I'm working on a project in which I'm hoping to integrate several small segments of pdlc film, which starts off diffuse white/'frosted', turns clear when excited with 110V AC at 50Hz and is apparently dimmable although I haven't tried that yet. This is the closest thing I have to a datasheet:enter image description here

I want to power 6 segments of film from a 1s lipo cell, which is already boosted to 5vdc for other parts of the project. In total I will be using 13sq.cm at most so they won't draw more than 1.5mA. I also need to figure out how to control the degree of transparency of each segment independently, preferably using PWM signals from an arduino.

Size is critical as everything needs to fit inside a handheld toy and it is already crowded!

Would it be feasible to create an AC signal using arduino PWM output and boost that to the required voltage?

All of the solutions I can find off-the-shelf for boosting the voltage are just too big for my project but also provide way more power than I need. Most of their bulk is transformer and heatsink. Is their a way to get the voltage gain at 50Hz without a (relatively speaking) bulky transformer? All of the smallest transformers I can find have a minimum frequency way above 50Hz.

  • \$\begingroup\$ Danger Will Robinson! Danger! Very, very poorly made spec sheet as only information. I am too tired to consider you an answer, but just want to say a sheet like that as only information would be a no-buy for me. Conflicting numbers, no unit in the table for optical characteristics, "power - 110v", meh. Just my opinion though. \$\endgroup\$ – Asmyldof Mar 24 '16 at 1:13
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    \$\begingroup\$ I would be inclined to do some experiments or if possible talk to the maker of the film to see if it could be driven with anything other than 50Hz AC. 50Hz is considerablly more of a PITA to produce at low power levels than either DC or high frequeny AC. \$\endgroup\$ – Peter Green Mar 24 '16 at 3:54
  • \$\begingroup\$ In fact, pdlc is almost equivalent to el set up, both being capacitors. The pdlc films work well at lower frequency and usually consume 5~7 w per square meter. The idea of using el drivers is a very good suggestion. \$\endgroup\$ – jairaj shetty Jul 12 '17 at 16:38

I would look into using a driver meant for electroluminescent wires and lamps ("EL Wires", "EL Lamps"). A while ago I rolled my own, using a MAX14521E. There are many companies making these driver ICs, and I expect that by now there may be appropriate off-the-shelf modules.

EL drivers are intended to drive a capacitive load with low current requirements. The "datasheet" that you have posted doesn't really say anything about how the load presents itself, although Wikipedia mentions that a PDLC structure "is in effect a capacitor."

The MAX14521E, to use as an example, is powered by 2.7-5.5 VDC. Its output voltage can be set (via I2C serial commands) from 0 - 300 \$V_{p-p}\$, and the output frequency is selectable from 50-800 Hz. It's a small chip, uses a tiny inductor (3 x 3 x 0.9 mm!), and no heatsinking is required.

That particular chip has four independent outputs, has dimming, automatic fade-in and fade-out, etc.

Different chips are able to drive varying loads. Make sure that you choose an IC that has an appropriate output current capability!


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