New, Smaller Lighting Keep Alive Circuit (120)

[@TheDCCGuy]

You may find that the super capacitor used in this circuit will pull in a lot of current when first starting the layout. This can cause some DCC systems to see it as a short circuit and will shut down in response. To avoid this problem put a 100 ohm resistor on one wire going to the input on the bridge rectifier. After doing this I managed to fire up 3 caboose lighting systems and a sound equipped loco at the same time using a PowerCab system rated at 1.4 amps. One side effect is the lights take longer to turn on, maybe 10 seconds but once on they are as bright as ever, and it will take a few minutes to completely charge the capacitor, .

[@markmatteo2417]

So if I were to use standard 3v hobby LEDs and strictly resistors, and no buckboard or trim pot, would I need one resistor for the capacitor, and one resistor for each LED?

[@TheDCCGuy]

@@markmatteo2417 I have not tried that arrangement so cannot say for sure. Not sure why I never tried it as it sounds reasonable. Try a 1000 ohm resistor with a single white LED but it has to be placed before the capacitor.

[@jamesfisher4326]

@@markmatteo2417 I'm assuming that you are running on DCC. First, you will need a 16 volt capacitor not the 3 volt super capacitor shown here. You will need two resistors. I use a 100 ohm resister between the track and the rectifier to reduce the inrush current. You will need an appropriate resistor between the capacitor and the LED, possibly about 1000 Ohms. The capacitor will charge up to full track voltage which will quickly destroy the LED without a resistor.

[@ltcterry2006]

One of the benefits of a Buck Converter over a resistor is that it uses pulse width modulation to reduce voltage rather than burning it up as resistance. If you put a suitable capacitor in front of the Buck Converter It will feed, for example, 12v into the Buck converter PWM on-off style 3V at a time (so to speak) so the feed is not interrupted and 12/3=4 lasts 4x on the supply side (OK, not counting conversion loss). For N Scale my plan is very similar to your (excellent, btw!) video but a small cap on the front, a 3v fixed Buck converter, 0.5F super cap, and 3V LED strips.

[@Maddogtrucking]

just built 10 of these both 3v and 12v with different capacitors. awsome tip. thank you

[@thomasgrassi8817]

Larry came back to this Using the wipers on the wheels gave me many issues shorts etc. I now use a brass tube on a wheel which I get from JB Wheelsets. They work much better than the wipers.

[@TheDCCGuy]

There are many ways to pickup power. DCCconcepts makes set just like the ESU ones and also offer coiled springs that go on the axle and pick up power that way. Whatever works for you-Larry

[@neilcarleton7721]

I ended up with a buck board that has the two small capacitors on the board. Works fine with an LED but after adding a 16 volt 1000 if capacitor, it does not stay on when powered off. The cap worked fine with just a bridge rectifier, resistor and LED. Thanks, Neil

[@si12volt1]

Thank you Larry I so far did 5 of my n scale cabooses with your Keep Alive Circuit and it works great fun lil project and a money saver ..keep them videos coming..learning a lot from you

[@RoamingAdhocrat]

this looks much neater than the "dead bug" version! I'd like to see if I can cram it into a UK N-gauge brake van ;)

[@panamafred1]

Yes! Wonderful explanation. I love learning about the electronics aspect of model railroading. Thank you!

[@titodalessandro1909]

I’ve been looking for an idea to light my passenger cars. This is a perfect idea thank you.

[@TheUllrichj]

Thanks Larry. These videos are very helpful.

[@bobmcweeney7459]

Great video, great circuit. Thanks Larry.

[@nolanknoepfle8044]

I’ve been experimenting with using the top strap from a athearn blue box for the pick up material. They are just scraped when you switch to dcc

[@new_comment]

Buckboards take so much tedious work out of lighting rolling stock, especially when you're working with surface mount components.

[@rjl110919581]

thank you for detailed video

[@markl3603]

DCC Concepts have wheel wipers and pickup springs. If your HO cabin car uses Bettendorf or Arch Bar trucks Kadee have them already fitted with pickups. They are #590 and #593. More expensive than fitting my own pickups but it saved me some time.

[@TheDCCGuy]

I’ve seen theirs too but forgot to mention them. They are similar to those made by ESU. I need to order a package to try on my cabs. The good thing is they are wheel wipers so can pick up from both rails on each truck potentially giving better pick up overall.

[@flyboy2610]

When I added DCC to a Bachmann 0-6-0, I needed a way to get power pickups from the tender. This will only work with wheel-sets having metal axles. I used a 1/4" length of 1/8" K & S copper tubing #8120 on each axle. The axles are 3/32" in diameter so the 1/8" tubing fits nicely, but does not slide over the wheel insulator, because that could be bad. I soldered a piece of fine flexible wire to each piece of copper tubing, removed one wheel from each wheel-set, slid the tubing over the axle, and reinstalled the wheel. I drilled a small hole in the bottom of the tender and fed the wires into the tender. I now had power from each axle on the tender. Depending on how you install the wheel-sets, you can have one truck provide positive current and the other provide negative, or you can have one positive and one negative on each truck. This is how I did mine. The pickups work great and have little resistance to rolling.

[@markgoodrich941]

@@flyboy2610 That is how I did my passenger car since I couldn't find any of the wipers. So far it works very well.

[@frankhellman6879]

Now if we could only have something that size for locos! :) Very nice job.

[@TheDCCGuy]

The TCS KA-1 and KA-2 keep alives are actually smaller.

[@frankhellman6879]

@@TheDCCGuy Thanks, I'll look at those.

[@ModelingSteelinHO]

Another Southern modeler ! Subscribed.

[@milanstanic2402]

Hi Larry - Question - Bridge Rectifier - Can I use DB107 (1000 volt / 1 amp ) in place of DB102 (100 volt / 1 amp) Please advise.

[@TheDCCGuy]

Don’t know why not, but I’ve never worked with any over about 30 volts.

[@milanstanic2402]

Thank you.

[@ricter591]

Thanks Larry!

[@johnkelley2468]

Larry, Is it possible to add a keep alive to LED strip lights?

[@TheDCCGuy]

Yes but you have to use the 12VDC version.

[@litsnsirn]

You should consider using a plastic tool to adjust the trim pot

[@caseyjones745]

Does the BuckBoard perform the same function as a resistor? Or, does a BuckBoard drop voltage and a resistor drops amps?

[@TheDCCGuy]

It acts as a rectifier and voltage regulator giving a fairly stable voltage fir your lights.

[@Longshadowsmodeltrees]

I try the Op's mode on those Bachmann RS-3 in N scale, no go....I think you can't change CV on Bachmann. Maybe someday you could do something for us N scalers, Great channel Larry. Bob

[@TheDCCGuy]

Very odd, you should be able to access them and change them since they are NMRA compatible. Just which ones are you trying to change and have you ever programmed a decoder before?

[@Longshadowsmodeltrees]

All the time, all Kato's and Atlas no problem, I email Bachmann will see what happens with them. Thank for all your help Larry. Bob

[@Maddogtrucking]

Quick question regarding adding a resistor to slow the inrush current. The 100ohm resistor is fine for 1 led but what if I have more leds. I assume the resistor value changes for every led that is added ?

[@TheDCCGuy]

The resistor is there to deal with the inrush current demand of the capacitor not the LED(s).

[@crockett11000]

Cool stuff, I will try it. But why not solder on a short piece/wire lead ( 1" to 3" long or more) of two conductor wire wrapped around the capacitor legs at the same time you solder it to the board?. Then you can add one or more LEDs and be able to place or move them around inside. I always install at least 2 LEDs in most cars and several in passenger cars, one pointed up and one pointing down for way better light dispersion, since most LEDs are directional at only 60 degrees. This also would prevent soldering twice to the same points or spots on the board and heating up the circut board and the cap twice. Heat is the enemy, especially very small circut boards with micro contact solder points that easily burn off. Oh , I also paint the inside of the car white to reflect and fill the interior with light better too, What a difference!... Just saying.... Great video and thank you for doing them!!!.

[@TheDCCGuy]

If it works for you that is great!

[@crockett11000]

@@TheDCCGuy It can work for all of us, on sharing info, leaning, teaching, techniques and vast experience that many of us old model railroaders have including mistakes...

[@dionking8184]

Stupid question from a non-electronics-experienced mechanical engineer who enjoys your videos: 1F seems like a lot. Doing the math, a 1F capacitor would keep a 3V 20mA LED going for a couple of minutes. You also mention the capacitor take time to charge, which on a DCC layout it's doing as long as there is power to the track, correct? So I guess it's not that big an issue. In any event, my question is, for a lighting keep-alive, where you only need power from the capacitor for a moment to prevent flickering, couldn't you get by with something like 0.01F? If not, why not? Is there some other advantage to the bigger capacitor (availability, cost, etc)? Thanks!

[@TheDCCGuy]

You can use smaller value ones and in my earlier video I did use one although the device itself was much larger. So if you can find a super cap like that go for it. I was looking for the smallest size at the time. It also means you can operate several LEDs off the same cap for use in passenger cars. So it’s all a tradeoff.

[@WilliamColden]

I have made up this device and I am puzzled by something. I have wired this into a Walthers passenger car Interior LED DC/DCC Lighting kit. I cut the connections on the light board between the contact pads and the rest of the circuit. Then I soldered in the nifty device ( learned from your video) and when I connected it directly to my dcc programming track (NCE PowerCab) using wires with alligator clips, it worked like a charm! The problem cam when installed the light in my passenger car. The lighting didn't work. Was there a problem with the track pickups in the trucks? No, I was measuring connectivity between wheels and the contacts in the car. And if I modified a Walthers lighting kit with a 25V 1000A capacitor, it worked fine although the dimming didn't happen immediately, it happened too rapidly. I have limited electronic knowledge having learned a little from KZbin. The only idea I could come up with is that the contacts between the trucks and the contact tabs might have too much resistance. Does that make any sense or am I missing something?

[@TheDCCGuy]

I have not looked at the Walthers lighting circuit so not sure what it contains that might be pulling excess current. What else is on the circuit board and how many lights are there and are the bulbs or LEDs? Also keep in mind that the circuit only needs to get you over dirty/dead spot not be a longterm power source.

[@WilliamColden]

@@TheDCCGuy There are 9 LEDs. The dcc current goes through a bridge rectifier, a small surface mount capacitor with a resistor connected to a voltage regulator which then connects to a strip of 9 LEDs. What has me buffaloed is that my modified light system works great with direct power from the track but not when that power is routed through the power pickup from the trucks to the power tabs inside the car. The one thing I haven't done is dismantle the car to see if there is any current control device wired to the power pickup in the the trucks. If all else fails, the Walthers light kit does work with just a capacitor connected to it, although it does dim slightly upon immediate loss of contact with the rail.

[@WilliamColden]

@@TheDCCGuy When all else fails carefully check all solder connections for solid contact! It works great and the light bars fit in quite nicely and don't dim at all when power is briefly interrupted. Thanks for your videos. I've learned a lot!

[@TheDCCGuy]

You discovered the 99% solution-check all wiring, especially connections. That’s usually the problem 99% of the time. Enjoy PS-the capacitor is likely polarity specific so needs the bridge rectifier to convert the DCC to DC.

[@mtnestr9850]

If you power LED lights by the wires from the DCC Decoder do you need a Bridge Rectifier or does the DCC Decoder have a Bridge Rectifier built-in?

[@TheDCCGuy]

Decoders do rectify track power as the electronic circuit is DC. However the voltage feed on many decoders is nit regulated so you still need dropping resistors. There are a few decoders that offer onboard resistors for powering LEDs.

[@PaulA-ey8pj]

High Larry, you're an absolute champion!How suucessful would it work in a HO loco as a keep alive for the loco? Thanks so much for sharing your knowledge with us all. Paul Australia

[@TheDCCGuy]

You wouldn’t go far on 3 volts, that isn’t enough power to even operate a mobile decoder. These are just designed for lights.

[@PaulA-ey8pj]

@@TheDCCGuy Thanks Larry for the reply. Really enjoying your Tubes! Cheers mate

[@jonruehle9186]

Larry, I have about 24 unlighted cars that I'd like to light. This circuit is easy to build. The hard part for me is getting power from the trucks to the the circuit. Nay video son this with a source for the pickups in the trucks? Thanks!

[@TheDCCGuy]

Check the Kadee website, I know they offer trucks with pickups. I mentioned several options for adding your own pickups to existing trucks in the video too. Maybe I need to do a video update with some of those options.

[@h2osmokey]

With the high frequency of the dcc a/c is it necessary to rectify to dc for the led? Seems the circuit would work with a smaller capacitor, resistor and LED. What say ye?

[@TheDCCGuy]

The buck board and capacitor are a DC devices thus the need to rectify the DCC source. The 3V cap is the minimum to light the white LED.

[@geraldjones2278]

Here's a question. Would this circuit work for a 1 1/2 volt incandescent bulb or two? I have some caboose lanterns with those bulbs and wondered if this buckboard can be reduced in voltage down to 1.5 or less to safely operate these lamps and if so, would this particular capacitor also work okay at that voltage?

[@TheDCCGuy]

These can go as low as 1 volt output so it should work. The capacitor should only put out the voltage it receives, but you may be able to find one rated at a lower voltage and lower cost. Either way I would test it on a single 1.5 volt bulb first.

[@Kamagong16]

Larry, i did an Ebay search for the Buck Modules & I saw most of them have 2 capacitors(?) already installed. Will they also work? Or Do i have to buy the ones which is on your video? Sorry but Im an electronics dummy. Thanks in advance....

[@TheDCCGuy]

I think these are the last ones I ordered. www.ebay.com/itm/10pcs-Mini360-3A-DC-Voltage-Step-Down-Power-Converter-Buck-Module-3-3V-5V-9V-12V-/132416658988?hash=item1ed4a5de2c

[@scottjackson3009]

I have enjoyed the videos, even though I have switched back to my Lionel. This circuit intrigues me with all of the possibilities it offers. Since I use AC for the track voltage as well as my accessories, can you (or the other readers) offer any insights? The track voltage is variable from 0 to 20 volts and I am looking for ways to tame it and convert it to 3v DC for some marker lamp pairs. Thx!

[@TheDCCGuy]

Take a look at my videos on lights for cabeese and passenger cars.

[@TimStonerock]

Where can I get pick up wheels with the brass collars over the axles that you have to solder to

[@TheDCCGuy]

No idea, what do you want to solder to what?

[@TimStonerock]

I'm looking for the pickup Wheels the ones with the brass colors on the axles

[@TheDCCGuy]

The only things like that I have seen are made by DCCconcepts and those have small springs wound around the axles for power pickup. With those the wire is soldered to the end of the spring wire.

[@nateshon3eastbroadtoprailr448]

Or you can use modified Kadee centering springs for pickup

[@donmarich5740]

I tried this with a capacitor 100 micro rated 25V with a led strip of 6 lights (12v) . Buck board overheated and lights will not come on any suggestions, poor soldering? I would appreciate any ideas.

[@TheDCCGuy]

What kind of capacitor were you using and what output voltage was the buck board rated for? Did you use the bridge rectifier?

[@donmarich5740]

I used a Jackcon 1000uf 25v on a MH-MINI-360 Buck board. I did use a bridge rectifier.@@TheDCCGuy

[@TheDCCGuy]

What voltage did you set it for? Since those are rated at 3 amps the amperage of the LEDs should not be an issue. Other than that you might have a solder bridge somewhere creating a short. Also make sure the capacitor is connected to the correct polarity contact.

[@donmarich5740]

Thanks, I'll try it again. Set dial(?) to the right (3 or lower). @@TheDCCGuy

[@TheDCCGuy]

No, in this case you said you are trying to operate a 12VDC LED strip so you need to set the buck board to put out 12 VDC. You will never light them with only 3VDC. Use a voltmeter to adjust the output potentiometer to 12VDC, don’t guess.

[@nfordf450]

If using a roko tv or the box. Press up on the remote. A box will appear on the lower left above the play bar. Once that box has a white ring around it press ok on the remote and the description will appear on the right side of the screen. I’ve been watching KZbin on my roko tv for over a year now and have figured out how to like and subscribe on it as well. Very much the same. Hope this helps someone

[@TheDCCGuy]

Great, it works! Last time I checked KZbin was still saying a method was in progress so I guess they got it done-Thanks

[@johnbutler8388]

What kind of electrical wire can you use for that you want something real flexible right

[@TheDCCGuy]

For the connections to the trucks you would want stranded wire in a small size but on the actual device it doesn’t matter since it doesn’t move about.

[@johnbutler8388]

@@TheDCCGuy thank you it is nice to have your experience on videos

[@thomasgrassi8817]

Hi Larry I noticed one view the wipers were under the trucks axle and the other view they were on top of the axle does this matter? I got mine from Jim Hinds Thanks tom

[@TheDCCGuy]

Doesn’t matter, just which ever way works best.

[@thomasgrassi8817]

@@TheDCCGuy thanks

[@davedefrehn6257]

Just a thought. Next time you do a car lighting video maybe you could show how to do pickups with a metal framed car for those folks who might have them.

[@TheDCCGuy]

I took a look at my brass caboose recently and the only way I see you could do it is to replace the metal trucks with plastic ones. Then it just becomes a matter of attaching a wire to the pickups and running it up through a hole drilled in the floor. Now if you mean metal trucks on a plastic car then you could do that just like the plastic trucks by only picking up power from one side per truck and passing power up through the mounting screws.

[@repeters1]

Could you send me or upload a close up of the buck board completed so I can see the info on the pieces? Thank you.

[@fallnflags5587]

A bit off subject...when you solder, what temp do you set a variable pot to? I realize different brands of solder’s will have different actual temps for any given setting, but in general is there recommended ranges for track work, ic boards or wire to wire soldering. Thanks Don

[@lgrfbs]

Since there is quite a lot that can vary between different solder varieties and solder stations, it is not very helpful if I give you a temperature here. Start by placing the solder on the tip of the soldering pen if the solder does not melt, you have too low a temperature and then you have to raise the temperature depending on what you are going to solder. One last thing keep the tip of the pen clean, so everything works much better over a longer period of time. Good luck to you.

[@TheDCCGuy]

It really varies with the size of the job snd size of the tip. It takes a lot more heat to solder feeders or joiners to rails since they act as heat sinks and can conduct heat away from the joint. You also will likely be using a bigger fatter tip which itself requires more heat. Small electrical joints generally require less heat and a pencil point tip. However once you get a feel for how to handle these variables you can work with higher temps since even with small joints it makes the job faster which in itself can lead to less chance of damage. So practice with some spare wire, track, and parts to develop that sense of how it works.

[@ericschrowang8315]

Larry Thank You for a well put together and informative video. Just a quick question. Why did you not use an SMT Super Cap? the cost difference is not much and it seems you could save even more space.

[@TheDCCGuy]

I have looked for them but could not find any of the ratings I used, specifically 3V, 1F. If you know of a source please share it with me.

[@davidvescovi1382]

@@TheDCCGuy One other thing, true super caps (1F etc.) typically have very high ESR ... am guessing you could probably eliminate the 100 ohm limiter with that.

[@repeters1]

Hi Larry, Can something like this be made / used for a DC system?

[@TheDCCGuy]

The difference is DCC is a constant 14 or so,volts where as DC can go from 0-14 volts. The answer is you can’t power a constant voltage device with a variable power source.

[@TomYouAreDoingItWrong]

@@TheDCCGuy This question is a good segway into my question. I am wondering about installing a rechargeable battery into a similar circuit to keep the rolling stock LEDs lit on a DC layout. Thanx!

[@bobherbert6494]

Larry - I read thru all the comments and no one else seems to have this problem. I tried 2 of the mini-360 buck boards and found them difficult if not impossible to adjust and then once adjusted do not hold the voltage. I am trying to get a constant 1.5v out for some grain of wheat bulbs. I have not connected the cap because it is 5.5v. My meter varies anywhere from 0 to 10 v without me touching anything. Fyi I am using a metal screwdriver, a bridge on the front end, a dc power supply set for about 12 v, and a 1k ohm surge protector. The only load is the meter. Perhaps there is something wrong with both boards. And perhaps I should not use a metal screwdriver. Do you have any other ideas?

[@TheDCCGuy]

Why the 1K resistor? I used a 100 ohm one with the or as a surge suppressor but if you’re not using one then you din’t need the resistor at all.

[@bobherbert6494]

@@TheDCCGuy Thank you very much. The 100 ohm resistor works great. Now I can set the voltage at 1.5v so I am thinking I do not need an output resistor. Or should I add 100 or 200 ohms there?

[@TheDCCGuy]

You don’t need the output resistor unless you are using a capacitor.

[@bobherbert6494]

Thank you for your quick response. Yes, I want to use a 1.5f 5.5v capacitor but when I place it across the output the voltage dropped to about 0.5v and could not be adjusted. Then after I also added a 50 ohm resistor across the output I could adjust the output to between 1 and 1.5 volts but not all the way to 1.5v. The load I want to use is two 1.5v grain of wheat bulbs (caboose marker lights) . When I added these in parallel with the 50 ohm resistor and capacitor, it seemed to still work. The 2 bulbs without the 50 ohm resistor was not enough load to make it work. My mini-360 seems to need a minimum load in order to work. That does not seem to be true with yours. I am not comfortable with this device.

[@TheDCCGuy]

Odd, but then I have never tried going down to 1.5V which maybe near enough to the lower end of the adjustment range to be unreliable. You could try using a higher output voltage with a dropping resistor to power the bulbs.

[@billbiondi5427]

Were can i purchase the 3volt 1f capacitor.

[@TheDCCGuy]

I provided a component and source list in the description. I just ordered a bunch from Mouser.com.

[@lauraspain29]

Hi Larry. I just received all components to build these from mouser using your supplied part nos. and the mini 360 buck boards, 20 of them, built one as a test and it works but it trips the short protection circuit in my NCE powercab several times while it charges. After a couple of trips it will set and works fine. If I add a second led it trips continuously. will this damage my power cab or is there a work around? Granted my electronic skills are limited at best so it's most likely an operator error. I am concerned that a string of passenger cars with these installed will be to much for the power cab and cause the short protection circuit to engage. Any insight would be appreciated.

[@TheDCCGuy]

Put a 100 ohm resistor in line to the capacitor to prevent the inrush current surge. PowerCabs have a very low amperage output so can easily be overwhelmed.

[@kevinindieart611]

Thanks

[@kevinindieart611]

Tried your suggestion installed 100 ohm 1/2 watt resistor in line with capacitor. Power Cab booted up first try. It has been on track for 30 minutes and has'nt charged. LED lights but if I move car it flickers so now I don't have constant lighting. I will experiment more. Maybe when I get a SB 5 to upgrade power cab perhaps it will work.

[@TheDCCGuy]

I just cranked up my PowerCab on a test track with one of the devices in the video and it works without an inrush resistor. I also ran a loco on the track at the same time and again no issues so I am at a loss to explain your results. I will test it with multiples tomorrow and see if I can challenge the PowerCab.

[@TheDCCGuy]

This morning I tried it with 3 cabs and that shut the PowerCab down. With 2 it started so I just tried tipping one while the other two lit up then dropped it back onto the rails and that worked too. The PowerCab is just too underpowered to take the inrush current of the 3 caps simultaneously. I’ll play around this week with placement of a resistor and see if we can get the inrush current down but I am afraid that the PowerCab just does not have enough capacity to handle it. I have never had the problem since I use a PSX4 set at about 3 amps or so plus it has special algorithms designed to handle current surges like that. I can turn on my 8 amp DCS240 system with 65 locos on the track and it will start right up.

[@gwmccoy]

Larry, I have a lot of the 12V LED strip lighting that I'd like to use up. Does someone make a 12V SuperCap, and would it work in this circuit? Thanks!

[@TheDCCGuy]

It would work but it would be huge. You’re better off using the circuit I showed in video 101, it works with the 12 volts strips.

[@gwmccoy]

@@TheDCCGuy Perfect! Thanks very much!

[@deplorableconstitutionalis2834]

this isnt compatible with just a plain dc system is it?

[@TheDCCGuy]

No, since with DC there is no constant power on the track the keep alive capacitor would not stay charged.

[@ltcterry2006]

As Larry said there's no constant power on the rails, but the circuit itself will work on DC. As long as there is more than 3V on the rails it will feed through the Buck Converter and come out 3V for the LED. With less than 3V on the rails it will eventually dim.

[@thomasgrassi8817]

Larry Where would you put the inrush resistor on this circuit on the wire from the truck? An do you have a model number so I can order them? Thanks Tom

[@TheDCCGuy]

Tom you need to read through the other coonents on videos. This question came up and I answered it: OK, I put a 100 ohm resistor on one wire going to the input on the bridge rectifier and managed to fire up 3 caboose lighting systems and a sound equipped loco at the same time. One side effect is the lights take longer to turn on, maybe 10 seconds but once on they are as bright as ever.

[@thomasgrassi8817]

@@TheDCCGuy Larry just ordered from Amazon 100 OHM resistors they will be here tomorrow. I will do a video and post on my channel the change to the circuit. I just started my channel yesterday and posted a video of my railroad crossing with the signals you get a chance subscribe and make comments thanks Tom

[@williamvaughn4603]

Larry built the circut and lights the led but as soon as I take the power off no light?????????????

[@TheDCCGuy]

Which circuit, how many LEDs, and which capacitors? The “white” LEDs require about 3 volts to light so any deviation from the design may provide inadequate power. If using the buck board circuit with the 3V supercap then make sure the output from the board is just below 3V to give enough voltage without blowing the supercap.

[@williamvaughn4603]

@@TheDCCGuy Yes 3V super cap and buck board set at 2.9V. As soon as power is shut off no light to led cool white.

[@blueridgebonsai9155]

@@williamvaughn4603 Well,since it does light up the buck board is working and dropping the voltage appropriately. How long have you left it sitting before turning it off, it may take a minute to adequately charge the cap? If you have a second capacitor swap it in just in case you got a bad one. Other than that I can’t think of any reason it wouldn’t work as long as it is wired with the correct polarity.

[@williamvaughn4603]

@@blueridgebonsai9155 Yes checked the polarity. left it on for 10 min and still nothing when it turns off will try swapping the cap. Thanks

[@stevetrust3219]

Hi Larry, I can’t find a bridge rectifier the same as yours in the UK (DFA 01 444A). Can I use any 100v 1A bridge rectifier? Steve.

[@TheDCCGuy]

I can’t see any reason why it should not work.

[@hdwood76fxe]

All electronics permanently closed. Sad 😔 Last orders shipped Sept 2023.

[@fredbrooks1386]

2

[@w.rustylane5650]

I can see that you are targeting an audience that knows absolutely nothing about electronics. Guess it pays to be a Ham radio operator with a good knowledge of electronics.

[@TheDCCGuy]

Yes, my audience ranges from folks like you to those who have no idea where to start so I have to shoot for the lowest common denominator.