Driver to drive?

[Michael A. Terrell]

krw@attt.bizz wrote:

On Mon, 25 Feb 2013 18:27:34 -0800, dave <ricketzz@earthlink.net
wrote:

On 02/25/2013 05:07 PM, krw@attt.bizz wrote:
On Mon, 25 Feb 2013 15:54:23 -0800, dave <ricketzz@earthlink.net
wrote:

On 02/25/2013 10:54 AM, Michael A. Terrell wrote:

dave wrote:

On 02/24/2013 05:37 AM, SoothSayer wrote:
On Sun, 24 Feb 2013 05:17:53 -0800, dave <ricketzz@earthlink.net> wrote:

On 02/24/2013 05:14 AM, Phil Allison wrote:
"dave"

You answered your own question. As long as the battery doesn't heat up on
a big charge you're probably OK.


** SLA or "gel cells" are prone to gassing when overcharged.

The pressure builds up inside until something gives - then you have bits
of battery and acid all over the place.

Voltage & current limited charging is the only safe and sensible way.



... Phil



They have vents.

Which are NOT meant for overcharge relief.


I didn't say they were. I was speaking to the "bits of battery and acid"
prediction above.


I've seen the results of several car batteries exploding. Maybe your
head should be under the hood when one blows.


Why is everyone so rude around here?

Why are you here?


I am here for entertainment, mainly.

Ah Ha!

most of the substantive stuff is
over my head, but the lead-acid battery is on the FCC exams you take for
an advanced license,

The ham + CHEESE test! ;-)

Oohhh! I'm impressed. You took a *real* FCC license exam. Did you
pass?

plus I used to maintain a fleet of trucks at a
construction company, where I also serviced 2-way radios and 5 mW
surveyor lasers.

So you know it all. Great!

 

[Jamie]

SoothSayer wrote:

On Tue, 26 Feb 2013 06:58:16 -0800, dave <ricketzz@earthlink.net> wrote:


A lot of mobile equipment will
not work properly on 12 Vdc.



Stop lying.

The devices designed for 13.6 v typically will operate within a supply
source voltage window.

12 volts is far too close to 13.6 for any device I can think of having
a problem. I think you are making shit up.

I hate to burst your bubble but he's correct, a lot of mobile equipment
do not work correctly at 12V. They need to be up to 13+ volts.

Jamie

 

[Phil Allison]

"dave"
Phil Allison wrote:

"dave"

** SLA or "gel cells" are prone to gassing when overcharged.

The pressure builds up inside until something gives - then
you have bits of battery and acid all over the place.

Voltage & current limited charging is the only safe and
sensible way.


They have vents.


** Most do not - eg:

http://cdn-products.austinkayak.com/p_8037_700.jpg

An acquaintance had a 12V gell battery like the one pictured explode
violently while doing just what the OP here is contemplating. He was
sleeping nearby at the time an got one HELL of a scare !!!!

Makers all warn against using unregulated ( ie raw, rectified AC )
chargers with gell or SLA batteries.


they always include a safety pressure relief valve.

** Kindly point this out in the pic I posted - smartarse.

The battery will simply blow apart if overcharged.


.... Phil

 

[SoothSayer]

On Tue, 26 Feb 2013 07:59:25 -0800, dave <ricketzz@earthlink.net> wrote:

On 02/26/2013 07:39 AM, SoothSayer wrote:
On Tue, 26 Feb 2013 06:58:16 -0800, dave <ricketzz@earthlink.net> wrote:

A lot of mobile equipment will
not work properly on 12 Vdc.


Stop lying.

The devices designed for 13.6 v typically will operate within a supply
source voltage window.

12 volts is far too close to 13.6 for any device I can think of having
a problem. I think you are making shit up.


http://forums.qrz.com/showthread.php?246634-ATX-Power-Supply-for-Ham-Radio

You're an idiot. Those are the supply OUTPUT voltages, not the input
requisite.

Which if you had any brains and took note, spans from 90 volts to 265
volts, which is also typical.

The 'typical" thing you missed is that DC fed devices ALSO operate
within a RANGE of voltage sources.

sheesh.

 

[dave]

So you know it all. Great!

I specifically stated that I did not. You may be a good engineer but
you are a shitty reader.

 

[dave]

On 02/26/2013 03:25 PM, Phil Allison wrote:

"dave"


they always include a safety pressure relief valve.

** Kindly point this out in the pic I posted - smartarse.

The battery will simply blow apart if overcharged.

Your photo only showed 3 sides of a six sided solid object. I do not
have X-ray vision.

 

On Wed, 27 Feb 2013 06:38:06 -0800, dave <ricketzz@earthlink.net>
wrote:

So you know it all. Great!


I specifically stated that I did not. You may be a good engineer but
you are a shitty reader.

I can't help it if you can't make up your mind.

 

[Gib Bogle]

On 27/02/2013 10:23 a.m., John Fields wrote:

But, more than likely not, since I requested that you elaborate with
an explanation of your "tricks" and you reply with snippage and
dodging.

Mine is bigger than yours

 

[John Larkin]

On Sat, 2 Mar 2013 16:42:19 -0800 (PST), "langwadt@fonz.dk" <langwadt@fonz.dk>
wrote:

On Mar 3, 12:12 am, John Larkin
jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Sat, 02 Mar 2013 12:37:10 -0800, Joerg <inva...@invalid.invalid> wrote:
Hi Folks,

Long story short, none of the DDS modules I've found so far has the
ability to be sweeped or FM-modulated. This one has a signal input
terminal block "SIN" but I received a response from the manufacturer
that it connects to nowhere, it has no function:

http://imall.iteadstudio.com/tools-and-equipment/im120723003.html

What I need in my case is DC-100Hz of sweep or FM bandwidth. Operating
frequency under 10kHz and sweep range up to 2kHz. Of course I can whip
up an analog solution but it won't be as precise and most of all not
really programmable.

Is there anything better? Cost is not a big issue but should be somewhat
small and a display would be nice.

This will do it, but it's overkill, roughly 100x your probable budget.

http://www.highlandtechnology.com/DSS/T346DS.shtml

If you wanted to roll your own, it would take a small FPGA and a DAC.


at 10kHz almost any mcu with a dac would do

-Lasse

One of the small ARMs with a onboard DAC would do. A periodic interrupt at 100
KHz or so could easily bang the DDS algorithm. 10, maybe 20 lines of code.


--

John Larkin Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom timing and laser controllers
Photonics and fiberoptic TTL data links
VME analog, thermocouple, LVDT, synchro, tachometer
Multichannel arbitrary waveform generators

 

[Bill Sloman]

On Sunday, 3 March 2013 12:27:51 UTC+13, Nico Coesel wrote:

Bill Sloman <bill.sloman@ieee.org> wrote:



On Mar 3, 11:35=A0am, n...@puntnl.niks (Nico Coesel) wrote:

Joerg <inva...@invalid.invalid> wrote:

Nico Coesel wrote:

Joerg <inva...@invalid.invalid> wrote:

<snip>

Joerg should be able to sweep his sine wave pretty smoothly by
incrementing/decrementing the last digit of his frequency-setting
number frequently. Whether he can do it frequently enough is another
question. He might have to program a PAL to do it for him.

That depends on whether the DDS is reset or not when the frequency
setting is updated. There has to be a reason the designers at
iteadstudio didn't implement the modulation. If it where simple they
would have implemented it.

Why do you think that?

The Analaog Devices DDS chips that I've looked at didn't seem to reset themselves when the frequency was changed.

The iteadstudio designers may have made life simpler for themselves in some way by chucking in an unnecessary reset command on top of every frequency change update, but that doesn't mean that just sending a frequency change command is going to be difficult.

--
Bill Sloman, Sydney

 

[Jasen Betts]

On 2013-03-03, Joerg <invalid@invalid.invalid> wrote:

use the a sound card, possible external usb?


Theoretically, yes. But since this whole thing will sit inside a PID
loop I'd then have to process the error signal (a phase information
measured in my box) in the PC. Meaning lots of code writing and that's
what I am trying to avoid as much as possible.

Plus, you get latency with a sound card which many be an issue if you need a
tight loop.


--
⚂⚃ 100% natural

 

[Jan Panteltje]

On a sunny day (Sat, 02 Mar 2013 15:47:46 -0800) it happened Joerg
<invalid@invalid.invalid> wrote in <apfhdaF874aU1@mid.individual.net>:

If necessary I could do it that way. But I am not really a good
programmer. Ideall would be a module that has FM modulation or sweep. It
doesn't have to be DDS, just stable and not too large. Ripping it out of
a function generator is ok as well, as long as it's not much more than
two cigarette packs or so in size.

74HC4046 is a good VCO.

If you need sinewave out, could a 4046 be used as clock for a DDS?
Never tried it.

 

[Nico Coesel]

Bill Sloman <bill.sloman@ieee.org> wrote:

On Sunday, 3 March 2013 12:27:51 UTC+13, Nico Coesel wrote:
Bill Sloman <bill.sloman@ieee.org> wrote:
=20
=20
=20
On Mar 3, 11:35=3DA0am, n...@puntnl.niks (Nico Coesel) wrote:
=20
Joerg <inva...@invalid.invalid> wrote:
=20
Nico Coesel wrote:
=20
Joerg <inva...@invalid.invalid> wrote:

snip

Joerg should be able to sweep his sine wave pretty smoothly by
incrementing/decrementing the last digit of his frequency-setting
number frequently. Whether he can do it frequently enough is another
question. He might have to program a PAL to do it for him.
=20
That depends on whether the DDS is reset or not when the frequency
setting is updated. There has to be a reason the designers at
iteadstudio didn't implement the modulation. If it where simple they=20
would have implemented it.

Why do you think that?

Sometimes chips behave different than advertised and the only way to
find out is to put them on a board and test them. I have no experience
with the DDS chip they use on the board Joerg found so your guess is
as good as mine. Another problem could be timing since the controller
on the board Joerg found is quite slow. If there is a lot of variation
in the time between updates, the sweep or FM modulated signal would
not be very clean or look more like a stepped sweep.

--
Failure does not prove something is impossible, failure simply
indicates you are not using the right tools...
nico@nctdevpuntnl (punt=.)
--------------------------------------------------------------

 

[Joerg]

Jasen Betts wrote:

On 2013-03-03, Joerg <invalid@invalid.invalid> wrote:

use the a sound card, possible external usb?

Theoretically, yes. But since this whole thing will sit inside a PID
loop I'd then have to process the error signal (a phase information
measured in my box) in the PC. Meaning lots of code writing and that's
what I am trying to avoid as much as possible.

Plus, you get latency with a sound card which many be an issue if you need a
tight loop.

If it did the usual 1msec USB response intervals it could scrape by for
the PID loop, barely. But if that ever gets interrupted there would be a
serious data kerfuffle.

--
Regards, Joerg

http://www.analogconsultants.com/

 

[Joerg]

Jamie wrote:

Joerg wrote:

Joerg wrote:

Hi Folks,

Long story short, none of the DDS modules I've found so far has the
ability to be sweeped or FM-modulated. This one has a signal input
terminal block "SIN" but I received a response from the manufacturer
that it connects to nowhere, it has no function:

http://imall.iteadstudio.com/tools-and-equipment/im120723003.html

What I need in my case is DC-100Hz of sweep or FM bandwidth. Operating
frequency under 10kHz and sweep range up to 2kHz. Of course I can whip
up an analog solution but it won't be as precise and most of all not
really programmable.

Is there anything better? Cost is not a big issue but should be somewhat
small and a display would be nice.



In case someone else is in a similar situation, I've just discovered two
interesting alternatives if no suitable DDS module can be found. The 1st
is ye olde XR2206 which I thought had gone unobtanium:

http://electronics-diy.com/product_details.php?pid=537&name=1Hz%20-%202MHz%20XR2206%20Function%20Generator%20Kit


The 2nd solution is rather ugly. I could take these DDS modules and
replace the oscillator with a LTC resistor-set silicon oscillator. Those
can be current steered. Of course then the digital frequency display of
the module would become fairly meaningless but could still sort of
signal if my PID loop has locked or not.


If you want to get that crude, you could always turn to an old stand by..
LM566

That has a square out that you can use to monitor in a counter for
example and a triangle out that you can wave shape into a sine wave.

That also includes a modulation input pin and it just happens
to be in your range.

But it puts out a square wave which I really can't use here. Has to be
sine and the potential range is too wide to cover that with a lowpass.
Else I could use a LTC resistor-controlled oscillaator by itself and
call it a day.

--
Regards, Joerg

http://www.analogconsultants.com/

 

[Joerg]

Tim Wescott wrote:

On Sat, 02 Mar 2013 12:37:10 -0800, Joerg wrote:

Hi Folks,

Long story short, none of the DDS modules I've found so far has the
ability to be sweeped or FM-modulated. This one has a signal input
terminal block "SIN" but I received a response from the manufacturer
that it connects to nowhere, it has no function:

http://imall.iteadstudio.com/tools-and-equipment/im120723003.html

What I need in my case is DC-100Hz of sweep or FM bandwidth. Operating
frequency under 10kHz and sweep range up to 2kHz. Of course I can whip
up an analog solution but it won't be as precise and most of all not
really programmable.

Is there anything better? Cost is not a big issue but should be somewhat
small and a display would be nice.

Soooooooo. Have you spent more time looking to date than it would have
taken to slap a DDS chip onto your board and make it work?

(I hate that question -- even when I'm asking it of myself).

No, with my code writing knowledge that would take a loooong time. We
could use a contract engineer for that part but it can become tough
because every time some loop behavior needs to change he or she has to
come again (because it must be tested on a fairly large setup). With
resistors and caps and diodes it's much easier.

--
Regards, Joerg

http://www.analogconsultants.com/

 

[Joerg]

langwadt@fonz.dk wrote:

On Mar 3, 6:45 am, Bill Sloman <bill.slo...@ieee.org> wrote:
On Sunday, 3 March 2013 12:27:51 UTC+13, Nico Coesel wrote:
Bill Sloman <bill.slo...@ieee.org> wrote:
On Mar 3, 11:35=A0am, n...@puntnl.niks (Nico Coesel) wrote:
Joerg <inva...@invalid.invalid> wrote:
Nico Coesel wrote:
Joerg <inva...@invalid.invalid> wrote:
snip

Joerg should be able to sweep his sine wave pretty smoothly by
incrementing/decrementing the last digit of his frequency-setting
number frequently. Whether he can do it frequently enough is another
question. He might have to program a PAL to do it for him.
That depends on whether the DDS is reset or not when the frequency
setting is updated. There has to be a reason the designers at
iteadstudio didn't implement the modulation. If it where simple they
would have implemented it.
Why do you think that?

The Analaog Devices DDS chips that I've looked at didn't seem to reset themselves when the frequency was changed.

The iteadstudio designers may have made life simpler for themselves in some way by chucking in an unnecessary reset command on top of every frequency change update, but that doesn't mean that just sending a frequency change command is going to be difficult.


a 16 bit SPI will only write 14bits of the frequency register, so
you'll need two writes unless you can do with just changing the MSB
part

the right way would to toggle between the two frequency registers, so
that would be 2*16bit, plus 16bit control register so 48bits per
update

but that is leaves ~30 cycles per bit to do the bit banging on the
16MHz MCU and get a ~10KHz update rate

You'd also have to calculate the new values for "xx Hertz up or down"
every time, xx depending on how much the output of the PID regulator
changed. I doubt those little uC would have enough ROM to store a large
LUT for that.

I did a few tricks like that in the past because I do write a lot of
code architecture. Almost every time the guys came back and said "Hey,
good idea but we'd run out of MIPS" or "We are almost out of memory
space already". That's the beauty of analog, no such limits

--
Regards, Joerg

http://www.analogconsultants.com/

 

[Jan Panteltje]

On a sunny day (Sun, 03 Mar 2013 07:16:30 -0800) it happened Joerg
<invalid@invalid.invalid> wrote in <aph7qmFj5hdU2@mid.individual.net>:

But it puts out a square wave which I really can't use here. Has to be
sine and the potential range is too wide to cover that with a lowpass.
Else I could use a LTC resistor-controlled oscillaator by itself and
call it a day.

Very long time a go I made a sine wave sweep generator for testing active audio filters
by using a 4046 VCO (linear f versus V), a 4040 counter, a 4k EPROM with a sine wave table,
and a 8 bit DAC.
Also had some opamp and integrator and 2 comparators, so it could sweep from f1 to f2.
That sort of thing can make a reasonable pure sinewave.
But you would need to be able to program an EPROM.
Not much that can go wrong with it, if you need more than 8 bits use 2 EPROMS.

 

[Jamie]

Joerg wrote:

Jamie wrote:

Joerg wrote:


Joerg wrote:


Hi Folks,

Long story short, none of the DDS modules I've found so far has the
ability to be sweeped or FM-modulated. This one has a signal input
terminal block "SIN" but I received a response from the manufacturer
that it connects to nowhere, it has no function:

http://imall.iteadstudio.com/tools-and-equipment/im120723003.html

What I need in my case is DC-100Hz of sweep or FM bandwidth. Operating
frequency under 10kHz and sweep range up to 2kHz. Of course I can whip
up an analog solution but it won't be as precise and most of all not
really programmable.

Is there anything better? Cost is not a big issue but should be somewhat
small and a display would be nice.



In case someone else is in a similar situation, I've just discovered two
interesting alternatives if no suitable DDS module can be found. The 1st
is ye olde XR2206 which I thought had gone unobtanium:

http://electronics-diy.com/product_details.php?pid=537&name=1Hz%20-%202MHz%20XR2206%20Function%20Generator%20Kit


The 2nd solution is rather ugly. I could take these DDS modules and
replace the oscillator with a LTC resistor-set silicon oscillator. Those
can be current steered. Of course then the digital frequency display of
the module would become fairly meaningless but could still sort of
signal if my PID loop has locked or not.


If you want to get that crude, you could always turn to an old stand by..
LM566

That has a square out that you can use to monitor in a counter for
example and a triangle out that you can wave shape into a sine wave.

That also includes a modulation input pin and it just happens
to be in your range.



But it puts out a square wave which I really can't use here. Has to be
sine and the potential range is too wide to cover that with a lowpass.
Else I could use a LTC resistor-controlled oscillaator by itself and
call it a day.

That puts out a triangle wave on a different pin, it's very linear for
your purpose with some basic wave shaping. And the freq range is 10:1

Oh well..

Jamie

 

[langwadt@fonz.dk]

On Mar 3, 6:45 am, Bill Sloman <bill.slo...@ieee.org> wrote:

On Sunday, 3 March 2013 12:27:51 UTC+13, Nico Coesel  wrote:
Bill Sloman <bill.slo...@ieee.org> wrote:

On Mar 3, 11:35=A0am, n...@puntnl.niks (Nico Coesel) wrote:

Joerg <inva...@invalid.invalid> wrote:

Nico Coesel wrote:

Joerg <inva...@invalid.invalid> wrote:

snip

Joerg should be able to sweep his sine wave pretty smoothly by
incrementing/decrementing the last digit of his frequency-setting
number frequently. Whether he can do it frequently enough is another
question. He might have to program a PAL to do it for him.

That depends on whether the DDS is reset or not when the frequency
setting is updated. There has to be a reason the designers at
iteadstudio didn't implement the modulation. If it where simple they
would have implemented it.

Why do you think that?

The Analaog Devices DDS chips that I've looked at didn't seem to reset themselves when the frequency was changed.

The iteadstudio designers may have made life simpler for themselves in some way by chucking in an unnecessary reset command on top of every frequency change update, but that doesn't mean that just sending a frequency change command is going to be difficult.

a 16 bit SPI will only write 14bits of the frequency register, so
you'll need two writes unless you can do with just changing the MSB
part

the right way would to toggle between the two frequency registers, so
that would be 2*16bit, plus 16bit control register so 48bits per
update

but that is leaves ~30 cycles per bit to do the bit banging on the
16MHz MCU and get a ~10KHz update rate


-Lasse