Multiple Keypresses

[Guest Glenn Weston]

Just had another thought on multiple keypresses, such as Shift-G for example, of coarse wiring the (shift) key & the letter key (G) to a double pole switch will give erratic results as the (G) contacts could possibly make before the (shift) contacts in the switch, therefore the character contacts have to be delayed by a certain amount of time, this could be achieved by a relay but would be much more expensive, Has anybody tried a simple coil on the character line to delay the current flow, this would be a very cheap & easy alternative & the coil would simply be in series with the switch. I am not sure of the timing factors involved but once known we should be able to design a coil to do the job.Thoughts anyone.Glenn.

[Guest MikePowell]

Glenn,Interesting thought, but I don't think it would give you the results you would like.Keyboards, actually any switch matrix encoder, works by progressively scanning a two dimensional array of switches. It's really the scan process that determines when a key closure is detected. An inductance in series with a switch would not change the scan timing, though if large enough it would prevent a key closure from being detected.Mike www.mikesflightdeck.com

[Guest]

What about experimenting with different value resistors?

[Guest Glenn Weston]

No that definately won't work Tony, as a resistor will not delay a current flow only restrict it.Glenn.