Digital Up/Down Selector for 8 Sources

Digital_up_down_sel_8.gif (18484 bytes)

O��� �� �� Electronic sel. 8 ���� ��� ��� ������ ��� ������� �������� 8 ������������ ����� . � �������   ����� ��� ������������ ���� ��� ��������� ��� � ������ ��� ������� ����� ���� - ���� ��������. ������ ������� ��� ������������� ���� ������ ��� �� ���������� Led 1-8. ���� ��� SL 1 connector �������� �� Relay ��� ���������� Relay Sel. 8 . ����������� �������� �� ���������������� �o IC 3 ��� ����� ���� 8-CHANNEL ANALOG MULTIPLEXER �������� ��� �������� , ����� Rele. ��� ������������ �����, ������ �� ������� ��� IC 3 , ��� ��� ���� ������ . ��� ������������� �� ��������� ��������� ����������� ���� �� IC3 ,�� ������� ������� ��� ����������� ����������� ��������� ��� ������� ��� ���� 8 ������� [�� ������� �� ����� ����������].


As with the Electronic sel. 8 we also have here a circuit with a choice of 8 different sources. The difference is that only two of the switches are used and the movement of commands is Up-Down in series. We have evidence of activity at each entrance by the corresponding Led 1-8. Throw the SL1 connector, we drive the Relay of the circuit Relay Sel. 8. Alternately we can use the IC3, which is a 8-channel multiplexer analog choices, without relay. For stereo use, we must use two IC3, one for each channel. If we place the correct [pairing] combination resistors before the IC3, the circuit becomes an electronic variable resistor with 8 steps.

Part List

R1-2=10Kohms C3-4=47nF63V   MKT IC3=74HC4051 Single 8-Ch. Analog [Comp. 4051]
R3-4=100Kohms C5-6=10uF16V IC4=74HC237
R5-8=100Kohms C7=47nF63V  MKT S1-2=Push Button sw
R9=10Kohms .D1-8=Led 3mm. S3=DIL 8P SW
R10=470 ohms IC1=4584
C1-2=100nF63V MKT IC2=74HC193

 

Sam Electronic Circuits 8/01