[Milsurplus] LM-18 and AC PS Questions.. More

[J Forster]

I see no indication of that, like holes in the switch handles.

I suppose the switch use depends partly on the 800 CPS power supply. If the
supply is an engine driven generator or APU the setting could well depend on
throttle settings and other loading. I think the switches, although they
adjust capacitive reactance, are really to adjust line voltage.

If the supply is a screaming mimi dedicated to the ASB-5 alone, the switch
settings might not need  changing, assuming the 28 VDC bus is relatively
stable. Also some of the inverters I've seen do have carbon pile regulators.
As I remember, those regulators adjust the field of the generator side to
maintain roughly constant output voltage. Does anyone have a schematic of a
typical inverter to verify this?

Also, does anyone know if there was a shortage of meters, or at least the
permanent magnet material (AlNiCo) used in them, in WW II ? That could be
part of the explanation.

Thanks,
-John


jcoward5452 at aol.com wrote:

> Wouldn't the switches be safty wired in the correct settings?
> Jay
>
> -----Original Message-----
> From: WA5CAB at cs.com
> To: jfor at quik.com; milsurplus at mailman.qth.net
> Sent: Sun, 27 May 2007 10:29 am
> Subject: Re: [Milsurplus] LM-18 and AC PS Questions.. More
>
> More likely "Touch these switches and you'll lose your beer ration".Â
> :-)
>
> In a message dated 5/27/2007 1:22:49 PM Central Daylight Time,
> jfor at quik.com writes:
>
> They did the same thing with the Power Control Box on the ASB-5 Radar.
> The early ones had three switches for capacitors to adjust power factor
> and an AC meter. They later dropped the meter but kept the switches. It
> seems absolutely nuts to me as it's most likely the switches would get
> twiddled and there would be no way of knowing the set voltages were way
> off. Overvoltage would not lad to long life for the four 15E finals.
>
> I see no provisions for any pre-flight setup either.  Maybe they were
> ordered "Do NOT Touch These Switches" ??
>
> Robert Downs - Houston