In article <5f2d847a-2a0a-4a06-8782-fb33ecc103fa@googlegroups.com>,
 captoro <lerameur101@gmail.com> wrote:

> Hello All,
> Making a project where I need to turn on a led when there is a glitch on my 
> RF C.B.
> Most often the noise I receive is on the negative side (-100mv to -2v) as 
> seen on the oscilloscope. I am using an opamp to amplify the voltage to 
> usable level. What I need to do is to invert the negative noise so I get the 
> positive and negative voltage so I do do not 'miss' any spikes.
> I only use a 9v battery to power the opamp. I do not have a negative supply. 
> Can someone give me an idea or direction to get what I am seeking

Ken-

Consider a peak-to-peak detector circuit.  (This has the same 
configuration as a voltage doubler circuit.)  Series capacitor feeds the 
junction of two stacked diodes.  Output of top diode has a capacitor to 
ground.  Choice of capacitors and load resistance determines the decay 
time of the output pulse.

One problem may be the forward bias voltage of the diodes.  Germanium is 
lower than silicon, schotky may be better, but may still not be low 
enough for the -100mv signal.  To get around the single supply, you 
might AC couple to an Op Amp input, and put the detector circuit on its 
output.

Fred

On 12/23/2014 09:10 AM, captoro wrote:
> On Tuesday, 23 December 2014 03:38:55 UTC-5, miso  wrote:
>> captoro wrote:
>>
>>> Hello All, Making a project where I need to turn on a led when
>>> there is a glitch on my RF C.B. Most often the noise I receive is
>>> on the negative side (-100mv to -2v) as seen on the oscilloscope.
>>> I am using an opamp to amplify the voltage to usable level. What
>>> I need to do is to invert the negative noise so I get the
>>> positive and negative voltage so I do do not 'miss' any spikes. I
>>> only use a 9v battery to power the opamp. I do not have a
>>> negative supply. Can someone give me an idea or direction to get
>>> what I am seeking
>>>
>>> regards, Ken
>>
>> Is a glitch different from someone talking?
>
> Just a push on the CB will create a packet of noise, thats all I
> need. The problem is , most of these packets are below zero !
>
> K
>

AC  couple it  into  a window  comparator.  Then you don't care about 
the polarity.

Cheers

Phil Hobbs

-- 
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net

On Tuesday, 23 December 2014 03:38:55 UTC-5, miso  wrote:
> captoro wrote:
> 
> > Hello All,
> > Making a project where I need to turn on a led when there is a glitch on
> > my RF C.B. Most often the noise I receive is on the negative side (-100mv
> > to -2v) as seen on the oscilloscope. I am using an opamp to amplify the
> > voltage to usable level. What I need to do is to invert the negative noise
> > so I get the positive and negative voltage so I do do not 'miss' any
> > spikes. I only use a 9v battery to power the opamp. I do not have a
> > negative supply. Can someone give me an idea or direction to get what I am
> > seeking
> > 
> > regards,
> > Ken
> 
> Is a glitch different from someone talking?

Just a push on the CB will create a packet of noise, thats all I need. The problem is , most of these packets are below zero !

K 

captoro wrote:

> Hello All,
> Making a project where I need to turn on a led when there is a glitch on
> my RF C.B. Most often the noise I receive is on the negative side (-100mv
> to -2v) as seen on the oscilloscope. I am using an opamp to amplify the
> voltage to usable level. What I need to do is to invert the negative noise
> so I get the positive and negative voltage so I do do not 'miss' any
> spikes. I only use a 9v battery to power the opamp. I do not have a
> negative supply. Can someone give me an idea or direction to get what I am
> seeking
> 
> regards,
> Ken

Is a glitch different from someone talking?

Hello All,
Making a project where I need to turn on a led when there is a glitch on my=
 RF C.B.
Most often the noise I receive is on the negative side (-100mv to -2v) as s=
een on the oscilloscope. I am using an opamp to amplify the voltage to usab=
le level. What I need to do is to invert the negative noise so I get the po=
sitive and negative voltage so I do do not 'miss' any spikes.
I only use a 9v battery to power the opamp. I do not have a negative supply=
. Can someone give me an idea or direction to get what I am seeking

regards,
Ken