Chip with simple program for Toy

[Nog]

The old Eccles-Jordan bistable multivibrator. The original flip-flop.


"Andrew Holme" <andrew@nospam.com> wrote in message
news:d3lmlb$n3j$1$8300dec7@news.demon.co.uk...

Thomas Vogel wrote:
What´s an MVB? Is it a special IC?

It might be a multivibrator.

 

[John Bokma]

Chris wrote:

Thomas Vogel wrote:
Where in the web can I find maps of circuits?

Hi, Thomas. They're called schematic diagrams.

http://www.uoguelph.ca/~antoon/circ/circuits.htm
^^^^^^^^^^^^
http://www.discovercircuits.com/list.htm
^^^^^^^^

or circuit diagrams, electronic circuits, or even circuits :-D


--
John MexIT: http://johnbokma.com/mexit/
personal page: http://johnbokma.com/
Experienced programmer available: http://castleamber.com/
Happy Customers: http://castleamber.com/testimonials.html

 

[Rein Wiehler]

Thomas Vogel wrote:

Where in the web can I find maps of circuits?

und was sollen denn das fuer mappen sein???

 

[Lord Garth]

<henszey@gmail.com> wrote in message
news:1113522107.742301.223560@f14g2000cwb.googlegroups.com...

How do I keep the peltier from trying pull more amps than the
powersupply can handle with out droping the voltage?

Thanks

You don't! You make sure your power supply has the necessary head room and
let the peltier take what it needs.

 

[John Popelish]

henszey@gmail.com wrote:

How do I keep the peltier from trying pull more amps than the
powersupply can handle with out droping the voltage?

If you built a switching buck regulator, you could lower the supply

voltage to the peltier so it would draw less current (and move less
heat). The current demand is roughly proportional to the supply
voltage. So, for instance, if you lowered the 15 volt supply to 10
volts, the peltier current would fall from 15 amps to 10 for a total
power to the peltier of 10 volts * 10 amperes = 100 watts.

Assuming the efficiency of the buck regulator was 90%, its input
current would be (100 watts * 100/90%)/ 15 volts = 7.4 amps.

 

[Lord Garth]

"Paul Hovnanian P.E." <Paul@Hovnanian.com> wrote in message
news:425F2CE6.A1258189@Hovnanian.com...

I want to be entombed in Yucca Mountain. That way its not likely that
any nosey anthropologists will try to dig me up for a few hundred
thousand years.

--

Good luck with digging a hole...

 

[cl]

I thought this thread died a couple weeks ago. What a bunch of bull crap. Oh
well, it's dead now, at least in my system. Killfiled.

<stratus46@yahoo.com> wrote in message
news:1113536945.833585.306630@f14g2000cwb.googlegroups.com...

And no trolls. Right?
GG

 

[Ban]

EDA_Master wrote:

******************************­***
******************************­***
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It includes a very good selection of free electronics books , SPICE
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tutorials , Circuits and Full Electronics Projects , Matlab tutorials
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Highly recommended !

Forum's address :
Hope you'll find it useful !

You are spamming a couple of NGs with your Ad, just be so kind to put [AD]
in the header, so we know what it is meant to be.
--
ciao Ban
Bordighera, Italy

 

[Lord Garth]

"jason" <cheanglong@gmail.com> wrote in message
news:1113574132.940016.48590@z14g2000cwz.googlegroups.com...

Sure Garth(or Jon). I will do my best as a learner and help people who
is in need
Thank you so much


Jason

Great, keep up with your studies!
You are welcome

 

[John Popelish]

Clive wrote:

Hi,

Most texts and web sites gloss over the secondary, or HT circuit, in an
automotive points based ignition circuit. Explanations simply say that
voltage produced at the HT post of the secondary winding enables the
spark to jump to ground, but do not explain the circuit from the other
end of the secondary winding to complete the circuit.

The layout of the circuit I am considering is where the -ve terminal of
the coils is connected to both the primary and secondary windings. I
hope the ascii rendering below explains the circuit.

As the points are open when the HT voltage is induced in the secondary,
it seems to me that the only routes are either through the condenser or
the battery.

Compared to the voltage produced by the HT winding, the battery
voltage is essentially zero, and therefore, the positive battery
terminal is essentially a ground connection.

If the LT coil is phased correctly with the HT coil, it adds another
1% or so to the HT output voltage.

I have only seen the role of the condensor discussed in terms of the
back EMF from the primary.

Its primary (excuse the pun) purpose is to control the rate of rise of
voltage as the points open, to minimize arching (which damages the
points and consumes energy that would otherwise go into the plug
spark). It has a minor effect on the spark characteristics at the plug.

Thanks,
Clive.


+ve HT distrib
----------o--c||C--O----------­()------------
| c||C |
| Primary c||C Secondary |
| c||C o
| |--| [] Spark Plug
[+] | . gap
[ ] -ve o |
[ ] Battery | Grnd ---
[ ] |----- -
[-] | |
| Points / === Condensor
| / |
--- Grnd |-----
- |
Grnd ---
-

 

[John Fields]

On 15 Apr 2005 13:04:14 -0700, "aman" <aman.bindra@gmail.com> wrote:

Is it possible to use 555 to generate a pulse which triggers after
every 24 hours.

---
Not by itself.
---

Am I looking at an RC time constant which is not at all feasible ?

---
Yes.

--
John Fields
Professional Circuit Designer

 

[Larry Brasfield]

"aman" <aman.bindra@gmail.com> wrote in message
news:1113594290.611535.21470@g14g2000cwa.googlegroups.com...

Is it possible to use 555 to generate a pulse which triggers after
every 24 hours. Am I looking at an RC time constant which is not at all
feasible ?

With a supercap, you could think of getting a few hours
with 20% accuracy. Your 24 hours is out of reach, as
Mr. Fields states. You need to be thinking about some
kind of digital accumulation of a shorter interval that can
be done more accurately.

--
--Larry Brasfield
email: donotspam_larry_brasfield@hotmail.com
Above views may belong only to me.

 

[Rudolf Wiesendanger]

I would try a 4060 or 74HC060(CMOS).
It contains a oscillator and a counter.
H.T.H

"aman" <aman.bindra@gmail.com> wrote in
news:1113594290.611535.21470@g14g2000cwa.googlegroups.com:

Is it possible to use 555 to generate a pulse which triggers after
every 24 hours. Am I looking at an RC time constant which is not at all
feasible ?

 

[Chris]

"aman" <aman.bindra@gmail.com> wrote in message
news:1113594290.611535.21470@g14g2000cwa.googlegroups.com...

Is it possible to use 555 to generate a pulse which triggers after
every 24 hours. Am I looking at an RC time constant which is not at all
feasible ?

No, and even if you could how long would it take to calibrate. A week, 2
weeks ....

Cheers.

 

[Michael Black]

"aman" (aman.bindra@gmail.com) writes:

Is it possible to use 555 to generate a pulse which triggers after
every 24 hours. Am I looking at an RC time constant which is not at all
feasible ?

No, that's why Exar introduced the 2240, which was a 555 (though without

some of the pins externally available) in a package with a 7-bit binary
counter. Via feedback you can set the divider to whatever you want,
and then you run the 555 at a decent rate. As people have pointed out,
you can then adjust the clock almost immediately, and you don't fuss
with the impossible of getting suitable components for such low timing
rates.

I have no idea if the 2240 is still available.

Of course, you might look at what the end game is. Having a detector
to note when the sun comes up (or goes down) may provide the same
effect, given that you specify 24 hours.

Michael

 

[Rich Grise]

On Wed, 13 Apr 2005 08:36:45 -0700, greenman_11_11 wrote:

Excellent suggestion, thank you very much. Another question: Is there
a digital potentiometer available that will carry a wiper current up to
25 ma continuously? If so, I could replace all those discreet
components with the pot, and get 256 resistor values instead of 8,
which would be nice for this project. The output of my circuit will
draw up to 20 ma of current at the lowest resistor value. I looked at
the AD8400 and it will only allow a max current of 5 ma when the wiper
is set at the lowest (50 ohm) setting. Is there another device similar
to the AD8400 that is designed to carry more current? Thanks for your
help.

This makes it actually sound like you're looking for a multiplying DAC
and buffer.

Is it a programmable _resistance_ you're actually looking for? Or are
you making a divider or something, to give a programmable voltage or
current?

Good Luck!
Rich

 

[Kim Sleep]

I was trying the same thing, and was able to accomplish this with a huge
electrolytic, and a huge value capacitor that would cycle every 12 hours,
quite accurately.
I once saw a circuit that pulsed a 555 every couple of hours, advancing a
4017. Once the 4017 advanced the required number of cycles, it reset, and
began counting again. so if you could get a 555 pulsing every 2 1/2 hours,
with a 4017 having 10 outputs , your pretty close.
"aman" <aman.bindra@gmail.com> wrote in message
news:1113594290.611535.21470@g14g2000cwa.googlegroups.com...

Is it possible to use 555 to generate a pulse which triggers after
every 24 hours. Am I looking at an RC time constant which is not at all
feasible ?

 

[Winfield Hill]

Michael Black wrote...

"aman" (aman.bindra@gmail.com) writes:
Is it possible to use 555 to generate a pulse which triggers after
every 24 hours. Am I looking at an RC time constant which is not at
all feasible ?

No, that's why Exar introduced the 2240, which was a 555 (though without
some of the pins externally available) in a package with a 7-bit binary
counter. Via feedback you can set the divider to whatever you want,
and then you run the 555 at a decent rate. As people have pointed out,
you can then adjust the clock almost immediately, and you don't fuss
with the impossible of getting suitable components for such low timing
rates.

I have no idea if the 2240 is still available.

Exar's XR-2240 was second-sourced, often with the same part number.
Plus there was Fairchild and TI's uA2240, and NSC's LM2240. In
the old days you could find one of these at suppliers like Jameco.
I looked and didn't see any, so perhaps it's the end of that era.

In the back of my mind I think there's a similar chip... Aha, yes
now I remember, it's Intersil's icm7240 series, also made by Maxim.
These are still available. For example, the popular ICM7242 is an
8-pin chip with a 555-style oscillator driving an 8-bit divider,
see http://www.intersil.com/cda/deviceinfo/0,1477,ICM7242,0.html

To finish the story, there are some other single-ICs using the
'2240 '7240 oscillator-plus-counter idea, but without the classic
relatively-precise 555-style oscillator. Examples are the CD4060
or 74HC6060, the mc14536 or mc4541, plus Philips' 74HCT5555, etc.
These use a different type of simple CMOS relaxation oscillator.

Unless you succumb to the PIC crowd :&gt, you may want to explore
a two-chip solution, which allows higher oscillator frequencies.


--
Thanks,
- Win

 

[Byron A Jeff]

In article <1113594290.611535.21470@g14g2000cwa.googlegroups.com>,
aman <aman.bindra@gmail.com> wrote:

Is it possible to use 555 to generate a pulse which triggers after
every 24 hours.

Not by itself. There's no way to generate a RC constant with any accuracy
over that long a period of time.

Am I looking at an RC time constant which is not at all feasible ?

Right.

It's tasks like this where flash microcontrollers really excell. Something
like a small PIC or AVR can knock out this application with a single chip
and no external parts except for maybe a transistor switch to get to the
same 200 mA output current of the 555.

BAJ

 

[Chris]

"js5895" <JoshTmp@nycap.rr.com> wrote in message
news:1113700028.363960.100080@o13g2000cwo.googlegroups.com...

Hi,

I have a 3-way wall switch that lights when the load is off.
It somehow seems to work with one wire or in series with the load.
how does that work? I understand basic electrical but, this is weird.

Thank you.

It's most likely a neon in series with the line/active/hot and the load and
neutral to complete the circuit. When the switch is in the on position it
shorts this out.
If it isn't lit, it means the globe is blown.

Cheers.