Re: Electrical noise removal

Started by Neil Jepsen June 30, 2003
Conrad
1. The BX24 must have a voltage regulator between the battery and the
PCB, preferably about 8volts output ( to give enough head room for the
regulator), and power the BX24 on pin 24 with +8. ( you could use a low
dropout 12v regulator)
2. The battery connection (for the bx24) should go directly to the
battery, not the ign or other 12volt supply that might have other stuff
on it. Put a 2A fuse in the line, close to the car battery.
3. The earth line ( 0v) should go to the battery-ve, not to the car
body.
4.Put a 100uf and several 0.1 uF capacitors to 0v on the input side of
the voltage regulator.
5. Put a 10uF and several 0.1 uF capacitors on the output side of the
reguulator.
6. A ferrite choke wouldn't hurt on the input to the regulator if you
have one.
7, If you are still having problems, try sheilded cable into and out off
the BX24 for the power supply leads and all the I/O leads ( last resort)

I have found the BX24 very immune to noise...I have several in terrible
environments ( eg driving 10Kw speed controllers with 10Kw motors),
without any problems. 400volt relays and contactors are a bit more of a
problem.
neil
Conrad A***** wrote:

> I am using a BX24 in an automotive application, I am powering it
> directly off the battery. I know microelectronics are sensitive to
> electrical noise and I am getting some glitchy behavior from my BX24
> with the car running. I was wondering what steps I could do to
> prevent this noise?
>
> Conrad Andres > Yahoo! Groups Sponsor


>
>





Thanks Conrad. Lets know how you go.

Conrad A***** wrote:

> Hey Neil so far so good, thanks for the help I appreciate it! For
> anyone who wants to know I did Steps #1, #4 and #5. Thanks again!
>
> Conrad Andres
>
> --- In , Neil Jepsen <njepsen@i...> wrote:
> > Conrad
> > 1. The BX24 must have a voltage regulator between the battery and
> the
> > PCB, preferably about 8volts output ( to give enough head room for
> the
> > regulator), and power the BX24 on pin 24 with +8. ( you could use
> a low
> > dropout 12v regulator)
> > 4.Put a 100uf and several 0.1 uF capacitors to 0v on the input
> side of
> > the voltage regulator.
> > 5. Put a 10uF and several 0.1 uF capacitors on the output side of
> the
> > reguulator. >
[click here]

>
>




The Choke would only go on the input side of the regulator and would
have another 0.047uF on its input side, to form a "pi" filter. The
function of the filter is to limit high frequency noise. The choke
would need to be capable of supplying all the current to the bx24 and
ancilliary circuits, which is only say 100mA. ( Any current hungrey
devices, relays etc should not be off the same supply anyway). A few
ferrite beads with several turns of 22swg wire will work for RF noise.
Alternatively you could wind 50 odd turns around a peice of ferrite rod
from a transistor radio antenna. The choke doesn't need a "voltage
rating". because it is only seeing about 15v DC.
Mark Newell wrote:

> Hi Neil,
>
> You wrote:
> .
> .
> .
> > 4.Put a 100uf and several 0.1 uF capacitors to 0v on the input side
> of
> > the voltage regulator.
> > 5. Put a 10uF and several 0.1 uF capacitors on the output side of
> the
> > reguulator.
> > 6. A ferrite choke wouldn't hurt on the input to the regulator if
> you
> > have one.
> .
> .
> .
> What would the "specifications" of the "ferrite ckoke" be and how does
> the
> specifications relate to volts, amps or noise frequency?? Since
> capacitors
> go on each side of the regulator, should there be chokes on both sides
> of
> the regulator for extra noise suppression?
>
> Thank you,
> Mark
>
> __________________________________ [Click Here!]

>
>




I am using a BX24 in an automotive application, I am powering it
directly off the battery. I know microelectronics are sensitive to
electrical noise and I am getting some glitchy behavior from my BX24
with the car running. I was wondering what steps I could do to
prevent this noise?

Conrad Andres



Thanks again Neil, I just realized that I had acutally an 8 volt
regulator on the board for something else, but I removed it so I
could use it for the power supply. I added a few caps to the input
side of the BX24 and it seemed to help but every once and a while it
would glitch.

I will try the 8 volt regulator out tomorrow and add a few caps for
extra measure. Thanks for the tips, I'll let you know how it goes.
Thanks Neil!

Conrad

--- In , Neil Jepsen <njepsen@i...> wrote:
> Conrad
> 1. The BX24 must have a voltage regulator between the battery and
the
> PCB, preferably about 8volts output ( to give enough head room for
the
> regulator), and power the BX24 on pin 24 with +8. ( you could use
a low
> dropout 12v regulator)
> 2. The battery connection (for the bx24) should go directly to the
> battery, not the ign or other 12volt supply that might have other
stuff
> on it. Put a 2A fuse in the line, close to the car battery.
> 3. The earth line ( 0v) should go to the battery-ve, not to the
car
> body.
> 4.Put a 100uf and several 0.1 uF capacitors to 0v on the input
side of
> the voltage regulator.
> 5. Put a 10uF and several 0.1 uF capacitors on the output side of
the
> reguulator.
> 6. A ferrite choke wouldn't hurt on the input to the regulator if
you
> have one.
> 7, If you are still having problems, try sheilded cable into and
out off
> the BX24 for the power supply leads and all the I/O leads ( last
resort)
>
> I have found the BX24 very immune to noise...I have several in
terrible
> environments ( eg driving 10Kw speed controllers with 10Kw motors),
> without any problems. 400volt relays and contactors are a bit
more of a
> problem.
> neil
> Conrad A***** wrote:
>
> > I am using a BX24 in an automotive application, I am powering it
> > directly off the battery. I know microelectronics are sensitive
to
> > electrical noise and I am getting some glitchy behavior from my
BX24
> > with the car running. I was wondering what steps I could do to
> > prevent this noise?
> >
> > Conrad Andres
> >
> >
> > Yahoo! Groups Sponsor > >
> > Your use of Yahoo! Groups is subject to the Yahoo! Terms of
Service.




Hi Neil,

You wrote:
.
.
.
> 4.Put a 100uf and several 0.1 uF capacitors to 0v on the input side of
> the voltage regulator.
> 5. Put a 10uF and several 0.1 uF capacitors on the output side of the
> reguulator.
> 6. A ferrite choke wouldn't hurt on the input to the regulator if you
> have one.
.
.
.
What would the "specifications" of the "ferrite ckoke" be and how does the
specifications relate to volts, amps or noise frequency?? Since capacitors
go on each side of the regulator, should there be chokes on both sides of
the regulator for extra noise suppression?

Thank you,
Mark

__________________________________



Hey Neil so far so good, thanks for the help I appreciate it! For
anyone who wants to know I did Steps #1, #4 and #5. Thanks again!

Conrad Andres

--- In , Neil Jepsen <njepsen@i...> wrote:
> Conrad
> 1. The BX24 must have a voltage regulator between the battery and
the
> PCB, preferably about 8volts output ( to give enough head room for
the
> regulator), and power the BX24 on pin 24 with +8. ( you could use
a low
> dropout 12v regulator)
> 4.Put a 100uf and several 0.1 uF capacitors to 0v on the input
side of
> the voltage regulator.
> 5. Put a 10uF and several 0.1 uF capacitors on the output side of
the
> reguulator.