Common street lamps or other bulbs: does it matter if you use DC or AC?

Incandescent bulbs will work on AC or DC. No reason that I know of that you can't do this.

Just be careful you don't turn the voltage up to high or you'll blow the bulbs.

If you have AC, the addition of a diode in one side of the line to the lamps will increase life a great amount.  I did this to a 70 year old set of 14VAC Christmas lights where there are 8 in series for  a 112 volt circuit in the days of 110VAC at the outlet, and none of them have burned out yet.  A 50-100 volt diode at a couple amps should do the trick for most setups.  Draw more current, then get a higher amp rated diode.

And....if you are using accessories like the Lionel (or anyone's) Gateman, crossing gate or similar, if you use a DC transformer to power them, you eliminate that distracting A/C hum that one gets when they activate. Problem is, most DC train transformers from HO and race car sets, are 15 to 18 volts, but low amperage.

Thus, it often takes a transformer per gate to activate the item. I tried hooking up two older crossing gates to one transformer the other night, and it got two gates less than halfway down.

I have read on here of some people using the outdoor lighting transformers sold at box stores and the like instead of older DC train items. I can't speak for those. Another plus is no worry about phasing.

Greg

@Super'O' man posted:

I was curious, so I was thinking of using a simple transformer for street illumination or other items that just have bulbs in them. You can find inexpensive DC transformers at shows, so I thought this would work. thanks

Incandescent bulbs are easy-peasy and agnostic when it comes to power, and easy to tell when something's not right. After all, such bulbs are basically just a heated wire encased in glass, with enough heating lag time that concepts like peak voltage and spikes are basically a non-issue. Any voltage or waveform that results in a satisfactory 'old-school' glow will work just fine. My home layout has a gallimaufry of salvaged power supplies distributed under the top.

Accessories may be another story. On the simple end, solenoid-powered devices (like old-school crossing gates) may have some issues with permanently magnetizing the iron slug when used with DC (running again on AC will reverse the effect), and many accessories require DC at specific voltages to properly power the device. Such devices can be permanently and terminally affected if you stray too far afield!

For such devices, I've found inexpensive buck converters (which can accept 10-35 volts AC or DC and output a regulated and adjustable DC voltage) very handy for grabbing whatever voltage is handy and adapting it to fit the need. For example, my recent animated bascule bridge project ended up using three such buck converters, one each to power the lift section gear motors (at 6 VDC), the many LEDs (at just under 3 VDC), and the two Tortoise switch machines powering the traffic control gates at each end (at 9 VDC). All three are powered with accessory voltage (roughly 14 VAC) from the same source.

In any event, good luck!

Buck Converters!? Nothing I am familiar with. From reading above, I though it might be a SS item that inputted AC and outputted DC, (similar to what I use to call a rectifier used with slot cars and HO) and you could regulate either or both.

I looked up to buy one, and found on a popular site, items that stated, "DC to DC Buck Converter 3.0-40V to 1.5-35V Adjustable Voltage Regulator Electronic Voltage Stabilizer Power Supply Step Down Module"     NOTE the input is DC. Cheap enough, 5 for $8...but not AC input. The ad notes that "Wide Input Voltage Range: The LM2596 buck converter supports a broad input voltage range from 3V to 40V, making it ideal for various applications, including DIY electronics, solar power systems, and more.(Input voltage must be at least 1.5V higher than the output voltage; no boost function)"

Out of 2 pages of them, not one that said AC input. What am I looking at that is not quite what I want? Or...is it??

I want to input AC to the "buck" item, and output DC to the Lionel crossing gate and watchman shanty. I have numerous slot/ho transformers (rectifers?) to run DC, very few have enough amperage even at 15 to 18V output. Help please.

Thank you, Greg (where did the term buck converter come from?)

@cngw posted:

Buck Converters!? Nothing I am familiar with. From reading above, I though it might be a SS item that inputted AC and outputted DC, (similar to what I use to call a rectifier used with slot cars and HO) and you could regulate either or both.

I looked up to buy one, and found on a popular site, items that stated, "DC to DC Buck Converter 3.0-40V to 1.5-35V Adjustable Voltage Regulator Electronic Voltage Stabilizer Power Supply Step Down Module"     NOTE the input is DC. Cheap enough, 5 for $8...but not AC input. The ad notes that "Wide Input Voltage Range: The LM2596 buck converter supports a broad input voltage range from 3V to 40V, making it ideal for various applications, including DIY electronics, solar power systems, and more.(Input voltage must be at least 1.5V higher than the output voltage; no boost function)"

Out of 2 pages of them, not one that said AC input. What am I looking at that is not quite what I want? Or...is it??

I want to input AC to the "buck" item, and output DC to the Lionel crossing gate and watchman shanty. I have numerous slot/ho transformers (rectifers?) to run DC, very few have enough amperage even at 15 to 18V output. Help please.

Thank you, Greg (where did the term buck converter come from?)

It seems "buck" is just a generic term to differentiate between voltage reduction and "boost" converters. And most as you noted need DC input.

No big deal, all you need is a simple 2-3 amp bridge rectifier and say a 220uF aluminum cap connected to the DC input end of the converter. This will make DC out of your AC. An AC supply of 12-14VAC should be adequate. I don't run the gateman accessory so I can't speak to whether a 3 amp supply is adequate or not to power it, but it should be. Hope that helps.

@cngw posted:

Buck Converters!? Nothing I am familiar with. From reading above, I though it might be a SS item that inputted AC and outputted DC, (similar to what I use to call a rectifier used with slot cars and HO) and you could regulate either or both.

I looked up to buy one, and found on a popular site, items that stated, "DC to DC Buck Converter 3.0-40V to 1.5-35V Adjustable Voltage Regulator Electronic Voltage Stabilizer Power Supply Step Down Module"     NOTE the input is DC. Cheap enough, 5 for $8...but not AC input. The ad notes that "Wide Input Voltage Range: The LM2596 buck converter supports a broad input voltage range from 3V to 40V, making it ideal for various applications, including DIY electronics, solar power systems, and more.(Input voltage must be at least 1.5V higher than the output voltage; no boost function)"

Out of 2 pages of them, not one that said AC input. What am I looking at that is not quite what I want? Or...is it??

I want to input AC to the "buck" item, and output DC to the Lionel crossing gate and watchman shanty. I have numerous slot/ho transformers (rectifers?) to run DC, very few have enough amperage even at 15 to 18V output. Help please.

Thank you, Greg (where did the term buck converter come from?)

Include "AC to DC" in your search and you'll find them.  Searched for "AC to DC voltage converter" on Amazon and here is the description for the first result (I think it's verboten to provide the link):

4PCS AC/DC to DC Step Down Buck Converter AC 5-30V DC 5-48V 24V 36V 48V to DC 2.5-35V 12V Voltage Regulator Board 2A Adjustable Volt Power Supply Module

Sounds like they are very flexible, I will have to get a few and experiment. Thanks for the info.

Greg

For all my building and street lights I use incandescent light bulbs. I actually really dislike LEDS, even though they are good forever, but very few give off the soft yellow light that was common until recently. To power them I use two MRC AC transformers. With these I can adjust the voltage and illuminate upwards of 35 small lights off of one transformer.

Miketg