Has anyone done this? I have a small N scale train that runs in a loop. The 5V from a USB connection seemed like a good speed. I wired up and cord for it but it works sporadically using my phone charger. Is there special charging circutry and not just a constant voltage? Thanks
Yes. Overcharging is very bad for batteries, but plugging the phone in and going to sleep is convenient. So the charger tries to sense if the battery is full. It'll also shut down for a time if it gets too warm. There are electronics and small appliances that aren't cordless, but are low voltage DC. Their wall warts are not chargers. They're just power packs.
I'd also recommend a wall-wart if you just want to supply power to the rails in an on-off fashion. An old computer power supply, or maybe a power supply for LED strip lighting may work. You could check out thrift stores or used electronic stores to find parts to salvage.
So it turns out that it was the engine not the power supply. The 5v had problems getting the motor to kick over but would keep it going once it was started. That seems to be why it ran some times. My other power pack had pulse power so it worked better at lower voltages. I tried a newer loco and it started right up. I'll have to go look for a higher voltage for this engine.
usually the charging logic is in the devices, not in the usb source. for example an usb stick or ssd doesn't need any charging logic.
So while this does provide you with the desired 5V, the circuitry inside the typical USB charger is usually as cheap as it gets. A simple kit like this one... https://www.amazon.com/Adjustable-R...96106&sprefix=diy+power+supply,aps,152&sr=8-8 Is a great power supply that will give you a variable output, with a voltage display and is robust enough to handle any train you put on your rails. You will find out my limiting the track to only one voltage, you will also limit which trains will run on that layout well. My Tram layout is set to one voltage setting due to the way I designed the circuitry. This now causes me to upload a different sketch every time I want to run a different tram on it. I am going to redesign some of the setup to allow for a variable speed control to allow a much easier selection of trams. I would recommend following a similar path... Learn from my mistake before making your own same one!
Be very careful running small trains on adjustable supplies that can go beyond 15V or so (N scale). 37V, if accidentally set, will fry a loco motor pretty quickly.
