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Re: Hacking cartridge HP 84/85

Posted: Wed Dec 25, 2019 10:18 am
by MAsic12345
Looks cool don't forget when testing about load limitation 1 amp
if it is not possible, then the head will last 3 seconds then it will burn

Re: Hacking cartridge HP 84/85

Posted: Wed Dec 25, 2019 8:59 pm
by MAsic12345
Pleasant viewing


Re: Hacking cartridge HP 84/85

Posted: Fri Feb 07, 2020 9:13 am
by myying
Hi
A HP applied patent US 20050088473A1 mentioned the ink drop weight relation with temperature.
The fire duration and supplied voltage are “not” both fixed data for HP pen(HP like use it.)
HP has a named TTOE(thermal turn on energy) calibration technology which lists in US5418558、 US5428376、US5428376…and so on.

There is output pin TSR(thermal sensing resistor) in HP pen which measures pen temperature. and also there is a circumstance-temperature sensor at PCB, then a complicated calculation, maybe storing embedded chip or burned as ID at factory. Once the ink was replaced another HP owned, it would be a new setting.