Chip with simple program for Toy

[Ken Smith]

In article <1163360427.487718.18100@h54g2000cwb.googlegroups.com>,
<luisdanielsilva@gmail.com> wrote:

I need to convert a 32 bit binary number to gray code. i know how to do
it bit by bit, but i need to do a function to do it, so that i don't
need to repeat code 32 times. Can anybody help me?

If you are doing this in assembly, the these ideas will help you.


32 bits fits into 4 bytes. You want 2 nested loops to do the process.

R0 or R1 can be used to work your way down the bytes as you process.

There is no XRL C,XXX instruction. If you want a little speed, you want
two copies of the inner workings. One for when you are complimenting bits
and one for when you aren't. If your input values happen to be near zero,
you can also include special code for skipping the unused part of the
field.




--
--
kensmith@rahul.net forging knowledge

 

[Rich Grise]

On Tue, 28 Nov 2006 20:09:24 -0800, Bill Bowden wrote:

Rich Grise wrote:
....
Oh, by the way: a link might be useful:
http://www.ee.ucl.ac.uk/~amoss/java/555.htm

Were you guys looking at a different page? How did I get to that one? ?:-/

I felt so clever some decades ago when I came up with this on my own that
I almost dislocated my shoulder patting myself on the back.

Yes, you are right. I forgot to look at the drawing. But actually the
diode isn't needed for 50% DC if you put Rb in series with pin 7, and
tie the cap from junction of Ra and Rb to ground. It's on page 10 of
the data sheet, but the ratio of Ra:Rb has to be 51:22 which makes
selecting the parts a little difficult. The diode is the easy way.

There's another one that I learned of quite recently - from one of the
posters in one of the electronics groups - it's where the output is
fed back to the timing cap, and that node goes to both threshold and
trigger, but it only works with a CMOS unit. It's the "less accurate"
one here:
http://home.cogeco.ca/~rpaisley4/LM555.html#14

Cheers!
Rich

 

Impmon wrote:

I tried Googling but all the formula for finding 555 timer frequency
is based on known capacitor and resistor values to find frequency.

I need to build a monostable timer to get 140Hz. I could throw in a
random capacitor and one resistor but my algebra skill is rusty (no
complex math formula in over 10 years!!)

The system will be running on 5v DC as it contains a few TTL chips.
--
When you hear the toilet flush, and hear the words "uh oh", it's already
too late. - by anonymous Mother in Austin, TX
Spam block in place, no emil reply is expected at all.

I can give you the formula that you need but you'll have todo the math.
formula to find the frequency of an rc network is Fsub c =1 over 2 x
pie x RxC

 

[Dr. Anton T. Squeegee]

In article <1165066997.820352.79920@l12g2000cwl.googlegroups.com>,
avonchick349@yahoo.com (known to some as avonchick349@yahoo.com)
scribed...

Do you have a valid email address and a premier or business PayPal
Account?

<snippety>

Yes, and I'm not stupid enough to risk losing it through
participation in an illegal and non-functional "chain letter" scam.

Post reported to Yahoo, Google Groups Abuse, and PayPal Security.


--
Dr. Anton T. Squeegee, Director, Dutch Surrealist Plumbing Institute
(Known to some as Bruce Lane, KC7GR)
http://www.bluefeathertech.com -- kyrrin a/t bluefeathertech d-o=t calm
"Salvadore Dali's computer has surreal ports..."

 

[Michael A. Terrell]

"Dr. Anton T. Squeegee" wrote:

In article <1165066997.820352.79920@l12g2000cwl.googlegroups.com>,
avonchick349@yahoo.com (known to some as avonchick349@yahoo.com)
scribed...

Do you have a valid email address and a premier or business PayPal
Account?

snippety

Yes, and I'm not stupid enough to risk losing it through
participation in an illegal and non-functional "chain letter" scam.

Post reported to Yahoo, Google Groups Abuse, and PayPal Security.

You missed their ISP: abuse@comcast.net


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[Charles Schuler]

shove it

 

[Charles Schuler]

shove it

 

[Anders N. Vinje]

Hello.
Take a look at this.
http://home.online.no/~annlaune/Electronics/Opampcircuit.bmp

I made two resistor divider networks. On making 1 V from a 12 V source. You
may need to change these if you have another powersupply with a diffrent
voltage. The best soulution would be if it is a voltage ref source.
The other divider makes the 5V go from 0V - 3V instead.
These er feed into buffer amplifiers so loading won`t be a problem. Then
these to voltages are added, and then inverted by the last opamp. So now u
got a input voltage going from 0-5V and a output going from 1-4V
This may not be the best soultion but it will work....


http://home.online.no/~annlaune/Electronics/Opampcircuit.bmp

Cheers

Anders n. Vinje


"The Grim Reaper" <dontbother@Idontwanttoknow.com> wrote in message
news:UuadnUdSkaQ55O7YnZ2dnUVZ8sudnZ2d@bt.com...

Hi all,

I'm wanting to get a voltage amplified in a negative way... the opposite
of amplified (!!??!).
For instance, if I put between 0 and 5 volts into the amp, I want a
corresponding 1 to 4 volts out - does that make sense??
In practice, I need to get between 0.1 and 0.35 volts from the 0 to 5 volt
input.

I've been googling for hours, re-learning everything about 741's, gain and
all that stuff I thought I'd remember from school... but no luck!
Perhaps I've been looking for the wrong thing?!? If anyone knows the
correct phrase to describe this type of circuit, it may point me in the
right direction!!

Thanks for any suggestions.
__________________________________
The Christmas Grimch

 

[Kingcosmos]

The Grim Reaper wrote:

Hi all,

I'm wanting to get a voltage amplified in a negative way... the opposite of
amplified (!!??!).
For instance, if I put between 0 and 5 volts into the amp, I want a
corresponding 1 to 4 volts out - does that make sense??
In practice, I need to get between 0.1 and 0.35 volts from the 0 to 5 volt
input.

When you state 'amplification in a negative way' you must mean
attenuation. Op-amps can be used as an attenuator. However I'm
confused...do you need a 1V to 4V or a 0.1V to 0.35V output signal from
a 0V to 5V input.

 

[ehsjr]

John Whittaker wrote:

Ok, more meat for the bones. The device is an electronic locker for the
rear end of my Jeep. The locker is engaged by an electromagnetic, and the
more current you allow it, the more it locks up. I would like to be able to
have a three position switch that would allow 1. no current, 2. 12 volts,
but limit the amperage to only 1 amp, and 3. 12 volts, and the total draw,
where it would be around 7 amps. This would allow me to have a limited slip
in one position, a stronger limited slip in the second, and the differential
completely locked up in the third and final. (even with no current, the
differential still has limited slip capability) Hope that helps.

John Whittaker

This will do it:

+12---+---o> o1
|
| o2------------+---[Ry1]---+
o | |
| o3---+--->|---+----|<-----+
Ry-1 |<| | |
N/O | +--------+---[Ry2]---+--- Gnd
| | |
| |<| RY2 +-----|<----+
| | | N/O
+-------o o------------------------+
| |
[.5R] |
| ----- |
+------+----Vin|LM317|Vout---+ |
| | ----- | |
| | Adj [1.2R] |
[TVS] [.1uF] | | |
| | +----------+-----+--- To locker
| |
Gnd ----+------+------------------------------- To Locker

The LM317 will need to be on a good heatsink. The Ry1 N/O
contact is the on/off switch. The RY2 N/O contact selects
whether the circuit provides 1 amp or full current. With
Ry1 energized, the circuit is on, and with Ry2 energized,
full current will be available from the circuit. With Ry1
energized and Ry2 not energized, 1 amp will be available
from the circuit.

Use automotive relays - their contacts are rated at 20 amps
or more. The 1.2 ohm resistor needs to be at least 2 watts.
The diodes can be 1N400x. The TVS can be a 1.5KE24CA and
the .5 ohm resistor can be two 1 ohm 10 watt resistors in
paralell. Those parts are used to give the LM317 some
protection from the jeep's electrical system which is likely
to produce some high voltage spikes.

Ed

 

[jasen]

On 2006-12-04, John Whittaker <jcwhitty@comcast.net> wrote:

Ok, more meat for the bones. The device is an electronic locker for the
rear end of my Jeep.

differential locker.

The locker is engaged by an electromagnetic, and the
more current you allow it, the more it locks up. I would like to be able to
have a three position switch that would allow 1. no current, 2. 12 volts,
but limit the amperage to only 1 amp, and 3. 12 volts, and the total draw,
where it would be around 7 amps.

put a 15W brake lamp in series with the line feeding it, that'll give reduce
the current to close enough to 1A. You could use a 10W (or larger) 10ohm
resistor - it'll get hot (as does the lamp) so mount it somewhere where
air circulates.

This would allow me to have a limited slip
in one position, a stronger limited slip in the second, and the differential
completely locked up in the third and final. (even with no current, the
differential still has limited slip capability) Hope that helps.

could work, could break something, have you checked that out?



--

Bye.
Jasen

 

[The Grim Reaper]

"Kingcosmos" <waynelittle@sbcglobal.net> wrote in message
news:1165203573.268598.166620@l12g2000cwl.googlegroups.com...

The Grim Reaper wrote:
Hi all,

I'm wanting to get a voltage amplified in a negative way... the opposite
of
amplified (!!??!).
For instance, if I put between 0 and 5 volts into the amp, I want a
corresponding 1 to 4 volts out - does that make sense??
In practice, I need to get between 0.1 and 0.35 volts from the 0 to 5
volt
input.

When you state 'amplification in a negative way' you must mean
attenuation. Op-amps can be used as an attenuator. However I'm
confused...do you need a 1V to 4V or a 0.1V to 0.35V output signal from
a 0V to 5V input.

I need the 0.1v to 0.35v from a 0v to 5v input. The 1v to 4v was just an

example.
If it can be done with some sort of resistor divider arrangement, then I'd
be able to calculate slightly different voltages - for manual calibration.

I've had another idea - scrap all the fiddling about and use a PIC chip....

_______________________
The Grim Reaper

 

[AJ]

"The Grim Reaper" <dontbother@Idontwanttoknow.com> wrote in message
news:UuadnUdSkaQ55O7YnZ2dnUVZ8sudnZ2d@bt.com...

Hi all,

I'm wanting to get a voltage amplified in a negative way... the opposite
of amplified (!!??!).
For instance, if I put between 0 and 5 volts into the amp, I want a
corresponding 1 to 4 volts out - does that make sense??
In practice, I need to get between 0.1 and 0.35 volts from the 0 to 5 volt
input.

I've been googling for hours, re-learning everything about 741's, gain and
all that stuff I thought I'd remember from school... but no luck!
Perhaps I've been looking for the wrong thing?!? If anyone knows the
correct phrase to describe this type of circuit, it may point me in the
right direction!!

Thanks for any suggestions.
__________________________________
The Christmas Grimch

Could you use a resistor divider buffered with an OP AMP configured as a
"voltage follower"?

Regards

AJ

 

[Ross Herbert]

On Sun, 3 Dec 2006 16:46:46 -0800, "John Whittaker"
<jcwhitty@comcast.net> wrote:

Ok, more meat for the bones. The device is an electronic locker for the
rear end of my Jeep. The locker is engaged by an electromagnetic, and the
more current you allow it, the more it locks up. I would like to be able to
have a three position switch that would allow 1. no current, 2. 12 volts,
but limit the amperage to only 1 amp, and 3. 12 volts, and the total draw,
where it would be around 7 amps. This would allow me to have a limited slip
in one position, a stronger limited slip in the second, and the differential
completely locked up in the third and final. (even with no current, the
differential still has limited slip capability) Hope that helps.

John Whittaker

Have you thought about the legal ramifications or implications of
fitting a simple DIY electromagnetic controller to your vehicle? It
may even be illegal to do so if it doesn't meet certain design
criteria. I don't know myself but I thought it might be worth a
mention.

Why not investigate controllers already designed and approved for such
applications? eg.
http://www.gkndriveline.com/gkn-driveline/jsp_en/solutions/tmd/emcd.jsp

 

[Chris]

The Grim Reaper wrote:

Hi all,

I'm wanting to get a voltage amplified in a negative way... the opposite of
amplified (!!??!).
For instance, if I put between 0 and 5 volts into the amp, I want a
corresponding 1 to 4 volts out - does that make sense??
In practice, I need to get between 0.1 and 0.35 volts from the 0 to 5 volt
input.

I've been googling for hours, re-learning everything about 741's, gain and
all that stuff I thought I'd remember from school... but no luck!
Perhaps I've been looking for the wrong thing?!? If anyone knows the
correct phrase to describe this type of circuit, it may point me in the
right direction!!

Thanks for any suggestions.
__________________________________
The Christmas Grimch

Hi, Grim. The key word you're looking for is "Non-inverting summing
amplifier". Google that and you'll be OK.

Since your gain is actually less than 1, you can use the input
resistors as an attenuator, and use the special case of the
non-inverting summer with a gain of 1 (also called a voltage follower),
like this (view in fixed font or M$ Notepad):

|
| +5V
| +
| | Vin
| .-. 0 to 5V ___
| R1| | o-----|___|--.
| | | 200K | 1/2LM358
| '-' 1/2LM358 | |\ Vo - approx.
| | +5V o----|+\ 0.1-0.35V
| .-. |\| | | >--o----o
| P1| |<---|+\ 0.1V___ | .--|-/ |
| | | | >--o-|___|--' | |/ |
| '-' .--|-/ | 10K | |
| | | |/| | | |
| === | === | '--------'
| GND | GND |
| '--------'
|
(created by AACircuit v1.28.6 beta 04/19/05 www.tech-chat.de)

Choose R1 to go with your P1 such that you can easily set it for 0.1V
at the output of the first voltage follower. Them the two resistors
give you an approximately 20:1 attenuation of the input signal, which
is what you need to get 0.25V span (0.35V - 0.1V).

1% resistors will get you in closer, but you get the idea, I guess.

Have a Grim holiday, sir.
Chris

 

2 resistors and Bobs your uncle..

 

[jasen]

On 2006-12-04, ehsjr <ehsjr@bellatlantic.net> wrote:

John Whittaker wrote:
Ok, more meat for the bones. The device is an electronic locker for the
rear end of my Jeep. The locker is engaged by an electromagnetic, and the
more current you allow it, the more it locks up. I would like to be able to
have a three position switch that would allow 1. no current, 2. 12 volts,
but limit the amperage to only 1 amp, and 3. 12 volts, and the total draw,
where it would be around 7 amps. This would allow me to have a limited slip
in one position, a stronger limited slip in the second, and the differential
completely locked up in the third and final. (even with no current, the
differential still has limited slip capability) Hope that helps.

John Whittaker

This will do it:

+12---+---o> o1
|
| o2------------+---[Ry1]---+
o | |
| o3---+--->|---+----|<-----+
Ry-1 |<| | |
N/O | +--------+---[Ry2]---+--- Gnd
| | |
| |<| RY2 +-----|<----+
| | | N/O
+-------o o------------------------+
| |
[.5R] |
| ----- |
+------+----Vin|LM317|Vout---+ |
| | ----- | |
| | Adj [1.2R] |
[TVS] [.1uF] | | |
| | +----------+-----+--- To locker
| |
Gnd ----+------+------------------------------- To Locker

The LM317 will need to be on a good heatsink.

What's the TVS for?

I can see it destroying the LM317 if a surge hits with
both relays energised.

the locker mechanism is likely a large electromagnet.

when RY2 opens you've got more problems. the inductance of the electromagnet
will fly back and exceed the voltage rating of the 317.

the locker mechanism is likely a large electromagnet.
but with a DC supply it's behavior is basically that of a resistor,

7A from 13.5V is pretty close to 2 ohms, another 11 in series will get him
close to 1A and avoids delicate semiconductors and the need for a heatsink.

ventilation is still needed.

Bye.
Jasen

 

[Chris]

Chris wrote:

The Grim Reaper wrote:
Hi all,

I'm wanting to get a voltage amplified in a negative way... the opposite of
amplified (!!??!).
For instance, if I put between 0 and 5 volts into the amp, I want a
corresponding 1 to 4 volts out - does that make sense??
In practice, I need to get between 0.1 and 0.35 volts from the 0 to 5 volt
input.

I've been googling for hours, re-learning everything about 741's, gain and
all that stuff I thought I'd remember from school... but no luck!
Perhaps I've been looking for the wrong thing?!? If anyone knows the
correct phrase to describe this type of circuit, it may point me in the
right direction!!

Thanks for any suggestions.
__________________________________
The Christmas Grimch

Hi, Grim. The key word you're looking for is "Non-inverting summing
amplifier". Google that and you'll be OK.

Since your gain is actually less than 1, you can use the input
resistors as an attenuator, and use the special case of the
non-inverting summer with a gain of 1 (also called a voltage follower),
like this (view in fixed font or M$ Notepad):

|
| +5V
| +
| | Vin
| .-. 0 to 5V ___
| R1| | o-----|___|--.
| | | 200K | 1/2LM358
| '-' 1/2LM358 | |\ Vo - approx.
| | +5V o----|+\ 0.1-0.35V
| .-. |\| | | >--o----o
| P1| |<---|+\ 0.1V___ | .--|-/ |
| | | | >--o-|___|--' | |/ |
| '-' .--|-/ | 10K | |
| | | |/| | | |
| === | === | '--------'
| GND | GND |
| '--------'
|
(created by AACircuit v1.28.6 beta 04/19/05 www.tech-chat.de)

Choose R1 to go with your P1 such that you can easily set it for 0.1V
at the output of the first voltage follower. Them the two resistors
give you an approximately 20:1 attenuation of the input signal, which
is what you need to get 0.25V span (0.35V - 0.1V).

1% resistors will get you in closer, but you get the idea, I guess.

Have a Grim holiday, sir.
Chris

Sorry -- I should have proofed this, but got busy on a call. A couple
of tweaks:

1) You adjust P1 so that there's 0.1V at the output of the second
voltage follower with a 0V input.

2) The 200K/10K divider is a 21:1 divider. A little sloppy there. Try
82K/4.3K for best 5% match, or 215K/11.3K for best 1% match.

3) The LM358 is a nice cheapie dual op amp, but you might have a little
trouble getting down to 0.1V without placing a 3.3K load resistor from
the outputs of the first and second voltage followers to GND. This is
in addition to the rest of the circuitry.

Cheers
Chris

 

[Chris Jones]

The Grim Reaper wrote:

Part 1 - I need to count/log the number of times a 3mm red LED flashes.
The flash (on) period is very short - looks like half a second-ish, and
the
period between flashes varies between 5 seconds and 2 minutes. I can't
interact with this circuit, so I've got to read it optically.
I've got a simple 741 voltage comparator setup that works OK with an LDR
(using a green, not red, LED as test input). However, I believe the
response time can be improved. Google as I might, I can't seem to find a
lot of information on phototransistors or other high speed, but cheap
optical sensors.
Any ideas appreciated.

Which brings me to Part 2; I've found what I thought was a phototransistor
in my pile of spare bits - photos here:
http://www.grsoftware.co.uk/PhotoTransistor.jpg but I can't for the life
of me find any specs on this part, and I can't even remember where I got
it from!!
The numbering on the side is R8305462T102. For an idea of scale, it's the
same size as a BC107 (T 192 case?!).
There is no base connector... I tried wiring it up as a simple input (in
the same circuit, replacing the LDR) but get no change in voltage,
resistance or
current from any legs!! Think it's bust?!?
Again, any ideas appreciated!!

Thanks
__________________________________
The Grim Reaper

I guess this is an electricity meter that has the flashing light - am I
right?

I found this:
http://www.bwired.nl/stroom.asp

Probably a phototransistor or a photodiode should work, but getting it close
to the LED will help a lot.

I would suggest trying the photodiode or phototransistor in series with a
very high value resistor (try 1M as a starting value, or a 1M variable
resistor in series with a 10k safety resistor would allow adjustment),
across a 9V battery. The photodiode would need to be connected in the
direction so that its anode is more negative than its cathode, otherwise it
will always conduct regardless of light level. A phototransistor would be
more sensitive, but the sensitivity would be less stable with temperature
and when substituting different phototransistors of the same type, As the
other poster suggested, you can measure the voltage across the resistor
with a digital multimeter, and this will indicate when current is flowing.
By using a high resistor value, the circuit will be more sensitive. You
then need to use some kind of comparator with a high input impedance, you
could use a 741, but the standby power consumption would be lower if you
use a CMOS inverter chip line CD4069, CD40106, 74C14 etc.

----------
| |
| ----- <====
| / \ <====
| / \
| -----
| | |\
| | | \
| *--------- >O----------
| | | /
| + | |/
------- <
--- >
| <
| >
| |
----------

Chris

 

[terry]

Tyro wrote:

I recently bought a Sony CMT-SPZ90DAB mini hi-fi with a DAB radio. The
aerial provided is a 2m length of wire connected to one female pin of a
a small plastic 3 pin plug which fits into a 3 male pin socket. There
is no other aerial connection. Reception in my area is very poor and I
have lost most of my favourite FM stations, and can receive only 6 DAB
frequencies.

I have a roof top mounted FM Yagi with 50 ohm co-ax and an internal
"slim jim" DAB aerial with 75 ohm co-ax and no way of connecting either
to the radio. Connecting to the single pin or the aerial wire, and
earthing the braid to casing doesn't work.

A Google search provided the following from a 2001 post to this group

"If you *must* go tampering inside this crap radio, connect the coax
inner via a small (100pf?) capacitor to wherever the dangly wire goes,
and the outer by another capacitor to the largest lump of copper you
can
find on the PCB."

Can anyone confirm that this is correct or have any other suggestions?
I know little about radio electronics and would appreciate help from
one of you knowledgeable boffins out there.

Here's hoping.
..

What frequencies do these DAB radios receive.
Satellites? Gigahertz etc.?
OP says he 'lost' his FM stations? Surely he needs an FM band radio to
receive them; using either a whip antenna or connecting to and pointing
his FM antenna in the proper direction?
Question puzzles, sorry.