[MAMS] DC-DC boost converter

[Zack Widup]

I would be interested in using this power supply portable to step up 12
volts to 28 volts for my little 50 watt 1296 amp. I am guessing the amp
will draw about 3A of current. If it can do this without generating noise,
I'd be very happy.
:-)

73, Zack W9SZ


On Wed, Oct 3, 2012 at 10:23 AM, Danny Pease <dpease at adams.net> wrote:

> The only testing  I have done so far is without a load of any kind. For
> what
> it is worth, I did not notice any extra noise on HF, 6 meter, 2 meter or
> 432
> gear and I tuned around a good bit listening for new noise. This was all
> done with the unit sitting on the bench, no shielding or bypassing at all.
> What it will do under load is yet to be determined. I have not tried
> listening at at various output levels either, all my noise testing so far
> has been at 24 VDC output. I did run the adjustment pot through the full
> range and with 13.4 VDC in I saw 13.1 to 35 VDC output.
>
> Most switching noise I have encountered has the largest effect at lower
> frequencies, although I hear many strong signals on 6 meters, but most are
> not switching power supply noise. Since this is a microwave group, it is
> possible any switching noise would not be an issue.
>
> Danny NG9R
>
>
> -----Original Message-----
> From: mams-bounces at mailman.qth.net [mailto:mams-bounces at mailman.qth.net]
> On
> Behalf Of Dr. Gerald N. Johnson
> Sent: Wednesday, October 03, 2012 9:53 AM
> To: mams at mailman.qth.net
> Subject: Re: [MAMS] DC-DC boost converter
>
> Two critical questions: What's its minimum load? What's its noise output?
>
> Switching supplies are based on some chip doing pulse width modulation.
> A boost converter often stores energy in an inductor with a pulse then lets
> the inductive kick supply the load through a rectifier, though it can be a
> step up transformer. In either case the control chip usually has a minimum
> pulse width of a couple % of the period, and smaller loads get higher
> voltage. Many a switching supply has a crowbar on the output and simply
> won't get past the first pulse if the load is too small.
>
> Many a switching supply is noisier than a transmitter on an antenna.
> Chinese engineering doesn't seem to care about stray noise either.
>
> 73, Jerry, K0CQ
>
> On 10/3/2012 9:37 AM, Zack Widup wrote:
> > That's a really good price. I'd consider building my own if they
> > weren't so cheap. I wonder about the quality. Maybe I'll order one, too.
> >
> > 73, Zack W9SZ
> >
> >
> > On Wed, Oct 3, 2012 at 9:02 AM, Danny Pease<dpease at adams.net>  wrote:
> >
> >> I picked up a DC-DC boost converter on EBay and it looks like it will
> >> fill the bill for those wanting to run devices that require voltage
> >> higher than
> >> 12 volts. The price was very reasonable, $7.39 shipped from China. It
> >> will accept a wide range of input voltage and has an adjustable
> >> output, will handle 150 watts at a max of 10 amps. I have not tried
> >> it out on the air yet so I cannot vouch for how clean it may be. If
> >> you are interested, look at item #280930034367 on EBay.
> >>
> >> Has anyone else had any experience using these devices?
> >>
> >> Danny NG9R
> >> dpease at adams.net
> >>
> >>
> ______________________________________________________________
> MAMS mailing list
> Home: http://mailman.qth.net/mailman/listinfo/mams
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:MAMS at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
> ______________________________________________________________
> MAMS mailing list
> Home: http://mailman.qth.net/mailman/listinfo/mams
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:MAMS at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>