powering teensy with 1500ma usb charger possible?

Hello,

Is it possible to power teensy through usb connected to wall charger with output 1000ma or 1500ma? I'm afraid to simply test it

The Teensy will run with any standard +5V USB power supply. It only draws about 25 mA plus whatever external loads (LEDs, etc) it is driving. The mA rating on your USB charger is just the maximum output current supported. In operation, the power supply sets a fixed voltage and the actual current draw is determined by the load (in this case, the Teensy) anywhere from 0.0 up to the maximum supported current. If you disconnect the load completely, then the supply delivers +5V at 0 mA.

It's harmless, but there is a catch. Some USB chargers will timeout and turn off because 25 mA is so low. It is possible to find models that don't do this. It is also possible to add a little circuit to the design that occasionally draws more current from the charger to keep the watchdog timer from expiring.

Paul wrote a blog post on this on his Dorkbot PDX blog.

Others on this forum have suggested both refinements to his circuit and models of USB charger that don't timeout. You'll need to do some searching.

thank you both! I think it will be fine regarding timeout - I have ethernet and display connected at all times.

Worked up a two-tone alarm decoder and night light control system for a fire station, using one of these power supplies seemed elegant and cheap, until the midnight call from the young fireman with good hearing complaining the switching noise from the power supply coming over the PA speaker system with keeping him up.