Oatley K25 PWM kit - feedback and questions

D

Des Bromilow

Guest
Folks,

Has anyone assembled this kit and used it?

It went together well, but had a few issues when connecting wires
(basically the 2.5mm2 wire) fitted into the terminals, but once I
tightened up the terminals, and mounted the board on a heatsink, the
rigidity of the cables snapped the terminal away from the PCB pin.

All fixed now, but the 5K external pot is basically giving me 0 speed
for the first 15 degrees of rotation, then full speed as a sudden step -
and all around to the remainder of the pot's rotation.

I figure it will have something to do with the opamp circuits and their
voltages, but with only a DMM at home, I'm kinda stumped to find the
cause - will presevere, but looking for some experienced guys to point
me in the right direction.

Thanks,
Des





--
remove the German anti-spam device before replying
 
"Des Bromilow" <desbromilow@yahoo.comV2> wrote in message
news:4d7245b3$0$99331$c30e37c6@exi-reader.telstra.net...
: Folks,
:
: Has anyone assembled this kit and used it?
:
: It went together well, but had a few issues when connecting wires
: (basically the 2.5mm2 wire) fitted into the terminals, but once I
: tightened up the terminals, and mounted the board on a heatsink, the
: rigidity of the cables snapped the terminal away from the PCB pin.
:
: All fixed now, but the 5K external pot is basically giving me 0 speed
: for the first 15 degrees of rotation, then full speed as a sudden step -
: and all around to the remainder of the pot's rotation.
:
: I figure it will have something to do with the opamp circuits and their
: voltages, but with only a DMM at home, I'm kinda stumped to find the
: cause - will presevere, but looking for some experienced guys to point
: me in the right direction.
:
: Thanks,
: Des
______________________________________

Mine worked OK, and is still working. What are you driving with it?

Colin
 
On 6/03/2011 5:48 AM, Colin Horsley wrote:
"Des Bromilow"<desbromilow@yahoo.comV2> wrote in message
news:4d7245b3$0$99331$c30e37c6@exi-reader.telstra.net...
: Folks,
:
: Has anyone assembled this kit and used it?
:
: It went together well, but had a few issues when connecting wires
: (basically the 2.5mm2 wire) fitted into the terminals, but once I
: tightened up the terminals, and mounted the board on a heatsink, the
: rigidity of the cables snapped the terminal away from the PCB pin.
:
: All fixed now, but the 5K external pot is basically giving me 0 speed
: for the first 15 degrees of rotation, then full speed as a sudden step -
: and all around to the remainder of the pot's rotation.
:
: I figure it will have something to do with the opamp circuits and their
: voltages, but with only a DMM at home, I'm kinda stumped to find the
: cause - will presevere, but looking for some experienced guys to point
: me in the right direction.
:
: Thanks,
: Des
______________________________________

Mine worked OK, and is still working. What are you driving with it?

Colin


Will be driving a 350W scooter motor - tried with just a multimeter
Click to expand...
across the output - volts ranged from 0.6VDC at the low end, then up to
23.5 - 24.0 VDC at the "fast" end. ("End" is relative to the step at the
10degree travel mark.)

With the motor connected, the motor is stationary at the low end, and
flat out at the higher end.

I did have a 6800uF electro cap across the output for smoothing, but it
made no difference (connected or not)



--
remove the German anti-spam device before replying
 
"Des Bromilow"
I did have a 6800uF electro cap across the output for smoothing, but it
made no difference (connected or not)
Click to expand...

** It's never a good idea to connect a large value cap across the output of
a PWM motor drive circuit. Such circuits need to see a resistive or
inductive load - in the latter case the current can then approximate
smooth DC.

A large value cap spoils the whole operation of the circuit and likely cause
excess peak current to flow in the switching mosfet.

The fact your 6800uF electro made no difference tells me that the PWM
oscillator is simply not running.


...... Phil
 
On Sat, 05 Mar 2011 22:16:21 +0800, Des Bromilow
<desbromilow@yahoo.comV2> put finger to keyboard and composed:

All fixed now, but the 5K external pot is basically giving me 0 speed
for the first 15 degrees of rotation, then full speed as a sudden step -
and all around to the remainder of the pot's rotation.
Click to expand...
I'd start by measuring the voltage at the wiper of the pot, at both
ends of travel, and at the centre. Is it linear or log?

The LM358 op-amp supply (pin #8) should measure 8.0V.

Pin #6 should be ...

8.0 x 47K / (47K + 39K) = 4.4V

BTW, here are the notes for the kit:
http://secure.oatleyelectronics.com/files/K252notes.pdf

To view the redacted circuit diagram, drag a border around the image
(Tools -> Basic -> Select Image), copy it to the clipboard (Ctrl-C or
Edit -> Copy), and then paste it into your favourite image viewer.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.
 
On Wed, 09 Mar 2011 16:18:25 +1100, Franc Zabkar
<fzabkar@iinternode.on.net> put finger to keyboard and composed:

To view the redacted circuit diagram, drag a border around the image
(Tools -> Basic -> Select Image), copy it to the clipboard (Ctrl-C or
Edit -> Copy), and then paste it into your favourite image viewer.
Click to expand...
Actually, dragging a border is not necessary. Just single-click on the
image to highlight it. You can see the circuit in the Clipboard Viewer
(Window -> Clipboard Viewer), but it is mirrored and rotated.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.
 
On 9/03/2011 3:46 PM, Franc Zabkar wrote:
On Wed, 09 Mar 2011 16:18:25 +1100, Franc Zabkar
fzabkar@iinternode.on.net> put finger to keyboard and composed:

To view the redacted circuit diagram, drag a border around the image
(Tools -> Basic -> Select Image), copy it to the clipboard (Ctrl-C or
Edit -> Copy), and then paste it into your favourite image viewer.

Actually, dragging a border is not necessary. Just single-click on the
image to highlight it. You can see the circuit in the Clipboard Viewer
(Window -> Clipboard Viewer), but it is mirrored and rotated.
Click to expand...
Is that using Adobe Acrobat? I'm using Foxit Reader and it doesn't work,
obviously the complete image is still present in the pdf file.
Tom
> - Franc Zabkar
 
Hi,
one thing to look for would be - are you using a linear potentiometer for
your external control?

Greg


"Des Bromilow" <desbromilow@yahoo.comV2> wrote in message
news:4d7245b3$0$99331$c30e37c6@exi-reader.telstra.net...
Folks,

Has anyone assembled this kit and used it?

It went together well, but had a few issues when connecting wires
(basically the 2.5mm2 wire) fitted into the terminals, but once I
tightened up the terminals, and mounted the board on a heatsink, the
rigidity of the cables snapped the terminal away from the PCB pin.

All fixed now, but the 5K external pot is basically giving me 0 speed for
the first 15 degrees of rotation, then full speed as a sudden step - and
all around to the remainder of the pot's rotation.

I figure it will have something to do with the opamp circuits and their
voltages, but with only a DMM at home, I'm kinda stumped to find the
cause - will presevere, but looking for some experienced guys to point me
in the right direction.

Thanks,
Des





--
remove the German anti-spam device before replying
Click to expand...
 
"gcd"
one thing to look for would be - are you using a linear potentiometer for
your external control?
Click to expand...

** The OP's symptoms are far worse than that would explain.

He's make some kind of stuff-up with the construction - like failing to
solder a few leads to their pads or bridging pads.




..... Phil
 
On Wed, 09 Mar 2011 15:56:57 +1000, Tom <tom@no.spam.invalid> put
finger to keyboard and composed:

Is that using Adobe Acrobat? I'm using Foxit Reader and it doesn't work
Click to expand...
Yes, my instructions were for Acrobat Reader. BTW, you can also
r-click the highlighted image and select Copy Image to Clipboard.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.
 
"Franc Zabkar"

Is that using Adobe Acrobat? I'm using Foxit Reader and it doesn't work

Yes, my instructions were for Acrobat Reader.
Click to expand...

** None of them work at all using XP.

PDF files are not internally compatible with Windows.



..... Phil
 
On 9/03/2011 8:21 PM, Franc Zabkar wrote:
On Wed, 09 Mar 2011 15:56:57 +1000, Tom<tom@no.spam.invalid> put
finger to keyboard and composed:

Is that using Adobe Acrobat? I'm using Foxit Reader and it doesn't work

Yes, my instructions were for Acrobat Reader. BTW, you can also
r-click the highlighted image and select Copy Image to Clipboard.

- Franc Zabkar
Click to expand...
Ive found free image from PDF extractor, it worked. Gave up Acrobat quite a while ago as its a huge to download, slow and sluggish.

Tom
 
"Phil Allison" <phil_a@tpg.com.au> wrote in message
news:8tp3cmF7i5U1@mid.individual.net...
"Franc Zabkar"


Is that using Adobe Acrobat? I'm using Foxit Reader and it doesn't work

Yes, my instructions were for Acrobat Reader.


** None of them work at all using XP.

PDF files are not internally compatible with Windows.



.... Phil
Click to expand...


Seems ok for me with XP Home SP3 + Adobe Reader 9. Copies image from adobe &
pastes into MS Paint. Image aspect is screwy but easily stretched back.

I guess Oately will change their "protection" now Francs exposed the
loophole.
 
On Wed, 09 Mar 2011 21:08:20 +1000, Tom <tom@no.spam.invalid> put
finger to keyboard and composed:

Ive found free image from PDF extractor, it worked. Gave up Acrobat quite a while ago as its a huge to download, slow and sluggish.
Click to expand...
I use both Foxit and Acrobat Reader. Some PDFs are handled better by
Acrobat, while some have "dictionary" errors and need to be handled by
Foxit. Therefore I have modified Windows Explorer's r-click menu to
give me a choice of "Open with Foxit" or "Open with Acrobat Reader".

I also speed up the launching of AR by disabling its unnecessary
plugins:
http://www.softpedia.com/get/Office-tools/PDF/Adobe-Reader-SpeedUp.shtml

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.
 
On Wed, 9 Mar 2011 20:29:21 +0800, "Dennis" <blubber@blibber.com> put
finger to keyboard and composed:

I guess Oately will change their "protection" now Francs exposed the
loophole.
Click to expand...
I first became aware of this security flaw when Mohammed Haneef's
barrister uploaded the transcripts of his AFP interview to the world.
I have a slow machine and on this particular day it was running even
slower than usual. I could see the original transcript contents being
rendered, then followed by the blacked out redactions. The stupid
barrister had exposed Haneef's private phone numbers, email addresses,
and home addresses, both in Australia and in India.

Worse still, an Italian schoolboy likewise exposed the redacted
information in publicly released US military documents.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.
 
On Mar 9, 10:29 pm, "Dennis" <blub...@blibber.com> wrote:
"Phil Allison" <phi...@tpg.com.au> wrote in message

news:8tp3cmF7i5U1@mid.individual.net...





"Franc Zabkar"

Is that using Adobe Acrobat? I'm using Foxit Reader and it doesn't work

Yes, my instructions were for Acrobat Reader.

** None of them work at all using XP.

PDF files are not internally compatible with Windows.

....  Phil

Seems ok for me with XP Home SP3 + Adobe Reader 9. Copies image from adobe &
pastes into MS Paint. Image aspect is screwy but easily stretched back.

I guess Oately will change their "protection" now Francs exposed the
loophole.
Click to expand...

I thought that Oatley were above these methods of doing things.

All this does is hurt their business and particularly support
reputation.
Their kits are normally so reasonably priced that the majority
wouldn't go to the trouble of trying to "roll their own".
 
On Mar 9, 8:33 pm, "Phil Allison" <phi...@tpg.com.au> wrote:
"Franc Zabkar"



Is that using Adobe Acrobat? I'm using Foxit Reader and it doesn't work

Yes, my instructions were for Acrobat Reader.

** None of them work at all using XP.

 PDF files are not internally compatible with Windows.

....  Phil
Click to expand...
I pulled a border around the image - hit CTRL C

opened corel draw, and pasted it. It was stretched, but could be
pulled back into shape and saved
 
"kreed"

I pulled a border around the image - hit CTRL C


** Seems to all depend on the version of Acrobat being used.

PDF files are impervious to any such coaxing on my PC.


..... Phil
 
On 10/03/2011 1:47 PM, Phil Allison wrote:
"kreed"

I pulled a border around the image - hit CTRL C


** Seems to all depend on the version of Acrobat being used.

PDF files are impervious to any such coaxing on my PC.


.... Phil
Click to expand...
Get PDF image extractor from:
http://www.somepdf.com/some-pdf-image-extract.html
Seems to work ok, they also have some utilities like text extractor and
more.

Tom
 
On Mar 10, 2:32 pm, Tom <t...@no.spam.invalid> wrote:
On 10/03/2011 1:47 PM, Phil Allison wrote:

"kreed"

I pulled a border around the image - hit CTRL C

** Seems to all depend on the version of Acrobat being used.
Click to expand...
9.41

   PDF files are impervious to any such coaxing on my PC.

....  Phil

Get PDF image extractor from:http://www.somepdf.com/some-pdf-image-extract.html
Seems to work ok, they also have some utilities like text extractor and
more.

Tom
Click to expand...
 
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