12-volt matrix input->output?

[Jan Panteltje]

That one is already 'on' at .8V, I'd rather use one that was on at about 6V

Seems I misread that, it opens at 2V, so that should be OK in both circuits,
4051 or 4028, but you still need the flyback diodes.

 

[Joerg]

Thus spake Joerg:




I've looked at the data sheet. Fewer pins to deal with (no inhibit, no
input/output control) -- looks more straightforward...

Yep, keep it simple

BTW we just brought a couple back from church and his name is the same
as yours. He is a retired mineral engineer. I told him and he said that
he never met another person with that name. At least not in the last
nine decades or so and this guy has been all over the world.

 

[Clifford Heath]

BTW we just brought a couple back from church and his name is the same
as yours. He is a retired mineral engineer. I told him and he said that
he never met another person with that name. At least not in the last
nine decades or so and this guy has been all over the world.

And presumably neither of them is the Jon English who sang
"Hollywood Seven"...? Can't be *that* rare a name...

 

[Joerg]

And presumably neither of them is the Jon English who sang
"Hollywood Seven"...? Can't be *that* rare a name...

If he writes his first name without the "h" that doesn't count

 

[rwmoekoe]

how d'u guys read the circuits written in this forum?

how d'u guys read the circuits written in this forum?

is there an application used to read such diagram u guys are drawing? (spice or things like that?)

thx for ur reply...

 

[jasen]

If you are already using relays then I think this can
be done with 3-off 4-pole changeover relays.

overkill... smaller relays are sufficient

+---------- W output
|
.-------------------|------.
NC | NC | NC
/ | / | /
/ | / | /
12v---A1 | 12v---B1 '---C1
|
NO---| NO----+----------NO
| |
| |
| | NC
| | /
| | /
| `------C2
|
| NO---> X output
|
|
| NC--------------NC
| / /
| / /
+-------B2 .-C3
|
NO---+----|----NO
| |
| `--------> Y output
|
|
|
|
|
`---------------> Z output

/|\ /|\ /|\
| | |
A-contacts B-contacts C-contacts

A-----. B-----. C-----.
| | |
___|___ ___|___ ___|___
| | | | | |
| CoilA | | CoilB | | CoilC |
|_______| |_______| |_______|
| | |
0v----+---------------+---------------+

 

[Tony Williams]

If you are already using relays then I think this can
be done with 3-off 4-pole changeover relays.

[/QUOTE]

overkill... smaller relays are sufficient

I guessed it could be simplified but was too lazy
to try it. Nice try, but could you check your
ascii diagram for typos, there seems to be
something wrong.

eg, Look at the req'd '010' input, '1000' output.

The B-relay is closed, connecting B1-NO and B2-NO.
This does not produce a 1 on the W output?

There are other anomolies. Contact C3 shorts
Y and Z together, but look at the '101' input,
this requires Y and Z to be different.

There's a typo or I'm not reading your circuit
correctly.

 

[Rich Grise]

http://focus.ti.com/lit/ds/symlink/cd4028b.pdf

Digikey has it in stock even in the old DIP version, 52 cents a pop. If
you need more than a milliamp or so you could use a driver from the ULN
series.

74AC138, and some diodes:

138 outputs: A B C D
000 | | | |
---------------------------
001 | | | |
---------------------------
010 | | | |
--------------X----X----X
011 | | | |
-------------------X----X
100 | | | |
---------X----X---------X
101 | | | |
--------------X---------X
110 | | | |
--------------X----X------
111 | | | |
--------------------------

Where "X" is one diode of a diode OR, connected the usual way;
the unused inputs default to 1111 for the output, since the 138
is active low. To make the default 0000, just strap all of the
unused outputs with all four diodes.

Have Fun!
Rich

 

[Rich Grise]

Yep, keep it simple

BTW we just brought a couple back from church and his name is the same
as yours. He is a retired mineral engineer. I told him and he said that
he never met another person with that name. At least not in the last
nine decades or so and this guy has been all over the world.

Not even Johnathan E from "Rollerball"? ;-)

Cheers!
Rich

 

[Rich Grise]

74AC138, and some diodes:

138 outputs: A B C D
000 | | | |
---------------------------
001 | | | |
---------------------------
010 | | | |
--------------X----X----X
011 | | | |
-------------------X----X
100 | | | |
---------X----X---------X
101 | | | |
--------------X---------X
110 | | | |
--------------X----X------
111 | | | |
--------------------------

Where "X" is one diode of a diode OR, connected the usual way;
the unused inputs default to 1111 for the output, since the 138
is active low. To make the default 0000, just strap all of the
unused outputs with all four diodes.

As long as I have it right here,
http://focus.ti.com/lit/ds/symlink/cd74ac138.pdf

This could be built on a protoboard with vertical diodes and flying
wires across their tops.

Ooops! It's a 5V part. I guess the 4028 will do it, but the outputs
aren't all nicely lined up like on the 138, so it'd be harder to do
on a protoboard.

Cheers!
Rich

 

[Joerg]

Not even Johnathan E from "Rollerball"? ;-)

To be honest I don't know who that is.

 

[Joerg]

As long as I have it right here,
http://focus.ti.com/lit/ds/symlink/cd74ac138.pdf

This could be built on a protoboard with vertical diodes and flying
wires across their tops.

Ooops! It's a 5V part. ...

It might have worked. For about 100msec or so ))

... I guess the 4028 will do it, but the outputs
aren't all nicely lined up like on the 138, so it'd be harder to do
on a protoboard.

No problem. In the lab nothing looks more high-tech than a nice big
Sauerkraut ball of wires.

 

[jasen]

I guessed it could be simplified but was too lazy
to try it. Nice try, but could you check your
ascii diagram for typos, there seems to be
something wrong.

eg, Look at the req'd '010' input, '1000' output.

The B-relay is closed, connecting B1-NO and B2-NO.
This does not produce a 1 on the W output?

There are other anomolies. Contact C3 shorts
Y and Z together, but look at the '101' input,
this requires Y and Z to be different.

There's a typo or I'm not reading your circuit
correctly.

OOPS! you're right

The circuit I posted was incorrect.
here's a corrected version.

.------------. .------> W output
| | |
| .--|--|------.
| NC | | | NC
| / | | | /
| / | | | /
12v-+--B1 | | '---C1
| |
NO--+ `---------NO
|
|
|
| NC
| /
| /
`---------C2

NO---> X output

.------------------.
  | |
NC | NC-----|--------NC
/ | / | /
/ | / | /
12v--A1 +-------B2 | .-C3
| | |
NO---' NO--. `--|-----NO
| |
| `--------> Y output
|
`--------------> Z output

/|\ /|\ /|\
| | |
A-contacts B-contacts C-contacts

A-----. B-----. C-----.
| | |
___|___ ___|___ ___|___
| | | | | |
| CoilA | | CoilB | | CoilC |
|_______| |_______| |_______|
| | |
0v----+---------------+---------------+

 

[Tony Williams]

The circuit I posted was incorrect.
here's a corrected version.

[snip rest]

That looks like a goer. Well done, nice bit
of simplification. Maybe use 4-off 2PCO
relays, (2 in // to get the 3x C-contacts),
in chassis-mount sockets. Add 3x flyback
diodes across the coils. Just wiring, no
soldering, no pcb.

 

[Jan Panteltje]

The circuit I posted was incorrect.
here's a corrected version.

[snip rest]

That looks like a goer. Well done, nice bit
of simplification. Maybe use 4-off 2PCO
relays, (2 in // to get the 3x C-contacts),
in chassis-mount sockets. Add 3x flyback
diodes across the coils. Just wiring, no
soldering, no pcb.

One company where I worked would have sold the OP a PLC

 

[Rich Grise]

To be honest I don't know who that is.

http://www.scifimoviepage.com/rollerball.html

Cheers!
Rich

 

[Tony Williams]

One company where I worked would have sold the OP a PLC

Someone around here, (and I shall remain anonymous),
did actually implement a 4-line to 12-line decoder
in a PIC. PIC, RC-clock, 12 output transistors, 12
base resistors, all on a small daughter board that
plugged into the original 4-line to 16-line IC socket.
One of those desperately desperate retrofit mods to
get him out of the brown stuff.

 

[John E.]

Tony Williams sez:

...implement a 4-line to 12-line decoder
in a PIC.

OP request a non-PIC solution.

Thanks,

 

[Joerg]

http://www.scifimoviepage.com/rollerball.html

Thanks. Didn't know that movie. Our theatre and TV intake is pretty
miniscule.

 

[Rich Grise]

Tony Williams sez:


OP request a non-PIC solution.

I thought we had a new "rule" here - anybody who says, "Use a PIC"
without showing their code shall be considered a "Troll". ;-)

Cheers!
Rich