Author Topic: Digital oscilloscope project/kit  (Read 124476 times)

Offline John Rudd

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Re: Digital oscilloscope project/kit
« Reply #100 on: December 31, 2015, 04:31:07 PM »
When it comes to soldering the ic to the board......Do Not be tempted to solder all the pins on one side one after another......

If its a qfp (quad flat pack, bit like mfi furniture..... :lol:)  solder the 4 corner pins first to secure to the board nice and level.....Then solder alternate pins on each side.....This will prevent the chip from overheating...if you are a bit overzealous with the solder, use solder wick to draw off the excess solder...dont use a solder sucker....risk of damage to chip or pcb.....
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Offline wheeltapper

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Re: Digital oscilloscope project/kit
« Reply #101 on: December 31, 2015, 04:47:46 PM »
No, I've got a 5"magnifier lamp with a shedload of LED's round the edge. :thumbup:
It makes a hell of a difference, those 0805's looked like house bricks.

I think if I ever had to solder 0603's again I need a smaller chisel tip for the iron. the smallest one I have is 2.4mm and I could get a 1.2 or a 0.8.

Roy.
I used to be confused, now I just don't know.

Offline Bluechip

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Re: Digital oscilloscope project/kit
« Reply #102 on: December 31, 2015, 04:50:44 PM »
I would suggest the 0.8mm tip. That's what I have on my Weller. Even that seems too big sometimes and I don't even do SMT.

Dave
I have a few modest talents. Knowing what I'm doing isn't one of them.

Offline wheeltapper

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Re: Digital oscilloscope project/kit
« Reply #103 on: December 31, 2015, 05:05:29 PM »
Hi Dave,
I've just ordered a 1.2 and a 0.8 straight after my last post.

the IC lands on the practice board are only 0.8 so anything bigger is going to be too big.

Roy.
I used to be confused, now I just don't know.

Offline Bluechip

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Re: Digital oscilloscope project/kit
« Reply #104 on: January 01, 2016, 03:37:25 AM »
Here you are, Rob ...

PCB for your PSU, not including diodes & LEDs ..

Done on ExpressPCB. Took about an hour.

Dave

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RobWilson

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Re: Digital oscilloscope project/kit
« Reply #105 on: January 01, 2016, 04:25:13 AM »
Morning and a happy new year to you  Dave   :wave:


You missed off my transformer lol , Your layout looks allot more efficient / better than mine  :thumbup: , I like the way you laid  out the  regulators .


All the best , Rob   

Offline John Rudd

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Re: Digital oscilloscope project/kit
« Reply #106 on: January 01, 2016, 04:29:25 AM »
Happy new year all.......  :thumbup:

Nicely done Dave... :bow:

Rob, the tranny connections are at the lhs side of the board..... To the left of the bridge...

If I were building it, I'd use a Molex 3 pin plug on the transformer leads, and use a matching 3 pin header on the board...a much neater approach rather than direct wiring but to each his own.... :D
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Offline Bluechip

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Re: Digital oscilloscope project/kit
« Reply #107 on: January 01, 2016, 04:34:53 AM »
And a Happy and Prosperous New Year to you Gents ...  :nrocks:

If I were doing it, I'd use a PCB mounting transformer ...   :thumbup:  like this:

http://cpc.farnell.com/camdenboss/ctfp6-12/transformer-6va-2x-12v/dp/TF01362

but as we seem to be stuck with a snivelling bit of a 3VA Chassis transformer I decided to make the rest of it look a bit Neolithic to suit ...  :lol:  :lol:

A bit nippy here ..  :(  not going out today  .... no sireeeeee 

Dave
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RobWilson

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Re: Digital oscilloscope project/kit
« Reply #108 on: January 01, 2016, 04:45:20 AM »


Rob, the tranny connections are at the lhs side of the board..... To the left of the bridge...



Morning and all the best  John , I did see the connector for the transformer  :thumbup:,  I want my massive 3VA on the board   :dremel:



If I were doing it, I'd use a PCB mounting transformer ...   :thumbup:  like this:

http://cpc.farnell.com/camdenboss/ctfp6-12/transformer-6va-2x-12v/dp/TF01362

but as we seem to be stuck with a snivelling bit of a 3VA Chassis transformer I decided to make the rest of it look a bit Neolithic to suit ...  :lol:  :lol:



Dave


Hi dave , whats my poor wee transformer ever done to you  :lol: :lol: :lol:

http://www.rapidonline.com/Electrical-Power/Blore-Bowron-A5004-PCB-Transformer-115V-115V-3VA-12V-12V-88-5350    ,  :)




Rob


Offline Bluechip

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Re: Digital oscilloscope project/kit
« Reply #109 on: January 01, 2016, 06:40:19 AM »
So, not a chassis transformer ???

Oh well, another wrong idea I've got.  :doh:     I blame Global Warming. I was OK until that kicked in ... must have addled my brain  :scratch:

I've made templates for the CPC trannies .

So it would be quite possible to mount it on the board.

Dave
I have a few modest talents. Knowing what I'm doing isn't one of them.

Offline wheeltapper

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Re: Digital oscilloscope project/kit
« Reply #110 on: January 01, 2016, 07:30:27 AM »
Hi, just a quick pic of my test board.


it's not too bad, at least the LED works. :zap:

Roy.
I used to be confused, now I just don't know.

Offline John Rudd

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Re: Digital oscilloscope project/kit
« Reply #111 on: January 01, 2016, 07:32:32 AM »
Rob,
ESR do a line in pcb trannies.......but I guess you aleeady knew that.....

They aint to far from you either at Cullercoats....( boy I love going to that place....lots of luverly conponents.... :lol:)

Roy,
Looks pretty good....( for a beginner.... :lol:) for a first attempt....

I have to admit when I'm reworking a board, the thinnest solder I have is .8 mm and I think thats too big...I ought to buy some paste really, but I'm a tight Yorkshireman...you know... :clap:
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Offline wheeltapper

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Re: Digital oscilloscope project/kit
« Reply #112 on: January 01, 2016, 08:06:06 AM »
Thanks John.
It is the first time I've used SMD's, I used 0.8mm on the 0603's and 0.7mm on the rest.

Considering that when I look at the board without my glasses I can't even see the damn components I'm quite pleased.

Roy.
I used to be confused, now I just don't know.

RobWilson

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Re: Digital oscilloscope project/kit
« Reply #113 on: January 01, 2016, 08:16:47 AM »
So, not a chassis transformer ???

Oh well, another wrong idea I've got.  :doh:     I blame Global Warming. I was OK until that kicked in ... must have addled my brain  :scratch:

I've made templates for the CPC trannies .

So it would be quite possible to mount it on the board.

Dave


Nope PCB mounted Dave as I shown  about 5 back .





Rob

RobWilson

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Re: Digital oscilloscope project/kit
« Reply #114 on: January 01, 2016, 08:20:17 AM »
Looking good Roy  :thumbup:


Looks like you will have no problems doing the SMD on the oscilloscope board . :dremel:




All the best Rob

RobWilson

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Re: Digital oscilloscope project/kit
« Reply #115 on: January 01, 2016, 08:27:11 AM »
Rob,
ESR do a line in pcb trannies.......but I guess you aleeady knew that.....

They aint to far from you either at Cullercoats....( boy I love going to that place....lots of luverly conponents.... :lol:)




I keep forgetting about ESR John  :bang: , they are only a few miles away .


Rob
« Last Edit: January 01, 2016, 10:33:55 AM by RobWilson »

Offline Bluechip

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Re: Digital oscilloscope project/kit
« Reply #116 on: January 01, 2016, 02:22:45 PM »
Here you are, Rob.

PCB Tranny now in. Looks a bit messy  :scratch: 

Back to my Becks & cashews ..  :beer:

Hope I've got 'em re-sized properly.

Dave

EDIT1   Near enuff ...  :loco:
EDIT2   Each dot is on a 0.1" pitch

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Re: Digital oscilloscope project/kit
« Reply #117 on: January 01, 2016, 02:42:01 PM »
Lookin good Dave  :thumbup:


My electronics /PCB software can't do a ground plane   :scratch:


I could not agree more ,,,,,,,,,,,,where be my beer  :beer:


Cheers Rob

Offline John Rudd

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Re: Digital oscilloscope project/kit
« Reply #118 on: January 01, 2016, 02:53:08 PM »
Dave,
I know you done well...... :bow:

But I think the distances between the copper infill are a bit close around the transformer.... :scratch:

I prefer at least 6mm creepage distance for safety... :zap:

Just  my 2 cents....while drinking my Carling cider.... :coffee:    Enjoy.... :)
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Offline philf

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Re: Digital oscilloscope project/kit
« Reply #119 on: January 01, 2016, 03:10:33 PM »

My electronics /PCB software can't do a ground plane   :scratch:


Rob,

Are you sure?

I managed to do a copper pour to fill. What i couldn't do was neatly connect a pad to the plane. I've uninstalled it now so can't tell you exactly how to do it.

 :beer:

Phil.
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RobWilson

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Re: Digital oscilloscope project/kit
« Reply #120 on: January 01, 2016, 03:16:45 PM »

My electronics /PCB software can't do a ground plane   :scratch:


Rob,

Are you sure?

I managed to do a copper pour to fill. What i couldn't do was neatly connect a pad to the plane. I've uninstalled it now so can't tell you exactly how to do it.

 :beer:

Phil.


Hi Phil

I think I am driving it correctly , I added the copper fill but I cant connect to it  :scratch: ,  I thought just add the copper fill ,then remove/delete  all the traces that are at 0 volts , but it just isolates the pads .


how did you get a connection ? 


Cheers Rob  :beer:

Offline philf

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Re: Digital oscilloscope project/kit
« Reply #121 on: January 01, 2016, 03:30:19 PM »

My electronics /PCB software can't do a ground plane   :scratch:


Rob,

Are you sure?

I managed to do a copper pour to fill. What i couldn't do was neatly connect a pad to the plane. I've uninstalled it now so can't tell you exactly how to do it.

 :beer:

Phil.


Hi Phil

I think I am driving it correctly , I added the copper fill but I cant connect to it  :scratch: ,  I thought just add the copper fill ,then remove/delete  all the traces that are at 0 volts , but it just isolates the pads .


how did you get a connection ? 


Cheers Rob  :beer:

Rob,

You have to draw a track from the pad to the filled area. (I found somewhere in the help that told me that was the only way.)

I found this in one of their tutorials which shows the filled area but no connections to any pads.



I don't know if you can get sufficient clearance for the pads for your transformer or whether you're stuck with a standard clearance. There will be a way round it I'm sure.

Other software allows you to specify on the pad properties if it's isolated or not.

In my PCB I used one plane for 0v to connect to my Pi and one plane for the 0v from my proximity sensor inputs. I wanted to keep both sides completely separate to keep the 24v away from the Pi which is limited to 3.3v on the inputs.

 :beer:

Phil.
« Last Edit: July 13, 2017, 01:14:29 PM by philf »
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Offline Bluechip

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Re: Digital oscilloscope project/kit
« Reply #122 on: January 01, 2016, 03:40:17 PM »
Dave,

But I think the distances between the copper infill are a bit close around the transformer.... :scratch:

I prefer at least 6mm creepage distance for safety... :zap:


Yes, quite right, there should be more clearance.

Did it when I was sober, [ or very nearly ], brain would be lacking some essential toxin and thus not on top form.

Rectified now. Back on full power, like a re-gunned CRT.

Dave

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Offline modeng200023

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Re: Digital oscilloscope project/kit
« Reply #123 on: January 02, 2016, 09:22:01 AM »
I have been following this topic with much interest.

Rob and John or anyone else with experience of using this scope, after using it for a while do you have any reservations bearing in mind that it is resonably priced?

The other thing I'd like ideas on is a case for it if anyone has thought about ready made ones.

John

RobWilson

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Re: Digital oscilloscope project/kit
« Reply #124 on: January 02, 2016, 10:01:55 AM »
I have been following this topic with much interest.

Rob and John or anyone else with experience of using this scope, after using it for a while do you have any reservations bearing in mind that it is resonably priced?

The other thing I'd like ideas on is a case for it if anyone has thought about ready made ones.

John

Hi John

    15 delivered its a cracking bit of fun ,it has  nowhere near  the capabilities of a good or even low end bench DSO ,but  for 15 I really can't find fault .

It has also generated a good bit crack on the forum and lead to other topics like a 3DP case , so if you could CAD model a case maybe someone could print one for it ,  I may stick mine in an ally

case , I bought longer bush buttons that come level with the screen , I just need to find away to bring the slide switches forward .


or there is this kits .

http://www.banggood.com/DSO068-DIY-Oscilloscope-Kit-With-Digital-Storage-Frequency-Meter-ATmega64-AVR-Microcontrol-p-981017.html


More than double the price ,but it has a case .


Maybe the more experienced chaps could chip in with some oscilloscope advice  :thumbup:



Cheers Rob