Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Everything Else Anything related to audio / video / electronics etc) BUT remember- we have many new forums where your thread may now fit! .... Parts, Equipment & Tools, Construction Tips, Software Tools......

need help deciphering circuit for foot control.
need help deciphering circuit for foot control.
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Thread Tools Search this Thread
Old 15th September 2011, 03:36 AM   #1
ching0n is offline ching0n  United States
diyAudio Member
Join Date: Jun 2011
Default need help deciphering circuit for foot control.

I'm going to build a pedal for my tig welder and am having trouble with a modified circuit I want to try. I've deciphered the 'simplified' circuit by now (pg.3), but would like to build the more complex one. Basically the one on page 4, I assumed the author meant for the builder to provide new headers, but where these connect to I have no idea.

The description is as follows:

Here is an update to the 91811 schematic. This
contains the OEM version of the machine [pages
1,2], my original modification for external heat and
timing control [page 4], and a substantially simplified
circuit providing external heat control alone [page 3].

This simplified external heat mod involves no surgery
to the control board. Tie-in to the PWM controller
is achieved by disconnecting the 3-pin connector from
the existing front panel 10K heat pot and routing it to
the board containing the added circuitry. This board
will supply it's own 3-pin cable/header which will then
connect to the original 10K pot PCB. The worst of
the modification is extracting GND and +12V from the
main board which can be found on the voltage
regulator U5, at pins #2 and #3 respectively. With
some soldering skill one should be able to make the
two connections without needing to unmount the
main PCB from the heat sink.

What I can't figure out is if the 'timing' he refers to is to control the 'shielding gas solenoid' or the heat timing (like some sort of pulse control). Also, the pedal I want to retrofit only has 15 degrees of motion on the pot, however I don't think this presents a problem since I'm guessing the signal is amplified; however, should I worry about the pot reading '0' ohms at any given position or is it ok for it to read some 'low' and 'high' value relative to one another?

To conclude, I read somewhere that this modification somehow takes care of interference that may be caused by the machine operating (dunno how); so my concern is can I build the circuit inside the pedal (extending whatever leads to the machine [will shielding be required?]) or should I keep the circuit near the machine?

Any and all help will be very much appreciated.
Attached Files
File Type: pdf 91811-schematic-unified (6).pdf (87.6 KB, 11 views)
  Reply With Quote


need help deciphering circuit for foot control.Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
CLONE Usher CP8571 -Help deciphering crossover xelos Multi-Way 1 1st June 2011 08:49 PM
Help deciphering crossover percy Multi-Way 26 15th May 2011 03:58 PM
deciphering my x-over need experienced help cmitch Multi-Way 11 21st November 2005 12:05 AM
IR MOSFETS -- part # deciphering rif Parts 2 6th May 2004 08:05 PM
Level Control Circuit palesha Solid State 3 13th August 2002 07:10 PM

New To Site? Need Help?

All times are GMT. The time now is 08:52 PM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio