Peter P wrote:
[...]
> Alternate way to do it (5 channels per IC):
>
>                               LEDs 2mA
>
>                            +----|<|---+
>                     |\     |          |         /|
> Signal o---1M----*---+ o----*----|>|---*--*-B---o +---+
>                 |   |/     |          |  |      \|   |
>                 |          |          |  |           |
>                 +----1M----+          |  +----1M-----+
>                                       |
>                                       v
>                                     other channels
>
> The inverters are CMOS4069B or similar. B is a PNP/NPN push-pull current
> booster, needed for more than 2 channels. Alternately use several gates in
> parallel for the bias source. E.g. 4069 can use 3 gates as bias and 3
> channels, gives 3 channels per chip.

I'm afraid I'm having difficulty reading the ASCII schematic...

Vitaliy 

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