Chip with simple program for Toy

"petrus bitbyter" <pieterkraltlaatditweg@enditookhccnet.nl> schreef in
bericht news:4825926d$0$15509$e4fe514c@dreader16.news.xs4all.nl...
"vic" <news@bidouille.org> schreef in bericht
news:48250145$0$5055$426a74cc@news.free.fr...
BobW wrote:
"BobW" <nimby_NEEDSPAM@roadrunner.com> wrote in message
news:B7mdnSJSKb17P77VnZ2dnUVZ_obinZ2d@giganews.com...
"vic" <news@bidouille.org> wrote in message
news:48233453$0$20289$426a74cc@news.free.fr...
Hi,

I have two common anode 7-segments displays, and only one wire to
drive them. I need to achieve the following : when the control signal
is +5V, display1 is ON and display2 is OFF. When the signal is 0V,
display1 is OFF and display2 is ON. When the signal is not connected
(high impedance), both displays are OFF.

I tried using a NPN transistor for display1 and a PNP for display2,
connecting their bases together. It works when the driving signal is
present, but when the signal is floating current flows from the base
of the PNP to the base of the NPN and both transistors turn each other
on, resulting in both displays being ON.

The circuit that didn't work :

VCC
+
|
|
___ |
o---------------------|___|--|
| |\
| VCC |
| + |
| | Display2
| | |
| ___ |/ |
Input---o---|___|--| GND
|
|
|
Display1
|
|
GND



Is there a way to achieve this ?

Thanks.
Try this:
5V
| 5V
R5 |
| |<---
|/-------------| Q3
----| Q1 |\--------- (to display 1 and then to GND)
| |>-- 5V
| | |
| | R3
| | |
---R1-----R2----------
| | |
| | R4
| |<--- |
|--| Q2 GND
|\
| |/--------- (to display 2 and then to 5V)
-------------| Q4
| |>----
R6 |
| GND
GND

Q1 and Q2 form a comparator so that when the input is floating they
will both be off. R3 and R4 set the input threshold.

When the input is high (5V) then Q1 will be on and that will turn on
Q3. When the input is low (GND) then Q2 will be on and that will turn
on Q4.

You can figure out the resistor values. They shouldn't be too critical,
but R3 and R4 need to be small enough to ensure enough drive for the
four transistors.

I hope I got the ascii art right as I had to compose it in a separate
word processor.

Bob
--
== NOTE: I automatically delete all Google Group posts due to
uncontrolled SPAM ==

I see, now, that your displays are both common anode. You'll need to add
another PNP (common emitter mode) driven by Q4.

As Monica Lewinsky used to say, "Close, but no cigar."

Bob

*gasp* 5 transistors needed to do what seemed simple at first glance ...

I don't quite understand what R5 and R6 are for, when Q1 and Q2 do not
conduct, the base current of Q3 and Q4 would be zero so the ressitors do
not seem necessary ?

Well I guess I could just try it and see if it works :)


Didn't you see my four transistors, four resistors solution yesterday?

+--------+------------------+-------+--Vcc
| | | |
___ |< | ___ |/ |
in----+--|___|---| | +--|___|--| |
| |\ | | |> |
| | | | | |
| | |< | | |
| +------| | +-----|
| | |\ | | |\
| .-. | | .-. |
| | | .---. | | | .---.
| | | | | | | | | |
| '-' | D | | '-' | D |
| | | | | | | |
| | '---' | | '---'
| | | | | |
------)------------+--------+------)-----------+-------+--GND
| |
+----------------------------+
created by Andy´s ASCII-Circuit v1.24.140803 Beta www.tech-chat.de


petrus bitbyter
Oops, checking out my own schematic I found it wrong. The one below is good.
I added a diode to make the voltage loss for both displays more equal. If
that loss is not acceptable you can use a five transistor variant shown by
someone else already. I added similar schematic below.


+--------+------------------+-------+--Vcc
| | | |
___ |< V .-. |
in----+--|___|---| - | | |
| |\ | | | |
| | | '-' |
| | |< | |/
| +------| +-----|
| | |\ | |>
| .-. | | |
| | | .---. ___ |/ .---.
| | | | | +--|___|--| | |
| '-' | D | | |> | D |
| | | | | | | |
| | '---' | '---'
| | | | | |
------)------------+--------+------)-----------+-------+--GND
| |
+----------------------------+




+------+---------------------+------+--Vcc
| | | |
___ |< | |< |
in---+--|___|--| | +--| |
| |\ | | |\ |
| | | .-. | |<
| | |< | | +----|
| +----| | | | |\
| | |\ '-' | |
| .-. | | | |
| | | .---. | | .---.
| | | | | ___ |/ .-. | |
| '-' | D | +--|___|--| | | | D |
| | | | | |> | | | |
| | '---' | | '-' '---'
| | | | | | |
-----)-----------+------+----)-----------+----+------+--GND
| |
+-----------------------+
created by Andy´s ASCII-Circuit v1.24.140803 Beta www.tech-chat.de

For a a Vcc of 5V all resistors can be 4k7. Transistors are general purpose
2N3904, 2N3906 or BC550, BC560.

petrus bitbyter
 
"steve" <kvsteve@gmail.com> wrote in message
news:a2c5fbe6-6beb-40f3-a0e1-3e1656e5e955@p25g2000pri.googlegroups.com...
I require alarm systems for both personal and house.

From seeing various alarm projects, there is no detail about how the
alarm is set off.

For example, a house alarm could be triggered by opening a door.

But the diy circuit notes merely say that power supply will trigger
the alarm on.

There should be a special kind of switch that will sense motion, or
breakage of a (window) latch, etc.

Could anyone please explain.
See:
http://www.mkwahler.net/alarm.GIF

When switch is open, LED illuminates.
When switch is closed, LED turns off.

Be sure to choose resistor to match your
desired voltage (e.g. for red LED with 5
volts use 330 ohms).

LED indicator could be replaced or supplemented
with e.g. a buzzer.

-Mike
 
"steve" <kvsteve@gmail.com> wrote in message
news:a2c5fbe6-6beb-40f3-a0e1-3e1656e5e955@p25g2000pri.googlegroups.com...
I require alarm systems for both personal and house.

From seeing various alarm projects, there is no detail about how the
alarm is set off.

For example, a house alarm could be triggered by opening a door.

But the diy circuit notes merely say that power supply will trigger
the alarm on.

There should be a special kind of switch that will sense motion, or
breakage of a (window) latch, etc.

Could anyone please explain.
See:
http://www.mkwahler.net/alarm.GIF

When switch is open, LED illuminates.
When switch is closed, LED turns off.

Be sure to choose resistor to match your
desired voltage (e.g. for red LED with 5
volts use 330 ohms).

LED indicator could be replaced or supplemented
with e.g. a buzzer.

-Mike
 
"vic" <news@bidouille.org> schreef in bericht
news:48264e41$0$9865$426a74cc@news.free.fr...
petrus bitbyter wrote:
Didn't you see my four transistors, four resistors solution yesterday?

+--------+------------------+-------+--Vcc
| | | |
___ |< | ___ |/ |
in----+--|___|---| | +--|___|--| |
| |\ | | |> |
| | | | | |
| | |< | | |
| +------| | +-----|
| | |\ | | |\
| .-. | | .-. |
| | | .---. | | | .---.
| | | | | | | | | |
| '-' | D | | '-' | D |
| | | | | | | |
| | '---' | | '---'
| | | | | |
------)------------+--------+------)-----------+-------+--GND
| |
+----------------------------+
created by Andy´s ASCII-Circuit v1.24.140803 Beta www.tech-chat.de



Sorry I missed your post. Looks like a good solution. Thanks !
Be aware that this schematic does not work. By modifiing my first schematic
(with one display connected to Vcc) to the second (with both diplays
connected to Gnd) I made a mistake. I posted the right schematic few minutes
before your post.

petrus bitbyter
 
"vic" <news@bidouille.org> schreef in bericht
news:48264e41$0$9865$426a74cc@news.free.fr...
petrus bitbyter wrote:
Didn't you see my four transistors, four resistors solution yesterday?

+--------+------------------+-------+--Vcc
| | | |
___ |< | ___ |/ |
in----+--|___|---| | +--|___|--| |
| |\ | | |> |
| | | | | |
| | |< | | |
| +------| | +-----|
| | |\ | | |\
| .-. | | .-. |
| | | .---. | | | .---.
| | | | | | | | | |
| '-' | D | | '-' | D |
| | | | | | | |
| | '---' | | '---'
| | | | | |
------)------------+--------+------)-----------+-------+--GND
| |
+----------------------------+
created by Andy´s ASCII-Circuit v1.24.140803 Beta www.tech-chat.de



Sorry I missed your post. Looks like a good solution. Thanks !
Be aware that this schematic does not work. By modifiing my first schematic
(with one display connected to Vcc) to the second (with both diplays
connected to Gnd) I made a mistake. I posted the right schematic few minutes
before your post.

petrus bitbyter
 
"steve" <kvsteve@gmail.com> wrote in message
news:a2c5fbe6-6beb-40f3-a0e1-3e1656e5e955@p25g2000pri.googlegroups.com...
I require alarm systems for both personal and house.

From seeing various alarm projects, there is no detail about how the
alarm is set off.

For example, a house alarm could be triggered by opening a door.

But the diy circuit notes merely say that power supply will trigger
the alarm on.

There should be a special kind of switch that will sense motion, or
breakage of a (window) latch, etc.
Passive IR sensors are used to detect "movement"
http://en.wikipedia.org/wiki/Passive_infrared_sensor

Piezoelectric vibration sensors are used to detect window breakage:
http://en.wikipedia.org/wiki/Piezoelectric_sensor

Magnetic reed switches are used to detect door and window opening etc.
http://en.wikipedia.org/wiki/Reed_switch

A bit of advice - DON'T try and build your own alarm, it's waste of time,
but one that is properly designed to be reliable and bug free to prevent
false alarms.

Dave.
 
"steve" <kvsteve@gmail.com> wrote in message
news:a2c5fbe6-6beb-40f3-a0e1-3e1656e5e955@p25g2000pri.googlegroups.com...
I require alarm systems for both personal and house.

From seeing various alarm projects, there is no detail about how the
alarm is set off.

For example, a house alarm could be triggered by opening a door.

But the diy circuit notes merely say that power supply will trigger
the alarm on.

There should be a special kind of switch that will sense motion, or
breakage of a (window) latch, etc.
Passive IR sensors are used to detect "movement"
http://en.wikipedia.org/wiki/Passive_infrared_sensor

Piezoelectric vibration sensors are used to detect window breakage:
http://en.wikipedia.org/wiki/Piezoelectric_sensor

Magnetic reed switches are used to detect door and window opening etc.
http://en.wikipedia.org/wiki/Reed_switch

A bit of advice - DON'T try and build your own alarm, it's waste of time,
but one that is properly designed to be reliable and bug free to prevent
false alarms.

Dave.
 
In article <MdKdnQNUvK94AbrVnZ2dnUVZ_hKdnZ2d@earthlink.com>,
"Michael A. Terrell" <mike.terrell@earthlink.net> wrote:

Do you remember that wall wart being the first one
recalled for being a fire hazard?
That was one of Western Electric's first uses of a third-party supplier.
In this case, it was Ault Manufacturing.

The Ault transformer recall was HUGE.

There are still MANY Western Electric dial-light transformers in service
to this day. Virtually all are powering NOTHING but have not been
unplugged.
--
:)
JR
 
"PinkFloyd43" <pinkFloyd43@hotmail.com> wrote in message
news:ul3Wj.6069$T1.3295@trnddc01...
Create a circuit with bright red LEDs that would attached
to the front and back of a motorcycle helmet that would
flash for x period of time when the operator moved their
head left to right, like saying NO, NO to a car about
ready to pull out in front on you....


Thanks!

I think I see what you want, but activating it with head movement on a
motorcycle would be unreliable.
If you ride you know that motorcyclist get bounced around a lot. I'll think
about it some more.

BTW: I removed your crossposts, way too many.

Tom
 
"PinkFloyd43" <pinkFloyd43@hotmail.com> wrote in message
news:ul3Wj.6069$T1.3295@trnddc01...
Create a circuit with bright red LEDs that would attached
to the front and back of a motorcycle helmet that would
flash for x period of time when the operator moved their
head left to right, like saying NO, NO to a car about
ready to pull out in front on you....


Thanks!

I think I see what you want, but activating it with head movement on a
motorcycle would be unreliable.
If you ride you know that motorcyclist get bounced around a lot. I'll think
about it some more.

BTW: I removed your crossposts, way too many.

Tom
 
"Dave.H" <the1930s@googlemail.com> wrote in message
news:5a7ffa61-189a-4c27-8e56-25dd8630d081@l17g2000pri.googlegroups.com...
Sorry about the long title, Google Groups screwed up, somehow

Dave
Why don't you just access the group without Google Groups.
 
"lerameur" <lerameur@yahoo.com> wrote in message
news:8e66cfa7-3f63-4096-a9e1-45ca17ef3679@34g2000hsh.googlegroups.com...
hello guys,

I usually find the parts I am looking for on digikey web site. I have
not order from there for a long time. But have they decrease
selectivity of products. I was looking for low pass filter chip.ie
MAX7480EPA, but it is non stock and minimum of 50.. and that is the
only with 2k fc. also I was looking for dtmf dialer, and they are now
obsolete. Is it just my luck or are they not keeping as many parts as
before ?
Several DTMF ICs are coming up with a google search for 'DTMF dialer ic'

If you get into a bind, let me know, I have several...I can part with one.
 
Ardent <iam@here.com.invalid> wrote in
news:412m2496jl1eta2g9vpbd51tj1edobiav2@4ax.com:

On Sat, 10 May 2008 10:38:20 +0100, "Andrew Holme" <ah@nospam.co.uk
wrote:

I was recently playing with miniature 32.768 KHz tuning-fork watch
crystals, which require extremely low drive levels;

Hi

Maybe you can hep me. I tried a 32.768 with 8051 microcontroller. I
used 11 pf capacitor and a 330k resistor in series and it worked well
on the breadboard. But when I made a pcb and soldered all the parts
exactly as was in the breadboard the crystal refused to oscillate.

What is missing?

Thanks for your time and attention
Archer
probably another 20-30 pf...

try something around 68 pf as a start.


----== Posted via Pronews.Com - Unlimited-Unrestricted-Secure Usenet News==----
http://www.pronews.com The #1 Newsgroup Service in the World! >100,000 Newsgroups
---= - Total Privacy via Encryption =---
 
Ď <phil-news-nospam@ipal.net> Ýăńářĺ óôď ěŢíőěá
news:fvljt71h38@news4.newsguy.com...
In alt.engineering.electrical "nobody >" <usenetharvested@aol.com> wrote:
| phil-news-nospam@ipal.net wrote:
|> In alt.engineering.electrical Timothy Daniels
SpamBucket@nospamplease.biz> wrote:
|
|> | Would you please sum up what you believe to be prudent
|> | protection (for electronic equipment) from nearby lightning strikes?
|> | I'm thinking of both in single-family homes and in condo/apartment
|> | buildings. What would you do to protect from in-house (or
in-building)
|> | surges, such as elevator motors suddenly shorting out, or welding
|> | equipment in use?
|
|> How much money are you willing to spend?
|
|
| The only thing I can think of that comes close is to have a heavy
| motor/generator set with a HUGE flywheel sitting in the basement.

How about driving a generator in the basement with either a heavy
fiberglass
axle rod driven at some distance by a (sacrificial) motor, or by a fluid
that
does not conduct electricity through a turbine system, similarly driven by
a
motor/pump at some distance.

Or a compelete diesel-hydraulic locomotive? (Diesel-hydraulic coupling,
Dieselhydraulische in german)?



--
Tzortzakakis Dimitrios
major in electrical engineering
mechanized infantry reservist
hordad AT otenet DOT gr
NB:I killfile googlegroups.
 
Ď <phil-news-nospam@ipal.net> Ýăńářĺ óôď ěŢíőěá
news:fvljt71h38@news4.newsguy.com...
In alt.engineering.electrical "nobody >" <usenetharvested@aol.com> wrote:
| phil-news-nospam@ipal.net wrote:
|> In alt.engineering.electrical Timothy Daniels
SpamBucket@nospamplease.biz> wrote:
|
|> | Would you please sum up what you believe to be prudent
|> | protection (for electronic equipment) from nearby lightning strikes?
|> | I'm thinking of both in single-family homes and in condo/apartment
|> | buildings. What would you do to protect from in-house (or
in-building)
|> | surges, such as elevator motors suddenly shorting out, or welding
|> | equipment in use?
|
|> How much money are you willing to spend?
|
|
| The only thing I can think of that comes close is to have a heavy
| motor/generator set with a HUGE flywheel sitting in the basement.

How about driving a generator in the basement with either a heavy
fiberglass
axle rod driven at some distance by a (sacrificial) motor, or by a fluid
that
does not conduct electricity through a turbine system, similarly driven by
a
motor/pump at some distance.

Or a compelete diesel-hydraulic locomotive? (Diesel-hydraulic coupling,
Dieselhydraulische in german)?



--
Tzortzakakis Dimitrios
major in electrical engineering
mechanized infantry reservist
hordad AT otenet DOT gr
NB:I killfile googlegroups.
 
"steve" <kvsteve@gmail.com> wrote in message
news:bef5b4d5-51d3-4d6d-9e5e-Thanks to everyone for their replies.

Please note that I had mentioned the requirement of a personal alarm
in my post.
My friend works as a social worker in a bad neighbourhood.
He is frail and therefore requires a personal protection device.
I was wondering if a stun device could be made, by collecting energy
in a single electronic part.
Then the energy could be released on the attacker.
They are called stun guns. May not be legal.

A cane is legal, learn how to use one of those:
http://www.gojushorei.com/canetechniques.htm

Also, try typing "personal alarm" into Google, plenty of help and/or panic
button devices available.

Dave.
 
"steve" <kvsteve@gmail.com> wrote in message
news:bef5b4d5-51d3-4d6d-9e5e-Thanks to everyone for their replies.

Please note that I had mentioned the requirement of a personal alarm
in my post.
My friend works as a social worker in a bad neighbourhood.
He is frail and therefore requires a personal protection device.
I was wondering if a stun device could be made, by collecting energy
in a single electronic part.
Then the energy could be released on the attacker.
They are called stun guns. May not be legal.

A cane is legal, learn how to use one of those:
http://www.gojushorei.com/canetechniques.htm

Also, try typing "personal alarm" into Google, plenty of help and/or panic
button devices available.

Dave.
 
"DFWguy" <aol@aol.com> wrote in message news:fC2Xj.7692$0h.3489@trnddc02...
Looking to do the following:

I have a SATA drive I want to be able to disable the power to on occasion.
Long and short, 3 wires and 3 voltages that I want to be able to cut off
via a switch (don't wanna have to open up my rig and just physically
disconnect the power supply).

v1 ----- switch ------- drive v1
v2 ----- switch ------- drive v2
v3 ----- switch ------- drive v2

Short of installing 3 different simple toggles, how could I go about doing
this? Is there a "3 in 1" type toggle available that I'm missing?

TIA! :)+

Not a good idea to just let the drive crash.
Tom
 
"Dave" <dspear99ca@yahoo.com> wrote in message
news:vrCWj.2124$Yp.1827@edtnps92...
In North America and Europe, many if not most power transformers in
consumer-grade equipment have windings which allow both 120 and 240VAC
operation... you'd just apply 240V to a centre tap on the primary winding
vs. 120 end-to-end to get the same voltage out. Dave
Not trying to be a noodge, but are you sure?
 
"Dave" <dspear99ca@yahoo.com> wrote in message
news:vrCWj.2124$Yp.1827@edtnps92...
In North America and Europe, many if not most power transformers in
consumer-grade equipment have windings which allow both 120 and 240VAC
operation... you'd just apply 240V to a centre tap on the primary winding
vs. 120 end-to-end to get the same voltage out. Dave
Not trying to be a noodge, but are you sure?
 

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