Need a circuit for a simple square wave generator with the l

B

Bill T

Guest
Hi anybody got any idea where I can find the most simpliest square wave
generator with the smallest component counts?
I'll need something with pulse width control

also need a circuit for detecting current, and once it reaches a level of
current, it will trigger an output
again, most simpliest circuit there can be with least amount of components!

Thanks a million in advance!
 
"Bill T" <bill24@optusnet.com.au> wrote in message
news:433f64ed$1@news1.veridas.net...
Hi anybody got any idea where I can find the most simpliest square wave
generator with the smallest component counts?
I'll need something with pulse width control

also need a circuit for detecting current, and once it reaches a level of
current, it will trigger an output
again, most simpliest circuit there can be with least amount of
components!

Thanks a million in advance!
Click to expand...
Try an application based on the 555 timer for your square wave generator.
Simple and minimal components.

Cheers,
Alan
 
"Bill T" <bill24@optusnet.com.au> wrote in message
news:433f64ed$1@news1.veridas.net...
Hi anybody got any idea where I can find the most simpliest square wave
generator with the smallest component counts?
I'll need something with pulse width control

also need a circuit for detecting current, and once it reaches a level of
current, it will trigger an output
again, most simpliest circuit there can be with least amount of
components!

Thanks a million in advance!
Click to expand...
sorry I should've meant "duty cycle control" when I said "pulse width
control"

the frequency I need to generate is from 10kHz to 20kHz so I hope it's a
simple circuit, thanks again!
 
"Bill T" <bill24@optusnet.com.au> wrote in message
news:433f6a40$1@news1.veridas.net...
"Bill T" <bill24@optusnet.com.au> wrote in message
news:433f64ed$1@news1.veridas.net...
Hi anybody got any idea where I can find the most simpliest square wave
generator with the smallest component counts?
I'll need something with pulse width control

also need a circuit for detecting current, and once it reaches a level of
current, it will trigger an output
again, most simpliest circuit there can be with least amount of
components!

Thanks a million in advance!


sorry I should've meant "duty cycle control" when I said "pulse width
control"

the frequency I need to generate is from 10kHz to 20kHz so I hope it's a
simple circuit, thanks again!
Click to expand...
And the voltage output and current demand doesn't really matter as I can use
transformers and transistors/MOSFETs to drive the output, so basically I
just want the most simpliest generator, thank you!
 
"Bill T"
Hi anybody got any idea where I can find the most simpliest square wave
generator with the smallest component counts?
I'll need something with pulse width control
Click to expand...

** This 555 circuit will give variable duty cycle or PWM:

http://www.cpemma.co.uk/555pwm.html


For operation at 10 kHz, change the pot ( VR1 ) to 10 kohms and C1 to 10
nF ( 0.01uF).



........... Phil
 
"Phil Allison" <philallison@tpg.com.au> wrote in message
news:3q9ahnFdfd5fU1@individual.net...
"Bill T"
Hi anybody got any idea where I can find the most simpliest square wave
generator with the smallest component counts?
I'll need something with pulse width control


** This 555 circuit will give variable duty cycle or PWM:

http://www.cpemma.co.uk/555pwm.html


For operation at 10 kHz, change the pot ( VR1 ) to 10 kohms and C1 to 10
nF ( 0.01uF).



.......... Phil
Click to expand...


will this be a square wave output or sine wave output?
 
"Bill T"
"Phil Allison"
"Bill T"
Hi anybody got any idea where I can find the most simpliest square wave
generator with the smallest component counts?
I'll need something with pulse width control


** This 555 circuit will give variable duty cycle or PWM:

http://www.cpemma.co.uk/555pwm.html


For operation at 10 kHz, change the pot ( VR1 ) to 10 kohms and C1 to
10 nF ( 0.01uF).



will this be a square wave output or sine wave output?
Click to expand...

** The output at pin 3 will be a very sharp rectangular wave - even at 10
kHz.

555s are very versatile - but do not do sine waves without great
provocation ;-)




............ Phil
 
"Bill T" <bill24@optusnet.com.au> wrote in message
news:433f9424@news1.veridas.net...
"Phil Allison" <philallison@tpg.com.au> wrote in message
news:3q9ahnFdfd5fU1@individual.net...

"Bill T"
Hi anybody got any idea where I can find the most simpliest square wave
generator with the smallest component counts?
I'll need something with pulse width control


** This 555 circuit will give variable duty cycle or PWM:

http://www.cpemma.co.uk/555pwm.html


For operation at 10 kHz, change the pot ( VR1 ) to 10 kohms and C1 to
10 nF ( 0.01uF).



.......... Phil




will this be a square wave output or sine wave output?
Click to expand...

Hi I just went through that page, and the circuit is a pulse width control
thingy, with only 1 control - pulse width, do I need a separate circuit to
generate and control the waveform? ie. another 555 circuit and somehow
connect them together?
 
"Phil Allison" <philallison@tpg.com.au> wrote in message
news:3q9intFdv4lmU1@individual.net...
"Bill T"
"Phil Allison"
"Bill T"
Hi anybody got any idea where I can find the most simpliest square wave
generator with the smallest component counts?
I'll need something with pulse width control


** This 555 circuit will give variable duty cycle or PWM:

http://www.cpemma.co.uk/555pwm.html


For operation at 10 kHz, change the pot ( VR1 ) to 10 kohms and C1 to
10 nF ( 0.01uF).



will this be a square wave output or sine wave output?


** The output at pin 3 will be a very sharp rectangular wave - even at
10 kHz.

555s are very versatile - but do not do sine waves without great
provocation ;-)




........... Phil
Click to expand...
when you say sharp rectangular wave do you mean square wave or sawtooth
wave?

I think I sort of understand the circuit better now, and it seems the value
of C1 will affect the frequency, whereas the VR1 will affect the pulse
width, but it seems the value of VR1 will affect the frequency too, but how
do you work out the values to affect the output frequency? Do you just use a
variable capacitor to replace C1?
 
"Bill T"
Hi I just went through that page, and the circuit is a pulse width control
thingy, with only 1 control - pulse width, do I need a separate circuit to
generate and control the waveform? ie. another 555 circuit and somehow
connect them together?
Click to expand...

** Nope - that is the *whole* kaboodle.

Just one 555 - surprisingly simple, what ?




......... Phil
 
"Bill T"


** Stop being a PITA and build one.

It works like a charm.



............. Phil
 
"Bill T" <bill24@optusnet.com.au> wrote in message
news:433f992b$1@news1.veridas.net...
"Phil Allison" <philallison@tpg.com.au> wrote in message
news:3q9intFdv4lmU1@individual.net...

"Bill T"
"Phil Allison"
"Bill T"
Hi anybody got any idea where I can find the most simpliest square
wave generator with the smallest component counts?
I'll need something with pulse width control


** This 555 circuit will give variable duty cycle or PWM:

http://www.cpemma.co.uk/555pwm.html


For operation at 10 kHz, change the pot ( VR1 ) to 10 kohms and C1 to
10 nF ( 0.01uF).



will this be a square wave output or sine wave output?


** The output at pin 3 will be a very sharp rectangular wave - even at
10 kHz.

555s are very versatile - but do not do sine waves without great
provocation ;-)




........... Phil




when you say sharp rectangular wave do you mean square wave or sawtooth
wave?

I think I sort of understand the circuit better now, and it seems the
value of C1 will affect the frequency, whereas the VR1 will affect the
pulse width, but it seems the value of VR1 will affect the frequency too,
but how do you work out the values to affect the output frequency? Do you
just use a variable capacitor to replace C1?
Click to expand...

ok, something clicked and I think I got it now, since you're using half of
VR1 to charge and the other half of VR1 to discharge, the whole VR1 value
determines the cycle. ie the waveform's frequency, so with a fixed value VR1
& C1 will yield a rough frequency value, but if I replace C1 with a variable
capacitor I will be able to fine tune the frequency value! Am I right?


so now where can I find a circuit for some "current monitor"? for eg. to
monitor the electric current passing through the motor M1? Would I use some
kind of op-amp or something?
 
Bill T wrote:
so now where can I find a circuit for some "current monitor"? for eg. to
monitor the electric current passing through the motor M1? Would I use some
kind of op-amp or something?
Click to expand...
It sounds like you are building a motor controller. Why not just buy
one? Or get plans for a "Motor controller", instead of getting plans for
each individual component of one?

Cheers,
Nicholas Sherlock
 
"Nicholas Sherlock" <n_sherlock@hotmail.com> wrote in message
news:dho69m$ehc$1@lust.ihug.co.nz...
Bill T wrote:
so now where can I find a circuit for some "current monitor"? for eg. to
monitor the electric current passing through the motor M1? Would I use
some kind of op-amp or something?

It sounds like you are building a motor controller. Why not just buy one?
Or get plans for a "Motor controller", instead of getting plans for each
individual component of one?

Cheers,
Nicholas Sherlock
Click to expand...
How much do they cost if I buy one? Where do I find them?
 
"Phil Allison" <philallison@tpg.com.au> wrote in message
news:3q9jraFdunacU1@individual.net...
"Bill T"

Hi I just went through that page, and the circuit is a pulse width
control thingy, with only 1 control - pulse width, do I need a separate
circuit to generate and control the waveform? ie. another 555 circuit and
somehow connect them together?


** Nope - that is the *whole* kaboodle.

Just one 555 - surprisingly simple, what ?




........ Phil
Click to expand...
It is surprising, and seems enough for what I need! Thanks!
 
Bill T wrote:
Hi anybody got any idea where I can find the most simpliest square wave
generator with the smallest component counts?
I'll need something with pulse width control

also need a circuit for detecting current, and once it reaches a level of
current, it will trigger an output
again, most simpliest circuit there can be with least amount of components!

Thanks a million in advance!
Click to expand...
A single chip microcontroller is the smallest component count solution
- 1 chip, no external components required except for your required
current sensor.
The PIC10F206 is a 6 pin SOT-23 package with internal 4MHz oscillator.
No PWM module, but you could probably do it in software.
The PIC12F683 is an 8 pin DIP/SO with 8MHz internal oscillator, 4
channel 10bit ADC, and a PWM module. The ADC could be used to detect
the current level.

Dave :)
 
For a wave generator Dick Smith had a kit imported (under one of these
strange names) it was cheap and on a board about 40mm by 40mm based on
555. it does most wave form with a jumper.
 
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