Pulse Generator
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Hi! I'm 13 years old, and am currently working on a Basic Stamp 2
powered datalogger. The project needs an external input of a 10ms
pulse every 1000ms. What is the best and simplest oscillator that I
could build to provide this input? I was planning on using a 555
timer IC, but had trouble getting the proper values for the R1, R2,
and C1 in the standard 555 oscillator circuit. I was wondering if
someone could provide me with the correct resistor and capacitor
values or a different simple pulse generation circuit. Thanks!
Jacob Power
powered datalogger. The project needs an external input of a 10ms
pulse every 1000ms. What is the best and simplest oscillator that I
could build to provide this input? I was planning on using a 555
timer IC, but had trouble getting the proper values for the R1, R2,
and C1 in the standard 555 oscillator circuit. I was wondering if
someone could provide me with the correct resistor and capacitor
values or a different simple pulse generation circuit. Thanks!
Jacob Power
Comments
> powered datalogger. The project needs an external input of a 10ms
> pulse every 1000ms. What is the best and simplest oscillator that I
> could build to provide this input? I was planning on using a 555
> timer IC, but had trouble getting the proper values for the R1, R2,
> and C1 in the standard 555 oscillator circuit. I was wondering if
> someone could provide me with the correct resistor and capacitor
> values or a different simple pulse generation circuit. Thanks!
The 555 is still your best bet. First, to make figuring the values easier,
download CS Microsystem's 555 calculator program -it's free and pretty neat.
http://www.csmicrosystems.com/timerdesigner/index.html
Next, since you may need a bunch of odd value resistors, get a few multi-
turn pots and use those instead of fixed resistors. That way, you can 'dial'
any value you want (within the range of the pot).
Enjoy.
Mark Hillier, VE6HVW
President, HVW Technologies Inc.
Canadian Distributors of Parallax Products and other Neat Stuff
Tel: (403)-730-8603 Fax: (403)-730-8903
See our NEW FPGA Experimenter Board
http://www.hvwtech.com/intro-fpga.htm
excellent resources on oscillators. I have learned so much from this list.
Thanks again!
Jacob Power
Original Message
Wrom: PHSCRTNHGSWZ
Sent: Thursday, September 19, 2002 7:52 AM
To: basicstamps@yahoogroups.com
Subject: Re: [noparse][[/noparse]basicstamps] Pulse Generator
> Hi! I'm 13 years old, and am currently working on a Basic Stamp 2
> powered datalogger. The project needs an external input of a 10ms
> pulse every 1000ms. What is the best and simplest oscillator that I
> could build to provide this input? I was planning on using a 555
> timer IC, but had trouble getting the proper values for the R1, R2,
> and C1 in the standard 555 oscillator circuit. I was wondering if
> someone could provide me with the correct resistor and capacitor
> values or a different simple pulse generation circuit. Thanks!
The 555 is still your best bet. First, to make figuring the values easier,
download CS Microsystem's 555 calculator program -it's free and pretty neat.
http://www.csmicrosystems.com/timerdesigner/index.html
Next, since you may need a bunch of odd value resistors, get a few multi-
turn pots and use those instead of fixed resistors. That way, you can 'dial'
any value you want (within the range of the pot).
Enjoy.
Mark Hillier, VE6HVW
President, HVW Technologies Inc.
Canadian Distributors of Parallax Products and other Neat Stuff
Tel: (403)-730-8603 Fax: (403)-730-8903
See our NEW FPGA Experimenter Board
http://www.hvwtech.com/intro-fpga.htm
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>Reply-To: basicstamps@yahoogroups.com
>To: basicstamps@yahoogroups.com
>Subject: [noparse][[/noparse]basicstamps] Pulse Generator
>Date: Thu, 19 Sep 2002 02:30:19 -0000
>
>Hi! I'm 13 years old, and am currently working on a Basic Stamp 2
>powered datalogger. The project needs an external input of a 10ms
>pulse every 1000ms. What is the best and simplest oscillator that I
>could build to provide this input? I was planning on using a 555
>timer IC, but had trouble getting the proper values for the R1, R2,
>and C1 in the standard 555 oscillator circuit. I was wondering if
>someone could provide me with the correct resistor and capacitor
>values or a different simple pulse generation circuit. Thanks!
>
>Jacob Power
>
>
>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/
>
>
Checkout this page:
http://www.doctronics.co.uk/555.htm
The 555 circuit will need an extra diode over normal circuits in order to
generate frequencies with a duty cycle less than 50%. Duty cycle being the
ratio between on and off time.
For your particular application look at "More astables Extended duty cycle
astable" That is the basic circuit that you need, but you can leave out the
LED and the 680R resistor. Also the resistor and capacitor values shown will
be different.
Sorry my maths could be a bit shoddy right now, but this is what I get:
High time = 0.69 X R1 X C
Low time = 0.69 X R2 X C
10.35 ms = 0.69 X 1K5 X 10uF
1035 ms = 0.69 X 150K X 10uF
R1 = 1K5
R2 = 150K
C = 10uF
There are many other combinations of resistors and capacitors, maybe you can
find values that give better timing. The values aren't likely to be perfect,
using standard resistors and capacitors, even if you can find a
theoretically perfect combination. Use 1% accurate components for better
accuracy too.
another good page to look at:
http://home.cogeco.ca/~rpaisley4/LM555.html
Paul
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I am in need of a pulse generator. I built one using a 555 timer and
a few parts. It drives an IR led to 40 khz. Does anyone have an idea
on making one with a wide range? Do they have an ic that can be used
to make a simple one?
Thanks,
Curtis
> Hello,
> I am in need of a pulse generator. I built one using a 555 timer and
> a few parts. It drives an IR led to 40 khz. Does anyone have an idea
> on making one with a wide range? Do they have an ic that can be used
> to make a simple one?
>
> Thanks,
> Curtis
We have two versions. One for 38 to 40kHz, and one for 455kHz.
http://www.rentron.com/remote_control/TX-IR.htm
http://www.rentron.com/remote_control/TX-IRHS.htm
Both can be used for simple IR carrier generation or IR serial communications.
You can find schematics for several applications & details on the same pages.
Regards,
-Bruce
tech@r...
http://www.rentron.com