10 Amps Into an 8 Amp Booster

[TwinStar]

Seeing as I have to be DCC compliant, I was wondering what would happen if you powered a Digitrax DB210 (http://www.digitrax.com/products/command-stations-boosters/db210/) with a 10 amp Mean Well power supply https://www.ebay.com/itm/Mean-Well-LRS-150F-15-150W-15V-10A-Single-Output-Switching-Power-Supply/122310427178?epid=670826694&hash=item1c7a45022a:g:0RYAAOSw2xRYeQ-r:rk:2:pf:0)

Would the DB210 limit the output to 8 amps?

[G8B4Life]

The DB210 will only draw what it needs at any given time from the power supply, so say if your only running a couple of trains drawing say 2 amps total from the DB210 then the DB210 will only be drawing 2 Amps (+ a little headroom) from the power supply. Except in circumstances such as catastrophic failure of the DB210 the DB210 won't draw more than it supplies (+ a little headroom for losses in the internal circuitry).

You always want more capacity in the power supply than what you want to power (in this case a DB210) uses; if you used an 8 Amp power supply and the DB210 was drawing 8 Amps a lot you'd be setting the power supply up for "early retirement" so you want more than 8A available to the DB210 even though it can't use the extra Amps. I forget the technical term for this. I don't know if 2A is much "headroom" in this case, Alan, our resident expert on using these things for everything in the train room should be able to say for certain.

Sorry, I'm rambling... The Mean Well supply you posted should work just fine for powering the DB210. Here is the spec sheet for it: https://www.meanwell.com/webapp/product/search.aspx?prod=LRS-150F

- Tim

[TwinStar]

Thanks Tim. So I'm guessing that I should have bought a 7A version for my DB150 (5A) instead of the 5A version?

[Alan]

Tim is spot on.

5A power supply with your DB150 is likely not a problem as seldom is there enough load (trains) to pull the full 5A. Power supply life is shortened only when the full rated current is delivered for an extended time.

[TwinStar]

Tim and Alan, I've wired my module set into two separate power districts and have opted for the DB220 instead of the DB210. Here's a link to my new power supply that I'm considering:

https://www.trcelectronics.com/View/Mean-Well/HRP-300-15.shtml?msclkid=9f91cbbb249a11d927809466b6433a20

Is this OK?

As an aside, we're hosting a private Free-mo setup in January and 3 of the operators will be RailPro and 1 is BlueRail.

Jacob

[Alan]

Yep, that should work fine.

[TwinStar]

Thanks Alan!

[G8B4Life]

It does look like a good supply. The only thing I note is that the DB220 takes a minimum of 15v for it's input and that's right on the specified voltage of the power supply. The power supply has a trimpot to adjust the voltage +- a couple of volts and you may need to do that so the DB220 doesn't chuck a hissy fit.

There must be a better way to become DCC compliant than purchasing a $200 booster though?

- Tim

[TwinStar]

It does look like a good supply. The only thing I note is that the DB220 takes a minimum of 15v for it's input and that's right on the specified voltage of the power supply. The power supply has a trimpot to adjust the voltage +- a couple of volts and you may need to do that so the DB220 doesn't chuck a hissy fit.

There must be a better way to become DCC compliant than purchasing a $200 booster though?

- Tim

Thanks for pointing out the voltage Tim. I was thinking I'd have to turn it up to 16V to match the other Digitrax supplies such as their PS2012E.

I need two 8 amp power supplies and the dual DB220 at $166 is a better deal than two single DB210's at $113 each.

The RailPro equivalent would be 3 PWR-56's for $270 so the DB220 for $166 and the HPR 300-15 for $80 (plus shipping) are very comparable.

[Alan]

There is conflicting information on the Digitrax site.

This document specifies 13.8v minimum on Pg7: https://www.digitrax.com/media/apps/products/command-stations-boosters/db220/documents/DB210%2BDB220_rev0.pdf

3.0Powering your DB210/DB220The DB210 is for use with DC POWER input ONLY, MAXIMUM INPUT 8 AMPS, 24VDC, DO NOT Exceed 25VDC maximum Input.  Minimum Input 13.8VDC.
...
It is recommended that when selecting a DC power supply the voltage should slightly exceed the scale track voltage you plan to run by about approximately 1 to 2V DC, and should provide sufficient current to support the chosen 3/5/8 Amp limit setting.  The DC input voltage should not exceed track scale voltage by more than 3V.

However, 15v is minimum recommended on Pg1 of this document: https://www.digitrax.com/media/apps/products/command-stations-boosters/db220/documents/Spec%20Sheet%20DB220.pdf

To further complicate the picture, a variety of voltages are shown at the bottom of this webpage: https://www.digitrax.com/tsd/KB1017/loconet-accessory-power-requirements/

PS2012e
The PS2012 provides the following dc voltage and current outputs depending on the Output Voltage Selector switch.
                        G setting provides 23V @ 12amps
                        HO setting provides 18V @ 15amps
                        N setting provides 13.8v @ 20amps
There are two sets of Output Connections.  These outputs are electrically the same.  The outputs need to be properly fused.  The “Y” cable included with the PS2012 has self-resetting 5amp current limiters.  If the PS2012 is used with the DCS200 or DB200 an 8amp fuse, circuit breaker or current limiter must be used.  If “Y” cable is used with the DCS200 or DB200 only 5 amps of power will be available, defeating the purpose of using an 8 amp. Booster.

PS514
The PS514 is a 70watt Universal AC Power Supply.  This power supply offers many different voltage outputs.  Set the voltage selector as follows:
                        G / O Scale – 20v
                        HO Scale – 16.8v
                        N Scale – 13.8 or 15v
Use the Blue electrical tip with the pigtail that is included with the Super Chief Xtra and Super Empire Builder Xtra Starter sets.  This power supply has been retired.

PS615
The PS615 is a 15 volt DC, 6A power supply.  It is included in the Evolution Starter set and is also sold separately.  It is for use with all current Command Stations operating at 5 amps.

Geez, as if DCC was complicated enough!

Like Tim says, there is a voltage adjust pot. All of my supplies, both cheapo and genuine Meanwell, have this feature. The range is the same on all of them +-1.7v even though the documentation states +-1.5v. So your 15v unit is good for 13.3v to 16.7v. If you want to replicate the Digitrax PS2012 unit then you would need an 18v version. Meanwell doesn't offer much at 18v but eBay is chock full of units.

I suspect anything 13.8v and up will work fine because your power supply is rated at 22 amps. If it were lower and closer to the booster's rated amperage then there may be an issue with voltage fluctuation if the power supply is asked to output full amperage. The booster will kick out long before your 22A supply fluctuates. Besides, 16 amps of trains running is a whole lot of trains!

13.8v is a "magic" standard voltage in the 12v powered world. Diodes are used on equipment inputs to protect the unit from people wiring it backwards. There is a small voltage drop across each diode. The next component in line is the internal regulator which also has a small voltage drop across it. Add up the drops and you get ~1.8v. End result - 13.8 yields internally stable 12 volts. The Digitrax N scale recommendation of 13.8v tells us the internal working voltage of the DB is 12v.

[G8B4Life]

The RailPro equivalent would be 3 PWR-56's for $270 so the DB220 for $166 and the HPR 300-15 for $80 (plus shipping) are very comparable.

I'll never get over the huge discounts from MSRP that you can get over there. Such a thing does not happen here.

A better comparison would be 3 PWR-56's for $270 vs 3 boosters and 3 power supplies (that closely match the RP specs) for whatever that would be worth. I think RP would come out ahead. It'd be even better if you could buy the PWR-56 without the included PA-2 power supply so you could choose your own large power supply enough to power several PWR-56's.

- Tim

[TwinStar]

There is conflicting information on the Digitrax site.

This document specifies 13.8v minimum on Pg7: https://www.digitrax.com/media/apps/products/command-stations-boosters/db220/documents/DB210%2BDB220_rev0.pdf

3.0Powering your DB210/DB220The DB210 is for use with DC POWER input ONLY, MAXIMUM INPUT 8 AMPS, 24VDC, DO NOT Exceed 25VDC maximum Input.  Minimum Input 13.8VDC.
...
It is recommended that when selecting a DC power supply the voltage should slightly exceed the scale track voltage you plan to run by about approximately 1 to 2V DC, and should provide sufficient current to support the chosen 3/5/8 Amp limit setting.  The DC input voltage should not exceed track scale voltage by more than 3V.

However, 15v is minimum recommended on Pg1 of this document: https://www.digitrax.com/media/apps/products/command-stations-boosters/db220/documents/Spec%20Sheet%20DB220.pdf

To further complicate the picture, a variety of voltages are shown at the bottom of this webpage: https://www.digitrax.com/tsd/KB1017/loconet-accessory-power-requirements/

PS2012e
The PS2012 provides the following dc voltage and current outputs depending on the Output Voltage Selector switch.
                        G setting provides 23V @ 12amps
                        HO setting provides 18V @ 15amps
                        N setting provides 13.8v @ 20amps
There are two sets of Output Connections.  These outputs are electrically the same.  The outputs need to be properly fused.  The “Y” cable included with the PS2012 has self-resetting 5amp current limiters.  If the PS2012 is used with the DCS200 or DB200 an 8amp fuse, circuit breaker or current limiter must be used.  If “Y” cable is used with the DCS200 or DB200 only 5 amps of power will be available, defeating the purpose of using an 8 amp. Booster.

PS514
The PS514 is a 70watt Universal AC Power Supply.  This power supply offers many different voltage outputs.  Set the voltage selector as follows:
                        G / O Scale – 20v
                        HO Scale – 16.8v
                        N Scale – 13.8 or 15v
Use the Blue electrical tip with the pigtail that is included with the Super Chief Xtra and Super Empire Builder Xtra Starter sets.  This power supply has been retired.

PS615
The PS615 is a 15 volt DC, 6A power supply.  It is included in the Evolution Starter set and is also sold separately.  It is for use with all current Command Stations operating at 5 amps.

Geez, as if DCC was complicated enough!

Like Tim says, there is a voltage adjust pot. All of my supplies, both cheapo and genuine Meanwell, have this feature. The range is the same on all of them +-1.7v even though the documentation states +-1.5v. So your 15v unit is good for 13.3v to 16.7v. If you want to replicate the Digitrax PS2012 unit then you would need an 18v version. Meanwell doesn't offer much at 18v but eBay is chock full of units.

I suspect anything 13.8v and up will work fine because your power supply is rated at 22 amps. If it were lower and closer to the booster's rated amperage then there may be an issue with voltage fluctuation if the power supply is asked to output full amperage. The booster will kick out long before your 22A supply fluctuates. Besides, 16 amps of trains running is a whole lot of trains!

13.8v is a "magic" standard voltage in the 12v powered world. Diodes are used on equipment inputs to protect the unit from people wiring it backwards. There is a small voltage drop across each diode. The next component in line is the internal regulator which also has a small voltage drop across it. Add up the drops and you get ~1.8v. End result - 13.8 yields internally stable 12 volts. The Digitrax N scale recommendation of 13.8v tells us the internal working voltage of the DB is 12v.

Thanks Alan.

I have a DCS52 as well. I need to see what voltage that power supply is putting out. 

[TwinStar]

The RailPro equivalent would be 3 PWR-56's for $270 so the DB220 for $166 and the HPR 300-15 for $80 (plus shipping) are very comparable.

I'll never get over the huge discounts from MSRP that you can get over there. Such a thing does not happen here.

A better comparison would be 3 PWR-56's for $270 vs 3 boosters and 3 power supplies (that closely match the RP specs) for whatever that would be worth. I think RP would come out ahead. It'd be even better if you could buy the PWR-56 without the included PA-2 power supply so you could choose your own large power supply enough to power several PWR-56's.

- Tim

Actually, a better comparison would be Digitrax equipment from different suppliers and ignoring the RailPro equipment. Digitrax DCC is required so even if the RailPro equipment were free it wouldn't alter my purchase. I have to have Digitrax DCC, like it or not (and trust me, I don't) and a DB220 is the most cost effective option to power my module set.

[G8B4Life]

Actually, a better comparison would be Digitrax equipment from different suppliers and ignoring the RailPro equipment.

Well I don't know where all that came from but I was comparing the cost of apples to the number of functionally equivalent apples. 3 x PWR-56's = 3 x Boosters and 3 x booster power supplies which is likely a greater cost than 3 x PWR-56's. Your comment is comparing apples to nothing which I don't get the point of.

Digitrax DCC is required so even if the RailPro equipment were free it wouldn't alter my purchase.

I never said anything about not purchasing the DigiTrax equipment. I know what's required for Free-mo, and DCC and how "open" (read propriety) it is is the main driver of why gave up on it. Didn't you also give up on it and start your own RailPro Free-mo standard?

I have to have Digitrax DCC, like it or not (and trust me, I don't)

I don't doubt you dislike it, you've mentioned it many times and I greatly dislike it as well.

and a DB220 is the most cost effective option to power my module set.

I never said it wasn't going to be. I never said not to purchase it in favour of something else. As I said further up I was comparing the cost of RailPro apples to the number of functionally equivalent DCC apples to correct the cost comparison. Nothing more.

- Tim

[TwinStar]

Digitrax DCC is required so even if the RailPro equipment were free it wouldn't alter my purchase.

I never said anything about not purchasing the DigiTrax equipment. I know what's required for Free-mo, and DCC and how "open" (read propriety) it is is the main driver of why gave up on it. Didn't you also give up on it and start your own RailPro Free-mo standard?


- Tim

Sorry Tim, I must have misunderstood and apologize for any confusion.

Yes, I was attempting to rewrite the Free-mo manual and lost, big time. I've found it much easier to swim alongside the stream than against it. DCC is here to stay in the Free-mo world for quite some time. Unfortunate but true. I have made some significant inroads on 3D printed tie fixtures and eliminating the bridge rails in favor of butt joints. My caster equipped adjustable height legs also have been well received.

I've purchased a DCS52, the power supply for my DB220, and will soon get the DB220 itself. 90% of the passenger trains that will operate across my module set are DCC equipped so I've decided to be a good neighbor and 'cooperate and graduate'.