Help with Scoreboard...

[ericgibbs]

hi oxbo,

Can you follow this circuit OK.?

 

[Oxbo Rene]

hi oxbo,

Can you follow this circuit OK.?

View attachment 40872

Good morning;
Is 6:45am right now, just stirring around here.
I believe you are about 5 hrs ahead of us.
Yes sir I understand your drawing.
Yes, all 0V/gnd's are common/tied to everything proper.
Will take me a few days to get the new configuration put together.
Got to find some 74LS06's.
We have a wonderful Electronics Surplus store in Orlando (Fl), might have to run over there and see if they have any.
So, will get back with you when I get it going again........

I think what I'm going to do is modify the existing buffer PCB to where I isolate the 74LS06's pwr,
then make a new PCB to contain all the caps and resistors, and just solder the new lines in onto the existing 74LS06's outputs...

MrDEB see attached....

 

[mbarazeen]

you said the drive board is working fine, hope you tested it with the 7segment supplied by the kit maker.
if that part is right then what you are stuggling with, is to interface your large display.
5V may not excite enough voltage for the large display LEDs.
out puts A,B,...G , DP, DY1..DY4 are current sink, your buffer must be able to handle it,
if you have seriesly connected the LED in your display, then use a paropper voltage source only for the display and change all resistorsR1-R8 to limit the current (30mA), i beleive no need to use a buffer circuit, if i have understood it correctly.

 

[Oxbo Rene]

you said the drive board is working fine, hope you tested it with the 7segment supplied by the kit maker.
if that part is right then what you are stuggling with, is to interface your large display.
5V may not excite enough voltage for the large display LEDs.
out puts A,B,...G , DP, DY1..DY4 are current sink, your buffer must be able to handle it,
if you have seriesly connected the LED in your display, then use a paropper voltage source only for the display and change all resistorsR1-R8 to limit the current (30mA), i beleive no need to use a buffer circuit, if i have understood it correctly.

Am using 12V to drive the big LEDs via MPSA64 Darlington transistors (see previously attached pic), kit works great.
Big LEDs require 8.8V @20ma (DP = 4.4V @ 20ma)


Mr Gibbs;
Went into Orlando to the Electronics Surplus place. Found some chips but they are mgf'd in Singapore (didn't have any made in USA) only number on them was 7406. So, will mess with them to see how they act, etc........
This conversion will take me a day or two, will be back with results, etc......
Tx's so much.........

 

[ericgibbs]

Am using 12V to drive the big LEDs via MPSA64 Darlington transistors (see previously attached pic), kit works great.
Big LEDs require 8.8V @20ma (DP = 4.4V @ 20ma)


Mr Gibbs;
Went into Orlando to the Electronics Surplus place. Found some chips but they are mgf'd in Singapore (didn't have any made in USA) only number on them was 7406. So, will mess with them to see how they act, etc........
This conversion will take me a day or two, will be back with results, etc......
Tx's so much.........

hi,
The 74LS are lower power than the standard 74 series of IC.
I would try the 7406's in the circuit, if they load the PIC pins too much it will be necessary use 74LS06.
If you have any 14pin IC pcb style sockets I would fit them on the buffer, if you do have to change over the 06's it will be easier.

 

[Oxbo Rene]

hi,
The 74LS are lower power than the standard 74 series of IC.
I would try the 7406's in the circuit, if they load the PIC pins too much it will be necessary use 74LS06.
If you have any 14pin IC pcb style sockets I would fit them on the buffer, if you do have to change over the 06's it will be easier.

Oh yes, everything I do is with sockets.
Just finished fabing the resistors board.
Hope to have the changes in place sometime tomorrow..........

 

[mbarazeen]

i think you can go for simple transistor buffering and get it done, i have just drawn an example how it can be, hope it might work. just see the attached.

 

[ericgibbs]

i think you can go for simple transistor buffering and get it done, i have just drawn an example how it can be, hope it might work. just see the attached.

hi,
As the PIC outputs are 0V and +5V levels, the transistors cannot be switched off.

 

[mbarazeen]

i missed that point , so what about using a photo coupler like K3010? the transistor output can be like a switch. DY1...3 and A,B... all can be wired to each photocoupler input. it can drive 20mA directly.

 

[ericgibbs]

i missed that point , so what about using a photo coupler like K3010? the transistor output can be like a switch. DY1...3 and A,B... all can be wired to each photocoupler input. it can drive 20mA directly.

hi,
If you connected the opt coupler emitter from the PIC pin to 0v, via a resistor then when the PIC pin went low [active] the opto detector would switch off, so the signal would be 'inverted'.

I think the choice of ULN's was a good idea when you consider the ULN is driving a 10 foot long cable.

If the remote display had been close to the Velleman pcb I would have used a 74LS07 as per the previous thread.

 

[Oxbo Rene]

Well;
The thing about it is that everything is already build and installed.
I believe the easiest way is by switching the inverter chips and their 12V pwr to 5v pwr.
Then adding in the resistors/caps (on a little separate board that I fabed up yesterday).
AND, I had to run out this morning to get a CAT scan, am back, now will get on that mod and
see what happens.
Will post when I get some results, probably will be a couple hrs or more, etc......
Tx's so much........

 

[mbarazeen]

hi,
If you connected the opt coupler emitter from the PIC pin to 0v, via a resistor then when the PIC pin went low [active] the opto detector would switch off, so the signal would be 'inverted'.

.

inverting it before driving the photo coupler is not a big deal. any how lets see what OP ends up with.

 

[Oxbo Rene]

OK,
Got good news, and a little bad news.
Good news = Definitely got segments switching according to the clock ! That's great ! ! !
!0's unit is out completely,
all "g" segments not lighting.
All segments that are lighting are very dim, haven't measured ma's but the other day I measured one and it was only 4ma.
I can troubleshoot these things......

The big thing is that the data transfer from the console to the big board "IS" working ! ! !
And I certainly appreciate everyone's help, especially Mr Gibbs ! ! !
I think I'll go ahead and order the HD74LS06's just for the sake of it, etc

Tx's so much, I'll post final pics whenever I get it all working proper, etc.
(Still got to solder/install Guest & Home Teams PCB, and, run segment wires for them, etc....)
Will be a little while.......
Oxbo

 

[Oxbo Rene]

Update;

Was looking at the whole system and just happen to notice a solder iron burn (melt) on the 25-pin cable, happened to have a spare one (15ft) and threw it in = Walla ! !
All LEDS (+) DP's operating "Perfectly" ! ! !
(Reminder to self = don't be so sloppy)

Now, have checked segment currents and all currents are only 4ma (DP's going to gnd through their respective resistors, also = 4ma.....
So, the ULN chips in the console must be OK because the Big LEDs are operating correctly.
I have 12V on all the emitters of the MPSA64's.
The problem is common to all MPSA64's but they must be working because the LEDs are operating, math says resistors are correct, am investigating further, etc
Main thing = they're all working perfectly...... (except for being dim)
(Hold off on current values, going to make an "official" measurement in the morning......)
Looking at them tonight, they look great, just dim in the day, etc........

 

[mbarazeen]

only four opto couplers can be used as shown with an inverter at the input, it can be one of the option for you incase if you couldnt solve the problem you have

 

[Oxbo Rene]

only four opto couplers can be used as shown with an inverter at the input, it can be one of the option for you incase if you couldnt solve the problem you have

Appreciate that.
Will keep circuit for future reference, etc.....
Tx's

 

[ericgibbs]

Appreciate that.
Will keep circuit for future reference, etc.....
Tx's

Morning oxbo,
The problem with 'mbarazeen's circuit, is that you cannot turn OFF the lower transistors.!

 

[Oxbo Rene]

Morning oxbo,
The problem with 'mbarazeen's circuit, is that you cannot turn OFF the lower transistors.!

Good morning Mr Gibbs;
I was just being nice.
I do keep lots of circuit diagrams that maybe might come in handy some day, etc.....
I'm soooooo happy this morning (5:30am).
The LEDs look fantastic at night time, I stood out there (back porch) last night and just watched them.
I've got to get down to some exacting measurements today on the current/voltage's.
How about this, what if I put in ULN2803/ULN2003A chips, would that make any difference?
Seems like they all just apply gnds at their outputs, etc .......
The thing is they are "Green" LEDS and are hardly distinguishable in the daytime, but the console LEDs are also green and good and bright at daytime,....
Ordered my other chips this morning, will be a few days....
Have a nice day...
Oxbo

 

[ericgibbs]

hi oxbo,
The ULNs I suggested are compatible with the 12V that would have come from the 74LS06, if you get the datasheets you will see they require different input levels.

Can you post a datasheet for the LED's, I can then look at the LED curent for you.

EDIT:
Found the datasheet for the Green led.
The recommend continuous segment current is 20mA, can you measure the voltage drop across the series 120R.?

Remember the LED's are multiplexed so it would be possible to increase the 'pulsed' current thru the LED's on order to increase their brightness.

 

[Oxbo Rene]

hi oxbo,
The ULNs I suggested are compatible with the 12V that would have come from the 74LS06, if you get the datasheets you will see they require different input levels.

Can you post a datasheet for the LED's, I can then look at the LED curent for you.

EDIT:
Found the datasheet for the Green led.
The recommend continuous segment current is 20mA, can you measure the voltage drop across the series 120R.?

Remember the LED's are multiplexed so it would be possible to increase the 'pulsed' current thru the LED's on order to increase their brightness.

Yep, as to the ULN--03's, I realized after I posted that they are for 5V stuff.....

Yep, gonna get out there in a minute and do a total measure of the components....
Will be back later......
(Here's the datasheet for the LEDs)--->
https://www.electro-tech-online.com/custompdfs/2010/04/SA40-18GWA.pdf