Frequency multiplying

[Sash]

Hi,

I'm wanting to build a circuit that receives a square wave input, and
outputs it with a slightly different frequency, depending on a user
adjustable value. I want to alter the frequency by about +/- 20% but it
needs to be adjustable on the fly, ie. a trim pot or similar.

Any ideas?

 

[Phil Allison]

"Sash" <run4et@yahoo.com> wrote in message

Hi,

I'm wanting to build a circuit that receives a square wave input, and
outputs it with a slightly different frequency, depending on a user
adjustable value. I want to alter the frequency by about +/- 20% but it
needs to be adjustable on the fly, ie. a trim pot or similar.

Any ideas?

** You will have to specify the range of frequencies involved AND the
application.

We need to know the application to get an idea of the performance
requirements, power supply needs and decide if a simpler way than YOUR idea
is possible and maybe preferable.





............ Phil

 

[David L. Jones]

"Sash" <run4et@yahoo.com> wrote in message news:<HtqdnVPuErewIwzdRVn-tw@inspired.net.au>...

Hi,

I'm wanting to build a circuit that receives a square wave input, and
outputs it with a slightly different frequency, depending on a user
adjustable value. I want to alter the frequency by about +/- 20% but it
needs to be adjustable on the fly, ie. a trim pot or similar.

Any ideas?

A Frequency To Voltage Converter followed by a Voltage Controlled
Oscillator.
Might be as easy as using a trimpot and a few other bits to adjust the
voltage from the FV converter which then goes into the VCO.
Totally depends on your frequency requirements and application, but
that's a good place to start.

Regards
Dave

 

[Phil Allison]

"David L. Jones" <tronnort@yahoo.com>

"Sash" <run4et@yahoo.com


I'm wanting to build a circuit that receives a square wave input, and
outputs it with a slightly different frequency, depending on a user
adjustable value. I want to alter the frequency by about +/- 20% but it
needs to be adjustable on the fly, ie. a trim pot or similar.

Any ideas?

A Frequency To Voltage Converter followed by a Voltage Controlled
Oscillator.
Might be as easy as using a trimpot and a few other bits to adjust the
voltage from the FV converter which then goes into the VCO.
Totally depends on your frequency requirements and application, but
that's a good place to start.

** What if the OP wants to vary the 1.8 GHz clock on their PC by +/- 20 %
??


With no details the question is just a mindless troll.




............ Phil

 

[Sash]

Sorry, should have included some background information.

I want to input a square wave from the speed sensor in the gearbox of a car,
and adjust this to calibrate the speedometer of the car. A different
differencial has been fitted and it changes the gearing and the speedo. I'm
not sure on the exact frequency's required but its as low as 10-15Hz
(preferably lower) and up to about 450 Hz.

Being in a car, it would run off 12V or less.

Is there any other information that would help?


"Phil Allison" <philallison@optusnet.com.au> wrote in message
news:4091cbef$0$25657$afc38c87@news.optusnet.com.au...

"Sash" <run4et@yahoo.com> wrote in message
Hi,

I'm wanting to build a circuit that receives a square wave input, and
outputs it with a slightly different frequency, depending on a user
adjustable value. I want to alter the frequency by about +/- 20% but it
needs to be adjustable on the fly, ie. a trim pot or similar.

Any ideas?




** You will have to specify the range of frequencies involved AND the
application.

We need to know the application to get an idea of the performance
requirements, power supply needs and decide if a simpler way than YOUR
idea
is possible and maybe preferable.





........... Phil

 

[Sash]

What sort of revices would I be looking at? Schematics?

Thanks,
Sash.


"David L. Jones" <tronnort@yahoo.com> wrote in message
news:894aa0b3.0404302316.41193f02@posting.google.com...

"Sash" <run4et@yahoo.com> wrote in message
news:<HtqdnVPuErewIwzdRVn-tw@inspired.net.au>...
Hi,

I'm wanting to build a circuit that receives a square wave input, and
outputs it with a slightly different frequency, depending on a user
adjustable value. I want to alter the frequency by about +/- 20% but it
needs to be adjustable on the fly, ie. a trim pot or similar.

Any ideas?

A Frequency To Voltage Converter followed by a Voltage Controlled
Oscillator.
Might be as easy as using a trimpot and a few other bits to adjust the
voltage from the FV converter which then goes into the VCO.
Totally depends on your frequency requirements and application, but
that's a good place to start.

Regards
Dave

 

[Bob M]

Hi Sash

I was faced with a similar challenge from a friend of mine. He changed
the ratio of his final drive in his truck for better gas mileage and
the speedo was off by 12% (reading low = speeding tickets). To build
an analogue circuit that can work from 0 to 450 hz (yes the output is
0 when you aren't moving) proved very difficult (extremely wide
capture ratio).

What I did instead was to calculate the exact change he made in the
final drive and then modify the speedo circuit. It had a micro in it.
All I did was replace the crystal with a new one that adjusted for the
change (12% slower). It actually worked, much to my amazement. You
might give this a try!


Cheers from Canada

Bob Morgoch

"Sash" <run4et@yahoo.com> wrote in message news:<PvudnbMJIL9bOQndRVn-hA@inspired.net.au>...

What sort of revices would I be looking at? Schematics?

Thanks,
Sash.


"David L. Jones" <tronnort@yahoo.com> wrote in message
news:894aa0b3.0404302316.41193f02@posting.google.com...
"Sash" <run4et@yahoo.com> wrote in message
news:<HtqdnVPuErewIwzdRVn-tw@inspired.net.au>...
Hi,

I'm wanting to build a circuit that receives a square wave input, and
outputs it with a slightly different frequency, depending on a user
adjustable value. I want to alter the frequency by about +/- 20% but it
needs to be adjustable on the fly, ie. a trim pot or similar.

Any ideas?

A Frequency To Voltage Converter followed by a Voltage Controlled
Oscillator.
Might be as easy as using a trimpot and a few other bits to adjust the
voltage from the FV converter which then goes into the VCO.
Totally depends on your frequency requirements and application, but
that's a good place to start.

Regards
Dave

 

[Julian Edgar]

"Sash" <run4et@yahoo.com> wrote in message
news:bISdnWHZras-OQnd4p2dnA@inspired.net.au...

Sorry, should have included some background information.

I want to input a square wave from the speed sensor in the gearbox of a
car,
and adjust this to calibrate the speedometer of the car. A different
differencial has been fitted and it changes the gearing and the speedo.
I'm
not sure on the exact frequency's required but its as low as 10-15Hz
(preferably lower) and up to about 450 Hz.

Being in a car, it would run off 12V or less.

Is there any other information that would help?

2004 Jaycar catalog, page 12 - Digital Speedo Corrector. It's not available
yet though.

Julian Edgar

 

[David L. Jones]

"Phil Allison" <philallison@optusnet.com.au> wrote in message news:<409361a5$0$4544$afc38c87@news.optusnet.com.au>...

"David L. Jones" <tronnort@yahoo.com
"Sash" <run4et@yahoo.com


I'm wanting to build a circuit that receives a square wave input, and
outputs it with a slightly different frequency, depending on a user
adjustable value. I want to alter the frequency by about +/- 20% but it
needs to be adjustable on the fly, ie. a trim pot or similar.

Any ideas?

A Frequency To Voltage Converter followed by a Voltage Controlled
Oscillator.
Might be as easy as using a trimpot and a few other bits to adjust the
voltage from the FV converter which then goes into the VCO.
Totally depends on your frequency requirements and application, but
that's a good place to start.



** What if the OP wants to vary the 1.8 GHz clock on their PC by +/- 20 %
??
With no details the question is just a mindless troll.

Only in your little world Phil.

I provided a potentially helpful reply without knowing the some
details which the poster obviously forgot to include. No big deal to
the rest of us, but obviously you have some sort of problem with it,
as always...
The post was as far from a "mindless troll" as I could imagine.

Regards
Dave

 

[David L. Jones]

"Sash" <run4et@yahoo.com> wrote in message news:<PvudnbMJIL9bOQndRVn-hA@inspired.net.au>...

What sort of revices would I be looking at? Schematics?

Thanks,
Sash.

A Frequency-Voltage converter chip can be found here:
http://www.national.com/parametric/0,1850,2979,00.html
Others are also available from other manufacturers.

VCO's are a bit harder, but a Google search should bring up some info
and schematics.

Regards
Dave

 

[Phil Allison]

"David L. Jones" <tronnort@yahoo.com>
"Phil Allison" <philallison@optusnet.com.au>

** What if the OP wants to vary the 1.8 GHz clock on their PC by +/-
20 %
??
With no details the question is just a mindless troll.

Only in your little world Phil.

** I live in the real world - shame you have such a low opinion of it.

Must be nice in that gilt edged ivory tower of yours - Dave.

I provided a potentially helpful reply without knowing the some
details which the poster obviously forgot to include.

** Get real you pathetic wanker !!!

You took a wild guess at the facts instead of waiting for the OP to supply
the relevant details.

No big deal to the rest of us,

** Stupidity is very common.

but obviously you have some sort of problem with it,

** You are obviously on very friendly terms with stupidity.

The post was as far from a "mindless troll" as I could imagine.

** That just shows what a pompous, posturing little fuckwit you really
e - Dave.

Same as ever.




............. Phil

 

[tony]

Another option - is it possible to recalculate the speedo scale and
print and attach a new one .... colour printers are quite good now


Have fun!

Tony


Sash wrote:

Hi,

I'm wanting to build a circuit that receives a square wave input, and
outputs it with a slightly different frequency, depending on a user
adjustable value. I want to alter the frequency by about +/- 20% but it
needs to be adjustable on the fly, ie. a trim pot or similar.

Any ideas?

 

[David L. Jones]

"Phil Allison" <philallison@optusnet.com.au> wrote in message news:<40960096$0$436$afc38c87@news.optusnet.com.au>...

"David L. Jones" <tronnort@yahoo.com
"Phil Allison" <philallison@optusnet.com.au


** What if the OP wants to vary the 1.8 GHz clock on their PC by +/-
20 %
??
With no details the question is just a mindless troll.

Only in your little world Phil.


** I live in the real world - shame you have such a low opinion of it.

Must be nice in that gilt edged ivory tower of yours - Dave.



I provided a potentially helpful reply without knowing the some
details which the poster obviously forgot to include.


** Get real you pathetic wanker !!!

You took a wild guess at the facts instead of waiting for the OP to supply
the relevant details.


No big deal to the rest of us,


** Stupidity is very common.


but obviously you have some sort of problem with it,


** You are obviously on very friendly terms with stupidity.


The post was as far from a "mindless troll" as I could imagine.


** That just shows what a pompous, posturing little fuckwit you really
e - Dave.

Same as ever.




............ Phil

LMAO!

Dave

 

[budgie]

On 4 May 2004 00:55:21 -0700, tronnort@yahoo.com (David L. Jones) wrote:

"Phil Allison" <philallison@optusnet.com.au> wrote in message news:<40960096$0$436$afc38c87@news.optusnet.com.au>...

(the usual snivelling crap)

............ Phil

LMAO!

Dave

David, do what 80% of aus.electroincs have done - plonk! Phyllis is just a
bitter old turd who abuses anybody who dares disagree with her.

 

[David L. Jones]

budgie <me@privacy.net> wrote in message news:<9b2f9018og38dc57c3cvkplb2qmhhfv1mb@4ax.com>...

On 4 May 2004 00:55:21 -0700, tronnort@yahoo.com (David L. Jones) wrote:

"Phil Allison" <philallison@optusnet.com.au> wrote in message news:<40960096$0$436$afc38c87@news.optusnet.com.au>...

(the usual snivelling crap)

............ Phil

LMAO!

Dave

David, do what 80% of aus.electroincs have done - plonk! Phyllis is just a
bitter old turd who abuses anybody who dares disagree with her.

The disadvantage of using Google Groups - No PLONK!

Dave

 

[Phil Allison]

"David L. Jones" <tronnort@yahoo.com

The disadvantage of using Google Groups - No PLONK!

** Is there no end to this snivelling little prick's Jone's hypocrisy ???

First he goes out of his way to personally abuse me for no good reason -
then has the fucking hide to whinge he has trouble ignoring me because he
choses to use Google Groups ????

Jim Rowe told me 13 years ago Jones was a wanker.




.............. Phil

 

[The Real Andy]

On Wed, 5 May 2004 20:36:16 +1000, "Phil Allison"
<philallison@optusnet.com.au> wrote:

Jim Rowe told me 13 years ago Jones was a wanker.

Whoa, now that was nasty!!

 

[David L. Jones]

"Phil Allison" <philallison@optusnet.com.au> wrote in message news:<4098c399$0$4544$afc38c87@news.optusnet.com.au>...

"David L. Jones" <tronnort@yahoo.com

The disadvantage of using Google Groups - No PLONK!

** Is there no end to this snivelling little prick's Jone's hypocrisy ???

First he goes out of his way to personally abuse me for no good reason -
then has the fucking hide to whinge he has trouble ignoring me because he
choses to use Google Groups ????

Jim Rowe told me 13 years ago Jones was a wanker.

LMAO!

If I only had a dollar for every time I've heard the same and a lot
worse about you Phil...
I wouldn't think about KillFiling you Phil, you make me laugh.

Regards
Dave

 

[Phil Allison]

"David L. Jones" <tronnort@yahoo.com>

"Phil Allison" <philallison@optusnet.com.au

** Is there no end to this snivelling little prick's Jone's hypocrisy
???

First he goes out of his way to personally abuse me for no good
eason -
then has the fucking hide to whinge he has trouble ignoring me because
he
choses to use Google Groups ????

Jim Rowe told me 13 years ago Jones was a wanker.

LMAO!

** Which proves the fact.

If I only had a dollar for every time I've heard the same and a lot
worse about you Phil...

** But you will not name them, none are not credible persons and they
have never had any contact with me.

I wouldn't think about KillFiling you Phil, you make me laugh.

** Good - you can watch while I destroy you.





............... Phil

 

[Rod Speed]

"Phil Allison" <philallison@optusnet.com.au> wrote in message news:4099f97d$0$25012$afc38c87@news.optusnet.com.au...

"David L. Jones" <tronnort@yahoo.com

"Phil Allison" <philallison@optusnet.com.au


** Is there no end to this snivelling little prick's Jone's hypocrisy
???

First he goes out of his way to personally abuse me for no good
eason -
then has the fucking hide to whinge he has trouble ignoring me because
he
choses to use Google Groups ????

Jim Rowe told me 13 years ago Jones was a wanker.

LMAO!



** Which proves the fact.



If I only had a dollar for every time I've heard the same and a lot
worse about you Phil...


** But you will not name them, none are not credible persons and they
have never had any contact with me.


I wouldn't think about KillFiling you Phil, you make me laugh.

Good - you can watch while I destroy you.

Just another of your pathetic little drug crazed fantasys, wanker.