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Bob Larter Bob Larter is offline
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Default UPS: "Do not connect laser printer..."

Greegor wrote:
On Jul 19, 1:19 pm, "Michael Robinson" wrote:
"whit3rd" wrote in message

...
On Jul 19, 11:21 am, notme wrote:

What is it about laser printers that causes UPS manufacturers to recommend
they not be powered by a "stepped approximation to sine" UPS? It's a SMSP,
isn't it? What makes it special such that it needs sine-only

The main heater (the one that fuses the toner so it sticks to the
paper) is usually run on a thermostat, using a big SCR (triac, to
be more specific). Those SCRs can trigger on fast-rising spikes
on the power line, by capacitive coupling from cathode to gate,
so steps in the power-in voltage are contraindicated.

So a heater of that sort takes its power directly from the line?


Do inkjet printers handle the simily waveform well?


It shouldn't be an issue at all for inkjets, only lasers.

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