counter help

[madmikejt12]

hi, i designed a circuit on crocodile technology and it seems to work up to the 4511 chip.
I will attatch a zip folder which contains the circuit as a .bmp and the crocodile technology file

the outputs of the 4511 dont seem to do anything increasing the powre to 9v blows the 4510 and 4511.
i am trying to get it to count down

the inputs to the 4511 count down in binary with each pulse

any ideas as to what is wrong?

Thanks
Mike

 

[RODALCO]

Don't you need series resistors for you 7 segment LED display ?
It looks like you want to drop full supply voltage through your LED's via the 4511 hence the burn out.
Try 560 Ohms ¼ Watt for each segment.

 

[madmikejt12]

put the resistors there, made no difference... the outputs a-g from the 4511 dont get any signal but you can see the output from the 4510 counting down from 9 in binary (which feeds into the 4511 inputs)

 

[Nigel Goodwin]

You MUST have the resistors there, and you've almost certainly killed the chip if you've tried it without - get a new good chip to try.

 

[madmikejt12]

i havnt tried making it yet, ive just simulated it on crocodile technology
i will try this ckt on monday and see if it works

until then i have another problem, i want the alarm to go off when the monostable timer goes off, i could use a NOT gate, but then before the switch is pressed, the o/p from pin 3 is low, therefore the alarm will go off

so in effect, i want the alarm to go off after pin 3 has gone high then low
.....
pin 3 high>pin 3 low>alarm goes off

 

[tunedwolf]

I suppose it's possible you have a common anode display there instead of a common cathode one ? it's hard to tell cos there's no part number on it...
The current limiting resistors need to be there otherwise it's disaster time, something between say 330R and 470R will do ya. I wouldn't use the NE555 either, use a cmos 7555 instead, or better yet, a 7556 which is a dual type.

 

[audioguru]

Why not look at the datasheet for the CD4511 if you use it and have trouble with it?
Why not look at datasheets first?

 

[madmikejt12]

it is a common cathode because at the bootom it says "v-"

i will have a look at the datasheet now

Thanks