ne555 square wave
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Posts: 46,084
At 10:01 AM 12/7/00 -0800, you wrote:
>
>
>
>>Reply-To: basicstamps@egroups.com
>>Subject: Re: [noparse][[/noparse]basicstamps] ne555
>
>It's been a while since I tried to use a 555 for anything serious (not
>since Stamp 1, at least), but as I remember it, you can't get a square wave
>from the usual two resistor-one capacitor configuration. The capacitor
>charges through two resistors and discharges through only one.
===> snip
A square wave is easy with the 555. Just connect the SINGLE resistor to the
output terminal instead of VCC. It's not perfect but pretty darn good.
Wayne
Wayne
Wayne Roderick P.E. (EE, ret)
CEO, Teton Short Line, (NMRA life-1721)
e-mail tetonsl@i... Pocatello Idaho, USA
http://www.ida.net/users/tetonsl/railroad
Note new URL- /biz/ becomes /users/
>
>
>
>>Reply-To: basicstamps@egroups.com
>>Subject: Re: [noparse][[/noparse]basicstamps] ne555
>
>It's been a while since I tried to use a 555 for anything serious (not
>since Stamp 1, at least), but as I remember it, you can't get a square wave
>from the usual two resistor-one capacitor configuration. The capacitor
>charges through two resistors and discharges through only one.
===> snip
A square wave is easy with the 555. Just connect the SINGLE resistor to the
output terminal instead of VCC. It's not perfect but pretty darn good.
Wayne
Wayne
Wayne Roderick P.E. (EE, ret)
CEO, Teton Short Line, (NMRA life-1721)
e-mail tetonsl@i... Pocatello Idaho, USA
http://www.ida.net/users/tetonsl/railroad
Note new URL- /biz/ becomes /users/
Comments
Is there any way you could add a bit more detail to getting a square wave
out of the 555, actually I got a NTE955.
Be great if I could get something that would blink an LED at 1 or 2 hertz,
but I'm not fussy at this point.
I spent about a couple hours here with Forest Mims book, if I'm getting
anything at all, I'd call it a real fast square wave.
Is there a quicky or rule of thumb equation for frequency output?
Thanks,
Mark
Original Message
From: Wayne Roderick <tetonsl@i...>
To: basicstamps@egroups.com <basicstamps@egroups.com>
Date: Thursday, December 07, 2000 9:16 PM
Subject: Re: [noparse][[/noparse]basicstamps] ne555 square wave
>At 10:01 AM 12/7/00 -0800, you wrote:
>>
>>
>>
>>>Reply-To: basicstamps@egroups.com
>>>Subject: Re: [noparse][[/noparse]basicstamps] ne555
>>
>>It's been a while since I tried to use a 555 for anything serious (not
>>since Stamp 1, at least), but as I remember it, you can't get a square
wave
>>from the usual two resistor-one capacitor configuration. The capacitor
>>charges through two resistors and discharges through only one.
>===> snip
>
>A square wave is easy with the 555. Just connect the SINGLE resistor to the
>output terminal instead of VCC. It's not perfect but pretty darn good.
>
>Wayne
>
>
>
>Wayne
>
>
>
>
>
>Wayne Roderick P.E. (EE, ret)
>CEO, Teton Short Line, (NMRA life-1721)
>e-mail tetonsl@i... Pocatello Idaho, USA
>http://www.ida.net/users/tetonsl/railroad
>Note new URL- /biz/ becomes /users/
>
>
>
>
>
>
I got the LED to blink with 100 ohm and 1M ohm and a .022uF cap.
By the equations in the book, this should give something like 328kH
But by my scope the LED is on for 15ms and off for 30ms.
The thought here is to use the 555 to run servos instead of looping the BS2
all over the place.
Original Message
From: techno masai <plunkettm@e...>
To: basicstamps@egroups.com <basicstamps@egroups.com>
Date: Friday, December 08, 2000 5:50 PM
Subject: Re: [noparse][[/noparse]basicstamps] ne555 square wave
>Wayne,
>
>Is there any way you could add a bit more detail to getting a square wave
>out of the 555, actually I got a NTE955.
>
>Be great if I could get something that would blink an LED at 1 or 2 hertz,
>but I'm not fussy at this point.
>
>I spent about a couple hours here with Forest Mims book, if I'm getting
>anything at all, I'd call it a real fast square wave.
>
>Is there a quicky or rule of thumb equation for frequency output?
>
>Thanks,
>
>Mark
>
Original Message
>From: Wayne Roderick <tetonsl@i...>
>To: basicstamps@egroups.com <basicstamps@egroups.com>
>Date: Thursday, December 07, 2000 9:16 PM
>Subject: Re: [noparse][[/noparse]basicstamps] ne555 square wave
>
>
>>At 10:01 AM 12/7/00 -0800, you wrote:
>>>
>>>
>>>
>>>>Reply-To: basicstamps@egroups.com
>>>>Subject: Re: [noparse][[/noparse]basicstamps] ne555
>>>
>>>It's been a while since I tried to use a 555 for anything serious (not
>>>since Stamp 1, at least), but as I remember it, you can't get a square
>wave
>>>from the usual two resistor-one capacitor configuration. The capacitor
>>>charges through two resistors and discharges through only one.
>>===> snip
>>
>>A square wave is easy with the 555. Just connect the SINGLE resistor to
the
>>output terminal instead of VCC. It's not perfect but pretty darn good.
>>
>>Wayne
>>
>>
>>
>>Wayne
>>
>>
>>
>>
>>
>>Wayne Roderick P.E. (EE, ret)
>>CEO, Teton Short Line, (NMRA life-1721)
>>e-mail tetonsl@i... Pocatello Idaho, USA
>>http://www.ida.net/users/tetonsl/railroad
>>Note new URL- /biz/ becomes /users/
>>
>>
>>
>>
>>
>>
>
>
>
>
>
>Wayne,
>
>Is there any way you could add a bit more detail to getting a square wave
>out of the 555, actually I got a NTE955.
>
>Be great if I could get something that would blink an LED at 1 or 2 hertz,
>but I'm not fussy at this point.
>
>I spent about a couple hours here with Forest Mims book, if I'm getting
>anything at all, I'd call it a real fast square wave.
>
>Is there a quicky or rule of thumb equation for frequency output?
>
>Thanks,
>
>Mark
Forrest Mims book is excellant for the hobbyist. If its the same one I
have, he gives you a circuit for a one-shot. Just move one end of the
resistor from the DC supply, pins 8 & 4 and reconnect it to the output pin 3.
The classic timing equation is T= 1.1 RC This would be for one-half cycle
so you need the RC product equal to one-half of your time period- .25
seconds for a two Hertz output. 1mFd with 0.270meg should do it. note how
the micros and Megs cancel out.
Sorry I don't have a convenient referance to compare the '955 with the
classic '555
Wayne Roderick P.E. (EE, ret)
CEO, Teton Short Line, (NMRA life-1721)
e-mail tetonsl@i... Pocatello Idaho, USA
http://www.ida.net/users/tetonsl/railroad
Note new URL- /biz/ becomes /users/
http://www.nteinc.com/specs/900to999/NTE955MC.html
and it seems to be a CMOS drop-in for the old 555, except it can only source
10ma and sink 100ma.
BTW Mark, some time ago I posted a simple 555 circuit to run servos,
controlled by a pot, if that's what you were looking for. If so, let me
know.
Ray McArthur
>
> Sorry I don't have a convenient referance to compare the '955 with the
> classic '555
Yes, please re-post the circuit on the 555's driving servos.
I don't know how I missed that post of yours.
Thanks for the link too.
I got to admit I'm getting a better understanding of the source and sink
concepts when you mention "it can only source 10ma and sink 100ma" because
I'm directly driving an LED from pin 3, while I got my ELPAC regulated 2A
5VDC supply hooked directly up to the NTE955.
So, I guess the NTE955 can send out 10ma to the LED, but would only pull
100ma from my supply, right?
Heck, I guess I'm going to measure that now to confirm.
Thanks again,
Mark
Original Message
From: Ray McArthur <rjmca@u...>
To: basicstamps@egroups.com <basicstamps@egroups.com>
Date: Friday, December 08, 2000 8:56 PM
Subject: Re: [noparse][[/noparse]basicstamps] ne555 square wave
>I took a quick look at
>http://www.nteinc.com/specs/900to999/NTE955MC.html
>and it seems to be a CMOS drop-in for the old 555, except it can only
source
>10ma and sink 100ma.
>
>BTW Mark, some time ago I posted a simple 555 circuit to run servos,
>controlled by a pot, if that's what you were looking for. If so, let me
>know.
>
>Ray McArthur
>>
>> Sorry I don't have a convenient referance to compare the '955 with the
>> classic '555
>
>
>
>
>
>
If you connect the LED/resistor from the 555 output to gnd, the LED lights
when the output is high...this is sourcing current. If you connect the
LED/resistor from +supply to the 555 output, it lights when the output is
low.. this is sinking current.
I will email the file to your email address.
Ray McArthur
> I got to admit I'm getting a better understanding of the source and sink
> concepts when you mention "it can only source 10ma and sink 100ma" because
> I'm directly driving an LED from pin 3, while I got my ELPAC regulated 2A
> 5VDC supply hooked directly up to the NTE955.
>
> So, I guess the NTE955 can send out 10ma to the LED, but would only pull
> 100ma from my supply, right?
>
> Heck, I guess I'm going to measure that now to confirm.
>
> Thanks again,
>
> Mark
>
Original Message
> From: Ray McArthur <rjmca@u...>
> To: basicstamps@egroups.com <basicstamps@egroups.com>
> Date: Friday, December 08, 2000 8:56 PM
> Subject: Re: [noparse][[/noparse]basicstamps] ne555 square wave
>
>
> >I took a quick look at
> >http://www.nteinc.com/specs/900to999/NTE955MC.html
> >and it seems to be a CMOS drop-in for the old 555, except it can only
> source
> >10ma and sink 100ma.
> >
> >BTW Mark, some time ago I posted a simple 555 circuit to run servos,
> >controlled by a pot, if that's what you were looking for. If so, let me
> >know.
> >
> >Ray McArthur
> >>
> >> Sorry I don't have a convenient referance to compare the '955 with the
> >> classic '555
> >
> >
> >
> >
> >
> >
>
>
>
>
Go to <http://www.schematica.com> and download the FREEWARE 555 Timer
Designer program and then look at program Application menu for samples.
Se also <http://home.iprimus.com.au/nooyen/servo.htm> for a Servo Pulse
Generator with NE556 Dual Timer
Bye
techno masai wrote:
>
> Wayne,
>
> Is there any way you could add a bit more detail to getting a square wave
> out of the 555, actually I got a NTE955.
>
> Be great if I could get something that would blink an LED at 1 or 2 hertz,
> but I'm not fussy at this point.
>
> I spent about a couple hours here with Forest Mims book, if I'm getting
> anything at all, I'd call it a real fast square wave.
>
> Is there a quicky or rule of thumb equation for frequency output?
>
> Thanks,
>
> Mark
>
Original Message
> From: Wayne Roderick <tetonsl@i...>
> To: basicstamps@egroups.com <basicstamps@egroups.com>
> Date: Thursday, December 07, 2000 9:16 PM
> Subject: Re: [noparse][[/noparse]basicstamps] ne555 square wave
>
> >At 10:01 AM 12/7/00 -0800, you wrote:
> >>
> >>
> >>
> >>>Reply-To: basicstamps@egroups.com
> >>>Subject: Re: [noparse][[/noparse]basicstamps] ne555
> >>
> >>It's been a while since I tried to use a 555 for anything serious (not
> >>since Stamp 1, at least), but as I remember it, you can't get a square
> wave
> >>from the usual two resistor-one capacitor configuration. The capacitor
> >>charges through two resistors and discharges through only one.
> >===> snip
> >
> >A square wave is easy with the 555. Just connect the SINGLE resistor to the
> >output terminal instead of VCC. It's not perfect but pretty darn good.
> >
> >Wayne
> >
> >
> >
> >Wayne
> >
> >
> >
> >
> >
> >Wayne Roderick P.E. (EE, ret)
> >CEO, Teton Short Line, (NMRA life-1721)
> >e-mail tetonsl@i... Pocatello Idaho, USA
> >http://www.ida.net/users/tetonsl/railroad
> >Note new URL- /biz/ becomes /users/
> >
> >
> >
> >
> >
> >
--
Arnaldo Braun
mailto:abraun@t...
Florianopolis - SC - Brasil
Actually, it wouldn't download for me, I got the "page unavailable" white
screen, maybe its only available in your country. Wonder how they do that,
but it is a good site and I wanted to get that pretty little resistor chart
thing they had too.
Thanks for the tip though, y tambien quero mas y mas apprendar espanol.
Mark
Original Message
From: Arnaldo Braun <abraun@t...>
To: basicstamps@egroups.com <basicstamps@egroups.com>
Date: Saturday, December 09, 2000 5:14 AM
Subject: Re: [noparse][[/noparse]basicstamps] ne555 square wave
>Hi
>
>Go to <http://www.schematica.com> and download the FREEWARE 555 Timer
>Designer program and then look at program Application menu for samples.
>
>Se also <http://home.iprimus.com.au/nooyen/servo.htm> for a Servo Pulse
>Generator with NE556 Dual Timer
>
>Bye
>
>techno masai wrote:
>>
>> Wayne,
>>
>> Is there any way you could add a bit more detail to getting a square wave
>> out of the 555, actually I got a NTE955.
>>
>> Be great if I could get something that would blink an LED at 1 or 2
hertz,
>> but I'm not fussy at this point.
>>
>> I spent about a couple hours here with Forest Mims book, if I'm getting
>> anything at all, I'd call it a real fast square wave.
>>
>> Is there a quicky or rule of thumb equation for frequency output?
>>
>> Thanks,
>>
>> Mark
>>
Original Message
>> From: Wayne Roderick <tetonsl@i...>
>> To: basicstamps@egroups.com <basicstamps@egroups.com>
>> Date: Thursday, December 07, 2000 9:16 PM
>> Subject: Re: [noparse][[/noparse]basicstamps] ne555 square wave
>>
>> >At 10:01 AM 12/7/00 -0800, you wrote:
>> >>
>> >>
>> >>
>> >>>Reply-To: basicstamps@egroups.com
>> >>>Subject: Re: [noparse][[/noparse]basicstamps] ne555
>> >>
>> >>It's been a while since I tried to use a 555 for anything serious (not
>> >>since Stamp 1, at least), but as I remember it, you can't get a square
>> wave
>> >>from the usual two resistor-one capacitor configuration. The capacitor
>> >>charges through two resistors and discharges through only one.
>> >===> snip
>> >
>> >A square wave is easy with the 555. Just connect the SINGLE resistor to
the
>> >output terminal instead of VCC. It's not perfect but pretty darn good.
>> >
>> >Wayne
>> >
>> >
>> >
>> >Wayne
>> >
>> >
>> >
>> >
>> >
>> >Wayne Roderick P.E. (EE, ret)
>> >CEO, Teton Short Line, (NMRA life-1721)
>> >e-mail tetonsl@i... Pocatello Idaho, USA
>> >http://www.ida.net/users/tetonsl/railroad
>> >Note new URL- /biz/ becomes /users/
>> >
>> >
>> >
>> >
>> >
>> >
>
>--
>
> Arnaldo Braun
> mailto:abraun@t...
> Florianopolis - SC - Brasil
>
>
>
>
Hi
I just tested and both links are OK. Perhaps a temporary problem?
You can try the FTP site
<ftp://ftp.islandnet.com/Schematica/files/SS55511.exe> and
<ftp://ftp.islandnet.com/Schematica/files/ResistorCC.exe>
[noparse]:)[/noparse] Sorry, you are wrong. In Brazil we speak portuguese and not
spanish...
techno masai wrote:
>
> Hi Arnaldo,
>
> Actually, it wouldn't download for me, I got the "page unavailable" white
> screen, maybe its only available in your country. Wonder how they do that,
> but it is a good site and I wanted to get that pretty little resistor chart
> thing they had too.
>
> Thanks for the tip though, y tambien quero mas y mas apprendar espanol.
>
> Mark
>
>
Original Message
> From: Arnaldo Braun <abraun@t...>
> To: basicstamps@egroups.com <basicstamps@egroups.com>
> Date: Saturday, December 09, 2000 5:14 AM
> Subject: Re: [noparse][[/noparse]basicstamps] ne555 square wave
>
> >Hi
> >
> >Go to <http://www.schematica.com> and download the FREEWARE 555 Timer
> >Designer program and then look at program Application menu for samples.
> >
> >Se also <http://home.iprimus.com.au/nooyen/servo.htm> for a Servo Pulse
> >Generator with NE556 Dual Timer
> >
> >Bye
> >
...snip...
> >
> > Arnaldo Braun
> > mailto:abraun@t...
> > Florianopolis - SC - Brazil