This project is for a student Quiz Bowl (think Jeopardy). Eight
handheld push button switches that turn on an led indicator (one for
each player) and energize a buzzer. It must also block all other
buttons so there are no simultaneous lights. Oh, and must be battery
powered.

Just to clue you in on my capabilities, the last course I took in
electronics was for tube radios. I can solder.

--Andy Asberry--
------Texas-----

easiest way to do this would be a small PLC. Eight inputs, pushbuttons.
eight outputs, buzzers and lights. a small bit of ladder logic and you're
done.

Hire out the PLC logic work. I see PLCs on eBay all the time, but you want
to get one your programmer person is familiar with.

Karl

you need 8 diodes, or an 8 input or gate, eight flip flops and a 5V
regulator (7805) and a 9v battery. or the buttons together with a the
diodes, also connect each button to a set input ona flip flop. use the or'd
button signal to strobe the clock line to all flip flops through a .01 uf
capacitor. use an 8 input AND gate to AND the negative outputs from the
flip flops and use the output of the gate to power the other side of the
switches.

(you can rework this with NOR/NAND logic if that is more convenient) - about
5 chips and 10 minutes to wire together.

you can do it with discretes or relays if that's easier for you, but with
TTL or CMOS logic you will use less power and it will be easier to move
around.

another way to do this is to use an 8 input latch, one input per switch,
triggered by the OR of the switches through a single shot circuit - might
take fewer chips.

look these chips up by type in a chip catalog and choose what is cheap and
available.


"Andy Asberry" wrote in message
...
This project is for a student Quiz Bowl (think Jeopardy). Eight
handheld push button switches that turn on an led indicator (one for
each player) and energize a buzzer. It must also block all other
buttons so there are no simultaneous lights. Oh, and must be battery
powered.

Just to clue you in on my capabilities, the last course I took in
electronics was for tube radios. I can solder.

--Andy Asberry--
------Texas-----


** Posted from http://www.teranews.com **

Use 8 dpdt 1v relays.All relay coils in series through the N.C.
contacts on each. When one button is pushed it energizes its coil
through a separate circuit with one of it's N.O. contacts with an
appropriate resistor as we're using a 12v battery. The other N.O.
contact operates it's LED and buzzer. Another pushbutton can be used
to reset.
Do I win the prize for simplicity?
Engineman
On Jul 16, 5:20�pm, Andy Asberry wrote:
This project is for a �student Quiz Bowl (think Jeopardy). Eight
handheld push button switches that turn on an led indicator (one for
each player) and energize a buzzer. It must also block all other
buttons so there are no simultaneous lights. Oh, and must be battery
powered.

Just to clue you in on my capabilities, the last course I took in
electronics was for tube radios. I can solder.

--Andy Asberry--
------Texas-----

Andy Asberry wrote:

This project is for a student Quiz Bowl (think Jeopardy). Eight
handheld push button switches that turn on an led indicator (one for
each player) and energize a buzzer. It must also block all other
buttons so there are no simultaneous lights. Oh, and must be battery
powered.

Just to clue you in on my capabilities, the last course I took in
electronics was for tube radios. I can solder.

--Andy Asberry--
------Texas-----

One of the cheap little basic programmable microcontrollers ought to do
the job, something with 16 I/O lines preferably so you don't need
additional support chips. I believe Radio Scrap carries some of the
Parallax micros, as does Fry's.

Oops, I meant a 9v battery. Do I win for simplicity or am i just
simple?
Engineman

On Jul 16, 7:34Â*pm, " wrote:
Use 8 dpdt 1v relays.All relay coils in series through the N.C.
contacts on each. When one button is pushed it energizes its coil
through a separate circuit with one of it's N.O. contacts with an
appropriate resistor as we're using a 12v battery. The other N.O.
contact operates it's LED and buzzer. Another pushbutton can be used
to reset.
Do I win the prize for simplicity?
Engineman
On Jul 16, 5:20�pm, Andy Asberry wrote:



This project is for a �student Quiz Bowl (think Jeopardy). Eight
handheld push button switches that turn on an led indicator (one for
each player) and energize a buzzer. It must also block all other
buttons so there are no simultaneous lights. Oh, and must be battery
powered.

Just to clue you in on my capabilities, the last course I took in
electronics was for tube radios. I can solder.

--Andy Asberry--
------Texas------ Hide quoted text -

- Show quoted text -

On Wed, 16 Jul 2008 19:20:35 -0500, Andy Asberry wrote:
This project is for a student Quiz Bowl (think Jeopardy). Eight
handheld push button switches that turn on an led indicator (one for
each player) and energize a buzzer. It must also block all other buttons
so there are no simultaneous lights. Oh, and must be battery powered.

Just to clue you in on my capabilities, the last course I took in
electronics was for tube radios. I can solder.
....

This is a fairly common question and you can see some really weird
solutions if you google for Jeopardy switches lights circuit.

If you don't want to use a PLC like Karl suggested, or a microprocessor,
as many would suggest, then see http://i18.tinypic.com/4uenm6a.jpg
a simple and straightforward circuit as discussed in following URL:
http://sci.tech-archive.net/Archive/.../msg03089.html
This solution uses about 9 parts per station, plus a bunch for the main
panel. It depends on SCR operation to interlock the stations, so only
the first-button-pressed station lights and stays lit.

Also see relays methods http://www.flickr.com/photos/65791337@N00/498510014/
and http://www.desmith.net/NMdS/Electronics/Jeopardy.html . The former
link is mentioned in informative thread about jeopardy-game-design-requests,
http://www.cervo.biz/ElectronicsDesi...est-66487.aspx
which is copied from the sci.electronics.design newsgroup where
jeopardy-game-design-requests are a FAQ.

Two of the weird ways:
http://electronicdesign.com/Articles...rticleID=10854
uses flipflops etc to arbitrate every pair of stations, so would
require about 28 FF's for 8 stations, and a mess of wiring.

http://www.discovercircuits.com/H-Co...cnprogress.htm (near
the middle) says "... they press the button ... a powerful xenon
flash is produced by the box ... A light detector in each of the
boxes detects the light flash and temporarily disables the [other
boxes]..."

-jiw

Andy Asberry wrote:

This project is for a student Quiz Bowl (think Jeopardy). Eight
handheld push button switches that turn on an led indicator (one for
each player) and energize a buzzer. It must also block all other
buttons so there are no simultaneous lights. Oh, and must be battery
powered.

Just to clue you in on my capabilities, the last course I took in
electronics was for tube radios. I can solder.

--Andy Asberry--
------Texas-----

http://www.google.com/search?hl=en&rls=com.microsoft:en-us:IE-SearchBox&rlz=1I7GGLD&sa=X&oi=spell&resnum=0&ct=re sult&cd=1&q=jeopardy+circuit+game&spell=1

There are already hundreds of circuits available online. Why design
another?


--
http://improve-usenet.org/index.html

If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm

Sporadic E is the Earth's aluminum foil beanie for the 'global warming'
sheep.

On 2008-07-17, William Noble wrote:

[ ... ]

another way to do this is to use an 8 input latch, one input per switch,
triggered by the OR of the switches through a single shot circuit - might
take fewer chips.

This -- with another flip-flop to latch out any subsequent
contact closures until a reset button is pressed.

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On Wed, 16 Jul 2008 19:34:50 -0700 (PDT), "
wrote:

Use 8 dpdt 1v relays.All relay coils in series through the N.C.
contacts on each. When one button is pushed it energizes its coil
through a separate circuit with one of it's N.O. contacts with an
appropriate resistor as we're using a 12v battery. The other N.O.
contact operates it's LED and buzzer. Another pushbutton can be used
to reset.
Do I win the prize for simplicity?
Engineman
On Jul 16, 5:20?pm, Andy Asberry wrote:

You are the first to speak a language I can understand.

Thanks for all the links.

--Andy Asberry--
------Texas-----

On 2008-07-17, wrote:
On Jul 16, 5:20?pm, Andy Asberry wrote:
This project is for a ?student Quiz Bowl (think Jeopardy). Eight
handheld push button switches that turn on an led indicator (one for
each player) and energize a buzzer. It must also block all other
buttons so there are no simultaneous lights. Oh, and must be battery
powered.

[ ... ]

Use 8 dpdt 1v relays.All relay coils in series through the N.C.
contacts on each. When one button is pushed it energizes its coil
through a separate circuit with one of it's N.O. contacts with an
appropriate resistor as we're using a 12v battery. The other N.O.
contact operates it's LED and buzzer. Another pushbutton can be used
to reset.
Do I win the prize for simplicity?

It depends on just how close in time the contact closures might
happen. Relays are a lot slower than logic circuits, so a tie might
happen with the relays which would not be one on the logic circuit
versions.

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On Wed, 16 Jul 2008 21:37:32 -0500, "Pete C."
wrote:


Andy Asberry wrote:

This project is for a student Quiz Bowl (think Jeopardy). Eight
handheld push button switches that turn on an led indicator (one for
each player) and energize a buzzer. It must also block all other
buttons so there are no simultaneous lights. Oh, and must be battery
powered.

Just to clue you in on my capabilities, the last course I took in
electronics was for tube radios. I can solder.

--Andy Asberry--
------Texas-----

One of the cheap little basic programmable microcontrollers ought to do
the job, something with 16 I/O lines preferably so you don't need
additional support chips. I believe Radio Scrap carries some of the
Parallax micros, as does Fry's.



I had an idle moment today and this little puzzle came to mind.
here is roughly how I would do it in one of the little GE PLC's.
(ladder logic using logicmaster)

it will look crap in a proportional font. use courier new in notepad
and you will see the typical logicmaster paper logic print.

you need to add the subroutine declaration and call in the main block
(placating the spell checkers out there).


|[ START LD SUBROUTINE BUZ ]
|
|[ VARIABLE DECLARATIONS ]
|
|[ START OF SUBROUTINE LOGIC ]
|
|
|ALW_ON +-----+
+--] [---+MOVE_+-
| | INT |
| | |
| CONST -+IN Q+-%R00001
| +00500 | LEN |
| |00001|
| +-----+
|
|
|%I0001 %I0002 %I0003 %I0004 %I0005 %I0006 %I0007 %I0008 +-----+ %Q0001
+--] [-----]/[-----]/[-----]/[-----]/[-----]/[-----]/[-----]/[---+OFDT
+---( )--
| |0.10s|
| | |
| %R00001-+PV |
| | |
| +-----+
| %R00002
|
|
|%I0002 %I0001 %I0003 %I0004 %I0005 %I0006 %I0007 %I0008 +-----+ %Q0002
+--] [-----]/[-----]/[-----]/[-----]/[-----]/[-----]/[-----]/[---+OFDT
+---( )--
| |0.10s|
| | |
| %R00001-+PV |
| | |
| +-----+
| %R00005
|
|
|%I0003 %I0002 %I0001 %I0004 %I0005 %I0006 %I0007 %I0008 +-----+ %Q0003
+--] [-----]/[-----]/[-----]/[-----]/[-----]/[-----]/[-----]/[---+OFDT
+---( )--
| |0.10s|
| | |
| %R00001-+PV |
| | |
| +-----+
| %R00008
|
|
|%I0004 %I0002 %I0003 %I0001 %I0005 %I0006 %I0007 %I0008 +-----+ %Q0004
+--] [-----]/[-----]/[-----]/[-----]/[-----]/[-----]/[-----]/[---+OFDT
+---( )--
| |0.10s|
| | |
| %R00001-+PV |
| | |
| +-----+
| %R00011
|
|
|%I0005 %I0002 %I0003 %I0004 %I0001 %I0006 %I0007 %I0008 +-----+ %Q0005
+--] [-----]/[-----]/[-----]/[-----]/[-----]/[-----]/[-----]/[---+OFDT
+---( )--
| |0.10s|
| | |
| %R00001-+PV |
| | |
| +-----+
| %R00014
|
|
|%I0006 %I0002 %I0003 %I0004 %I0005 %I0001 %I0007 %I0008 +-----+ %Q0006
+--] [-----]/[-----]/[-----]/[-----]/[-----]/[-----]/[-----]/[---+OFDT
+---( )--
| |0.10s|
| | |
| %R00001-+PV |
| | |
| +-----+
| %R00017
|
|
|%I0007 %I0002 %I0003 %I0004 %I0005 %I0006 %I0001 %I0008 +-----+ %Q0007
+--] [-----]/[-----]/[-----]/[-----]/[-----]/[-----]/[-----]/[---+OFDT
+---( )--
| |0.10s|
| | |
| %R00001-+PV |
| | |
| +-----+
| %R00020
|
|
|%I0008 %I0002 %I0003 %I0004 %I0005 %I0006 %I0007 %I0001 +-----+ %Q0008
+--] [-----]/[-----]/[-----]/[-----]/[-----]/[-----]/[-----]/[---+OFDT
+---( )--
| |0.10s|
| | |
| %R00001-+PV |
| | |
| +-----+
| %R00023
|
|[ END OF SUBROUTINE LOGIC ]
|

turned out to be an interesting 10 minute exercise.

Stealth Pilot

On Fri, 18 Jul 2008 17:01:42 +0800, Stealth Pilot
wrote:


|%I0008 %I0002 %I0003 %I0004 %I0005 %I0006 %I0007 %I0001 +-----+ %Q0008
+--] [-----]/[-----]/[-----]/[-----]/[-----]/[-----]/[-----]/[---+OFDT
+---( )--
| |0.10s|
| | |
| %R00001-+PV |
| | |
| +-----+
| %R00023
|
|[ END OF SUBROUTINE LOGIC ]
|



I poked it into notepad as an exercise as I suggested.
it comes out munged up after each ofdt.
put a space after the T and press delete and it will reform correctly.
Stealth Pilot

Stealth Pilot wrote:

On Wed, 16 Jul 2008 21:37:32 -0500, "Pete C."
wrote:


Andy Asberry wrote:

This project is for a student Quiz Bowl (think Jeopardy). Eight
handheld push button switches that turn on an led indicator (one for
each player) and energize a buzzer. It must also block all other
buttons so there are no simultaneous lights. Oh, and must be battery
powered.

Just to clue you in on my capabilities, the last course I took in
electronics was for tube radios. I can solder.

--Andy Asberry--
------Texas-----

One of the cheap little basic programmable microcontrollers ought to do
the job, something with 16 I/O lines preferably so you don't need
additional support chips. I believe Radio Scrap carries some of the
Parallax micros, as does Fry's.

I had an idle moment today and this little puzzle came to mind.
here is roughly how I would do it in one of the little GE PLC's.
(ladder logic using logicmaster)

it will look crap in a proportional font. use courier new in notepad
and you will see the typical logicmaster paper logic print.

you need to add the subroutine declaration and call in the main block
(placating the spell checkers out there).


Ow.

Simpler in basic. Just a loop doing a peek of the input port looking for
a value other than 255 (presuming switches pull low). Looping a some 10s
of killoHertz should be plenty fast in any of the current little micro
chips. After that it's a simple test to see which line went low or if
there is a tie. Gives you the ability to handle that rare tie better,
perhaps a rapid flash on the appropriate LEDs, can also do sound effects
easily.

Equally easy in PIC assembler. 10 "bit test and skip" in a row where they
skip over a jump to light the correct LED, which just loops waiting for the
"clear" button and jumps back to the 10 Test and skips, some thing like
this...

ALLOFF:
MOVLW 0xFF ;assumes high is off
MOVWF PORTC
MOVWF PORTD

CHECKSWITCHS:
BTFSS PORTB,0 ;test 1st switch, skip if it's not pushed
BRA TUNRON0 ;go turn on LED
BTFSS PORTB,1
BRA TUNRON1
BTFSS PORTB,2
BRA TUNRON2
BTFSS PORTB,3
BRA TUNRON3
BTFSS PORTB,4
BRA TUNRON4
BTFSS PORTB,5
BRA TUNRON5
BTFSS PORTB,6
BRA TUNRON6
BTFSS PORTB,7
BRA TUNRON7
BTFSS PORTA,0 ;note we switch to port A for the last 2 switchs
BRA TUNRON8
BTFSS PORTA,1
BRA TUNRON9
BRA CHECKSWITCHS ;keep trying.


TURNON0:
BCF PORTD,7 ;buzzer on
BCF PORTC,0 ;assumes lo is on
BTFSS PORTA,3 ;is the "clear putton pushed?
BRA ALLOFF ;yes go turn everything off
BRA TURNON0 ;keep checking

TURNON1:
BCF PORTD,7 ;buzzer on
BCF PORTC,1 ;assumes lo is on
BTFSS PORTA,3 ;is the "clear putton pushed?
BRA ALLOFF ;yes go turn everything off
BRA TURNON1 ;keep checking

;;;8 more of these for each LEDS.... last 2 would use bits in PORTD

Wanna see it in C...
How about a couple of C++ classes...
Mabe JAVA?, or are you a PHP type?... ohh I know you want it in PYTHON...


Theres also no need for debouncing the push buttons since once one pushed
you hang in the led loop for clear and vica-versa..

Of course this dosen't test for "multiple pushs at once", but that wasn't
part of the spec :-) Pretty easy to do though, just read all the switchs at
once.

You could also make the program slightly more complicated and after you
light the correct LED jump to a loop that either pulses the buzzer... of
buzzes it for a set ammount of time and then goes quite, but still leaves
the LED on...

FYI PIC's run just fine off batteries and have a built in 8MHZ Oscillator
and cost 3 bucks... parts list would be the PIC, 4 external resistors, the
buzzer, switchs, and LED's.. LEDS will need current limit R's unless you buy
the expensive ones with them built in. Other external R's are because only
one port on the PIC has builtin pullups for 8 of the 11 switchs, the 11th is
"clear button" or you *could* just power it down. and back up. :-)

--.- Dave


"Pete C." wrote in message
...

Stealth Pilot wrote:

On Wed, 16 Jul 2008 21:37:32 -0500, "Pete C."
wrote:


Andy Asberry wrote:

This project is for a student Quiz Bowl (think Jeopardy). Eight
handheld push button switches that turn on an led indicator (one for
each player) and energize a buzzer. It must also block all other
buttons so there are no simultaneous lights. Oh, and must be battery
powered.

Just to clue you in on my capabilities, the last course I took in
electronics was for tube radios. I can solder.

--Andy Asberry--
------Texas-----

One of the cheap little basic programmable microcontrollers ought to do
the job, something with 16 I/O lines preferably so you don't need
additional support chips. I believe Radio Scrap carries some of the
Parallax micros, as does Fry's.

I had an idle moment today and this little puzzle came to mind.
here is roughly how I would do it in one of the little GE PLC's.
(ladder logic using logicmaster)

it will look crap in a proportional font. use courier new in notepad
and you will see the typical logicmaster paper logic print.

you need to add the subroutine declaration and call in the main block
(placating the spell checkers out there).


Ow.

Simpler in basic. Just a loop doing a peek of the input port looking for
a value other than 255 (presuming switches pull low). Looping a some 10s
of killoHertz should be plenty fast in any of the current little micro
chips. After that it's a simple test to see which line went low or if
there is a tie. Gives you the ability to handle that rare tie better,
perhaps a rapid flash on the appropriate LEDs, can also do sound effects
easily.

I had a new hardware only idea, this will guarantee no logic races, though
under a rather odd circumstance it coudl be "unfair"

use a counter with at least 8 discrete outputs and a 555 oscilator set to
some conveninent frequency - say 20 Khz. the counter will now energize one
of 8 outputs one at a time in rapid succession.

each counter output goes to a switch. Each counter output also drives an
LED through a resistor. All LEDs will glow dimly.

Other end of all switches goes to a latch (two NAND gates will do the
trick). when you press a switch (any switch) the latch sets.

Output of latch goes to 555 "enable" line dragging it to the "disable"
condition - oscillator stops, counter stops - the LED on the line that was
active when the switch is pressed will glow brightly, all others off.

chip count is four, if I counted right, power draw is minimal, particularly
with CMOS.


** Posted from http://www.teranews.com **

On Wed, 16 Jul 2008 19:20:35 -0500, Andy Asberry
wrote:

You guys can continue visiting over this. I'm gonna run over to eBay
and pick up one of the $59, ten player stations. Now that I know what
they are called.

--Andy Asberry--
------Texas-----