[Fwd: Re: [basicstamps] Sensing RPM on a small gas engine (Briggs&Stratton 8hp)]
Archiver
Posts: 46,084
The gauge of the wire is not important regarding the amount of voltage
received. I would start with 10-15 turns of 22 or smaller gauge wire,
insulated and see what kind of voltage you get. You need approx. .6
volts or higher to trigger. You may need to have some amplification to
get it high enough. The lm 386 is a cheap amplifier that will easily
give 200X of amplification. Instrument grade op-amps are also available
that might be better suited. I will try to build you one if you like.
Contact me off list, if interested..
HTH,
Leroy
Original Message
Subject: Re: [noparse][[/noparse]basicstamps] Sensing RPM on a small gas engine
(Briggs&Stratton 8hp)
Date: Mon, 15 Apr 2002 01:01:00 -0700 (PDT)
From: Jay Mann <jay_mann2000@y...>
Reply-To: basicstamps@yahoogroups.com
To: basicstamps@yahoogroups.com
Leroy,
I have a schmidt trigger inverter. The problem I having is that I can
not get enough of a pulse to trigger it using a simple coil.. Any ideas
as to gauge and number of turns? etc?
Thanks,
J
received. I would start with 10-15 turns of 22 or smaller gauge wire,
insulated and see what kind of voltage you get. You need approx. .6
volts or higher to trigger. You may need to have some amplification to
get it high enough. The lm 386 is a cheap amplifier that will easily
give 200X of amplification. Instrument grade op-amps are also available
that might be better suited. I will try to build you one if you like.
Contact me off list, if interested..
HTH,
Leroy
Original Message
Subject: Re: [noparse][[/noparse]basicstamps] Sensing RPM on a small gas engine
(Briggs&Stratton 8hp)
Date: Mon, 15 Apr 2002 01:01:00 -0700 (PDT)
From: Jay Mann <jay_mann2000@y...>
Reply-To: basicstamps@yahoogroups.com
To: basicstamps@yahoogroups.com
Leroy,
I have a schmidt trigger inverter. The problem I having is that I can
not get enough of a pulse to trigger it using a simple coil.. Any ideas
as to gauge and number of turns? etc?
Thanks,
J
Comments
ignition problems. I think it had a transistor with a floating
base at the end of a two conductor cable. The high voltage
from the spark would "fire" the transistor when it was close enough
to be affected by the electromagnetic pulse. That would then pull
a resistor down. The thing worked pretty well and didn't have to be
in contact with the high voltage plug wire.
HTH
Gary
That would be good.. I am having some troubles getting any good signal using a
similiar method.. could the insulation on the plug wire be designed to reduce
emf? if this is true would I be best to try and uninsulate and ad insulation of
my own that wouldn't block the emf?
Your thoughts?
Leroy Hall <leroy@f...> wrote: The gauge of the wire is not important
regarding the amount of voltage
received. I would start with 10-15 turns of 22 or smaller gauge wire,
insulated and see what kind of voltage you get. You need approx. .6
volts or higher to trigger. You may need to have some amplification to
get it high enough. The lm 386 is a cheap amplifier that will easily
give 200X of amplification. Instrument grade op-amps are also available
that might be better suited. I will try to build you one if you like.
Contact me off list, if interested..
HTH,
Leroy
Original Message
Subject: Re: [noparse][[/noparse]basicstamps] Sensing RPM on a small gas engine
(Briggs&Stratton 8hp)
Date: Mon, 15 Apr 2002 01:01:00 -0700 (PDT)
From: Jay Mann
Reply-To: basicstamps@yahoogroups.com
To: basicstamps@yahoogroups.com
Leroy,
I have a schmidt trigger inverter. The problem I having is that I can
not get enough of a pulse to trigger it using a simple coil.. Any ideas
as to gauge and number of turns? etc?
Thanks,
J
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.
Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
Do You Yahoo!?
Yahoo! Tax Center - online filing with TurboTax
[noparse][[/noparse]Non-text portions of this message have been removed]
you more voltage than you need or want, much less fry your stamp. If 15
turns don't work, try 30, 60, 100. You will get there. Maybe you could
find a toroid or small circular coil, like on tv HV power supply that
could give you more turns. Looks like either more turns or more
amplification. Take your pick..
Leroy
Jay Mann wrote:
>
> Leroy,
> That would be good.. I am having some troubles getting any good signal using a
similiar method.. could the insulation on the plug wire be designed to reduce
emf? if this is true would I be best to try and uninsulate and ad insulation of
my own that wouldn't block the emf?
> Your thoughts?
>
alternating signal. just tap into the points wire, and run it to the stamp
pin. You would need some signal conditioning I would imagine. You dont want
to fry the stamp. Maybe a high meg ohm resistor on the stamp pin. You have a
1-1 count here on the breaker points.
At 03:27 PM 4/15/2002 -0400, you wrote:
>I would not suggest reducing the insulation thickness. This might get
>you more voltage than you need or want, much less fry your stamp. If 15
>turns don't work, try 30, 60, 100. You will get there. Maybe you could
>find a toroid or small circular coil, like on tv HV power supply that
>could give you more turns. Looks like either more turns or more
>amplification. Take your pick..
>
>Leroy
>
>Jay Mann wrote:
>>
>> Leroy,
>> That would be good.. I am having some troubles getting any good signal
using a similiar method.. could the insulation on the plug wire be designed
to reduce emf? if this is true would I be best to try and uninsulate and ad
insulation of my own that wouldn't block the emf?
>> Your thoughts?
>>
>
>
>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.
>
>
>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>
Sincerely
Kerry
Admin@M...
WWW server hosting [url=Http://mntnweb.com]Http://mntnweb.com[/url]
Kerry Barlow
p.o. box 21
kirkwood ny
13795
607-775-1132
anymore.
richard
Original Message
From: "Leroy Hall" <leroy@f...>
To: <basicstamps@yahoogroups.com>
Sent: Monday, April 15, 2002 2:27 PM
Subject: Re: [noparse][[/noparse]Fwd: Re: [noparse][[/noparse]basicstamps] Sensing RPM on a small gas engine
(Briggs&Stratton 8hp)]
> I would not suggest reducing the insulation thickness. This might get
> you more voltage than you need or want, much less fry your stamp. If 15
> turns don't work, try 30, 60, 100. You will get there. Maybe you could
> find a toroid or small circular coil, like on tv HV power supply that
> could give you more turns. Looks like either more turns or more
> amplification. Take your pick..
>
> Leroy
>
> Jay Mann wrote:
> >
> > Leroy,
> > That would be good.. I am having some troubles getting any good signal
using a similiar method.. could the insulation on the plug wire be designed
to reduce emf? if this is true would I be best to try and uninsulate and ad
insulation of my own that wouldn't block the emf?
> > Your thoughts?
> >
>
>
> 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.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
richard
Original Message
From: "Kerry Barlow" <admin@m...>
To: <basicstamps@yahoogroups.com>
Sent: Monday, April 15, 2002 3:11 PM
Subject: Re: [noparse][[/noparse]Fwd: Re: [noparse][[/noparse]basicstamps] Sensing RPM on a small gas engine
(Briggs&Stratton 8hp)]
> Cant you count the pulses coming off the breaker points? They are an
> alternating signal. just tap into the points wire, and run it to the stamp
> pin. You would need some signal conditioning I would imagine. You dont
want
> to fry the stamp. Maybe a high meg ohm resistor on the stamp pin. You have
a
> 1-1 count here on the breaker points.
>
> At 03:27 PM 4/15/2002 -0400, you wrote:
> >I would not suggest reducing the insulation thickness. This might get
> >you more voltage than you need or want, much less fry your stamp. If 15
> >turns don't work, try 30, 60, 100. You will get there. Maybe you could
> >find a toroid or small circular coil, like on tv HV power supply that
> >could give you more turns. Looks like either more turns or more
> >amplification. Take your pick..
> >
> >Leroy
> >
> >Jay Mann wrote:
> >>
> >> Leroy,
> >> That would be good.. I am having some troubles getting any good signal
> using a similiar method.. could the insulation on the plug wire be
designed
> to reduce emf? if this is true would I be best to try and uninsulate and
ad
> insulation of my own that wouldn't block the emf?
> >> Your thoughts?
> >>
> >
> >
> >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.
> >
> >
> >Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
> >
> >
> >
> Sincerely
> Kerry
> Admin@M...
> WWW server hosting [url=Http://mntnweb.com]Http://mntnweb.com[/url]
> Kerry Barlow
> p.o. box 21
> kirkwood ny
> 13795
> 607-775-1132
>
>
>
>
> 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.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
work. This signal is not a clean sharp pulse that the coil discharge is
and it would need some signal conditioning, but would be much more
'friendly' to work with. Electronic Ignition? Here we go again !!
[noparse]:)[/noparse])))))))))
Leroy
Richard Friedrich wrote:
>
> right, that is what I meant with the voltage divider suggestion
>
>ignition problems. I think it had a transistor with a floating
A neon lamp will light up in the vicinity of a spul wire, also. A
photo diode or phototransistor could watch for the light.
Carl
For those of you who have a gas engine from Briggs&Stratton. Turns out that the
newer gas engines have an scr controlled ignition module for spark timing.On
this device is a handy tab (the tab where the kill switch connects). This tab
is connected to the trigger coil of the SCR. Upon inspection with a scope a sine
wave type thing was found that was proportional to the engine rpm.. I used a cap
and a resistor to make it a little nicer and I was able to get a sine wave type
pulse with a magnitude of about 2-10v depending on the values of resistors and
caps. I think I will use this with a comparator or schmidt trigger into a
flip-flop to measure my RPM using pulsin.
I would like to thank all of you who responded in such short time. I am a
college kid who has a final presentation due this week and that circuit was the
last of my problems (I HOPE)
Thanks,
J
carl@g... wrote: >Used to have a "spark detector" that was used for
troubleshooting
>ignition problems. I think it had a transistor with a floating
A neon lamp will light up in the vicinity of a spul wire, also. A
photo diode or phototransistor could watch for the light.
Carl
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.
Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
Do You Yahoo!?
Yahoo! Tax Center - online filing with TurboTax
[noparse][[/noparse]Non-text portions of this message have been removed]