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View Full Version : What Classes of PWMs Are There?



volomike
08-20-2008, 12:34 PM
I need to make a decision on getting a PWM. Can someone in the know reply here and let me know what classes of PWMs there are out there, and perhaps share some avoids, pros, cons, links, and costs?

GOplayer
08-25-2008, 11:54 AM
1: What is the voltage that we want to turn on and off, using PWM? Is it 12 DCV or 20,000 DCV or somewhere between? Perhaps we want to (have to) experiment ourselves since this data is being kept secret, hence we need a device that we can control it DC voltage throughput?
1/A: What frequency we need to turn the unit on/off? (pulsate) Same dilemma applies as above.
2: How to restrict Ampere flow? Is this function built into the PWM or a separate gadget does it before or after the PWM?
3: Can I create the same effect as a PWM by creating a micro switch that instead of turning on/off it sends the electricity to multiple HOD Generators but one at a time? Form the HOD Generator point of view the electricity is coming and not coming then coming again, hence it is pulsating, is it not?
3/A: If pointer #3 is a viable solution then what would this device called or best defined as…?

These are my questions that I am asking in search of the same thing as you are. Keep me posted of your findings and I do the same.
Z

ridelong
08-31-2008, 03:49 PM
volomike,

A pulse width modulator (PWM) is a device that turns a circuit full on or full off.

The amount of on time is called the duty cycle. if a pwm is at 50% duty cycle it is on 1/2 the time and off 1/2 the time. That is how they control average current. If a load draws 10 amps at 12 volts, installing a pwm running 50% duty cycle at 12 volts would reduce the average current to 5 amps.

Most pwm for sale have adjustable frequency and adjustable duty cycle. I think people get the impression that somehow they can "tune" the frequency of the pwm to match the generator and magically generate huge volumes of gas. I tried, it does not work.

The duty cycle is the important thing to adjust because it allows you to control current.

There are other types less known. I just posted a schematic on the "control current" thread on this site. It monitors current and changes the duty cycle to maintain the set current no matter how the load changes. Check it out.

So the answer is, most are about the same. Just make sure the pwm is current rated for what you want, too small and "POOF".

HHO King
09-26-2008, 06:44 PM
Extreme HHO has adjustable frequency pwm's completely assembled with the gauge and fan.

The link is http://www.extremehho.com

Boltazar
09-26-2008, 08:07 PM
The only one I see at this site is rated for 6.5 Amps Whats that going to produce?

H2OPWR
10-02-2008, 02:13 AM
Please be aware of profit takers on this site. I just checked out the extremehho site just posted. The PWM they sell for $50.00 is just a
MX066 DC motor control that is readily available for about $25.00. Just google MX066 and then stay away from screwers. We are here to help each other not screw each other in the a@#

mytoyotasucks
10-02-2008, 11:54 AM
The only one I see at this site is rated for 6.5 Amps Whats that going to produce?

if u buy a pwm make sure it is capable of running 20 amp continuously.
anything under that is a waste of money.

You should know the actual use of pwm's are to run dc motors so they dont over heat.

HHO King
10-04-2008, 07:56 PM
Please be aware of profit takers on this site. I just checked out the extremehho site just posted. The PWM they sell for $50.00 is just a
MX066 DC motor control that is readily available for about $25.00. Just google MX066 and then stay away from screwers. We are here to help each other not screw each other in the a@#

That's not an MX066 and they don't cost $25.00 either. It's an lx066 and it's not a piece of junk like the MX066.

Where can i find a 30 amp lx066 for $25.00?

DigitalMocking
10-04-2008, 08:29 PM
That's not an MX066 and they don't cost $25.00 either. It's an lx066 and it's not a piece of junk like the MX066.

Where can i find a 30 amp lx066 for $25.00?


http://www.amazon.com/Electronic-Controller-Device-Modulator-LX066/dp/B000WYAN92/ref=sr_1_6?ie=UTF8&s=miscellaneous&qid=1223166527&sr=8-6

amazon has them for 29.95.

There were a few other places just by googling that I found it cheaper, just look around. Go try to gouge other people you dirtbag.