Electronics Forums > pulsed DC and transformers

# pulsed DC and transformers

mrdarrett@gmail.com
Guest
Posts: n/a

 06-21-2008, 06:31 AM
I'm trying to figure out if I could drive a transformer with pulsed
DC, and have it work (not saturate, overheat, etc.)

Ideally I'd like to pulse a self-wound toroidal transformer with
12VDC, on the primary, and get 48VDC out of the secondary, center-
tapped to get +/-24V on each leg. I plan to use a 555 in astable
mode, 50% duty cycle, driving a mosfet to feed the transformer
primary, at frequencies I haven't determined yet - anywhere from 100
Hz to 100 kHz.

Wikipedia has this:

The time-derivative term in Faraday's Law shows that the flux in the
core is the integral of the applied voltage.[11] Hypothetically an
ideal transformer would work with direct-current excitation, with the
core flux increasing linearly with time.[12] In practice, the flux
would rise very rapidly to the point where magnetic saturation of the
core occurred, causing a huge increase in the magnetising current and
overheating the transformer. All practical transformers must therefore
operate under alternating (or pulsed) current conditions.

so it implies a transformer can be driven by pulses. In practice,
what happens when driving a transformer with pulsed DC? Should I
stick to low frequencies? Go for higher frequencies?

Thanks,

Michael

Bob Eld
Guest
Posts: n/a

 06-21-2008, 02:37 PM

<(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> I'm trying to figure out if I could drive a transformer with pulsed
> DC, and have it work (not saturate, overheat, etc.)
>
> Ideally I'd like to pulse a self-wound toroidal transformer with
> 12VDC, on the primary, and get 48VDC out of the secondary, center-
> tapped to get +/-24V on each leg. I plan to use a 555 in astable
> mode, 50% duty cycle, driving a mosfet to feed the transformer
> primary, at frequencies I haven't determined yet - anywhere from 100
> Hz to 100 kHz.
>
> Wikipedia has this:
>
> The time-derivative term in Faraday's Law shows that the flux in the
> core is the integral of the applied voltage.[11] Hypothetically an
> ideal transformer would work with direct-current excitation, with the
> core flux increasing linearly with time.[12] In practice, the flux
> would rise very rapidly to the point where magnetic saturation of the
> core occurred, causing a huge increase in the magnetising current and
> overheating the transformer. All practical transformers must therefore
> operate under alternating (or pulsed) current conditions.
>
> so it implies a transformer can be driven by pulses. In practice,
> what happens when driving a transformer with pulsed DC? Should I
> stick to low frequencies? Go for higher frequencies?
>
>
> Thanks,
>
> Michael

Keep the DC out of the transformer, especially a torroid as they have little
tolerance for DC offset. Transformers or inductors that tolerate DC offsets
have air gaps or the equivalent to limit saturation.

The simple way is to drive the transformer through a capacitor, thus
blocking all DC into it's primary. The secondary will convey the pulse, but
the zero volt position will be somewhere in the middle of the pulse so that
the area above zero equals the area below zero. DC can be restored with
appropriate diodes.

For example say the original pulse train was positive going 4 Volts for 1
msec. then zero volts for 3 msec.

If the transformer ratio is 1 : 1, then the secondary would show 3 Volts
positive for 1 msec and 1 Volt negative for 3 msec. The positive area equals
the negative area. Of course, if the pulse width changes, the zero line
would shift to equalize areas. Faraday's law.

Joerg
Guest
Posts: n/a

 06-21-2008, 08:43 PM
Bob Eld wrote:
> <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
>> I'm trying to figure out if I could drive a transformer with pulsed
>> DC, and have it work (not saturate, overheat, etc.)
>>
>> Ideally I'd like to pulse a self-wound toroidal transformer with
>> 12VDC, on the primary, and get 48VDC out of the secondary, center-
>> tapped to get +/-24V on each leg. I plan to use a 555 in astable
>> mode, 50% duty cycle, driving a mosfet to feed the transformer
>> primary, at frequencies I haven't determined yet - anywhere from 100
>> Hz to 100 kHz.
>>
>> Wikipedia has this:
>>
>> The time-derivative term in Faraday's Law shows that the flux in the
>> core is the integral of the applied voltage.[11] Hypothetically an
>> ideal transformer would work with direct-current excitation, with the
>> core flux increasing linearly with time.[12] In practice, the flux
>> would rise very rapidly to the point where magnetic saturation of the
>> core occurred, causing a huge increase in the magnetising current and
>> overheating the transformer. All practical transformers must therefore
>> operate under alternating (or pulsed) current conditions.
>>
>> so it implies a transformer can be driven by pulses. In practice,
>> what happens when driving a transformer with pulsed DC? Should I
>> stick to low frequencies? Go for higher frequencies?
>>
>>
>> Thanks,
>>
>> Michael

>
> Keep the DC out of the transformer, especially a torroid as they have little
> tolerance for DC offset. Transformers or inductors that tolerate DC offsets
> have air gaps or the equivalent to limit saturation.
>
> The simple way is to drive the transformer through a capacitor, thus
> blocking all DC into it's primary. ...

Yes, I'll second that. Else the time from core saturation to plume of
smoke can be just microseconds. Last time I did that (experimental PWM
stalled while I was doing other work in the office) it took two days to
get the stench out of the area.

[...]

--
Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
Use another domain or send PM.

mrdarrett@gmail.com
Guest
Posts: n/a

 06-21-2008, 09:26 PM
On Jun 21, 1:43 pm, Joerg <(E-Mail Removed)>
wrote:
> Bob Eld wrote:
> > <(E-Mail Removed)> wrote in message
> >news:(E-Mail Removed)...
> >> I'm trying to figure out if I could drive a transformer with pulsed
> >> DC, and have it work (not saturate, overheat, etc.)

>
> >> Ideally I'd like to pulse a self-wound toroidal transformer with
> >> 12VDC, on the primary, and get 48VDC out of the secondary, center-
> >> tapped to get +/-24V on each leg. I plan to use a 555 in astable
> >> mode, 50% duty cycle, driving a mosfet to feed the transformer
> >> primary, at frequencies I haven't determined yet - anywhere from 100
> >> Hz to 100 kHz.

>
> >> Wikipedia has this:

>
> >> The time-derivative term in Faraday's Law shows that the flux in the
> >> core is the integral of the applied voltage.[11] Hypothetically an
> >> ideal transformer would work with direct-current excitation, with the
> >> core flux increasing linearly with time.[12] In practice, the flux
> >> would rise very rapidly to the point where magnetic saturation of the
> >> core occurred, causing a huge increase in the magnetising current and
> >> overheating the transformer. All practical transformers must therefore
> >> operate under alternating (or pulsed) current conditions.

>
> >> so it implies a transformer can be driven by pulses. In practice,
> >> what happens when driving a transformer with pulsed DC? Should I
> >> stick to low frequencies? Go for higher frequencies?

>

>
> >> Thanks,

>
> >> Michael

>
> > Keep the DC out of the transformer, especially a torroid as they have little
> > tolerance for DC offset. Transformers or inductors that tolerate DC offsets
> > have air gaps or the equivalent to limit saturation.

>
> > The simple way is to drive the transformer through a capacitor, thus
> > blocking all DC into it's primary. ...

>
> Yes, I'll second that. Else the time from core saturation to plume of
> smoke can be just microseconds. Last time I did that (experimental PWM
> stalled while I was doing other work in the office) it took two days to
> get the stench out of the area.
>
> [...]
>
> --
> Regards, Joerg

Gee, power electronics seems like so much fun. Maybe I chose the
wrong major at the university... ;-)

Thanks,

Michael

Joerg
Guest
Posts: n/a

 06-21-2008, 11:14 PM
(E-Mail Removed) wrote:
> On Jun 21, 1:43 pm, Joerg <(E-Mail Removed)>
> wrote:
>> Bob Eld wrote:
>>> <(E-Mail Removed)> wrote in message
>>> news:(E-Mail Removed)...
>>>> I'm trying to figure out if I could drive a transformer with pulsed
>>>> DC, and have it work (not saturate, overheat, etc.)
>>>> Ideally I'd like to pulse a self-wound toroidal transformer with
>>>> 12VDC, on the primary, and get 48VDC out of the secondary, center-
>>>> tapped to get +/-24V on each leg. I plan to use a 555 in astable
>>>> mode, 50% duty cycle, driving a mosfet to feed the transformer
>>>> primary, at frequencies I haven't determined yet - anywhere from 100
>>>> Hz to 100 kHz.
>>>> Wikipedia has this:
>>>> The time-derivative term in Faraday's Law shows that the flux in the
>>>> core is the integral of the applied voltage.[11] Hypothetically an
>>>> ideal transformer would work with direct-current excitation, with the
>>>> core flux increasing linearly with time.[12] In practice, the flux
>>>> would rise very rapidly to the point where magnetic saturation of the
>>>> core occurred, causing a huge increase in the magnetising current and
>>>> overheating the transformer. All practical transformers must therefore
>>>> operate under alternating (or pulsed) current conditions.
>>>> so it implies a transformer can be driven by pulses. In practice,
>>>> what happens when driving a transformer with pulsed DC? Should I
>>>> stick to low frequencies? Go for higher frequencies?
>>>> Thanks,
>>>> Michael
>>> Keep the DC out of the transformer, especially a torroid as they have little
>>> tolerance for DC offset. Transformers or inductors that tolerate DC offsets
>>> have air gaps or the equivalent to limit saturation.
>>> The simple way is to drive the transformer through a capacitor, thus
>>> blocking all DC into it's primary. ...

>> Yes, I'll second that. Else the time from core saturation to plume of
>> smoke can be just microseconds. Last time I did that (experimental PWM
>> stalled while I was doing other work in the office) it took two days to
>> get the stench out of the area.
>>
>> [...]
>>
>> --
>> Regards, Joerg

>
>
>
> Gee, power electronics seems like so much fun. Maybe I chose the
> wrong major at the university... ;-)
>

Chemistry can be fun, too. One of my friends ended in the hospital. "My
lab is now one hellacious black hole and the door is gone as well."

--
Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
Use another domain or send PM.

mrdarrett@gmail.com
Guest
Posts: n/a

 06-22-2008, 10:54 PM
On Jun 21, 4:14 pm, Joerg <(E-Mail Removed)>
wrote:
> (E-Mail Removed) wrote:
> > On Jun 21, 1:43 pm, Joerg <(E-Mail Removed)>
> > wrote:
> >> Bob Eld wrote:
> >>> <(E-Mail Removed)> wrote in message
> >>>news:(E-Mail Removed)...
> >>>> I'm trying to figure out if I could drive a transformer with pulsed
> >>>> DC, and have it work (not saturate, overheat, etc.)
> >>>> Ideally I'd like to pulse a self-wound toroidal transformer with
> >>>> 12VDC, on the primary, and get 48VDC out of the secondary, center-
> >>>> tapped to get +/-24V on each leg. I plan to use a 555 in astable
> >>>> mode, 50% duty cycle, driving a mosfet to feed the transformer
> >>>> primary, at frequencies I haven't determined yet - anywhere from 100
> >>>> Hz to 100 kHz.
> >>>> Wikipedia has this:
> >>>> The time-derivative term in Faraday's Law shows that the flux in the
> >>>> core is the integral of the applied voltage.[11] Hypothetically an
> >>>> ideal transformer would work with direct-current excitation, with the
> >>>> core flux increasing linearly with time.[12] In practice, the flux
> >>>> would rise very rapidly to the point where magnetic saturation of the
> >>>> core occurred, causing a huge increase in the magnetising current and
> >>>> overheating the transformer. All practical transformers must therefore
> >>>> operate under alternating (or pulsed) current conditions.
> >>>> so it implies a transformer can be driven by pulses. In practice,
> >>>> what happens when driving a transformer with pulsed DC? Should I
> >>>> stick to low frequencies? Go for higher frequencies?
> >>>> Thanks,
> >>>> Michael
> >>> Keep the DC out of the transformer, especially a torroid as they have little
> >>> tolerance for DC offset. Transformers or inductors that tolerate DC offsets
> >>> have air gaps or the equivalent to limit saturation.
> >>> The simple way is to drive the transformer through a capacitor, thus
> >>> blocking all DC into it's primary. ...
> >> Yes, I'll second that. Else the time from core saturation to plume of
> >> smoke can be just microseconds. Last time I did that (experimental PWM
> >> stalled while I was doing other work in the office) it took two days to
> >> get the stench out of the area.

>
> >> [...]

>
> >> --
> >> Regards, Joerg

>
> > Gee, power electronics seems like so much fun. Maybe I chose the
> > wrong major at the university... ;-)

>
> Chemistry can be fun, too. One of my friends ended in the hospital. "My
> lab is now one hellacious black hole and the door is gone as well."
>
> --
> Regards, Joerg
>
> http://www.analogconsultants.com/
>
> "gmail" domain blocked because of excessive spam.
> Use another domain or send PM.

What did he try to do... make nitrogen tri-iodide or something silly
like that?

Yep, chemistry can be fun. So far I made 40 cc's of ethanol from the
kids' leftover food scraps. Just have to scale it up by a factor of
10^9 or so...

Michael

Joerg
Guest
Posts: n/a

 06-22-2008, 11:33 PM
(E-Mail Removed) wrote:
> On Jun 21, 4:14 pm, Joerg <(E-Mail Removed)>
> wrote:
>> (E-Mail Removed) wrote:
>>> On Jun 21, 1:43 pm, Joerg <(E-Mail Removed)>
>>> wrote:
>>>> Bob Eld wrote:
>>>>> <(E-Mail Removed)> wrote in message
>>>>> news:(E-Mail Removed)...
>>>>>> I'm trying to figure out if I could drive a transformer with pulsed
>>>>>> DC, and have it work (not saturate, overheat, etc.)
>>>>>> Ideally I'd like to pulse a self-wound toroidal transformer with
>>>>>> 12VDC, on the primary, and get 48VDC out of the secondary, center-
>>>>>> tapped to get +/-24V on each leg. I plan to use a 555 in astable
>>>>>> mode, 50% duty cycle, driving a mosfet to feed the transformer
>>>>>> primary, at frequencies I haven't determined yet - anywhere from 100
>>>>>> Hz to 100 kHz.
>>>>>> Wikipedia has this:
>>>>>> The time-derivative term in Faraday's Law shows that the flux in the
>>>>>> core is the integral of the applied voltage.[11] Hypothetically an
>>>>>> ideal transformer would work with direct-current excitation, with the
>>>>>> core flux increasing linearly with time.[12] In practice, the flux
>>>>>> would rise very rapidly to the point where magnetic saturation of the
>>>>>> core occurred, causing a huge increase in the magnetising current and
>>>>>> overheating the transformer. All practical transformers must therefore
>>>>>> operate under alternating (or pulsed) current conditions.
>>>>>> so it implies a transformer can be driven by pulses. In practice,
>>>>>> what happens when driving a transformer with pulsed DC? Should I
>>>>>> stick to low frequencies? Go for higher frequencies?
>>>>>> Thanks,
>>>>>> Michael
>>>>> Keep the DC out of the transformer, especially a torroid as they have little
>>>>> tolerance for DC offset. Transformers or inductors that tolerate DC offsets
>>>>> have air gaps or the equivalent to limit saturation.
>>>>> The simple way is to drive the transformer through a capacitor, thus
>>>>> blocking all DC into it's primary. ...
>>>> Yes, I'll second that. Else the time from core saturation to plume of
>>>> smoke can be just microseconds. Last time I did that (experimental PWM
>>>> stalled while I was doing other work in the office) it took two days to
>>>> get the stench out of the area.
>>>> [...]
>>>> --
>>>> Regards, Joerg
>>> Gee, power electronics seems like so much fun. Maybe I chose the
>>> wrong major at the university... ;-)

>> Chemistry can be fun, too. One of my friends ended in the hospital. "My
>> lab is now one hellacious black hole and the door is gone as well."
>>
>> --
>> Regards, Joerg
>>
>> http://www.analogconsultants.com/
>>
>> "gmail" domain blocked because of excessive spam.
>> Use another domain or send PM.

>
>
> What did he try to do... make nitrogen tri-iodide or something silly
> like that?
>

I don't remember. But it made the news.

> Yep, chemistry can be fun. So far I made 40 cc's of ethanol from the
> kids' leftover food scraps. Just have to scale it up by a factor of
> 10^9 or so...
>

There was an ad for an ethanol machine that can make 30gal/week or so at
home. In the fine print: You had to pour in lots of leftover booze.
Yeah, right. Who'd have gallons of "leftover" Whiskey for that?

--
Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
Use another domain or send PM.

mrdarrett@gmail.com
Guest
Posts: n/a

 06-23-2008, 01:24 AM
On Jun 22, 4:33 pm, Joerg <(E-Mail Removed)>
wrote:
> (E-Mail Removed) wrote:
> > On Jun 21, 4:14 pm, Joerg <(E-Mail Removed)>
> > wrote:
> >> (E-Mail Removed) wrote:
> >>> On Jun 21, 1:43 pm, Joerg <(E-Mail Removed)>
> >>> wrote:
> >>>> Bob Eld wrote:
> >>>>> <(E-Mail Removed)> wrote in message
> >>>>>news:(E-Mail Removed)...
> >>>>>> I'm trying to figure out if I could drive a transformer with pulsed
> >>>>>> DC, and have it work (not saturate, overheat, etc.)
> >>>>>> Ideally I'd like to pulse a self-wound toroidal transformer with
> >>>>>> 12VDC, on the primary, and get 48VDC out of the secondary, center-
> >>>>>> tapped to get +/-24V on each leg. I plan to use a 555 in astable
> >>>>>> mode, 50% duty cycle, driving a mosfet to feed the transformer
> >>>>>> primary, at frequencies I haven't determined yet - anywhere from 100
> >>>>>> Hz to 100 kHz.
> >>>>>> Wikipedia has this:
> >>>>>> The time-derivative term in Faraday's Law shows that the flux in the
> >>>>>> core is the integral of the applied voltage.[11] Hypothetically an
> >>>>>> ideal transformer would work with direct-current excitation, with the
> >>>>>> core flux increasing linearly with time.[12] In practice, the flux
> >>>>>> would rise very rapidly to the point where magnetic saturation of the
> >>>>>> core occurred, causing a huge increase in the magnetising current and
> >>>>>> overheating the transformer. All practical transformers must therefore
> >>>>>> operate under alternating (or pulsed) current conditions.
> >>>>>> so it implies a transformer can be driven by pulses. In practice,
> >>>>>> what happens when driving a transformer with pulsed DC? Should I
> >>>>>> stick to low frequencies? Go for higher frequencies?
> >>>>>> Thanks,
> >>>>>> Michael
> >>>>> Keep the DC out of the transformer, especially a torroid as they have little
> >>>>> tolerance for DC offset. Transformers or inductors that tolerate DC offsets
> >>>>> have air gaps or the equivalent to limit saturation.
> >>>>> The simple way is to drive the transformer through a capacitor, thus
> >>>>> blocking all DC into it's primary. ...
> >>>> Yes, I'll second that. Else the time from core saturation to plume of
> >>>> smoke can be just microseconds. Last time I did that (experimental PWM
> >>>> stalled while I was doing other work in the office) it took two days to
> >>>> get the stench out of the area.
> >>>> [...]
> >>>> --
> >>>> Regards, Joerg
> >>> Gee, power electronics seems like so much fun. Maybe I chose the
> >>> wrong major at the university... ;-)
> >> Chemistry can be fun, too. One of my friends ended in the hospital. "My
> >> lab is now one hellacious black hole and the door is gone as well."

>
> >> --
> >> Regards, Joerg

>
> >>http://www.analogconsultants.com/

>
> >> "gmail" domain blocked because of excessive spam.
> >> Use another domain or send PM.

>
> > What did he try to do... make nitrogen tri-iodide or something silly
> > like that?

>
> I don't remember. But it made the news.
>
> > Yep, chemistry can be fun. So far I made 40 cc's of ethanol from the
> > kids' leftover food scraps. Just have to scale it up by a factor of
> > 10^9 or so...

>
> There was an ad for an ethanol machine that can make 30gal/week or so at
> home. In the fine print: You had to pour in lots of leftover booze.
> Yeah, right. Who'd have gallons of "leftover" Whiskey for that?
>
> --
> Regards, Joerg
>
> http://www.analogconsultants.com/
>
> "gmail" domain blocked because of excessive spam.
> Use another domain or send PM.

Haha.

A co-worker told me he was going to buy this:

http://www.efuel100.com/t-product.aspx

Only \$6,988 after tax credits.

"To operate simply load EFuel100 feedstock (table sugar with ethanol
yeast mix) into the fermentation tank and select the fermentation
option on the control panel to begin the process. It will take between
10lbs to 14lbs of sugar to produce 1 gallon of ethanol. The
MicroFueler is capable of producing 5 gallons of ethanol per day once
fermentation is complete."

He asked me for my comments on the process flow diagram. I gave him
about 5 areas where I would do it differently... plus I told him, with
sugar about \$2.50 for 5 lbs at Wal-Mart, it didn't seem economical.
But he's already sent in the down payment... we'll see how it goes...

Michael

Joerg
Guest
Posts: n/a

 06-23-2008, 06:51 PM
(E-Mail Removed) wrote:
> On Jun 22, 4:33 pm, Joerg <(E-Mail Removed)>
> wrote:
>> (E-Mail Removed) wrote:
>>> On Jun 21, 4:14 pm, Joerg <(E-Mail Removed)>
>>> wrote:
>>>> (E-Mail Removed) wrote:
>>>>> On Jun 21, 1:43 pm, Joerg <(E-Mail Removed)>
>>>>> wrote:
>>>>>> Bob Eld wrote:
>>>>>>> <(E-Mail Removed)> wrote in message
>>>>>>> news:(E-Mail Removed)...
>>>>>>>> I'm trying to figure out if I could drive a transformer with pulsed
>>>>>>>> DC, and have it work (not saturate, overheat, etc.)
>>>>>>>> Ideally I'd like to pulse a self-wound toroidal transformer with
>>>>>>>> 12VDC, on the primary, and get 48VDC out of the secondary, center-
>>>>>>>> tapped to get +/-24V on each leg. I plan to use a 555 in astable
>>>>>>>> mode, 50% duty cycle, driving a mosfet to feed the transformer
>>>>>>>> primary, at frequencies I haven't determined yet - anywhere from 100
>>>>>>>> Hz to 100 kHz.
>>>>>>>> Wikipedia has this:
>>>>>>>> The time-derivative term in Faraday's Law shows that the flux in the
>>>>>>>> core is the integral of the applied voltage.[11] Hypothetically an
>>>>>>>> ideal transformer would work with direct-current excitation, with the
>>>>>>>> core flux increasing linearly with time.[12] In practice, the flux
>>>>>>>> would rise very rapidly to the point where magnetic saturation of the
>>>>>>>> core occurred, causing a huge increase in the magnetising current and
>>>>>>>> overheating the transformer. All practical transformers must therefore
>>>>>>>> operate under alternating (or pulsed) current conditions.
>>>>>>>> so it implies a transformer can be driven by pulses. In practice,
>>>>>>>> what happens when driving a transformer with pulsed DC? Should I
>>>>>>>> stick to low frequencies? Go for higher frequencies?
>>>>>>>> Thanks,
>>>>>>>> Michael
>>>>>>> Keep the DC out of the transformer, especially a torroid as they have little
>>>>>>> tolerance for DC offset. Transformers or inductors that tolerate DC offsets
>>>>>>> have air gaps or the equivalent to limit saturation.
>>>>>>> The simple way is to drive the transformer through a capacitor, thus
>>>>>>> blocking all DC into it's primary. ...
>>>>>> Yes, I'll second that. Else the time from core saturation to plume of
>>>>>> smoke can be just microseconds. Last time I did that (experimental PWM
>>>>>> stalled while I was doing other work in the office) it took two days to
>>>>>> get the stench out of the area.
>>>>>> [...]
>>>>>> --
>>>>>> Regards, Joerg
>>>>> Gee, power electronics seems like so much fun. Maybe I chose the
>>>>> wrong major at the university... ;-)
>>>> Chemistry can be fun, too. One of my friends ended in the hospital. "My
>>>> lab is now one hellacious black hole and the door is gone as well."
>>>> --
>>>> Regards, Joerg
>>>> http://www.analogconsultants.com/
>>>> "gmail" domain blocked because of excessive spam.
>>>> Use another domain or send PM.
>>> What did he try to do... make nitrogen tri-iodide or something silly
>>> like that?

>> I don't remember. But it made the news.
>>
>>> Yep, chemistry can be fun. So far I made 40 cc's of ethanol from the
>>> kids' leftover food scraps. Just have to scale it up by a factor of
>>> 10^9 or so...

>> There was an ad for an ethanol machine that can make 30gal/week or so at
>> home. In the fine print: You had to pour in lots of leftover booze.
>> Yeah, right. Who'd have gallons of "leftover" Whiskey for that?
>>
>> --
>> Regards, Joerg
>>
>> http://www.analogconsultants.com/
>>
>> "gmail" domain blocked because of excessive spam.
>> Use another domain or send PM.

>
>
> Haha.
>
> A co-worker told me he was going to buy this:
>
> http://www.efuel100.com/t-product.aspx
>
> Only \$6,988 after tax credits.
>
> "To operate simply load EFuel100 feedstock (table sugar with ethanol
> yeast mix) into the fermentation tank and select the fermentation
> option on the control panel to begin the process. It will take between
> 10lbs to 14lbs of sugar to produce 1 gallon of ethanol. The
> MicroFueler is capable of producing 5 gallons of ethanol per day once
> fermentation is complete."
>
> He asked me for my comments on the process flow diagram. I gave him
> about 5 areas where I would do it differently... plus I told him, with
> sugar about \$2.50 for 5 lbs at Wal-Mart, it didn't seem economical.
> But he's already sent in the down payment... we'll see how it goes...
>

It's disturbing. I see many well-educated people fall prey to hype
technologies. Predominantly the overly eco- bio- whatever leaning folks.
The millisecond they get criticized they often react with "Ah,
baloney" but without being able to furnish any data to support their own
theory. Kind of like warmingists ...

--
Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
Use another domain or send PM.

mrdarrett@gmail.com
Guest
Posts: n/a

 06-23-2008, 08:10 PM
On Jun 23, 11:51 am, Joerg <(E-Mail Removed)>
wrote:

~snip~

> It's disturbing. I see many well-educated people fall prey to hype
> technologies. Predominantly the overly eco- bio- whatever leaning folks.
> The millisecond they get criticized they often react with "Ah,
> baloney" but without being able to furnish any data to support their own
> theory. Kind of like warmingists ...
>
> --
> Regards, Joerg
>
> http://www.analogconsultants.com/
>
> "gmail" domain blocked because of excessive spam.
> Use another domain or send PM.

Yes, truly.

The site I posted above used to mention some sort of tax-free, cheap
inedible sugar from Mexico. I tried seeking more info via the web,
but no luck. (What kind of sucrose is inedible ??? And why?) The
website's FAQ has since removed the reference to the cheap Mexican
sugar.

One of the ways I would have done it differently, by the way, would
have involved just going to restaurants and collecting starchy food
scraps (rice, bread, potatoes)... toss in a little bit of alpha-
amylase enzyme (0.1% by mass) to convert starch to glucose, that the
yeast can eat.

Global warming... well, if it's true, I can start a coconut farm in