| ??? 01/31/07 19:03 Read: times Msg Score: +1 +1 Informative |
#131827 - sometimes Responding to: ???'s previous message |
Richard Erlacher said:
I've only seen one example in the past 15 years, where a voltage more positive than -2 volts produced sufficient contrast. I often use a 20K pot to the -10 or so available from the MAX-232 or equivalent that's already present. SomeLCDs use a positive voltage for contrast, like the Optrex part I used in my LCD test project. The contrast voltage ended up being very near zero, too. -a |
