, LDR plus pot
to
set turn-on level:

(V+)----*----------------*
| |
| R
| R
| R
| R
*---* |
| | ---
| R \ / -----
*-> R ----- -----
R |
R | | D
| | |---*
| | |<--; 2N7000
*----------J |---*
| | | S
| |
L |
D |
R |
| |
| |
(V-)----*----------------*




Man that was easy. Just had to get the MOSFET. Thank you, Phil Hobbs.

I spent so much time wrestling with that other configuration, and this
just
flew together. And damn, but it works nice. Much appreciated.

---
Geez, I feel kind of miffed since my (Jan's) solution would allow you
to rid yourself of the LDR and its associated circuitry.

With that in mind, why would you find Doctor Phil's circuit, which is
wasteful of power and money by having it drive an unnecessary LDR,
superior to mine?

--
JF

Hey John. No offense intended, believe me. Your ASCII description
translated into a schematic where my tiny photocell (I'm guessing that's
what V3 was) was set up as 4 VDC, rather than .4 VDC, which is what it
actually put out. And even then, when I set it all up, it looked like it
ought to work, but it didn't. No idea why, other than that there is
something about the tiny photocell that I don't know. Finally gave up on
using that component. When my Digikey parts came in I put them together and
they took off. That version worked, so I used it. Now I'm trying to find a
6V solar cell smaller than the 6"X6" behemoth I currenty have in place.
Will probably go with one from Amazon that is 4"X3" and flexible.
Click to expand...
---
No problem, but the circuit I was referring to wasn't the one with the
tiny PV, it was the one with a PNP driving the LED which I posted as
an LTspice circuit list along with two other circuits.

Here it is in ASCII:

.. 2N3906
.. +-[1N5817>]-+---------E C-+
.. | | B |
.. +-----------|-----+ | |
.. | | | | [42]
.. |+ |+ [POT]<--+ |
.. [PV] [BAT] |10k [LED]
.. | | | |K
.. +-----------+-----+---------+

Notice no LDR and its associated resistor. :)

Anyway, as long as you have something that works, that's what matters.

BTW, make sure that you get a PV array with the capacity to charge the
battery enough, during the day, so that the LED stays on for as long
as you need it to at night.

--
JF
 
"John Fields" <jfields@austininstruments.com> wrote in message
news:4g90a75lo5tbg5vvf0etujv1obruinnhva@4ax.com...
On Wed, 19 Oct 2011 13:05:27 -0500, "Dave" <db5151@hotmail.com> wrote:


"John Fields" <jfields@austininstruments.com> wrote in message
news:ft8s975344d866mo12ucjjef15hlsuce33@4ax.com...
On Mon, 17 Oct 2011 20:41:06 -0500, "Dave" <db5151@hotmail.com> wrote:


"Phil Hobbs" <pcdhSpamMeSenseless@electrooptical.net> wrote in message
news:4E9CC414.9000401@electrooptical.net...
On 10/17/2011 06:53 PM, Dave wrote:
"Phil Hobbs"<pcdhSpamMeSenseless@electrooptical.net> wrote in
message
news:4E8EDB7A.3060309@electrooptical.net...
On 10/07/2011 06:36 AM, Dave wrote:
As per my post in SEB, I am trying to use a photo resistor and
sunlight
to
turn off a transistor that would otherwise be conducting like
crazy,
but
can't quite make the leap of comprehension as to how to actually do
this.
Please see attached schematic parts that show more or less what I
am
trying
to do this with. No part number for the photoresistor, sorry. It
drops
from multi-megohms in the dark to single-digit Ohms in the light
and
seems
perfectly capable of carrying the 30 to 50 mA current I am working
with
at
the voltages indicated. Would really appreciate it if someone
could
offer a
hint as to how I should proceed with as few components as possible
(small
circuit board.) I hope that my method of posting the schematic
portion
of
what I a working with is not too obtuse. Couldn't figure out any
other
way
to do it...

Many thanks...

Dave




You're wasting a gross amount of current in that bias network. How
about
a nice MOSFET?

Say a 2N7002, source to V-, drain to series resistor+LED, LDR plus
pot
to
set turn-on level:

(V+)----*----------------*
| |
| R
| R
| R
| R
*---* |
| | ---
| R \ / -----
*-> R ----- -----
R |
R | | D
| | |---*
| | |<--; 2N7000
*----------J |---*
| | | S
| |
L |
D |
R |
| |
| |
(V-)----*----------------*




Man that was easy. Just had to get the MOSFET. Thank you, Phil
Hobbs.

I spent so much time wrestling with that other configuration, and
this
just
flew together. And damn, but it works nice. Much appreciated.

---
Geez, I feel kind of miffed since my (Jan's) solution would allow you
to rid yourself of the LDR and its associated circuitry.

With that in mind, why would you find Doctor Phil's circuit, which is
wasteful of power and money by having it drive an unnecessary LDR,
superior to mine?

--
JF

Hey John. No offense intended, believe me. Your ASCII description
translated into a schematic where my tiny photocell (I'm guessing that's
what V3 was) was set up as 4 VDC, rather than .4 VDC, which is what it
actually put out. And even then, when I set it all up, it looked like it
ought to work, but it didn't. No idea why, other than that there is
something about the tiny photocell that I don't know. Finally gave up on
using that component. When my Digikey parts came in I put them together
and
they took off. That version worked, so I used it. Now I'm trying to find
a
6V solar cell smaller than the 6"X6" behemoth I currenty have in place.
Will probably go with one from Amazon that is 4"X3" and flexible.

---
No problem, but the circuit I was referring to wasn't the one with the
tiny PV, it was the one with a PNP driving the LED which I posted as
an LTspice circuit list along with two other circuits.

Here it is in ASCII:

. 2N3906
. +-[1N5817>]-+---------E C-+
. | | B |
. +-----------|-----+ | |
. | | | | [42]
. |+ |+ [POT]<--+ |
. [PV] [BAT] |10k [LED]
. | | | |K
. +-----------+-----+---------+

Notice no LDR and its associated resistor. :)

Anyway, as long as you have something that works, that's what matters.

BTW, make sure that you get a PV array with the capacity to charge the
battery enough, during the day, so that the LED stays on for as long
as you need it to at night.

--
JF
Click to expand...
Hey again. Oh, sorry, I missunderstood. Will have to go back and take
another look at that particular circuit. I didn't know if I had any
2N3906s, and didn't push it past that. Will definetly check it out though.

And yes, I am working to make sure that I am able to charge the batteries
sufficiently to keep things running as long as possible. Thanks for
mentioning that though, and the encouragement.

Take it easy...

D
 
On 2011-10-24, act pcb <act.pcb6@gmail.com> wrote:
American circuit technology is the leading manufacturer of various
types of circuit boards which are the veins & arteries of any
electronic goods for performing the critical tasks.
Click to expand...
problem is they also produce spam.

these guys:

http://www.audesine.com/proto-pcbs

on the other hand never spam and produce professional pcbs ins small
quantities at hobbyist friendly prices.



--
⚂⚃ 100% natural

--- Posted via news://freenews.netfront.net/ - Complaints to news@netfront.net ---
 
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