|
![](/i/fill.gif) |
>>>> So what might be a good value for a pull-down resistor then?
>>>>
>>>> (4.5V supply, 74HCxx ICs.)
>>>
>>> A very common choice is 10 kOhm.
>>
>> OK. That should only be a few pence...
>
> Unless you are connecting a switch to the input, I don't see why you'd
> need a pull-down resistor, just connect it directly to ground.
Indeed. So it looks like I'm going to end up needing a seperate
pull-down resistor for each "external" input to the logic system. I was
hoping I could get away with just one, but that apparently won't work at
all...
Oh well, I guess I'm not going to have all that many manual inputs.
The other problem is that I suspect connecting an LED to an output drags
the voltage out of spec, so I probably can't connect the same output to
an input. I guess I'll just buy myself a hex buffer and be done with it.
Post a reply to this message
|
![](/i/fill.gif) |