Re: transistor base input
- From: gearhead <nospam@xxxxxxxxxxxx>
- Date: Thu, 1 May 2008 12:27:44 -0700 (PDT)
On Apr 30, 2:55 pm, Randy Day <randy....@xxxxxxxx> wrote:
lerameur wrote:
[snip]
just as 5 volt.
When the voltage from my source is between 6v and 9 volts, my chip
reads high (or 5v)
otherwise the chip reads low or zero.
like I said, the source is the voltage going to the siren, so it is
almost always ZERO.
When siren goes off, the voltage jumps anywhere between 6 to 9 volts.
Then the chip should read high
Just use your micro as a digital input; no analog required.
6-9vdc in --10K-----+------ micro
|
/\ 5v zener diode
|
Gnd
HTH
You should rethink the 10k resistor.
You chose to make your input signal the max specified impedance for
the chip -- without even allowing for the additional impedance of the
source signal, or just plain old wiggle room; which you can easily
afford. You should also consider zener current. A smaller resistor
is in order, maybe by an order of magnitude.
.
- Follow-Ups:
- Re: transistor base input
- From: John Popelish
- Re: transistor base input
- References:
- Re: transistor base input
- From: John Popelish
- Re: transistor base input
- From: lerameur
- Re: transistor base input
- From: Randy Day
- Re: transistor base input
- Prev by Date: Re: 12 Volt Regulated Supply
- Next by Date: Re: 12 Volt Regulated Supply
- Previous by thread: Re: transistor base input
- Next by thread: Re: transistor base input
- Index(es):
Relevant Pages
|
