IR printing power consumption (DM42)

Discussion around the Swiss Micros DM42 calculator.
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mcc
Posts: 155
Joined: Fri Jun 23, 2017 3:10 am

IR printing power consumption (DM42)

Post by mcc » Sat Mar 31, 2018 5:38 am

Hi,

this is not a question which needs a scientifically accurate answer... ;) ;) ;)

My own """experiences""" with IR-diodes are totally obsoleted.

What is the power consumption while IR-printing with the DM42?

Is it like "One IR-print of all 25 registers is equal to about 2 years of constantly using the DM42 without printing"
or is it more like "IR printing is not using any power from the CR2032...instead it uses advanced free energy technology" ?

Or more realistic: I have not a single idea how to rate IR-printing in relation to the subminimal power consumption
of the DM42...please help me to remove my cluelessness in this case... ;) :)

Cheers
Meino
DM 42 - SN: 00373, Firmware v.:3.7 / 3.7.1 as compiled by SwissMicros

grsbanks
Posts: 652
Joined: Tue Apr 25, 2017 9:23 am
Location: Preston, Lancs, UK

Re: IR printing power consumption (DM42)

Post by grsbanks » Sat Mar 31, 2018 9:13 am

The answer is somewhere between your two extremes :)

Depending on battery voltage at the time of printing, when the IR diode is switched "on" it is drawing up to around 3mA. Redeye protocol means that it is on only for a very brief period at a time, with ones and zeroes being represented by variable length bursts of pulses. I'm not sure what the duty cycle of these pulses is but looking at waveforms I would guess that the overall duty cycle of a print job is in the region of 20%, bringing the overall current drain during a print job down to 600uA.

Contrast this with the CPU, which is constantly sucking up about 10mA when doing intensive calculations (and when printing because the CPU is modulating the pulses for the Redeye protocol).

So, yes, there is an impact due to the IR diode, but it's actually the CPU that uses up the most power while printing!
Not SwissMicros staff, just an enthusiast.

mcc
Posts: 155
Joined: Fri Jun 23, 2017 3:10 am

Re: IR printing power consumption (DM42)

Post by mcc » Sat Mar 31, 2018 10:28 am

Hi grsbanks,

thanks for the infos! :)

...but I hadn't have the CPU in the view, when thinking about power consumption while printing...

Good to know!

Cheers!
Meino
DM 42 - SN: 00373, Firmware v.:3.7 / 3.7.1 as compiled by SwissMicros

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