[NLRS] Re: W4RRY battery booster

[John (JK) Kalenowsky, K9JK]

Not sure if this will got to the reflector due to some issues with this
ISP using a server that is on a "bad server" list (sorbs.net) from which
qth.net will not accept/forward submissions so doing a "Reply All".

I've looked "under the hood" of the one that I have (23 A rated version)
and the "switching controller" is actually an SG2524 (interesting that 
he used the "extended commercial temp range", -40 to +85 degrees C, 
version instead of the SG3524 which is only rated to cover 0 to +70 
degrees C). I do not recall the other pass/switch devices and am not at 
home to be able to peek at present. The inductors/transformers looked to 
be hand wound and were on toroidal cores.

I can do some more looking (maybe even take a picture), if anyone is 
interested in further detail.

73, JK
----- Original Message ----- 
From: "Chris Elmquist" <chrise at pobox.com>
To: "tosca005" <tosca005 at umn.edu>
Cc: <nlrs at mailman.qth.net>; <jcplatt1 at mmm.com>
Sent: 2006, January 30, Monday 14:31
Subject: Re: [NLRS] Re: battery booster


>
>
> On Monday (01/30/2006 at 01:16PM -0600), tosca005 wrote:
>>
>> It is a switching regulator, working in a buck/boost mode.  If
>> the voltage is higher than target, it "bucks" it down.  If the
>> voltage is lower than target, it "boosts" it up.  (A Google
>> search for "buck boost switching regulator" would probably be
>> productive.)
>
> yes... I suspected it was a switching converter running in buck/boost
> mode.  Otherwise, you would not get any regulation at the output.
> If you just added some volts-- like putting another battery in series,
> then your output would be unregulated.  Add 3.8v to 10 and you get
> 13.8
> but add 3.8 to 12 and you have 15.8.  Not cool.
>
> So, it is just a switching converter with sufficiently sized FETs and
> inductors to carry your 20 or 23A load.
>
> I suspect if you take the lid off, you will find a National or Linear
> Tech PWM controller in there.
>
> Thanks.
>
> Chris
> -- 
> Chris Elmquist
> mailto:chrise at pobox.com
> http://www.pobox.com/~chrise
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