Is an infrared printer still worth getting?

[teenix]

(10-04-2021 05:03 PM)ijabbott Wrote:  Actually, come to think of it, I wonder what rating the bridge rectifier has, and could it be damaged by a beefy PSU when printing without batteries?

The bridge rectifier diodes are probably similar to IN400x series. Following them is a 7806 6V 1 amp regulator IC, so the print heads (on average because of PWM drivers) probably consume less than that. I believe the power adaptor is a 9V AC type and probably supplies an amp or so.

There is only one diode either in series with batteries, or three with external supply, which would suggest that the requirements for the external supply, assuming IN400x for all diodes operating around 1 amp, would be (3 x 1V) + 5V = 7-8VDC.

I don't expect there to be any current limiting on the print heads, so using a wall wart that supplies 9VDC at 1 amp (or above) might do premature damage to the heads. One of those 3-12V switchable types would probably do for a 7.5VDC output.

cheers

Tony