Thanks Mel - Voltage regulators

[trainnut1250]

Mel,

Just wanted to say thanks for posting a link to the inexpensive voltage regulators out of china...My local train group has bought quite a few of these and I personally now have a good sized stash of them.

For those of you who are curious:

We are talking an adjustable voltage regulator -  40-1.3 VDC output at 2 amps with a digital readout for $1.99...You cant buy the parts for that price!

These run cool and are the perfect ticket for stepping down supply voltages for grain of wheat structure lighting and leds. For those of you who use resistors to step down a power supply voltage these are much better when there are lots of lights or leds to hook up...

I dont want to post a link due to forum rules against advertising but you will find them on that auction site. Perfect example of how a tip from someone on the forum can be very helpful at times.

 

thanks,

 

Guy

[7j43k]

I don't see how posting a link would be advertising.  YOU'RE not the one with the product.  Then it might be.

Please reconsider the link.  If they don't like it, I'm sure they will remove it.

 

Ed

[trainnut1250]

Ed,

 

Here is the link:

 

https://www.ebay.com/itm/NEW-BUCK-STEP-DOWN-LM2596-POWER-CONVERTER-MODULE-DC-4-0-40-TO-1-3-37V-VOLTMETER-/351486640764?hash=item51d63c827c

 

Guy

[7j43k]

Thanks, Guy.

 

At those prices, I expect I'll just buy some and set 'em aside until I figure what I need them for.

 

Ed

[richg1998]

Very nice.

I have used LM317 regulators, couple resistors, couple caps for some years but that one is great with a display.

Did many for myself and the club I beloonged to.

Rich

[7j43k]

I just bought a dozen with absolutely no use for them.  Yet.  But they're so cheap.  And so cute.

I just hope I remember where I stored them when I finally need some.

 

 

Ed

[rrinker]

 These and similar devices are available from many sellers. If this is the one you ordered from and had no problems getting the item - that makes this one as good or better than many.

 One thing I would do is check with a meter - sometimes those built in meters aren't exactly accurate. Not a big deal for many things where the voltage can vary a bit with no issues. I have a 10 pack of the similar buck converter that doesn't have the voltmeter (just set them with an external meter), and a 5 pack of little LED voltmeters. 3 of the 5 checked out (within tolerance) of my meter, the other two were off - but they have an adjustment potentiometer on the board and I was able to dial them in to be as accurate as the others. 

 I have plans to use a whole lot of these - instead of running a 5V power bus around my layout, I plan to run 12V, and use these to drop to 5V to power my control circuits. That way if there is any drop in the main bus due to how long it has to be, the voltage will still be above the circuit requirements, with the buck converters dropping it to the required 5V. Thus even if the 12V bus hits 10V, the circuits will still get their required 5V. 

 Not that it matters for most model railroad uses, but compared to a linear regulator, these types of dc-dc convertors are noisy. As in, lots of ripple on the DC output. But it's not a problem for the things anyone here would be using them for.

                               --Randy

 

[trainnut1250]

7j43k

I just bought a dozen with absolutely no use for them.  Yet.  But they're so cheap.  And so cute.

I just hope I remember where I stored them when I finally need some.

 

 

Ed

 

 

Yep!!! hard to resist aren't they??

I have eight or so "in stock". I have an engine house, a cannery distirct and a 5 foot long icing station that all have many small lights. These will come in handy...

 

Guy

[7j43k]

rrinker

 

 One thing I would do is check with a meter - sometimes those built in meters aren't exactly accurate. Not a big deal for many things where the voltage can vary a bit with no issues. I have a 10 pack of the similar buck converter that doesn't have the voltmeter (just set them with an external meter), and a 5 pack of little LED voltmeters. 3 of the 5 checked out (within tolerance) of my meter, the other two were off - but they have an adjustment potentiometer on the board and I was able to dial them in to be as accurate as the others. 

 

 

The insructions seem to say (English as a second language!) the same thing about adjusting the pot.

 

 

Ed,

 

whose Chinese is a little weak.

[RR_Mel]

trainnut1250

Mel,

Just wanted to say thanks for posting a link to the inexpensive voltage regulators out of china...My local train group has bought quite a few of these and I personally now have a good sized stash of them.

 

thanks,

 

Guy

 

Thanks for the good words Guy.  I really like using the DC to DC Buck-Boost type converters.  Switching power supplies are much more efficient than regulators.  Very little heat from switching power supplies.

 

I’ve been installing a 8 amp converter this afternoon for my Arduino Random Lighting Controllers.  I use 12 volt 35ma to 100ma GOW bulbs in all of my structures because they look more realistic to me than LEDs.  I set the converter to 8½ volts, running the 12 volt bulbs at 70% increases their life.  High current is the price I pay for incandescent bulbs.  I also use 12 volt switching power supplies for all of my layout accessories.  They run super cool.

 

I also use a high current converter for my vehicle lighting, I have about 100 vehicles using three 1mm 1½ volt micro bulbs in each vehicle at 15ma per bulb.  I set the converter to 90% (1.35 volts) again for extended life.  300 bulbs X .0135ma = 3.75 amps at 1.35 volts.  Again the itty bitty incandescent bulbs look more realistic than LEDs.

 

The high current DC to DC Buck Converters hold their regulation to ± .01 volt from no load to full load (0 to 12 amps).

 

 

Mel

 

Modeling the early to mid 1950s SP in HO scale since 1951

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

 

I'm beginning to realize that aging is not for wimps.

 

[trainnut1250]

Mel & Randy,

I see that I have been using the wrong terminology here - it should be converter rather than regulator...

Mel,

I like the look of the mini bulbs where you can see the bulb, other wise I'm OK with the warm glow LEDS where the light source is not visible to the viewer. I run the bulbs under voltage as well.

Guy

[RR_Mel]

I go berserk with micro bulbs, I’ve only lost two GOW bulbs since 2000 and three 1mm micro bulbs.  I used to kept count until I got to 400.  They add up quickly when you use a dozen or more in every structure.  With the addition of the Arduino lighting controllers it will be even faster.

 

http://melvineperry.blogspot.com/p/page-15.html

 

The switching power supplies really helped the heat dissipation.  I have two 12 volt 15 amp and one 12 volt 30 amp switching power supplies and 6 DC to DC convertors powering my accessories.  I can’t feel any heat from them.  When I was using regulators I had to use cooling fans to keep stuff cool. 

 

I don't mix and match LEDs and incandescent lighting because of the voltage difference.  I use the standard color code for my wiring with the exception of 1.4 volts, 1.4 Volts Blue/White, 4.5 Volts Yellow/White, 5 volts Green/White, 8.5 volts Grey/White, 10 volts Black/White.  I went with 16 conductor flat ribbon cable for the Arduino Random Lighting.  All my wiring is home run to my control panel mostly using Telco frame wire.  The flat ribbon cable is cheaper than #24 hookup wire.  $18 delivered for 100' spool of16 conductor ribbon wire.

 

 

Mel

 

Modeling the early to mid 1950s SP in HO scale since 1951

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

 

I'm beginning to realize that aging is not for wimps.

 

[BATMAN]

These look more appealing to me than resistors. So just to be clear, Can I ask for an example of how it would all go together with the supplies I have on hand.

LED 3.0-3.2 V/20MA

38AWG Soderon Magnet wire.   http://www.ngineering.com/wire_specifications.htm 

24 lights required in structure.

1. How many LEDs can be put on one circuit using the above wire?

2. What would the output of the power converter be set to.

I have old transformers and have amassed a large box full of wall warts over the years, so what makes the best power source?

Would the lights be in series or parallel?

Thanks for helping me get it right.

 

[RR_Mel]

BATMAN

These look more appealing to me than resistors. So just to be clear, Can I ask for an example of how it would all go together with the supplies I have on hand.

LED 3.0-3.2 V/20MA

38AWG Soderon Magnet wire.   http://www.ngineering.com/wire_specifications.htm 

24 lights required in structure.

1. How many LEDs can be put on one circuit using the above wire?

2. What would the output of the power converter be set to.

I have old transformers and have amassed a large box full of wall warts over the years, so what makes the best power source?

Would the lights be in series or parallel?

Thanks for helping me get it right.

 

 

About the only way you can get away from using resistors with LEDs is by using a current regulator such as a NS150010YT1G in series with a string of LEDs.

 

The DC to DC convertors I’m using only go to 28 volts.  Figuring 3 volts per white LED, nine in series would be max.

 

The maximum current of #38 wire is 130 ma so it will easily handle 10 to 20ma LEDs.

 

I wouldn’t use more than 12 volt power supplies on my layout.  I can get in enough trouble at 12 volts.  I even use a separate source and grounds for my 1.4 volts to prevent accidental problems, even with my 60 years of electronic experience.

 

Mel

 

Modeling the early to mid 1950s SP in HO scale since 1951

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

 

I'm beginning to realize that aging is not for wimps.

 

[RR_Mel]

I thought I would do an up date on the DC to DC convertors.  After getting the convertors installed with permanent wiring on my layout (one foot of 16 gauge stranded wire on the primary side) they are very stable staying within ± .01 volts between 0 to 8 amps at 8.6 volts.

 

I have three Arduino random light controllers (up to 2.6 amps total) operating from the convertors and 5 amps from my existing layout lighting, there is very little dissipated from the convertor or the 12 volt switching power supply at full load.

 

 

 

Mel

 

Modeling the early to mid 1950s SP in HO scale since 1951

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

 

I'm beginning to realize that aging is not for wimps.

 

[rrinker]

 Like most cheap Chinese electronics, YMMV - as I mentioned, 2 of the pack of 5 I got needed the one capacitor soldered back on. They worked even with the loose capacitor, but had a lot of ripple when I looked at the output on my scope. The ones that were good and the other two after repair were quite good for such a cheap product. I will be using these things all over my layout just so I don;t have to run multiple voltage accessory busses everywhere. I figure I can run about 115V or so and use these whenever I need to tap off a lower voltage, as long as I stay within the current limits of the buck converter. I did some testing by feeding them with my variable bench power supply and checking the output - they can run down to very close to the output voltage before they can no longer maintain the set output, and there seemed to be no issues taking them up to 30 volts (limit of my power supply) and having them deliver a steady 5V output.

 It is generally believed that the chip is a counterfeit, as the entire buck converter module costs less than you cna usually buy the chip for, let alone the cost of the inductor, capacitors, and other components. But, as long as they work. I've seen two variations, one has the big input and output capacistors with the terminals oriented to the top and bottom of the board - pointing to the input and output terminals. The other, the ones I have,m have the capactor pads aligned along the length of the board. This is why 2 of mine had the caps loose - when they cut apart the board panels, the sheared too close to the edge and it more or less cut off the one pad. I will be looking for the other type from now on.

                                     --Randy

 

[RR_Mel]

This is the one I’m using Randy.

 

 

I also bought some of the cheapo digital volt meters (.56” 0-30 VDC $1.39) for each convertor and using Amazing Goop glued them to the capacitors.

 

 

No mistake with the convertor voltages that way.

 

Mel

 

Modeling the early to mid 1950s SP in HO scale since 1951

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

 

I'm beginning to realize that aging is not for wimps.

 

[rrinker]

 That's a much heftier version than the ones I have, mine are tiny - smaller than that meter even. I picked up some even smaller volt meters, too, bare board, no enclosure. I may need some of those larger ones for structure lighting, that model I can see should be able to supply a decent amount of current with the heat sinks and all. Mine are tiny little boards, less than half the size of an Arduino Nano or Micro.

                                   --Randy

 

[RR_Mel]

Randy

 

That convertor measures 2½” X 1⅞” and will handle 8 amps ambient, 12 amps forced air cooling.  At 8 amps they run very cool.  I set the current regulators to 8 amps on all of the convertors.

 

I bought a 30 amp 12 volt switching power supply for my 4½ to 12 volt accessories, I use a separate 12 volt 15 amp switching power supply for my 1.4 volts that powers my 1mm micro bulbs (vehicle headlights) so that I can isolate the grounds.  With isolated power that makes it harder to accidently screw up and pop 300 micro bulbs.

 

EDIT:

 

I have run them about ten hours every day for the last week and the regulation is solid as a rock!

 

Mel

 

Modeling the early to mid 1950s SP in HO scale since 1951

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

 

I'm beginning to realize that aging is not for wimps.