Basic question about a "breadboard"

[Ignoramus27362]

I bought some DIP breadboard. In my naivete, I thought that there were
power rails on the perimeter, and then every hole in the middle is
electrically isolated, so that I can connect whetever I want to
whatever I want.

It turns out that it is not the case! There are little strips in the
back of the breadboard so that all points on every "vertical" line
have the same potential, they are connected. WTF? What is this even
useful for?

I wasted a bunch of time laying stuff out on it (started with just a
555 timer to get some practice), until I realized what was going
on. (the strips connecting points on every vertical line were not
visible behind sticky foam on the back. I had to peel that foam to
see).

WTF?

For now, I will try to just solder wires to my 555 timer.

i
--

 

[Ignoramus27362]

forget it, I figured it out. ICs should go in the middle.

i

I bought some DIP breadboard. In my naivete, I thought that there were
power rails on the perimeter, and then every hole in the middle is
electrically isolated, so that I can connect whetever I want to
whatever I want.

It turns out that it is not the case! There are little strips in the
back of the breadboard so that all points on every "vertical" line
have the same potential, they are connected. WTF? What is this even
useful for?

I wasted a bunch of time laying stuff out on it (started with just a
555 timer to get some practice), until I realized what was going
on. (the strips connecting points on every vertical line were not
visible behind sticky foam on the back. I had to peel that foam to
see).

WTF?

For now, I will try to just solder wires to my 555 timer.

i

--

 

[Pooh Bear]

I bought some DIP breadboard. In my naivete, I thought that there were
power rails on the perimeter, and then every hole in the middle is
electrically isolated, so that I can connect whetever I want to
whatever I want.

It turns out that it is not the case! There are little strips in the
back of the breadboard so that all points on every "vertical" line
have the same potential, they are connected. WTF? What is this even
useful for?

It's what *everyone* used to use.

You use a cutting tool to break those strips up as required.

It's so intuitive to me that I can't actually think of how to explain it
any better.


Graham

 

[[email protected]]

It's what *everyone* used to use.

You use a cutting tool to break those strips up as required.

It's so intuitive to me that I can't actually think of how to explain it
any better.

The cutting tool is called a "spot face cutter" - usually corrupted to
"a spotty-faced cutter". A ggogle search on the proper name produced
this

http://www.eleinmec.com/article.asp?11

which does provide an explanation, with pictures. It isn't a great
explanation - I always solder my integrated circuits directly into
strip-board, because the sort of sockets that make good electrical
contact with the IC pins ( and maintain good contact for more than a
few months) cost rather more than most ICs.

 

[Ignoramus4371]

The cutting tool is called a "spot face cutter" - usually corrupted to
"a spotty-faced cutter". A ggogle search on the proper name produced
this

http://www.eleinmec.com/article.asp?11

which does provide an explanation, with pictures. It isn't a great
explanation - I always solder my integrated circuits directly into
strip-board, because the sort of sockets that make good electrical
contact with the IC pins ( and maintain good contact for more than a
few months) cost rather more than most ICs.

This sounds nice. Seems like breadboard is no good for anything byt
prototyping.

i

 

[Tim Wescott]

This sounds nice. Seems like breadboard is no good for anything byt
prototyping.

i

If you're talking about the solderless breadboards, AKA "protoboards",
the ones made out of white plastic that you plug things into then yes,
they're only good for prototyping -- they fail under high current, high
vibration, or when the mood strikes them. I find them very useful for
small stuff where I know I'm going to have to dink around to get things
right.

When used properly a _soldered_ breadboard will last as long as anything
else in the world -- but it's much harder to change things around.

 

[Ignoramus4371]

If you're talking about the solderless breadboards, AKA "protoboards",
the ones made out of white plastic that you plug things into then yes,
they're only good for prototyping -- they fail under high current, high
vibration, or when the mood strikes them. I find them very useful for
small stuff where I know I'm going to have to dink around to get things
right.

When used properly a _soldered_ breadboard will last as long as anything
else in the world -- but it's much harder to change things around.

Are they called soldered breadboards? Or something else? I would like
to buy one.

i
--

 

[Don Foreman]

This sounds nice. Seems like breadboard is no good for anything byt
prototyping.

i

It isn't even good for that where high current, high dI/dt, or RF is
involved.

 

[Tim Wescott]

Are they called soldered breadboards? Or something else? I would like
to buy one.

i

They're usually called prototyping board. Radio Shack has some that
exactly match the layout of their solderless breadboards which is handy
if you have something that works -- you can just transfer the circuit
over. If you want something bigger, denser, or higher quality look in
the Digi-Key or Mouser catalogs in their "prototyping" section. Vector
is the big name, selling "Vectorboard". There's a gazillion options,
but I usually look for the ones that have three or four holes/circuit
with interlaced ground and power -- these will do for most lower
frequency stuff; for RF or high power it's best to just dead bug the
thing over unetched copper or lay out a board & send it to a quick turn
house.

 

[Joel Kolstad]

This sounds nice. Seems like breadboard is no good for anything byt
prototyping.

Radio Shack used to sell a regular PCB with the same layout as one of their
solderless breadboards... dunno if they still do, though.

I have seen people use solderless breadboards in prototype systems for many
months at a time (even a year!), and I've even seen people literally box up
solderless breadboards to ship to someone else who needed access to prototype.
Obviously this isn't recommended, but my experience has been that the things
are somewhat more rugged than you might initially expect.

You can even build single transistor oscillators on the things to better than
100MHz, although the parasitics start to look pretty significant up there.

 

[Ignoramus4371]

Radio Shack used to sell a regular PCB with the same layout as one of their
solderless breadboards... dunno if they still do, though.

I have seen people use solderless breadboards in prototype systems for many
months at a time (even a year!), and I've even seen people literally box up
solderless breadboards to ship to someone else who needed access to prototype.
Obviously this isn't recommended, but my experience has been that the things
are somewhat more rugged than you might initially expect.

You can even build single transistor oscillators on the things to better than
100MHz, although the parasitics start to look pretty significant up there.

You see, this thing will operate in a relatively hostile environment,
inside of a welding machine with a big cooling fan. Hence some
vibration, although not too much. It will house a gate driver that
needs to turn gates on and off relatively quickly (sub
microsecond). Also there could be some EMI as well.

i

 

[Marte Schwarz]

Hi Ignoramus

You see, this thing will operate in a relatively hostile environment,
inside of a welding machine with a big cooling fan. Hence some
vibration, although not too much. It will house a gate driver that
needs to turn gates on and off relatively quickly (sub
microsecond). Also there could be some EMI as well.

No, No, itis NOT the right tool for designing Gateunits. Forget this very
quickly. A gate-Unit for bigger IGBT as you want to use should have

as short wires as they can (not possible in a solderless breadboard)
as low resistance as possible (not possible in a solderless breadboard)
the possibility to give several amperes to the gates (not possible in a
solderless breadboard)...

That is the wrong tool for this work.

Marte

 

[Arie de Muynck]

"Joel Kolstad" ...

You can even build single transistor oscillators on the things to better than
100MHz, although the parasitics start to look pretty significant up there.

Yesterday evening it took a collegue 1.5 hours to build a 1800 MHz TV FM
transmitter on breadboard, and it was spot-on (pun intended) first time,
good video quality. He added a MAR amplifier today and got a 10 meter reach.
Total size was about 1 x 1.5 cm, all components in SMD soldered between
pads. A nice demonstration of what you can do with the stuff...

Regards,
Arie de Muynck

 

[martin griffith]

"Joel Kolstad" ...

Yesterday evening it took a collegue 1.5 hours to build a 1800 MHz TV FM
transmitter on breadboard, and it was spot-on (pun intended) first time,
good video quality. He added a MAR amplifier today and got a 10 meter reach.
Total size was about 1 x 1.5 cm, all components in SMD soldered between
pads. A nice demonstration of what you can do with the stuff...

Regards,
Arie de Muynck

do you have a picture of the breadboard?


martin

 

[Chris Jones]

Hi Ignoramus


No, No, itis NOT the right tool for designing Gateunits. Forget this very
quickly. A gate-Unit for bigger IGBT as you want to use should have

as short wires as they can (not possible in a solderless breadboard)
as low resistance as possible (not possible in a solderless breadboard)
the possibility to give several amperes to the gates (not possible in a
solderless breadboard)...

That is the wrong tool for this work.

Marte

It's ok for debugging the basic oscillator which only runs at a few hundred
Hz, but I wouldn't connect it to the welder in case one of the contacts
went flaky at the wrong time. As you say, solderless breadboard is no good
for the gate driver, the inductance in the gate circuit should be under
20nH or so for it to work well.

Chris

 

[Arie de Muynck]

"martin griffith" ...

do you have a picture of the breadboard?

Should be available this weekend, I'll post a link.

Regards,
Arie de Muynck