Post by lamazoid on Apr 6, 2014 9:59:57 GMT -8
Recently, i set myself a goal to build automotive arc welder, powered from ONE standard 12 volt car battery (typically 55 A/h).
I'm not sure if anyone interested in that here, but my search over 'net puts out almost nothing, so anyway it's a new and perspective
direction of development
Now i'll put on a small review of the project details, and what i found.
If we won't take into account direct welding, which is possible only with 2+ (preferably 3 or 4) series connected batteries,
there are only THREE working solutions, and all of them were developed in Russia (hah, at least in that we are ahead the world )
(in historical order):
1. "АСП-1" (A - S - P - 1) addon to russian cars, made by VAZ.
in fact, that was a current relay, which connecs the alternator and battery, making them work together, depending on weld current.
modifications of car circuitry were needed to make it work. and also, it was usable only for old non-electronic cars, as any modern ECU will just burn with transient surges.
here i put original factory description, its in Russian, but contains schematics and photos:
rghost.ru/53825614
and another simplified version of this, with just manual switch placed on electrode holder, instead of current relay.
rghost.ru/53825806
2. "САТ-1" (S - A - T - 1) another factory-made welder, capable to run from most 12 and 24v. Claimed 80A weld current from 12v. and up to 200A from 24v.
This was actually a soviet student degree work, which was later manufactured in small amounts by a factory, which was idle due to bad economic situation of 90x.
The welder consisted of 10 modules, connected in parallel.
The noticeable thing about the circuit is that current from the battery passes DIRECTLY to the welding path through one diode.
Other diode in conjunction with inductor forms additional boost converter, which "feeds" the arc with higher voltage.
The % relation of direct and "feed" current is unknown, but i suppose that from 12v this "feed" part plays main role,
because otherwise the arc will just not start.
As we see here, technology is very old, components are weak and unreliable. Today is just a museum item
3. modern and working prototype, made by crazy Ukrainian hobbyist. He says, it can weld with 3mm rod from just 12v battery, even without having it installed on car and running the engine.
the operation principle is almost the same as previous - simple boost converter topology.
description & photos here:
www.electrik.org/forum/index.php?s=f9b92e30446cd771f2e7983486cb6076&showtopic=94&st=80
as you see, it is made mostly from old crap, found on junkyard I respect this creativity, but definately that should be converted to modern element base and simplified.
and thats what i'm currently trying to do.
I'm not sure if anyone interested in that here, but my search over 'net puts out almost nothing, so anyway it's a new and perspective
direction of development
Now i'll put on a small review of the project details, and what i found.
If we won't take into account direct welding, which is possible only with 2+ (preferably 3 or 4) series connected batteries,
there are only THREE working solutions, and all of them were developed in Russia (hah, at least in that we are ahead the world )
(in historical order):
1. "АСП-1" (A - S - P - 1) addon to russian cars, made by VAZ.
in fact, that was a current relay, which connecs the alternator and battery, making them work together, depending on weld current.
modifications of car circuitry were needed to make it work. and also, it was usable only for old non-electronic cars, as any modern ECU will just burn with transient surges.
here i put original factory description, its in Russian, but contains schematics and photos:
rghost.ru/53825614
and another simplified version of this, with just manual switch placed on electrode holder, instead of current relay.
rghost.ru/53825806
2. "САТ-1" (S - A - T - 1) another factory-made welder, capable to run from most 12 and 24v. Claimed 80A weld current from 12v. and up to 200A from 24v.
This was actually a soviet student degree work, which was later manufactured in small amounts by a factory, which was idle due to bad economic situation of 90x.
The welder consisted of 10 modules, connected in parallel.
The noticeable thing about the circuit is that current from the battery passes DIRECTLY to the welding path through one diode.
Other diode in conjunction with inductor forms additional boost converter, which "feeds" the arc with higher voltage.
The % relation of direct and "feed" current is unknown, but i suppose that from 12v this "feed" part plays main role,
because otherwise the arc will just not start.
As we see here, technology is very old, components are weak and unreliable. Today is just a museum item
3. modern and working prototype, made by crazy Ukrainian hobbyist. He says, it can weld with 3mm rod from just 12v battery, even without having it installed on car and running the engine.
the operation principle is almost the same as previous - simple boost converter topology.
description & photos here:
www.electrik.org/forum/index.php?s=f9b92e30446cd771f2e7983486cb6076&showtopic=94&st=80
as you see, it is made mostly from old crap, found on junkyard I respect this creativity, but definately that should be converted to modern element base and simplified.
and thats what i'm currently trying to do.