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Do you also sell your buck controller and easy bridge boards? I would be interested in those as well.
[edit]
Yes I do, and I have a new batch just in :) Still working on it, but lets not get side-tracked for the UD27 topic and I'll post those in my QCW thread when I'm worked on them a bit more since they are very much a work in progress and I have no immediate plans for documentation, so you'll have to be able to figure out things by yourself. Drop me a PM otherwise.
Hopefully the updated 2.7 design is working for everyone. So far I've also got it working on a conventional 100kHz DRSSTC with great results making 4 to 5 ft of spark with a foot long secondary.
Registered Member #3450
Joined: Sun Nov 28 2010, 05:01AM
Location:
Posts: 61
loneoceans wrote ...
Polonium210 wrote ...
Do you also sell your buck controller and easy bridge boards? I would be interested in those as well.
Yes I do, and I have a new batch just in :) Still working on it, but lets not get side-tracked for the UD27 topic and I'll post those in my QCW thread when I'm worked on them a bit more.
Hopefully the updated 2.7 design is working for everyone. So far I've also got it working on a conventional 100kHz DRSSTC with great results.
Some updates - found an error on the PCB (both Rev A and B w.r.t. the 24VDC input) thanks to Daniel, but with a simple fix so no worries!
Problem:
This happens when the 24VDC jack is used instead of the AC input. The 24VDC jack goes directly to the 24V rail. However, the 9V switching regulator's input is not connected to the 24V rail but rather the rectified AC rail. I originally wired it this way to reduce added load on the 24V regulator since the 9V switching regulator accepts up to 34V input but it looks like I got ahead of myself! You would think that this meant that the 9V and 5V rails would not be powered, but it turns out that inside the 24V regulator, there is a diode in series with about 28k from the output to the input, hence allowing the regulator to 'conduct backwards'. This also explains why the board still checked out ok on the voltage rails and still works in driving coils, probably helped by the generous amount of logic bus capacitance and the fact that the logic doesn't draw too much power.
Fix:
If you're using AC input, there is no problem. If you are using DC input, you can supply 26.5VDC into the AC jack instead - the diode bridge drops about 0.5V and the 7824 drops about 2V for 24V on the 24V rail.
If you're using the DC input, the problem can be solved by a simple fix: - simply solder on a diode from the output to the input of the 7824 regulator (i.e. classic reverse protection diode). So when the 24V rail is powered via DC input, current flows across the regulator. The diode I used for D14 (GSD2004W-E3-08) as a reverse protection diode across the 9V switching regulator can be used, or any other general purpose diode like a 1N4001 will be fine. This can be soldered directly across the legs of the 7824 regulator and fits perfectly. Make sure the diode is from the output to the input, as shown in the attached diagram.
I will also be updating the schematics etc to reflect this error, but in the future I think it makes more sense to go back to the 9V regulator input powered from the 24V rail for the next revision.
For those interested, I've got a new Rev C board order (and probably last batch) which I will place this weekend. It doesn't have many changes, but I ran out of Rev B boards so here's the next order:
- Improved silkscreen for less confusion - Fixed error in UD2.7A/B boards - Daisy chained 9V regulator back to original for maximum 28VAC input (19 - 26.5VAC nominal) - Improved regulator thermal pads for better heat performance - Other cosmetic improvements
If you're interested, drop me a PM so I can estimate a good order size. Otherwise I probably won't order too many. Price should be in the ballpark of $10 to $8 depending on order size, same green HASL finish. :)
Registered Member #102
Joined: Thu Feb 09 2006, 08:15PM
Location: Raleigh, NC
Posts: 169
I have always wondered about this in PCB design: do sharp edges and pockets from pads (where components interface with the board) cause any kind of losses? Or are they just nit picky pet peeves that bother me aesthetically and end up being something i should get over?
I have always wondered about this in PCB design: do sharp edges and pockets from pads (where components interface with the board) cause any kind of losses? Or are they just nit picky pet peeves that bother me aesthetically and end up being something i should get over?
What do you mean by sharp edges and pads and what sort of losses are you referring to? Are you talking about solder pads? If there are no solder pads how do you solder components on the board? At the frequencies we are working at, pcb layout is generally not too big of a deal, but once you get into RF stuff and high speed signalling, traces and layout matter a lot - you can use them to make antennas, capacitors, inductors, and all sort of RF magic things. :)
Anyway boards have been ordered, hope I have enough since it's a smaller order this time.
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