Air compressors have losses . V belts are a waste , not necessary .
I just bought 6 HarborFright 40400 DIRECT drive ( 8 gallon tank) for
$100 each .
I can series them , output of one could enter the crankcase of the next
stage then directed to the head intake valves .....IF the seals would hold ..
But 1 stage is efficient if PSI is below about 60 ( 4:1 ratio ) ...
At 110 PSI , its a big loss to have only one stage .
Auto a/c is over 10:1 on a hot day and condenser is not gulping 50 MPH
air .
Or i could parallel 4 , staggering the start up by 5 seconds .
This is more efficient than a $600 , 5 H.P. , 12 CFM belt drive ,
I could also put a 6004 2-RS ball bearing on crankshaft ..
I needed these for the H.F. 4 amp PLASMA cutter .
at half the price ( $700 ) of competition , i bought 2 . I also
bought 50 Zirconium/halfnium electrodes ( abt $250 ).
I can reshape the copper cups , easily .
This 40 amp Plasma uses a 4 transistor "H" bridge ... BAD idea ,
but as i said , i got a low price on the cutter ..
Modern circuitry uses only 1 or 2 transistors a single primary winding ,
driving it in one direction , NOT a half bridge , just a simple one sided
forward converter . This way transistors saturate the core , then hit it again
saturate the core etc etc . This is enhernetly safer than the complicated
current mode chips driving alternate NPN's . But i could always take out
the extra transistors , save them for a rainy day , use only 2 for even higher
output . 2 NPN IGBT's inparallel will drive MORE , than the lossy H bridge .
Plasma uses a mcu AT91xxxx . waste of mcu ....
Torch electrode is negative . copper cup with .8 mm hole is POSITVE , but
has a huge choke of 2.2 mil henries . Theres no capacitors
in the circuit , so the pulsating D.C. is limted by the choke and is called
Pilot arc ( aka starting arc ).
The zirconium electrode is pulled away from copper cup as soon
as circuit measures current in the ground cable .
Small cables used here cause plasma uses 90 vdc at
low amps ( 10 amps can cut 1/8" steel )
pull torch away from work , and pilot arc starts again .
NO MOVING PARTs , nothing to wear out ,
except chrome plated tiny electrodes at $6 each .
Lincoln electric inc' said they cut 1/2" plate
and got 450 feet of cut with each electrode .
Plasma cuts fast narrow and encredibly clean.
I bought 3 H.F. Stick/T.I.G. inverter welders ( red box ),
i call it "e-welder" . Buzz boxes can't limit the current , set at
100 amps
they go to 200 amps til you can pull it free !
But e-welder can "fold back current " instantly . And it will go out , if
you pull the electrode away , even to an 1/4" !
Buzz box just increases the voltage !
All my friends are raving about it . im doin diagrams on it .
It will power a Wire Feed . It needs circuit mods to hold D.C Voltage constant .
It does not use mcu's , only a current mode controller and an
IGBT half bridge , . dumb ! MJE13007's cost $0.12 each and are lower
loss when enough are paralled to the same amps as the IGBT's ...
Insulated Gate Bipolar Transistor is much higher loss , much higher cost ,
passing 20 amps , IGBT have about 2.5 to 3.5 volts of LOSS , MJE13007's in parallel can do 0.5 vdc !
paralleld Schottkies can use current sensing to shut them down on
over heat . It has a tiny 60hz transformer to power CONTROL ckt .
Ill replace it w/ 80 to 260 VAC switcher , then add big
Caps and Diodes to MOD it to run on 110vac . Now its 220vac ONLY .
They use a current mode controller chip and 4 surface mnt NPN's to drive
yet another transformer to drive the IGBT gates ! waste of circuitry !
Even if transformer doesnt have a winding to drive the bases , you can add
a tiny toroid in output , as all C.F. flourescents have ,..
ALL cost effective IBMPC power supplies saturate the transformer , to
save a chip . But output has a chip that sends back a signal to control the
MJE13007 , ussualy just to shut it dn prematurely , then allow it to self start
into the next cycle ...
One MJE13007 and a tiny transformer makes 450 watts ! That was my plan til HF
inverter showed up . I bought 20 PC power supplies from MCM and started
figuring how to parallel them to weld with .
Inverters can run 100% duty cycle with low cost MODs .
Plasma cut be MODed to do 40 amps at 100% duty cycle .
e-welder can do 130 amps at 100% .
The Ferrite transformer is the limit .
It stops working at a very low "Curie" temperature .
simply force a little air over it ! e-welder has fan far away ..
I also got 6 HF 13HP gas engines , i will MOD to Atkison cycle ,
since the CAM allready has centrifugal advance ...
I got 2 , 13hp , 5500 WATT gas GenSets .. they use brushes in alternator .
Ill be busy for months modifying this stuff !
BTW WiFi will be your new cell phone . The world will link up WiFi
and a new GUI method of communication . No voice , nor text , you will
have 8 buttons that send ICONs and Thumbnails and European traffic warnings
that will be understood by all humans , no need to translate ...
The B.W. is very wide . You can vu a Hollywood movie on WiFi , and with a dish
you can link at over 80 miles . The world will simply store and forward in
a cooperative way .. Also the new pocket PC is a GP2X game box , w/
80 GB HDD .. some one hooked a WiFi to GP2X .
Much easier to do in Linux ,, than in WXP op systems
snipped-for-privacy@yahoo.com from Guadalajara MX ..