Decoder BCD with TTL logic to DEC (1 from 8) not only for antenna switch

This is simply but powerful decoder from BCD data in TTL logic to one of eight. You can use it everywhere you have less wires than you need and also with BCD (TTL) output devices (like Microham). You need only 4 wires and control up to 8 outputs. There is universal output driver. You can drive outputs by switching to GND or + Vcc voltage. BCD inputs include RF and high voltage protection.

Main functions:

• BCD to DEC matrix table
• Outputs 0 to 7 or 1 to 8 (jumper)
• Universal OUTPUT: + or gnd
• BCD input HIGH with 2,6 to 9V - designed for TTL logic
• RF and high voltage protections
• Both drivers (ULN and TBD) are included
• PCB size = 90 x 52
• Available as
• Assembled: ready to use

Parameters:

• Output current max. 500mA
• EXTernal voltage for relays with different voltage than 12V
• Voltage drop for TBD driver typ. 0,2V for +12V input and 0,6V for BCD wires power input
• Voltage drop for ULN driver typ. 0,8V for +12V input and 1,3V for BCD wires power input
• Input voltage > 13V is recommended for 12V relays
• Control voltage for BCD input is TTL compatible and up to 15V (min 2,6V for active HIGH)
• Low loss in switching driver
• Universal output switching: to GND or + Vcc
• Compatible with Microham ACC
• RF and high voltage input protections

Use:

• Universal decoder BCD to DEC
• Compatible with Ameritron switches
• When you miss wires to your tower :)
• Remote Control expander

Matrix table for inputs and outputs:

Connection of control cables and power supply:

• With external power voltage wire
• One more wire
• BCD wires can use smaller voltage 2,6 to 9 V
• For longer distance

Output 0 or 8:

• Compatible with MFJ antenna switch
• Easy to set by Jumper

Output driver:

• Universal outputs - switching to GND or + voltage
• Easy to set by Jumper
• Easy to replace driver ULN (- out) / TBD (+ out)

Open collector device:

Devices with the open collector (like B26-PA RF2K-S) needs external pull up resistors picture

Example with 6-to-1:

• Need four (five) wires between controller and BCD-to-DEC converter
• GND, (+12V) and three control wires
• Output must be with TBD driver (+ out)

Example with 4-to-1:

• Need four (three) wires between controller and BCD-to-DEC converter
• GND, (+12V) and three control wires
• Output must be with TBD driver (+ out)

Example with Microham devices:

• Need four (three) wires between controller and BCD-to-DEC converter
• GND, (+12V) and three control wires
• Output must be with TBD driver (+ out)

Example with Microham devices:

• Need four (three) wires between controller and BCD-to-DEC converter
• GND, (+12V) and three control wires
• Output must be with TBD driver (+ out)

Do you need higher voltage version - compatible with +12V? Continue there:

Do you need decoder BCD to 16 (Yaesu band decoder) not only for antenna switch? Continue there:

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BCD TTL to DEC decoder board
Schematic and board pic	sch	brd
We believe open source is a better way of doing things. View and download the Shield Schematic and PCB files. The hardware designs are released under the Attribution-NonCommercial 2.0 Generic