This SHOULD make some happy

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manie

Senior Member
For BB, Hippy, Dippy, Westaus, BCJ, Eclectic, Andrew, JGlenn, Boriz and anybody else, happiness is:- "Manie now wants to buy a breadboard" ! The reason is simple. Something did not work on the PCB as intended ! For all newbies (like me) the following could have been prevented by buildng/testing on breadboard first.... Fortunately, I could easily salvage the PCB by shifting some resistors from 0V to +5V etc. but still....

Scenario:
Drive 2n7000 Mosfets from 40x1 outputs (gate to high), Mosfet then drives external (off board) power Mosfet or Transistor. Mosfet drain connected to +5V, sink to external driver.(See attached schematic)
Result:
Output from 2N7000 was insufficient ! Only 2.4V appeared on sink output. I wanted more.
Cure:
Change pulldown resistors (on Mosfet gate) to pull up resistors on PNP tranny. Replace Mosfets with PNP BC37's. Fortunately pnp's legs same configuration as Fets. (+5v remains +5V etc). Now I can drive external switch.

Shematics below show: "Old" incorrect circuit on left and "New" working circuit on right. If some noob learns something then my problem was worth it.

Hey guys, I could solve this one before asking ! Your education is working ! Keep it up ! And THANKS !
Manie
 

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BeanieBots

Moderator
Oh Manie, you missed out MR. BREADBOARD himself, Stan AKA Manuka.

Hope have many happy hours with your new breadboard.
They really do save a lot of tears.
 
M

manie

Senior Member
Thanks guys. Here is the one I'm getting off THEEE bay:

http://cgi.ebay.com/Double-sided-Breadboard-prototype-PCB-1160-holes_W0QQitemZ350200219494QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item51898f4766&_trksid=p4634.c0.m14.l1262&_trkparms=|301:0|293:3|294:30

What do you think ? Looks OK ? I have also purchased a board populated with 24 high bright UV LED's. Took 4 = 96 LED's. Should be OK for PCB exposure ? 45K to 48K mcd's at 385 to 395 nm... Link:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=350195761433

As for breadboarding, easier is maybe not inspiring enough ? But it ought to be quicker though....
Manie
 
J

jglenn

Senior Member
I like wirewrap myself, with a real Gardner Denver Gun, of course. Digikey has prestripped wires that save a lot of time. I used the white strip breadboards a long time ago, but 2 things bug me:

The jumpers and parts fall out sometimes and you have to figure out how to put them back in.

A wirewrap board takes me the same amount of time, and is smaller and in a usable form, just put it in a metal or plastic box. Believe it or not I have done some video circuits this way, but you have to be very careful, a ground plane ww perf, and VERY short connections, some are twisted pairs. You can still change ww circuits, they have unwrapper tools.

Good luck!
 
E

eclectic

Moderator
manie said:
Thanks guys. Here is the one I'm getting off THEEE bay:

http://cgi.ebay.com/Double-sided-Breadboard-prototype-PCB-1160-holes_W0QQitemZ350200219494QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item51898f4766&_trksid=p4634.c0.m14.l1262&_trkparms=|301:0|293:3|294:30

What do you think ? Looks OK ? I have also purchased a board populated with 24 high bright UV LED's. Took 4 = 96 LED's. Should be OK for PCB exposure ? 45K to 48K mcd's at 385 to 395 nm... Link:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=350195761433

As for breadboarding, easier is maybe not inspiring enough ? But it ought to be quicker though....
Manie
Click to expand...
Manie.

PLEASE check. It's not my money or time, but
is your first link a breadboard, or a PCB?

e

Editadd

"Real" breadboards are white(ish) plastic.
(Polystyrene/ Polyethylene / Polysome-thing)
And about 5 -10 mm thick
 
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A

Andrew Cowan

Senior Member
The first link is not a breadboard. It is a PCB in breadboard layout.

Second: I have one cluster of UV LEDs from SureElectronics (the link you posted to is for three clusters). This will be no good for exposing PCBs. With it 80cm from the wall, the spot of light is 10cm wide, and not uniform brightness. These LEDs are far too directional for what you want. SMD LEDs are usually wider angle, as they have no lens.

My breadboards are from SureElectronics. (here).

You get over 500 jump wires, and 5 good sized bread boards.

If anyone in the UK wants a few jump wires, I have too many! PM me!

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manie

Senior Member
Maybe chopping the LED tops with Dremel cutting disk ? I think Boriz mentioned doing it ?
Ah sh...t ! Thats that then ! Will lay out something on the "Bread" board and solder it then use it as permanent installation thingy......
 
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Andrew Cowan

Senior Member
I've done that to LEDs before. Either dremel, file or sand down the top, and then polish it with 2000 grit wet and dry paper. Gives a nice wide beam. If you don't polish it, it will just make it a bit dimmer.

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manie

Senior Member
Andrew, these are supposed to be +- 47000 mcd's !! I would hate to polish 96 LED's ! Think I'll just top'em off ! Surely the brightness would still be OK at a few cm's from the board, especially if there is 96 of them ?
I've asked Sure Electr. to change the purchase to another board. I'll see what they say...

Manie
 
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Andrew Cowan

Senior Member
Probably - it will just take longer. Whether that's 2 seconds instead of 1 second, or 15 minutes instead of 5 minutes, I have no idea! Sounds like some testing it in order!

I'm sure you'll have fun :)

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manie

Senior Member
Fun yes but the cost of pre-sensitised board here is not good ! Will have to test on small pieces...:p
 
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manuka

Senior Member
Manie: Although predictably applauding extensive BB use, I too am confused about your actual purchase. Additionally I'd not waste good money on the supplied wires that come with many BB kits, but instead grab some nifty jumpers. Of course for the final "presentation" breadboarded layout, neat solid strand wiring, preferably also using simple BBROYGBPGW colour coding (Pin0= Black, Pin1= Brown, Pin2= Red, Pin3= Orange etc), IMHO is near essential. Stan
 

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Andrew Cowan

Senior Member
Those wires are the ones that came with my breadboard. I'd recommend sureelectronics breadboards (unless Dippy reads this).

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Edit - I have several hundred jum wires - PM me if you are in the UK and want some.
 
lbenson

lbenson

Senior Member
I got a set of five of the Sure breadboards a year or so ago. Unfortunately, some of the power/ground rows on the outer edges did not have continuity from one end to the other. I would check each one and put in jumpers as needed to prevent a great deal of puzzling. Otherwise they were fine, tho I prefer the ones which have power and ground on each side.
 
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Andres Rodriguez

New Member
manie said:
Maybe chopping the LED tops with Dremel cutting disk ? I think Boriz mentioned doing it ?
......
Click to expand...
That will work, and you do not need to polish them after you cut them or sand them. Just put a drop of plastic model cement and spread it over the flat spot. The cement will melt the LED surface and, when it is dry, the surface will be perfectly smooth.
 
M

manie

Senior Member
Anrew, I'm so glad I mentioned cutting them here first, NO polishing for me ! It seems there are some VERY clever people out there !

Stan, those jumpers "looks" like the ones comming with the 2860 hole BB from Sure. I thought that the "BB PCB" advertised is a BB..... apparently not. I've asked Sure to cancel the order so that I can take the 4 panel 2860 holes BB which comes with 2 bundles of jumpers. Link:
http://cgi.ebay.com/2-860-Tiepoint-Solderless-Breadboard-Includes-Jumpwires_W0QQitemZ350202000101QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item5189aa72e5&_trksid=p4634.c0.m14.l1262&_trkparms=|301:1|293:3|294:30
At 17 US its only 146 ZAR, cheap at the price and it has the Power rails on each panel also.

Ibenson, thanks for the heads-up on the power rails, I'll check ALL bus's for continuity before use. LED's with R's at the end with +v and 0V at the start of each bus should do it ?

Now I just hope Sure is OK with a swap around...
 
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Andrew Cowan

Senior Member
Good move getting those jumpers. Some are a bit weak (I have had about 3 fall apart), but when you get several hndred, that is no problem.

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manie

Senior Member
Can you get them separate to the BB ? Then I'll get some extra.

The jumpers were the real reason I never used BB'ing. Stripping all those wires made it easier to just build it on final PCB.....
 
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Andrew Cowan

Senior Member
Yes you can. DO a search for breadboard in sureelectronics's shop, and you can buy individual bundles.

But 200 should be enough...

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boriz

Senior Member
@Andrew “My breadboards are from SureElectronics. (here).”

LOL. I bought the exact same package :)
 
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manie

Senior Member
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lbenson

lbenson

Senior Member
The last item looks the same as the Allelectronic.com wires I use here: http://www.allelectronics.com/make-a-store/item/JW-140/140-PIECE-JUMPER-WIRE-ASSORTMENT/-/1.html

But half the price and lower shipping cost from China. I like those wires--no stripping and bending, and very neat. Wish I could buy only the shorter 6 sizes alone--I use them up at about three or four times the rate of the longer ones. I like the 840-tie-point breadboards sold by that vendor (tho I've gotten them from phanderson at nearly the same price after shipping). For smaller projects I often cut them with a bandsaw into two or three or even four pieces--good 08M size. I may scavenge the chips but I rarely undo the wiring.
 
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Andrew Cowan

Senior Member
I bought one of these at great expense (£9.99 maplins):


Made of solid core wire, it is fantastic for 'official prototying' - coursework etc. Very neat, very tidy. However, it isn't qick and easy - for that, the flexible jumpers can't be beat.

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