[HomeBrew] Transformers as Inductors

[wabate]

Jim,

Sorry, but I vote for #1, Stupid idea....  Of course, I have had worse 
ideas.  I don't believe there will be any current spikes.  I'm also not 
sure what a current spike is, technically, and why it would be 
necessarily detrimental.  I've heard of voltage spikes (transients) 
though.  They can cause damage.  Your ASL500 is not a hard load as in an 
on/off toggle switch.  It ramps up in current with time, especially 
under SSB conditions.  So I would not worry about spikes.

If you want to smooth out spikes, a capacitor would be the better choice 
than an inductor.  You already have one in the two car batteries.  You 
can think of a battery as an extremely high value capacitor!  I would 
also ditch the #16 wire.  That is a meltdown waiting to happen.  Size 
wire according to ampacity.  Measure the voltage drop at each portion of 
your system.  I would not tolerate more than a 5% to 10% drop, total.  A 
10% voltage drop typically causes a 19% drop in power!

Jim, I think you are making a mountain out of a mole hill.  But keep 
thinking and asking questions.

73,

Bill, K3PGB

Jim Miller wrote:
> ** Please do NOT cross-post messages when posting to HOMEBREW **
> 
> I would like to "buffer" the current spikes drawn by the ALS500 solid
> state amplifier (85 amp peaks) from my 70 amp Astron RS70M supply.
> Seems like an inductor in the power line would do just the trick.
> Not having a bunch of inductors under the bench, I thought maybe I
> could use a big transformer as an inductor by using either the
> primary or secondary winding in series as the inductor.  I have some
> HEAVY ones available (not even considering the old pole pig).
> 
> Just so you have the complete story - I have two 12 volt car
> batteries in parallel and on a maintenance charger under the bench
> now that are connected directly to the "battery buss bars" and then
> on to the amplifier.  The power supply is connected to "power supply
> buss bars" (fed by the RS70M) as is the remainder of the equipment.
> I then have (currently) 25 feet (only 4 foot needed, excess wound in
> a coil) of 16 gauge wire running between the two sets of buss bars (I
> know, it is too small BUT it is used to CREATE resistance to help
> buffer the shock of the current spikes from the power supply and the
> remainder of the equipment) through a manual air conditioner
> disconnect contactor like on the outside of your house by the A/C
> unit (removed from the box and mounted on the leg of my bench).  This
> also provides power failure backup for my entire station.  Intentions
> are to also connect the computer UPS battery bank through external
> wiring to the power buss for extended PC operation as well.  A
> generator provides extended period outage backup and backup station
> lighting will be off of the UPS.
> 
> On the inductor:
> 
> 1. Stupid idea - won't work?
> 
> 2. Which winding - primary or secondary winding would be best? -
> primary best but have to use the secondary because of the current
> required?
> 
> 3. Should I try to find a 120 to 24 volt or a 120 to 6 volt?  Which
> would be best?
> 
> 4. What to do with the other winding?  Nothing?  Resistor?  Big or
> small?  a big electrolytic capacitor?  Short it out?
> 
> I actually don't see why it wouldn't work.  I just don't have the
> electrical expertise to know how to set it up.
> 
> Thanks es 73, de Jim KG0KP
> 
> 
> _______________________________________________ HomeBrew mailing list
>  HomeBrew at mailman.qth.net 
> http://mailman.qth.net/mailman/listinfo/homebrew
> 
>