design help

Lots of scientific types still program in FORTRAN. Astronomers, I've been told.

FORTRAN is now over 50 years old.

John

Do I have to give all the money back?

John

Have you ever sat down and actually done a micro cpu design? I have. It's fun. And with cheap FPGA's, it's not even expensive nor does it require any soldering skills.

Consider the question along the lines of 8-bit widths. You might understand. If not, I can provide some examples. But it's better (easier on me) if you think about it a little bit, first.

Jon

your analysis appears correct, but yes,

trigger operates at 1/3 vcc

one fix is to add a resistor in series with the 2n2222 base, eg: 1Ks to 330 and put a 680 in series with the base,

the circuit appears to have too many parts, but that's just a feeling I've not read the specifications carefully.

+--+--+-----------+----- +12V | | | | | +| | | 2200uF | === | . . . .|. . . . | | | . VCC(8) . | | | . . | | `--RES(4) OUT(3)---------+----+ [1M] | . LM555 . | _|_ | +--------TH(6) DIS(7)-- | | /| relay coil | | . . | | / | +--+--------TR(2) CV(5)-- _|_ |/__| | . . /_\\ | |o . GND(1) . | | 1n4001 diode |o . . . .|. . . . | | | | | | +-[10]------------+------------+----+--- ground assuming relay coil resistance is more than 120 ohms this should do what you want. (last time I measures a headlight relay it was 430 ohms) The 10 ohm capacitor is to prevent high currents when the switch closes.

Y'know, ASCII-art editing is really a crappy way to design circuits. You wind up doing the 'art' part pushing round ASCII at a time when your is brain off the circuit.

I left an inappropriate feedback path when cut-n-pasting the above ckt from its predecessor.

+12v -+- | .-------------------+----------+ | | | [R1] [R3] | | | | | | | | |

apparenly without a diode parallel to the relay?

jusdging by some of the efforts seen here pics may be asier to program than 555s

5 parts not counting the switch and relay eh?

I did it in that including the diode.

I think so.

If it's just to tell 1 and l apart, a decent font will do it in zero.

Here you go, my one 555 design for 2009:-

VCC + | 1N4005 +---+------+--+ VCC | | | | | | + | | | | o /o | | | - C| / | | | ^ C| / .-. .-----------. | C| o 1K0| | | 4 8 | | | | | | | | | | '-' +-----| 6 | | | | 1N4148 | | 3|-+--+ +---->|-----+------+-----| 2 | | | | | TLC555 | | | | | 7 |- \\ o | + .-. | | \\ ### | | | 1 5 |- \\. --- | | '-----------' o 100uF | '-' | | | | 1M5 | | | | | === === === === GND GND GND GND

Best regards, Spehro Pefhany

--
"it\'s the network..."                          "The Journey is the reward"
speff@interlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com

Here you go, my one 555 design for 2009:-

VCC + | 1N4005 +---+------+--+ VCC | | | | | | + | | | | o /o | | | - C| / | | | ^ C| / .-. .-----------. | C| o 1K0| | | 4 8 | | | | | | | | | | '-' +-----| 6 | | | | 1N4148 | | 3|-+--+ +---->|-----+------+-----| 2 | | | | | TLC555 | | | | | 7 |- \\ o | + .-. | | \\ ### | | | 1 5 |- \\. --- | | '-----------' o 100uF | '-' | | | | 1M5 | | | | | === === === === GND GND GND GND

Best regards, Spehro Pefhany

--
"it\'s the network..."                          "The Journey is the reward"
speff@interlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com

--
Maybe, but you certainly don\'t have any room to criticize, what with the
paucity of parts on that abomination above.

Anyway, I opted out of the 555 solution and went for a comparator.

JF

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Sure; it\'s a switch debouncer.

JF

For your coding transgressions, YES! ;-)

--
You didn\'t just misunderstand the polarities, you misunderstood the
circuit\'s raison d\'être. 

Big difference.

Besides, you\'re the one who\'s always preaching about being careful,
checking your work, etc., etc., etc., so it seems sort of hypocritical
that you\'d give this app a lick and a promise.

I've

t the

on

But I

te

istor

lay

The

there

in

(posted from google groups since it has not appeared after being sent twice from Forte)

Here you go, my one 555 design for 2009:-

VCC + | 1N4005 +---+------+--+ VCC | | | | | | + | | | | o /o | | | - C| / | | | ^ C| / .-. .-----------. | C| o 1K0| | | 4 8 | | | | | | | | | | '-' +-----| 6 | | | | 1N4148 | | 3|-+--+ +---->|-----+------+-----| 2 | | | | | TLC555 | | | | | 7 |- \\ o | + .-. | | \\ ### | | | 1 5 |- \\. --- | | '-----------' o 100uF | '-' | | | | 1M5 | | | | | =3D=3D=3D =3D=3D=3D =3D=3D=3D =3D=3D=3D GND GND GND GND

Best regards, Spehro Pefhany

-- "it's the network..." "The Journey is the reward" snipped-for-privacy@interlog.com Info for manufacturers:

m Embedded software/hardware/analog Info for designers: m

--
That was later on, and it isn\'t accurate at all.

What you like to do is try to belittle anyone who catches one of your
errors in an attempt to make their position questionable and therefore
trivialize the error.

Typical cheater tactics.

--
Clever.

Damn fine use of the internal divider and the output sink. 

Best one yet!

JF

"Paucity of parts"? I'm trying to come up with the simplest circuit that will work, and you're trying to come up with the most complex one. Different design goal.

John

Ooh, French.

Yup, you're a real beauty.

John