Reading tachometer signal...
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Posts: 46,084
Hello,
I'm trying to find out what is the best route in reading a tachometer
signal from a motor. I will have to tap into the coil ignition side
wire. The wire shows 12+ volts with the key on ignition with the
engine off then shows ground every time the coil fires when the motor
is running. This will show a low AC signal and maybe higher than 5
volts at higher rpms. I think I'll have to read how many times the
wire will show ground per second. Is there a way to connect it to the
Stamp or will I need some sort of external chip.
Thanks,
Cozz
I'm trying to find out what is the best route in reading a tachometer
signal from a motor. I will have to tap into the coil ignition side
wire. The wire shows 12+ volts with the key on ignition with the
engine off then shows ground every time the coil fires when the motor
is running. This will show a low AC signal and maybe higher than 5
volts at higher rpms. I think I'll have to read how many times the
wire will show ground per second. Is there a way to connect it to the
Stamp or will I need some sort of external chip.
Thanks,
Cozz
Comments
volts. One challenge is going to be the circuit that will interface to the
negative side of the ignition coil. Indeed, the signal is 12 volts and 0 volts,
but
for short periods of time just after the coil ground is "let go" the voltage
will reach close to 300 volts.
I have messed with this several times, and because of my stupidity, I have
yet to design a good circuit that can supress the 300 volt spikes seen on an
oscope as the coil ground is let go. Any ideas out there? Some LC circuit?
In any event, once the interface circuit is done and you have a clean signal,
an opto isolator is in order.
To read the signal with your stamp, you could use the PULSIN command and
measue the HIGH time of the pulse, which will give you the time between coil
events. Another command is COUNT that will measure the number of pulses for a
given
period, but this is unlikely the command you want if you need to fire an
injector or some other thing.
Another note assuming this is a modern engine.......for any given rpm the
time between pulses will change based on engine load.....because as the ignition
timing changes, the time when to fire the coil changes.
Have you considered taking the signal from the Crankshaft or Camshaft
position sensor? The signal from these sensors is often a "clean" 0 to 5 volts
DC
and will be much easier to deal with than the negative side of the coil.
Hello,
I'm trying to find out what is the best route in reading a tachometer
signal from a motor. I will have to tap into the coil ignition side
wire. The wire shows 12+ volts with the key on ignition with the
engine off then shows ground every time the coil fires when the motor
is running. This will show a low AC signal and maybe higher than 5
volts at higher rpms. I think I'll have to read how many times the
wire will show ground per second. Is there a way to connect it to the
Stamp or will I need some sort of external chip.
Thanks,
Cozz
[noparse][[/noparse]Non-text portions of this message have been removed]
smartdim@a... writes:
I don't think you will see a low level AC, but you will see 0 volts and 2
volts.
I don't think you will see a low level AC, but you will see 0 volts and 12
volts.
0 and 12, not 0 and 2
[noparse][[/noparse]Non-text portions of this message have been removed]
output wire (that is going to the distributor) of the coil? If its a
somewhat newer car you might want to piggy back off the crank angle sensor
(CAS).
-Rob
Original Message
From: <smartdim@a...>
To: <basicstamps@yahoogroups.com>
Sent: Sunday, December 21, 2003 10:30 AM
Subject: Re: [noparse][[/noparse]basicstamps] Reading tachometer signal...
> I don't think you will see a low level AC, but you will see 0 volts and 2
> volts. One challenge is going to be the circuit that will interface to the
> negative side of the ignition coil. Indeed, the signal is 12 volts and 0
volts, but
> for short periods of time just after the coil ground is "let go" the
voltage
> will reach close to 300 volts.
>
> I have messed with this several times, and because of my stupidity, I have
> yet to design a good circuit that can supress the 300 volt spikes seen on
an
> oscope as the coil ground is let go. Any ideas out there? Some LC
circuit?
>
> In any event, once the interface circuit is done and you have a clean
signal,
> an opto isolator is in order.
>
> To read the signal with your stamp, you could use the PULSIN command and
> measue the HIGH time of the pulse, which will give you the time between
coil
> events. Another command is COUNT that will measure the number of pulses
for a given
> period, but this is unlikely the command you want if you need to fire an
> injector or some other thing.
>
> Another note assuming this is a modern engine.......for any given rpm the
> time between pulses will change based on engine load.....because as the
ignition
> timing changes, the time when to fire the coil changes.
>
> Have you considered taking the signal from the Crankshaft or Camshaft
> position sensor? The signal from these sensors is often a "clean" 0 to 5
volts DC
> and will be much easier to deal with than the negative side of the coil.
>
>
> Hello,
> I'm trying to find out what is the best route in reading a tachometer
> signal from a motor. I will have to tap into the coil ignition side
> wire. The wire shows 12+ volts with the key on ignition with the
> engine off then shows ground every time the coil fires when the motor
> is running. This will show a low AC signal and maybe higher than 5
> volts at higher rpms. I think I'll have to read how many times the
> wire will show ground per second. Is there a way to connect it to the
> Stamp or will I need some sort of external chip.
>
> Thanks,
> Cozz
>
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
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Body of the message will be ignored.
>
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>
coil is fired. In fact, I think that's how a coil fires in the first
place. Charge it like a cap then ground the positve side. I just want
to read the RPM's and nothing more. I don't need to control any
injectors and what not. If this is the case then I really like the
COUNT feature. Should I place anything inline from the coil lead to
the stamp other than a resistor? I'm afraid of burning the Stamp out.
Thanks,
Cozz
--- In basicstamps@yahoogroups.com, smartdim@a... wrote:
> I don't think you will see a low level AC, but you will see 0 volts
and 12
> volts. One challenge is going to be the circuit that will interface
to the
> negative side of the ignition coil. Indeed, the signal is 12 volts
and 0 volts, but
> for short periods of time just after the coil ground is "let go"
the voltage
> will reach close to 300 volts.
>
> I have messed with this several times, and because of my stupidity,
I have
> yet to design a good circuit that can supress the 300 volt spikes
seen on an
> oscope as the coil ground is let go. Any ideas out there? Some LC
circuit?
>
> In any event, once the interface circuit is done and you have a
clean signal,
> an opto isolator is in order.
>
> To read the signal with your stamp, you could use the PULSIN
command and
> measue the HIGH time of the pulse, which will give you the time
between coil
> events. Another command is COUNT that will measure the number of
pulses for a given
> period, but this is unlikely the command you want if you need to
fire an
> injector or some other thing.
>
> Another note assuming this is a modern engine.......for any given
rpm the
> time between pulses will change based on engine load.....because as
the ignition
> timing changes, the time when to fire the coil changes.
>
> Have you considered taking the signal from the Crankshaft or
Camshaft
> position sensor? The signal from these sensors is often a "clean"
0 to 5 volts DC
> and will be much easier to deal with than the negative side of the
coil.
> [noparse][[/noparse]Non-text portions of this message have been removed]
side of the coil is a DC signal with respect to chassis ground.
Again, assuming a standard vehicle ignition system, it works as follows:
the coil is grounded to build up current in the coil primary windings, then
the ground on the coil is QUICKLY released, which causes the high voltage that
will jump the spark plug gap and of course, ignite the fuel air mixture in the
combustion chamber.
You ABSOLUTELY need some circuit to interface that negative side of the
ignition coil to the Stamp or you WILL burn out the stamp. The Stamp input pins
want a TTL level signal (basically 0 to 5 volts) and a 12 volt signal will
damage
the stamp.
With regards to the voltage you are reading, you mentioned -12 volts.....are
seeing minus 12 volts? What kind of engine is this?
ken
I honestly think it is AC because I read a full -12 volts when the
coil is fired. In fact, I think that's how a coil fires in the first
place. Charge it like a cap then ground the positve side. I just want
to read the RPM's and nothing more. I don't need to control any
injectors and what not. If this is the case then I really like the
COUNT feature. Should I place anything inline from the coil lead to
the stamp other than a resistor? I'm afraid of burning the Stamp out.
Thanks,
Cozz
[noparse][[/noparse]Non-text portions of this message have been removed]
double check the power on the coil. You're maybe right.
What conversion is best to convert from 12 volts to TTL?
Thanks,
Cozz
--- In basicstamps@yahoogroups.com, smartdim@a... wrote:
> If you are talking about a "standard" automobile ignition coil, the
negative
> side of the coil is a DC signal with respect to chassis ground.
>
> Again, assuming a standard vehicle ignition system, it works as
follows:
>
> the coil is grounded to build up current in the coil primary
windings, then
> the ground on the coil is QUICKLY released, which causes the high
voltage that
> will jump the spark plug gap and of course, ignite the fuel air
mixture in the
> combustion chamber.
> You ABSOLUTELY need some circuit to interface that negative side of
the
> ignition coil to the Stamp or you WILL burn out the stamp. The
Stamp input pins
> want a TTL level signal (basically 0 to 5 volts) and a 12 volt
signal will damage
> the stamp.
> With regards to the voltage you are reading, you mentioned -12
volts.....are
> seeing minus 12 volts? What kind of engine is this?
>
> ken
>
cozz.home@v... writes:
It's an old Ford. One side of the coil is always grounded. I'll
double check the power on the coil. You're maybe right.
What conversion is best to convert from 12 volts to TTL?
Thanks,
Cozz
Cozz,
There are a myrad of ways to convert the 0 to 12 volts to a TTL level signal,
and here are two ways.
METHOD ONE
Safest way to protect your stamp........use a 4n35 opto isolator (this is a
dip 8 package).
Connect pin 1 to the 0 to 12 volts signal THROUGH a 1k ohm resistor.
Connect pin 2 to the vehicle ground
Connect pin 5 to the Stamp +5 volt supply THROUGH a 4.7k ohm resistor
Also connect pin 5 to your Stamp input pin
Connect pin 4 to the Stamp ground
Optional.....connect pin 6 to the Stamp groung THROUGH a 1k ohm resistor.
The "protection" for your stamp will come from the vehicle ground NOT
connected to the stamp power supply ground.
When the coil is not grouned, the Stamp input pin will receive a logic 0
(close to zero volts)
When the coil is ground, the Stamp input pin will receive a logic 1, 5 volts.
METHOD TWO
Get a 2n2222 or 2n3904 NPN transistor.
Connect the emitter to ground
Connect the collector to the Stamp +5 volts supply THROUGH 4.7k ohms
Connect the collector to the Stamp input pin
Connect the 0 to 12 volt signal to the base THROUGH 10k ohms.
This will give you the same inversion......coil not grouned Stamp gets logic
0 and visa versa.
The stamp will not be harmed by this setup unless there is some failure with
the transistor........and that is why the opto isolator mentioned first is a
safe way in my opinion to interface the coil to the stamp
ken
[noparse][[/noparse]Non-text portions of this message have been removed]
What about using a hall effect sensor or similar? You could also wrap a
couple loops of wire around a spark plug wire or the + side of the ignition
coil.
There are also opto-isolators that can take 12V. This might be best. You
want to be completely isolated in case of voltage spikes.
Jonathan
Original Message
From: "cozz4ever" <cozz.home@v...>
To: <basicstamps@yahoogroups.com>
Sent: Tuesday, December 23, 2003 7:53 PM
Subject: [noparse][[/noparse]basicstamps] Re: Reading tachometer signal...
> It's an old Ford. One side of the coil is always grounded. I'll
> double check the power on the coil. You're maybe right.
>
> What conversion is best to convert from 12 volts to TTL?
>
> Thanks,
> Cozz
>
>
> --- In basicstamps@yahoogroups.com, smartdim@a... wrote:
> > If you are talking about a "standard" automobile ignition coil, the
> negative
> > side of the coil is a DC signal with respect to chassis ground.
> >
> > Again, assuming a standard vehicle ignition system, it works as
> follows:
> >
> > the coil is grounded to build up current in the coil primary
> windings, then
> > the ground on the coil is QUICKLY released, which causes the high
> voltage that
> > will jump the spark plug gap and of course, ignite the fuel air
> mixture in the
> > combustion chamber.
> > You ABSOLUTELY need some circuit to interface that negative side of
> the
> > ignition coil to the Stamp or you WILL burn out the stamp. The
> Stamp input pins
> > want a TTL level signal (basically 0 to 5 volts) and a 12 volt
> signal will damage
> > the stamp.
> > With regards to the voltage you are reading, you mentioned -12
> volts.....are
> > seeing minus 12 volts? What kind of engine is this?
> >
> > ken
> >
>
>
> To UNSUBSCRIBE, just send mail to:
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>
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>
>
>
>
heard to work with untill the TFI cleans it up. I would like to go to
the coil and make it a universal setup of sorts.
Thanks,
Cozz
--- In basicstamps@yahoogroups.com, "Jonathan Peakall"
<jpeakall@p...> wrote:
> Cozz,
>
> What about using a hall effect sensor or similar? You could also
wrap a
> couple loops of wire around a spark plug wire or the + side of the
ignition
> coil.
>
> There are also opto-isolators that can take 12V. This might be
best. You
> want to be completely isolated in case of voltage spikes.
>
> Jonathan
cozz.home@v... writes:
I was told that the signal from the hall effect sensor was really
heard to work with untill the TFI cleans it up. I would like to go to
the coil and make it a universal setup of sorts.
Thanks,
Cozz
Strongly recommend the 4n35....but it is a DIP 6 and not a DIP 8 as I
incorrectly stated in an earlier post.
[noparse][[/noparse]Non-text portions of this message have been removed]
SNIP
> There are also opto-isolators that can take 12V. This might be best. You
> want to be completely isolated in case of voltage spikes.
>
> Jonathan
Having worked with Ignition coil pick-up for a tach signal I can tell you for
sure there will be plenty of spikes!
I have had success using a 4n33 with a 100K resistor in series and a 5v zener
across the LED, this limits the current and keeps the
voltage down in both directions. You will also need a cap across the E-C of the
output and a 100k pull-up to allow time to read the
spike period.
KF4HAZ - Lonnie
Instead of using Zener diodes to clamp transients, use a TRANSZORB.
These devices are designed to clamp-off transients (very fast and
high energy levels).
They are better than Zeners or even MOVs.
another post. I'll give those a try. If anything I'll go to the
4n35's.
Thanks,
Cozz
--- In basicstamps@yahoogroups.com, smartdim@a... wrote:
Strongly recommend the 4n35....but it is a DIP 6 and not a DIP 8 as I
incorrectly stated in an earlier post.
I need to be able to jump from test engine to test engine really
quick. So..
Does anyone know where I could find info for getting the tach signal
from an antenna or wire wrapped around the plug wire? I've heard of
this before but have never seen an actual unit in operation or had
one to copy. I figure I'll just count the time between spikes with
the pulsin command.
Thanks for any help.
Craig
inductive pickup and is cheap, cheap, cheap. You should be able to find a
trigger
signal in the pc board. Just be careful as the flash unit has around 3kv on it.
Alan Bradford
Plasma Technologies
In a message dated 12/26/2003 6:21:21 PM Eastern Standard Time,
n2oinjection@y... writes:
This is great information. I'm attempting a similar thing, but....
I need to be able to jump from test engine to test engine really
quick. So..
Does anyone know where I could find info for getting the tach signal
from an antenna or wire wrapped around the plug wire? I've heard of
this before but have never seen an actual unit in operation or had
one to copy. I figure I'll just count the time between spikes with
the pulsin command.
Thanks for any help.
Craig
[noparse][[/noparse]Non-text portions of this message have been removed]
The automotive industry has inductive clamp on pickups for spark plug wires.
There are several out there. Here is a link to just one.
Snap Vantage Mt2400 Power Graphing Meter
In a message dated 12/26/2003 3:21:19 PM Pacific Standard Time,
n2oinjection@y... writes:
I need to be able to jump from test engine to test engine really
quick. So..
Does anyone know where I could find info for getting the tach signal
from an antenna or wire wrapped around the plug wire? I've heard of
this before but have never seen an actual unit in operation or had
one to copy. I figure I'll just count the time between spikes with
the pulsin command.
Thanks for any help.
Craig
[noparse][[/noparse]Non-text portions of this message have been removed]
I do have a clamp from a Sun timing light, but my problem has become
a little more troublesome the hardware.
I have a chassis dyno for motorcycles. Getting access to plug wires
is easy on Harleys and import bikes (prior to 1986), but late model
sport bikes have so much body work, it can take 30 minutes to get
the tank, sidepanels and sometimes airbox removed. Then I sometimes
discover the bikes have a coil in cap set up that only allows me a
low voltage signal.
I do have the ability to perform the above , but most customers are
so cheap, they think that the $30 base dyno run shouldin clude the
1/2 hour to disassemble their bike and the 1/2 hour to reassemble it
as well.
So, since I building my own BS2 based interface for the dyno (to
include Wideband O2 data logging) I figured I might be able to pick
up ignition signal with out removing body work. Sometimes I can see
the plug wires with just a little body work removed, but thre is not
enough room for the clamp to get in there. Hence the antenna idea.
I like the idea of disassembling a timing light though. Sounds like
I would at least get an isolated signal. I'll have to look into
that if I can't find an antenna or quick 'wire-wrap' method.
Thanks for the help and ideas.
Craig
--- In basicstamps@yahoogroups.com, smartdim@a... wrote:
> Craig,
>
> The automotive industry has inductive clamp on pickups for spark
plug wires.
> There are several out there. Here is a link to just one.
>
> Snap Vantage Mt2400 Power Graphing Meter
>
>
>
> In a message dated 12/26/2003 3:21:19 PM Pacific Standard Time,
> n2oinjection@y... writes:
> I need to be able to jump from test engine to test engine really
> quick. So..
>
> Does anyone know where I could find info for getting the tach
signal
> from an antenna or wire wrapped around the plug wire? I've heard
of
> this before but have never seen an actual unit in operation or had
> one to copy. I figure I'll just count the time between spikes
with
> the pulsin command.
>
> Thanks for any help.
> Craig
>
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
My 2ct. A mike fitted on the exhaust?
ECO
Original Message
From: "Craig" <n2oinjection@y...>
To: <basicstamps@yahoogroups.com>
Sent: Saturday, December 27, 2003 9:38 AM
Subject: [noparse][[/noparse]basicstamps] Re: Reading tachometer signal...
> Thanks for the quick response guys,
>
> I do have a clamp from a Sun timing light, but my problem has become
> a little more troublesome the hardware.
>
> I have a chassis dyno for motorcycles. Getting access to plug wires
> is easy on Harleys and import bikes (prior to 1986), but late model
> sport bikes have so much body work, it can take 30 minutes to get
> the tank, sidepanels and sometimes airbox removed. Then I sometimes
> discover the bikes have a coil in cap set up that only allows me a
> low voltage signal.
>
> I do have the ability to perform the above , but most customers are
> so cheap, they think that the $30 base dyno run shouldin clude the
> 1/2 hour to disassemble their bike and the 1/2 hour to reassemble it
> as well.
>
> So, since I building my own BS2 based interface for the dyno (to
> include Wideband O2 data logging) I figured I might be able to pick
> up ignition signal with out removing body work. Sometimes I can see
> the plug wires with just a little body work removed, but thre is not
> enough room for the clamp to get in there. Hence the antenna idea.
>
> I like the idea of disassembling a timing light though. Sounds like
> I would at least get an isolated signal. I'll have to look into
> that if I can't find an antenna or quick 'wire-wrap' method.
>
> Thanks for the help and ideas.
> Craig
>
>
> --- In basicstamps@yahoogroups.com, smartdim@a... wrote:
> > Craig,
> >
> > The automotive industry has inductive clamp on pickups for spark
> plug wires.
> > There are several out there. Here is a link to just one.
> >
> > Snap Vantage Mt2400 Power Graphing Meter
> >
> >
> >
> > In a message dated 12/26/2003 3:21:19 PM Pacific Standard Time,
> > n2oinjection@y... writes:
> > I need to be able to jump from test engine to test engine really
> > quick. So..
> >
> > Does anyone know where I could find info for getting the tach
> signal
> > from an antenna or wire wrapped around the plug wire? I've heard
> of
> > this before but have never seen an actual unit in operation or had
> > one to copy. I figure I'll just count the time between spikes
> with
> > the pulsin command.
> >
> > Thanks for any help.
> > Craig
> >
> >
> > [noparse][[/noparse]Non-text portions of this message have been removed]
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and Body
of the message will be ignored.
>
>
> Yahoo! Groups Links
>
> To visit your group on the web, go to:
> http://groups.yahoo.com/group/basicstamps/
>
> To unsubscribe from this group, send an email to:
> basicstamps-unsubscribe@yahoogroups.com
>
> Your use of Yahoo! Groups is subject to:
> http://docs.yahoo.com/info/terms/
>
>
>
compressors. There was a contact mic bolted to the head, and we could see
rpm, as well as various harmonically related vibrations that could indicate
bad bearing, etc...
Perhaps a simple contact "mic" would do the trick.
Mike Sokol
www.modernrecording.com
mikes@m...
" One should not increase, beyond what is necessary,
the number of entities required to explain anything"...
-William of Occam-
Original Message
From: "ECO" <ecourt@b...>
To: <basicstamps@yahoogroups.com>
Sent: Saturday, December 27, 2003 5:35 AM
Subject: Re: [noparse][[/noparse]basicstamps] Re: Reading tachometer signal...
> Craig
> My 2ct. A mike fitted on the exhaust?
> ECO
>
>
Original Message
> From: "Craig" <n2oinjection@y...>
> To: <basicstamps@yahoogroups.com>
> Sent: Saturday, December 27, 2003 9:38 AM
> Subject: [noparse][[/noparse]basicstamps] Re: Reading tachometer signal...
>
>
> > Thanks for the quick response guys,
> >
> > I do have a clamp from a Sun timing light, but my problem has become
> > a little more troublesome the hardware.
> >
> > I have a chassis dyno for motorcycles. Getting access to plug wires
> > is easy on Harleys and import bikes (prior to 1986), but late model
> > sport bikes have so much body work, it can take 30 minutes to get
> > the tank, sidepanels and sometimes airbox removed. Then I sometimes
> > discover the bikes have a coil in cap set up that only allows me a
> > low voltage signal.
> >
> > I do have the ability to perform the above , but most customers are
> > so cheap, they think that the $30 base dyno run shouldin clude the
> > 1/2 hour to disassemble their bike and the 1/2 hour to reassemble it
> > as well.
> >
> > So, since I building my own BS2 based interface for the dyno (to
> > include Wideband O2 data logging) I figured I might be able to pick
> > up ignition signal with out removing body work. Sometimes I can see
> > the plug wires with just a little body work removed, but thre is not
> > enough room for the clamp to get in there. Hence the antenna idea.
> >
> > I like the idea of disassembling a timing light though. Sounds like
> > I would at least get an isolated signal. I'll have to look into
> > that if I can't find an antenna or quick 'wire-wrap' method.
> >
> > Thanks for the help and ideas.
> > Craig
> >
> >
> > --- In basicstamps@yahoogroups.com, smartdim@a... wrote:
> > > Craig,
> > >
> > > The automotive industry has inductive clamp on pickups for spark
> > plug wires.
> > > There are several out there. Here is a link to just one.
> > >
> > > Snap Vantage Mt2400 Power Graphing Meter
> > >
> > >
> > >
> > > In a message dated 12/26/2003 3:21:19 PM Pacific Standard Time,
> > > n2oinjection@y... writes:
> > > I need to be able to jump from test engine to test engine really
> > > quick. So..
> > >
> > > Does anyone know where I could find info for getting the tach
> > signal
> > > from an antenna or wire wrapped around the plug wire? I've heard
> > of
> > > this before but have never seen an actual unit in operation or had
> > > one to copy. I figure I'll just count the time between spikes
> > with
> > > the pulsin command.
> > >
> > > Thanks for any help.
> > > Craig
> > >
> > >
> > > [noparse][[/noparse]Non-text portions of this message have been removed]
> >
> >
> > To UNSUBSCRIBE, just send mail to:
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and Body of the message will be ignored.
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to be pretty good at picking up ignition noise, and perhaps it can be hacked
to suit your needs.
In a message dated 12/27/2003 12:39:49 AM Pacific Standard Time,
n2oinjection@y... writes:
Thanks for the quick response guys,
I do have a clamp from a Sun timing light, but my problem has become
a little more troublesome the hardware.
I have a chassis dyno for motorcycles. Getting access to plug wires
is easy on Harleys and import bikes (prior to 1986), but late model
sport bikes have so much body work, it can take 30 minutes to get
the tank, sidepanels and sometimes airbox removed. Then I sometimes
discover the bikes have a coil in cap set up that only allows me a
low voltage signal.
I do have the ability to perform the above , but most customers are
so cheap, they think that the $30 base dyno run shouldin clude the
1/2 hour to disassemble their bike and the 1/2 hour to reassemble it
as well.
So, since I building my own BS2 based interface for the dyno (to
include Wideband O2 data logging) I figured I might be able to pick
up ignition signal with out removing body work. Sometimes I can see
the plug wires with just a little body work removed, but thre is not
enough room for the clamp to get in there. Hence the antenna idea.
I like the idea of disassembling a timing light though. Sounds like
I would at least get an isolated signal. I'll have to look into
that if I can't find an antenna or quick 'wire-wrap' method.
Thanks for the help and ideas.
Craig
[noparse][[/noparse]Non-text portions of this message have been removed]
Seems to me that if you wrap an insulated wire around the plug wire, & tie
one end to the motor the other will give you a signal that you can use, The
more turns the more voltage, so you decide if turns or amplifiation with an op
amp would suit your needs,
regards,
Leroy
From: "Craig" <n2oinjection@y...>
Date: 2003/12/26 Fri PM 06:20:20 EST
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] Re: Reading tachometer signal...
This is great information. I'm attempting a similar thing, but....
I need to be able to jump from test engine to test engine really
quick. So..
Does anyone know where I could find info for getting the tach signal
from an antenna or wire wrapped around the plug wire? I've heard of
this before but have never seen an actual unit in operation or had
one to copy. I figure I'll just count the time between spikes with
the pulsin command.
Thanks for any help.
Craig
To UNSUBSCRIBE, just send mail to:
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Seems to me that if you wrap an insulated wire around the plug wire, & tie
one end to the motor the other will give you a signal that you can use, The
more turns the more voltage, so you decide if turns or amplifiation with an op
amp would suit your needs,
regards,
Leroy
From: "Craig" <n2oinjection@y...>
Date: 2003/12/26 Fri PM 06:20:20 EST
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] Re: Reading tachometer signal...
This is great information. I'm attempting a similar thing, but....
I need to be able to jump from test engine to test engine really
quick. So..
Does anyone know where I could find info for getting the tach signal
from an antenna or wire wrapped around the plug wire? I've heard of
this before but have never seen an actual unit in operation or had
one to copy. I figure I'll just count the time between spikes with
the pulsin command.
Thanks for any help.
Craig
To UNSUBSCRIBE, just send mail to:
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Seems to me that if you wrap an insulated wire around the plug wire, & tie
one end to the motor the other will give you a signal that you can use, The
more turns the more voltage, so you decide if turns or amplifiation with an op
amp would suit your needs,
regards,
Leroy
From: "Craig" <n2oinjection@y...>
Date: 2003/12/26 Fri PM 06:20:20 EST
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] Re: Reading tachometer signal...
This is great information. I'm attempting a similar thing, but....
I need to be able to jump from test engine to test engine really
quick. So..
Does anyone know where I could find info for getting the tach signal
from an antenna or wire wrapped around the plug wire? I've heard of
this before but have never seen an actual unit in operation or had
one to copy. I figure I'll just count the time between spikes with
the pulsin command.
Thanks for any help.
Craig
To UNSUBSCRIBE, just send mail to:
basicstamps-unsubscribe@yahoogroups.com
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HALF a turn around the ignition wire is enough to ignite a small Neon
bulb.
If you have a screwdriver with a Neon light in it to detect the live
wire of 220 Volts is will light as soon as it is placed close to an
ignition wire.
It is a nice and cheap tool to find out which sparkplugs in your
engine are working OK :-).
Be carefull, this could easily blow up your OpAmp!!
Regards,
Klaus
--- In basicstamps@yahoogroups.com, <leroy@f...> wrote:
> Craig,
>
> Seems to me that if you wrap an insulated wire around the plug
wire, & tie
> one end to the motor the other will give you a signal that you can
use, The more turns the more voltage, so you decide if turns or
amplifiation with an op amp would suit your needs,
>
> regards,
>
> Leroy
>
> From: "Craig" <n2oinjection@y...>
> Date: 2003/12/26 Fri PM 06:20:20 EST
> To: basicstamps@yahoogroups.com
> Subject: [noparse][[/noparse]basicstamps] Re: Reading tachometer signal...
>
> This is great information. I'm attempting a similar thing, but....
>
> I need to be able to jump from test engine to test engine really
> quick. So..
>
> Does anyone know where I could find info for getting the tach
signal
> from an antenna or wire wrapped around the plug wire? I've heard
of
> this before but have never seen an actual unit in operation or had
> one to copy. I figure I'll just count the time between spikes with
> the pulsin command.
>
> Thanks for any help.
> Craig
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the
Subject and Body of the message will be ignored.
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>
> To visit your group on the web, go to:
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How about using this neon bulb to trigger a photo-transistor. That would
seem to bullet-proof, and completely isolated to boot... Stick both in a
little piece of black PVC and cover the ends with e-tape.
Mike Sokol
www.modernrecording.com
mikes@m...
" One should not increase, beyond what is necessary,
the number of entities required to explain anything"...
-William of Occam-
Original Message
From: "klausdejong" <klausdejong@x...>
To: <basicstamps@yahoogroups.com>
Sent: Saturday, December 27, 2003 2:55 PM
Subject: [noparse][[/noparse]basicstamps] Re: Reading tachometer signal...
> Mind You,
>
> HALF a turn around the ignition wire is enough to ignite a small Neon
> bulb.
>
> If you have a screwdriver with a Neon light in it to detect the live
> wire of 220 Volts is will light as soon as it is placed close to an
> ignition wire.
> It is a nice and cheap tool to find out which sparkplugs in your
> engine are working OK :-).
>
> Be carefull, this could easily blow up your OpAmp!!
>
> Regards,
>
> Klaus
>
>
> --- In basicstamps@yahoogroups.com, <leroy@f...> wrote:
> > Craig,
> >
> > Seems to me that if you wrap an insulated wire around the plug
> wire, & tie
> > one end to the motor the other will give you a signal that you can
> use, The more turns the more voltage, so you decide if turns or
> amplifiation with an op amp would suit your needs,
> >
> > regards,
> >
> > Leroy
> >
> > From: "Craig" <n2oinjection@y...>
> > Date: 2003/12/26 Fri PM 06:20:20 EST
> > To: basicstamps@yahoogroups.com
> > Subject: [noparse][[/noparse]basicstamps] Re: Reading tachometer signal...
> >
> > This is great information. I'm attempting a similar thing, but....
> >
> > I need to be able to jump from test engine to test engine really
> > quick. So..
> >
> > Does anyone know where I could find info for getting the tach
> signal
> > from an antenna or wire wrapped around the plug wire? I've heard
> of
> > this before but have never seen an actual unit in operation or had
> > one to copy. I figure I'll just count the time between spikes with
> > the pulsin command.
> >
> > Thanks for any help.
> > Craig
> >
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed. Text in the
> Subject and Body of the message will be ignored.
> >
> >
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> >
> > To visit your group on the web, go to:
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> >
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> Your use of Yahoo! Groups is subject to:
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>
> HALF a turn around the ignition wire is enough to ignite a small Neon
> bulb.
>
> If you have a screwdriver with a Neon light in it to detect the live
> wire of 220 Volts is will light as soon as it is placed close to an
> ignition wire.
> It is a nice and cheap tool to find out which sparkplugs in your
> engine are working OK :-).
>
> Be carefull, this could easily blow up your OpAmp!!
>
The only problem may be that the neon can't flash fast enough -- but you
may be able to use a photo-resitive cell and measure the relative
brightness of the neon to get an approximate speed.
I used this method to build a ringer interface on a telephone about 25
years ago, long before they had these phone flashers and stuff for the
hearing impaired.
> How about using this neon bulb to trigger a photo-transistor. That would
> seem to bullet-proof, and completely isolated to boot... Stick both in a
> little piece of black PVC and cover the ends with e-tape.
cheap automotive timing lights that were just a big neon bulb. It would be a
simple enough test to rig. An o-scope would be the definitive test, but
certainly a B-stamp could catch the pulses until they ran together from too
many RPMs. Just keep upping the revs until your counter went stupid and said
zero RPM.
Mike Sokol
www.modernrecording.com
mikes@m...
301-739-6842 (Office)
301-964-5682 (Mobile)
" One should not increase, beyond what is necessary,
the number of entities required to explain anything"...
-William of Occam-
Original Message
From: "Bill Boyer" <daweasel@s...>
To: "Basic Stamp List" <basicstamps@yahoogroups.com>
Sent: Saturday, December 27, 2003 3:20 PM
Subject: Re: [noparse][[/noparse]basicstamps] Re: Reading tachometer signal...
> Dang, you beat me to it.
>
> The only problem may be that the neon can't flash fast enough -- but you
> may be able to use a photo-resitive cell and measure the relative
> brightness of the neon to get an approximate speed.
>
>
> I used this method to build a ringer interface on a telephone about 25
> years ago, long before they had these phone flashers and stuff for the
> hearing impaired.
>
> > How about using this neon bulb to trigger a photo-transistor. That would
> > seem to bullet-proof, and completely isolated to boot... Stick both in a
> > little piece of black PVC and cover the ends with e-tape.
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
>
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>
> To visit your group on the web, go to:
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>
>
http://www.statorgator.com/
The r/c heli version outputs a 5V level signal.
> I do have a clamp from a Sun timing light, but my problem has become a
> little more troublesome the hardware.
>
> I have a chassis dyno for motorcycles. Getting access to plug wires is
> easy on Harleys and import bikes (prior to 1986), but late model sport
> bikes have so much body work, it can take 30 minutes to get the tank,
> sidepanels and sometimes airbox removed. Then I sometimes discover the
> bikes have a coil in cap set up that only allows me a low voltage
> signal.
>
[noparse][[/noparse]Non-text portions of this message have been removed]
Thanks for all the input guys. Looks like I have few experiments to
try. Thanks for the help. I'll kep you all posted on my progress.
I'm sure I'll be back with other BS2 questions when I get further
along.
Craig.
--- In basicstamps@yahoogroups.com, "Mike Sokol" <mike.sokol@m...>
wrote:
> I thought about the neon trigger speed issue, but seem to remember
really
> cheap automotive timing lights that were just a big neon bulb. It
would be a
> simple enough test to rig. An o-scope would be the definitive
test, but
> certainly a B-stamp could catch the pulses until they ran together
from too
> many RPMs. Just keep upping the revs until your counter went
stupid and said
> zero RPM.
>
> Mike Sokol
> www.modernrecording.com
> mikes@m...
> 301-739-6842 (Office)
> 301-964-5682 (Mobile)
>
> " One should not increase, beyond what is necessary,
> the number of entities required to explain anything"...
> -William of Occam-
>
>
>
Original Message
> From: "Bill Boyer" <daweasel@s...>
> To: "Basic Stamp List" <basicstamps@yahoogroups.com>
> Sent: Saturday, December 27, 2003 3:20 PM
> Subject: Re: [noparse][[/noparse]basicstamps] Re: Reading tachometer signal...
>
>
> > Dang, you beat me to it.
> >
> > The only problem may be that the neon can't flash fast enough --
but you
> > may be able to use a photo-resitive cell and measure the relative
> > brightness of the neon to get an approximate speed.
> >
> >
> > I used this method to build a ringer interface on a telephone
about 25
> > years ago, long before they had these phone flashers and stuff
for the
> > hearing impaired.
> >
> > > How about using this neon bulb to trigger a photo-transistor.
That would
> > > seem to bullet-proof, and completely isolated to boot... Stick
both in a
> > > little piece of black PVC and cover the ends with e-tape.
> >
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed. Text in the
Subject and
> Body of the message will be ignored.
> >
> >
> > Yahoo! Groups Links
> >
> > To visit your group on the web, go to:
> > http://groups.yahoo.com/group/basicstamps/
> >
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> > basicstamps-unsubscribe@yahoogroups.com
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> > Your use of Yahoo! Groups is subject to:
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> >
> >