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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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 Posted: Tue Apr 01, 2014 3:21 pm |
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Use http://www.postimage.com or http://www.imageshack.com
or some other free image hosting service.
Upload your schematic to that website. Preferably a .JPG file or some
other commonly used image format.
Then post a link to your image here in the forum.
Test it before you post it. Make sure the link works.
Also, it should not require us to login to see the image.
We don't want to have to login to see it. Just click on it. |
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thebenman
Joined: 31 Mar 2014
Posts: 9
Location: India
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| Posted: Tue Apr 01, 2014 7:34 pm |
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| PCM programmer wrote: | Use http://www.postimage.com or http://www.imageshack.com
or some other free image hosting service.
Upload your schematic to that website. Preferably a .JPG file or some
other commonly used image format.
Then post a link to your image here in the forum.
Test it before you post it. Make sure the link works.
Also, it should not require us to login to see the image.
We don't want to have to login to see it. Just click on it. |
I am attaching the circuit schematic here
I am sorry if the image appears slightly blurred i had a hard time converting it from .doc format  |
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temtronic
Joined: 01 Jul 2010
Posts: 9245
Location: Greensville,Ontario
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| Posted: Wed Apr 02, 2014 9:04 am |
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The emitters of all the optocouplers are grounded ! NO signals will be sent to the FETs.
Also _mclr is tied low, so PIC will never run...
And no ground connecting power supplies to PIC, regulators not grounded either.
If this schematic 'works' in Proteus you now know why I NEVER use it !
hth
jay |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19550
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| Posted: Wed Apr 02, 2014 10:02 am |
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The MCLR will work. He is showing a push to break switch. However it's life may well be limited. Sorting out a charged capacitor each time it is released. Ugh.
The supplies are done 'invisibly', a Proteus 'way of working', that is totally regrettable...
However the optos won't work, and the floating supplies are shown generating 0v.
There is no connection shown or implicit between the 12v supply, and the supply being controlled by the FET's.
If it was wired right switching speeds will be appalling. 1KR feeding a FET gate. Odds are tens of uSec switching time....
Look at an off the shelf high side/low side FET driver IC. These have the supply inverter present to generate the supplies to the high side FET (remember this needs several volts above the top supply rail), and the isolation all in one package.
As drawn it is a 'problem'... |
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thebenman
Joined: 31 Mar 2014
Posts: 9
Location: India
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| Posted: Wed Apr 02, 2014 11:14 am |
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This schematic is actually on hardware now :( Anyway i use Proteus only to measure the duty cycle of the PWM from PIC. The separate circuits showing the transformer, rectifier share a common ground with the rest of the circuit, it's only that it is showed separately here. However, i was wondering on how to make sure the _mclr can be tied high to get the PIC up and running.
The voltage sources V2, V3 etc. shows the multiple inputs to be connected, turns out the bottom circuit works fine but not the top one |
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temtronic
Joined: 01 Jul 2010
Posts: 9245
Location: Greensville,Ontario
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| Posted: Wed Apr 02, 2014 12:28 pm |
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Oh knew what the _mclr switch was supposed to show, but a 'push to break' switch should have the 'wiper' on the bottom side of the NC contacts. Yeah, I'm nitpicking but schematics MUST show the proper connections if anyone other than the original designer is to work on it.
As far as wiring _mclr in the 'real world', a simple 10k pullup and a NO pushbutton to ground will work fine.
Any PIC datasheet does show how to wire up _mclr.......
hth
jay |
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Mike Walne
Joined: 19 Feb 2004
Posts: 1785
Location: Boston Spa UK
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| Posted: Wed Apr 02, 2014 3:54 pm |
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| thebenman wrote: | Hey,
I have actually build (that is almost !!) a multiple input multiple output DC-DC converter. What it does is it basically takes the two voltage sources and converts them to a different level such as addition, subtraction of the two circuits etc. Each seprate circuit (addition, subtraction) has two mosfets each in them. The mosfets needs to be switched on/off alternatively at a switching frequency of 50Khz.
I sorry i do not know much about ASCII charts, although i only have a .doc file of the circuit schematic :( |
When you say 'built', do you mean with real hardware or Proteus?
I've had a look at your schematic, I'm horrified.
There's so much wrong, it can't do anything useful.
Even with the schematic, I'm unsure exactly what you're trying to do.
A schematic should be imformative, yours is definitely not.
You've made it hard work to glean anything from it.
I don't want to sound negative, so here are some hints.
1) Use a simple convention. You're reading this text left to right, top to bottom.
2) Do the same with schematics, signal flow left to right, power top to bottom. (Where you can.)
3) Avoid lines crossing each other several times.
4) Make schematic as neat, clear and concise as possible.
5) Keep lines straight with minimum number of kinks.
6) If not showing control circuit power connections for clarity, then label prominently.
7) Where you've got multiple circuits, most of the time just one will suffice.
8) Move blocks around to achieve the above objectives.
Have a look at some the ASCII art on this forum to get the idea.
Mike |
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