Universal Input Power Supply as DC-DC Converter?

I'm having trouble sourcing an affordable, low power, high voltage, isolated DC-DC converter. Has anyone used a power supply such as below as a DC-DC in their bike?

I've used those many times with good results. Depending on the model, the minimum voltage you need to run it may vary widely. Pretty much anything will work at 72v and above. I've seen some that would work all the way down to 24v. Also, if the input voltage drops too low, it won't be able to make the rated output current.

The ones with a wide input voltage range, usually 90v - 240vac, generally work better.

coleasterling said:

Has anyone used a power supply such as below as a DC-DC in their bike?

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I've used 48V Meanwell power supplies adjusted down to 42V to charge my ebike and it's worked well. The key is current limiting. If it uses true current limiting (i.e. limit to 120% of the supply's rating or something) it will work fine. If it uses "shut down and restart on overload" then it won't work. Sometimes you can glean this from the data sheet, but sometimes it's not apparent until you actually try it.

You should have no problem with a 30s pack. Almost any switching PS will work with that much. Added bonus is that these are always isolated output.

coleasterling said:

But I'm looking to use this to power the low voltage systems on my bike, not charge the cells. I need to maintain HV/LV isolation and there aren't many options in terms of straight DC-DC converters that are under 100W.

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The unit you have selected will work - but a bit suboptimally for common automotive/motorcycle lighting. It's a 12V supply which is pretty low for automotive accessories which are not really 12V at all.

Conventional automotive stuff is really designed to work with voltages in the range 13.8-14.4V as produced by the alternator - not as supplied by the battery at rest. In point of fact, cars will run fine at 15V or more, although battery life is shortened because of the high terminal charging voltage. Common lighting and accessories will certainly operate at the euphemistic '12V', but lights will be dimmer, etc. It's essentially the difference in headlight intensity before and after you start the engine on your car.

Laptop supplies are a nice alternative and come in some handy voltages. A convenient choice is the Toshiba ADP-60RH power supply. This is a 15V 4A supply that is readily available (e.g. eBay search). There are threads on ES about this and similar units, including this one from 2007 by fechter "Cheap DC-DC converters for over 60v input.". I've tried this particular Toshiba model and it works nicely, is isolated, and waterproof to boot. At 15V it's fine for automotive stuff and will punch up your lighting noticeably over the 12V supply you linked.

That said, it you are using more elaborate LED lighting with a supporting buck converter and/or current regulator, then input voltage really won't have a visible effect.

FWIW: I run a bike on 16V using a strobed DOT Optronics LED tail/brake light on the back and it's markedly brighter than another bike with the same light and a more conventional automotive 13.5V converter.