[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Full-Bridge -vs- Half-Bridge

Original poster: "Steven Ward" <srward16-at-hotmail-dot-com> 

Terry is completely correct, but generally our switching devices can only 
take so much current.  So say if you are running right at the SOA ratings 
of a device in a half-bridge, then moved up to a full bridge, you would 
have to adjust your "load" so that you do not exeed the current rating of 
the device.

What it boils down to, David, is that a full-bridge will switch about 2X 
the power (because its 2X the voltage swing and you want current to stay 
the same (usually)).

An example would be for Jimmy Hynes DRSSTC, he recently ran it half-bridge 
and got 60" sparks, full bridge got him 93" or so i think... this does not 
follow what i said above (since he didnt modify his load, though he DID run 
it with more cycles ;-) so its *like* a lower Z load sorta... it uses more 
current), but it should give you at least a rough idea of what it boils 
down to in real life.


>From: "Tesla list" <tesla-at-pupman-dot-com>
>To: tesla-at-pupman-dot-com
>Subject: Re: Full-Bridge -vs- Half-Bridge
>Date: Fri, 25 Jun 2004 08:00:20 -0600
>Original poster: Terry Fritz <teslalist-at-twfpowerelectronics-dot-com>
>In general, a full bridge will deliver twice the voltage swing.  This also 
>produces twice the current to the load.  Thus the power goes up four times.
>         Terry
>At 10:33 AM 6/24/2004, you wrote:
>>I posted this last week but didn't get any answers, so
>>I'll try one last time ;-)
>>On Fri, 18 Jun 2004 12:52:22 -0700 (PDT),
>>humanb-at-chaoticuniverse-dot-com wrote:
>> >
>> > Hi, can someone tell me just how much more power a
>> > H-bridge can process over a Half-Bridge? It's not just
>> > 2X as much is it? It isn't that simple, is it? Also,
>> > what would be the best way to calculate the optimum
>> > Capacitance in the voltage divider for a Half-Bridge?
>> > Currently I am using two 1uF caps, but when running a
>> > resonant tank one may want to adjust this, so I would
>> > like to find a way to calculate the optimum ballance.
>> >
>> > Thanks,
>> >
>> > David Trimmell