Re: Wico XY Pattern Generator - Schematic capture complete

On Nov 12, 2011 8:55 PM, "Zitt Zitterkopf" <zittware@hotmail.com> wrote:
>
> Rodger,
>
> I like the idea of the 4040 conversion because it replaces 3 chips for
the cost of 1. Meets the goal of the redesign. It should also greatly
simplify routing of the pcb.
>
> Was there a typo w/ regards to the 4040 conversion?
> 11 goes to U3 pins 3 & 11
> should read
> 11 goes to U2 pins 3 & 11

Yes should be U2 instead of U3.

> also; !Q from U6B seems to be missing.
> My assumption is to move U1D to be A8 in and !A8 out which feeds U6A CLK
(pin 3).

No reason to not leave U1d and U6b as is. Just don't connect HC4040 pin 1
at all (U6 pin 9 will provide A8).

> John
>
> From: Rodger Boots
> Sent: Friday, November 11, 2011 10:02 PM
> To: vectorlist@vectorlist.org
> Subject: Re: VECTOR: Wico XY Pattern Generator - Schematic capture
complete
> Errors that I can see (and why they are errors).
>
> On U2, GET RID OF R40 and connect pin 3 to pin 11 (pin 2 stays connected
to pin 12). This sets U2 to divide by 9 instead of 10. As it is now U2
does basically nothing. With the outputs at 0000, a clock will bring pin
12 high which then causes a reset that takes the outputs back to 0000.
Pins 8, 9, or 11 will never be anything other than 0.
>
> Oddly enough, U2 can be either a 74HC90 OR a 74HC93---circuit will work
the same either way.
>
> U3, U4, & U5 outputs are mostly going to the wrong places. The original
ionpool.net schematic had the pin numbers right, but the pin names wrong.
You should have switched the pin names instead of the pin numbers.
>
> U3 pin 12 is fine (goes to U3 pin 1)
> 9 is fine (goes nowhere)
> 8 should go to U4 pin 14 and U9 pin 2
> 11 shouldn't go to anything
> U4 pin 12 is fine (A0)
> 9 should be A1 (does NOT go to U5 pin 14)
> 8 should be A2
> 11 should be A3 and connects to U5 pin 14
> U5 pin 12 is fine (A4)
> 9 should be A5 (does NOT go to U1 pin 9)
> 8 should be A6
> 11 should be A7 and connects to U1 pin 9
>
> That's the end of what I've found so far. Don't read the rest of this
unless you want to start modifying things.
>
> - - - - - - - - - - - - -
>
> If you wanted an easy way to lose a couple of chips, U3, U4, & U5 could
be replaced with a 74HC4040 with the pins used like this:
>
> 74HC4040 pin 1 goes to A8 and connects to U1 pin 3
> 2 goes to A2
> 3 goes to A1
> 4 goes to A3
> 5 goes to A0
> 6 goes to U9 pin 2
> 7 goes nowhere
> 8 goes to ground
> 9 goes nowhere
> 10 goes to ground
> 11 goes to U3 pins 3 & 11
> 12 goes to A5
> 13 goes to A4
> 14 goes to A6
> 15 goes to A7
> 16 goes to +5
>
> U1D and U6B get totally removed from the circuit.

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Received on Sat Nov 12 22:16:50 2011