Multiplying Frequency

[snip]

Naaah! The averaging is in the tranny.

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
I love to cook with wine.      Sometimes I even put it in the food.

Since the OP is feeding a transmission controller CPU, will the micro be fast enough?

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
I love to cook with wine.      Sometimes I even put it in the food.

Torque converter, engine, flywheel perhaps? The tranny's all gears, right?

--
  Keith

Since we don't know the maximum frequency, it's hard to tell.

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

Thanks for your reply, Mike. To divide by 100 would i use a counter and a flip flop to make the duty cycle 50%.

-Rich

It's a lot of trouble to open up a trans and i have no idea where to find a replamemt gear. Also the down time would be very long.

-Rich

The speedometer reads up to 140 although i would never drive that fast. The maxium input frequency would be 140x36.5 = 5.11kHz.

-Rich

I haven't done much digital stuff for years, so maybe someone else could help you with that. There may be a /10 counter that will give you a 50% DC so you wouldn't need a seperate F/F.

Mike

------------------------------------------------------------------------ The odds of a single modest length protein randomly forming is approx

1 in 10^260. By comparison the number atoms in the known universe has been estimated at 10^80 atoms. Figues are from the writings of Nobel Prize winner Francis Crick in 1981.

I'm missing posts so maybe already suggested. Use a couple of Microchip's (were TelCom) nice TC9400 v-f f-v chips. They'll run from 12V and the (well written) app note AN795, page 11, shows the exceedingly simple frequency division setup. john

=&section=&NextRow=&ssUserText=tc9400

In article , Mike wrote: [....]

74xx90 has a divide by 5 and a divide by 2. If you do it in the 5 then 2 order, you get a squarewave.

--
--
kensmith@rahul.net   forging knowledge

In article , Jim Thompson wrote: [....]

No, thats just the divider chain. The PLL looks like this:

ASCII art:

Pulse in ---------- )!!

Sno-o-o-o-ort ;-)

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
I love to cook with wine.      Sometimes I even put it in the food.

and maybe a CD/74HC/74HCT4059 for the /118 in the PLL.

Mike

------------------------------------------------------------------------ The odds of a single modest length protein randomly forming is approx

1 in 10^260. By comparison the number atoms in the known universe has been estimated at 10^80 atoms. Figues are from the writings of Nobel Prize winner Francis Crick in 1981.

I think a PLL over such a wide frequency range will have issues, since the loop bandwidth will be determined by the low end.

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
I love to cook with wine.      Sometimes I even put it in the food.

Say that might be usable as a quality upgrade in John's AM modulator. You should patent that leather.

Don

One cute method is to use a VCO with an exponential characteristic (easily done with a BJT) and loop filters based on OTAs. That way you can make all the feedback poles and zeroes keep constant ratios with the operating frequency. I designed a 100 Hz - 30 MHz lock-in amplifier that way, back in the palmy days.

Cheers,

Phil Hobbs

That's one helluva way to get the same response as a gear ;-)

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
I love to cook with wine.      Sometimes I even put it in the food.

In article , Phil Hobbs wrote: [...]

You can also use a switched capacitor filter as the loop filter and clock it from the VCO.

--
--
kensmith@rahul.net   forging knowledge

The problem with that method is that it's going to have an amazingly nasty nonlinear transient response, with all sorts of parametric things happening--you want the loop filter's response to depend on where the VCO ought to be, rather than where it is.

Or maybe I'm just being a nervous Nellie. Has that actually been made to work?

Cheers,

Phil Hobbs