2
\$\begingroup\$

What kind of displays can I use effectively with a coin cell battery (CR2450)? The backlight or the entire display would be on only when necessary. From previous answers I know that a liquid crystal display without backlight can be used but I wanted to know if there is some kind of display with good visibility at night. Is there some kind of "ultra-low-power" display with good visibility at night?

\$\endgroup\$
  • 1
    \$\begingroup\$ Anything that emits light is going to consume significant energy to do so. Your options are those used by watches: fluorescent or very reflective backing, user-triggered brief backlight, e-paper (huge hassle to obtain and drive), or (for very infrequently changing displays) mechanical high-contrast segments. \$\endgroup\$ – pjc50 Apr 23 '14 at 15:36
  • \$\begingroup\$ To be clear, you want it to constantly emit light, not light up on demand like the backlight on some digital watches? \$\endgroup\$ – John U Apr 23 '14 at 15:59
  • \$\begingroup\$ The backlight or the entire display would be up only on demand, there's no problem. \$\endgroup\$ – Rui Lima Apr 23 '14 at 16:11
  • 1
    \$\begingroup\$ 5mA is a lot for CR2450 battery. \$\endgroup\$ – Kamil Apr 23 '14 at 18:32
  • \$\begingroup\$ You're right. THat was bugging me because I saw a project that used a coin cell battery (the LIR2032) but, now that I take a closer look to that battery's datasheet it has a maximum discharge current of 70mA. \$\endgroup\$ – Rui Lima Apr 23 '14 at 21:33
4
\$\begingroup\$

LCD display with a tritium backlight (half-life ~12 years) should be possible. The tritium emits beta particles that can excite phosphors to emit visible light. Glass is typically used to contain the tritium gas.

Watches have been made incorporating this principle, some Ball watches currently use tritium capsules for analog dial illumination, and there is at least one company claiming to offer micro-capsules.

enter image description here

Don't expect spectacular brightness, even nuclear-powered illumination has its limits.

\$\endgroup\$
0
\$\begingroup\$

E-paper needs no power to maintain state, but has low refresh rate. With a LED side light it is visible even at night.

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.