Handbook for Sound Engineers

944 Chapter 25

Figure 25-113. Rider pot multiplexing and address decoding.

Figure 25-114. An A/D converter (as part of the system in Fig. 25-113).

Multiplexted

bus to A/D

converter

Sixteen

rider pots

1/4 4011

1/4 4011

0 1 2 3 4

Channel

select

line

1/4 4011

4028

1/4 4011

3

2

1

0

Select

outputs

to switch

(5, 2, B, A)

VAD (Valid A/D decode address)

4028

Address bus

4051

4051

Multiplex

analogue

bus

Multiturn

zero trim

10 V reference

Bus buffer

AD507Gain trim

AD7574

Up

1/4 4011

RD

Busy

10 V reference Wait R/W 0 1 2 3 4 5 6 7 VAD Data Bus

Valid A/D decide address

+5 V