Most power efficient display of single digits and color flap

[izico]

I'm redesigning a board game toy now.

The first version use color flaps rotated by shaft to show color, red or blue, and it uses 7 segment LED to display a single digit of player score.

I'm thinking of replacing the color flap with red and blue LED or other means to show these 2 colors.

But we want the battery to last as long as possible.

And of course a MCU will be used for control.

Anybody have better idea about how to keep the power consumption as small as possible to have the battery replacement few? Any means are open, mechanical or electrical or else, the LED current consumption is too high, 1ma is just a very dim color on LED, and we have 18 color flaps to be replaced, it's a lot current consumption.

 

[Tom.G]

With zero standby power, those color flaps are probably the lowest power display available. They are even used around here in roadside 'informational' RADAR speed indicators. (They slowed the traffic the first few months they were up.)

The next lowest power would be a Liquid Crystal Display (LCD) but you have to drive them with Alternating Current, no DC component allowed. That means some active logic running while the display is active. They are used in pocket calculators, digital watches, cell phones, etc. Since they are a capacitive display, their power usage is almost zero. You can drive them with very low power CMOS logic.

 

[meBigGuy]

I agree
Your lowest power all electrical solution will probably be an LCD display with an LED side light. (I have not done the power analysis)

For example, http://www.good-display.com/products_detail/&productId=141.html

Microcontroller families generally have devices with LCD drivers.
PIC16F913 is one example --- there may be smaller ones.

 

[Tom.G]

Or if you don't need to read the display in the dark you can use a reflective display and eliminate the LED.

 

[izico]

Or if you don't need to read the display in the dark you can use a reflective display and eliminate the LED.

Tom's suggestion give me a hint of a design using a single large screen reflective LCD, we will put a 6x6 membrane push button on top of it, (36 buttons are located evenly for player to press to gain territory, the red/blue color flap means who occupy the square of that position already or if it's still not occupied by anybody), so our job will be show score on top, and show territory with different color.

This looks the most power efficient electrical solution by now, at least much better than 2 7-segment display and 18 discrete LED.

 

[izico]

I have forgotten to tell the board is 11"x8.5" in size, with this size the LCD cost is inhibitive.

So it seems only 2 choices now:
1. Color LED enclosed in same color plastic cover which tend to enhance the same color, and bundle together with a large rechargeable battery with high voltage such as the 9v battery used in many multimeters, and bundle a charger circuit or even a charger together like how the mobile phone is sold.

The current consumption will be some tens ma but with a 9v 1000mah battery it can still last some hundreds hours, it's still OK for mist users.

2. Some electromechanical method to rotate the color flaps, by now I have not thought of any affordable solution, but motor control is an obvious solution though quite inhibitively expensive.

 

[meBigGuy]

http://www.flipdots.com/electromagnetic-large-7-segment-display.html#.Vwa41XolloE

 

[izico]

http://www.flipdots.com/electromagnetic-large-7-segment-display.html#.Vwa41XolloE [/QUOTE

http://www.flipdots.com/electromagnetic-large-7-segment-display.html#.Vwa41XolloE

This is the last word now, thanks for your info very much.

I have contacted them for price but from some online search it's quite expensive.

It looks a lot custom parts are needed to build such a flipdot by myself, permanent magnet, solenoid, I will survey but not optimistic about design cost and final BOM cost.

I guess we need to use the LED + high voltage high mAh rechargeable battery + charger solution finally, it looks to be the most economical solution.

 

[meBigGuy]

For LCD you can buy 7 LCD segments and place them in the correct geometry to save cost on the glass area (you pay by the overall area)

Have you looked into Vacuum florescent displays?

 

[izico]

For LCD you can buy 7 LCD segments and place them in the correct geometry to save cost on the glass area (you pay by the overall area)

Have you looked into Vacuum florescent displays?

I have never used VFD, but from some datasheet and FAQ searched online it consumes more power than LED on the same lumen light.