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Author Topic: Need Help LOW frequency square wave oscillator circuit needed  (Read 20342 times)

Offline magnetman12003

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Hi,

Please review the U tube link below.

I wish to construct a low frequency square wave oscillator that will give me the same results as the function generator shown on the below U tube link. 

I plan to use a 12 volt DC 5 amp power supply to power it.  However the degaussing coil I will use is 13 inches in diameter.

 Can anyone point me towards a real simple circuit that I can make that will  give me the same inverted square wave the inventor is using? The inventor calls out the setup he used on his funtion generator.

 My unit will have to be more powerful as I will be using the larger coil.   All help appreciated.

http://www.youtube.com/watch?v=x-aHeHkQumQ&feature=channel


Thanks, Tom

Offline DreamThinkBuild

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Re: Need Help LOW frequency square wave oscillator circuit needed
« Reply #1 on: July 20, 2009, 05:30:44 PM »
Here are some "simple" low hertz circuits but they may have to be fed to a driver section for your high power output.

This will generate a 1.5hz wave on the second stage.
http://www.hackcanada.com/homegrown/wetware/ces/dope/ces_jau_2.html

Or you could always use this other design as a base then tweak the 7555 timing for multiple outputs on 4017.
http://www.redcircuits.com//Page19.htm

Offline mscoffman

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Re: Need Help LOW frequency square wave oscillator circuit needed
« Reply #2 on: July 20, 2009, 06:17:37 PM »
check out;

http://www.alldatasheet.com/datasheet-pdf/pdf/67458/INTERSIL/ICM7242.html

These long range timers are essentially an NE555 oscillator
type circuit followed by a divide by 256 set of flip-flops
in one circuit pack. Note: the "part equivalent" table, a little
further down the page. Running this into an IRF511 power
Fet transistor gate pin should do it for having a slow power
squarewave signal.

:S:MarkSCoffman

Offline magnetman12003

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Re: Need Help LOW frequency square wave oscillator circuit needed
« Reply #3 on: July 21, 2009, 03:09:52 AM »
Hi All,

I have been given this circuit to look at. What you see has been corrected later by Martin C.  Whats your thoughts on this? 
This looks as simple as it gets to construct.

Maybe I can use it on myself if it does not work with the degaussing loop. Ha

I just found out the new 12 inch degaussing loop I bought has a 79 ohm resistance.

http://www.hackcanada.com/homegrown/wetware/ces/ebs_4069_corrected.gif


http://www.hackcanada.com/homegrown/wetware/ces/ebs_4069_corrected.gif

Offline the_big_m_in_ok

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Re: Need Help LOW frequency square wave oscillator circuit needed
« Reply #4 on: July 21, 2009, 04:28:26 AM »
@all,
Have a look at :

http://www.electronic-circuits-diagrams.com/oscillatorsimages/oscillatorckt1.shtml

The circuit can be set up to output a square wave of only a few Hz.

There should be a whole lot more on the 'Web to look at, just by GOOGLing it.

--Lee

Offline supermuble

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Re: Need Help LOW frequency square wave oscillator circuit needed
« Reply #5 on: August 24, 2009, 03:08:08 AM »
555 timer is the easiest, with two transistors. Very very easy.

You can produce a square wave positive going pulse waveform by removing the PNP transistor. Put the load between the collector on the NPN transistor (top side of it) and the positive lead. You can produce a square AC pulse by removing the transformer.



Offline dankie

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Re: Need Help LOW frequency square wave oscillator circuit needed
« Reply #6 on: August 24, 2009, 03:27:41 AM »
Hi

Use the cd4047 in free running mode , a guaranteed 50/50

Hookup the resistor and capacitor as shown in the datasheet .

Everything is self explanatory .

here is a nice circuit if you need this to work as an inverter .

http://www.circuitstoday.com/wp-content/uploads/2008/02/simple-12-to-220-v-inverter.JPG

Offline MileHigh

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Re: Need Help LOW frequency square wave oscillator circuit needed
« Reply #7 on: August 24, 2009, 05:32:09 AM »
Just use a standard 555 timer circuit with a larger capacitor and appropriate resistor.

MileHigh

Offline supermuble

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Re: Need Help LOW frequency square wave oscillator circuit needed
« Reply #8 on: August 24, 2009, 05:44:54 AM »
Here are the basic square wave DC pulse 555 timer circuits. For driving a load, just place a transistor on the output and feed it to the base of a transistor.