Seeking info -- wiring a Buck Converter for an accessory

Mike,

I had a similar experience as I thought it was broken.  After playing around a while, I figured out that it took many turns of the adjusting screw before I had any change in output voltage.  Then it changed really easily without significant turns.  Also, does it have a visual display to show voltage?  There may be a button to alternate the reading between input and output voltage.  It’s possible that it is reading the input voltage.  FWIW

Bob

The above is corret, …..my buddy Pete turned me onto them too,…..I found you’re turning that screw what seems for hours and finally the voltage comes down…….defies logic IMO, but that’s how they work,…..

Pat

@Bob Golfs posted:

Mike,

I had a similar experience as I thought it was broken.  After playing around a while, I figured out that it took many turns of the adjusting screw before I had any change in output voltage.  Then it changed really easily without significant turns.  Also, does it have a visual display to show voltage?  There may be a button to alternate the reading between input and output voltage.  It’s possible that it is reading the input voltage.  FWIW

Bob

Bob G.

No, my Buck Converter doesn't have a LED readout.  I've seen that version on the web; it seems like a nifty feature.

Mike M.

@harmonyards posted:

The above is corret, …..my buddy Pete turned me onto them too,…..I found you’re turning that screw what seems for hours and finally the voltage comes down…….defies logic IMO, but that’s how they work,…..

Pat

Pat:

Apparently I gave up too soon with turning the adjustment screw.  I'll return to the test bench and apply more (many more) turns of that screw.  I wish that adjustment screw was LARGER in size!

Mike M.

Thanks for the helpful tips!

Mike M.

The adjustment pot is a 10-turn or sometimes even a 20-turn pot.

Actually the name 'buck converter' is a new one to me, until looking it up and finding it is really a truncated 'buck-boost' converter, actually a bit more descriptive giving a direction to what used to be called just DC-to-DC converters where you didn't know if you got more or less DC without referring to the label.    One thing I did note, none of them I found while exploring options were advertised with taking in AC to make DC.  That's just a basic power supply.  Keep in mind that many of these use switching technology in the 100-500Khz range of frequencies, and while they are supposed to meet FCC guidelines on causing interference. many of them can be very dirty, radiating a signal that interferes with AM radio reception and could affect command signals on your tracks.  A noisy one connected to a long bus wire around your layout is similar to hooking an antenna to a RF noise generator.   I've been using dedicated regulated linear supplies for 5, 9, 12 VDC needs on the layout, no radiated noise, just DC, Mean Well makes very good switchers in several voltage and current ranges, and they are very quiet RF racket wise, but I see that they have gone up in price quit a bit.  A 5 volt supply I paid $8 for is now $25.

@CALNNC posted:

Actually the name 'buck converter' is a new one to me, until looking it up and finding it is really a truncated 'buck-boost' converter, actually a bit more descriptive giving a direction to what used to be called just DC-to-DC converters where you didn't know if you got more or less DC without referring to the label.  

No, "buck converter" is correct!  There are actually three different configurations of these DC-DC switching boards.

• Buck Converter: Steps the input voltage down.
• Boost Converter: Steps the input voltage up.
• Buck/Boost Converter: Steps the input voltage down or up.

Let me clarify ...

I intend to use an Acxico Buck Converter to change an AC input to it of about 12 volts to a DC output of 9 volts.  Am I  "out  of bounds" of expectations of this device?

Mike Mottler    LCCA 12394
mottlermike10@gmail.com

That should work fine.  The 12VAC turns into around 16-17 VDC through the bridge and capacitor filter, and is more than enough differential for the buck converter.

GRJ;

Thanks for a prompt and helpful reply.

Mike Mottler    LCCA 12394
mottlermike10@gmail.com