WTE MReX-PCB User Manual Download Page 7

Christchurch, NZ

MReX-PCB User Guide V1.02

LEDs Outputs

Connecting the LEDs using Open Drain (bypassing PCB resistors)

 The LED outputs are open drain/collectors suitable for sinking a maximum of 50mA.  The example
is being used to drive an LED from an external supply.  Should the output be presented to potential 
ESD conditions (such as any terminal screw or external connection), ESD devices should be fitted.  
If the output is to be used to control a small relay, it is essential that a flyback diode is fitted across 
the coil of the relay. 

Only the Cathode connections of the LEDS are shown here.  They are connected to an open drain 
output.  As shown in the simplified schematic above, it is the users responsibility to select a resistor 
that suits the application, and then connect to a suitable power source that has a common GND.

© WTE Limited, 2021 – Christchurch New Zealand

           

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Summary of Contents for MReX-PCB

Page 1: ...Christchurch NZ MReX PCB User Guide V1 02 MReX PCB Mini Transmitter User Guide WTE Limited 2021 Christchurch New Zealand Page 1 of 13...

Page 2: ...Contents Introduction 3 Electrical 4 PCB Pinout 5 Programming the MReX Module 6 Inputs 6 LEDs Outputs 7 LED Piezo Resistor Configuration 8 Piezo connection 10 Physical Dimensions 12 Disclaimer 13 WTE...

Page 3: ...to a system and incorporates the MReX 460 Module For command use and detailed operation consult the MReX 460 User Manual Not shown is the antenna connection This may be an SMA connector fitted to the...

Page 4: ...Christchurch NZ MReX PCB User Guide V1 02 Electrical The following schematic shows how the MReX 460 module is routed to connection pads WTE Limited 2021 Christchurch New Zealand Page 4 of 13...

Page 5: ...trically tied to pin 7 7 Green LED Cathode open drain output 8 Green LED Anode not connected if LED is powered externally 9 Piezo This pin is electrically tied to pin 8 10 Contact Input 4 Connection t...

Page 6: ...loading configuration or uploading new firmware Do NOT apply voltage to this pin if batteries are fitted Note Serial connection is 3 3V TTL The MReX PROG USB to serial adaptor can be provided for seri...

Page 7: ...rminal screw or external connection ESD devices should be fitted If the output is to be used to control a small relay it is essential that a flyback diode is fitted across the coil of the relay Only t...

Page 8: ...ezo sounder is fitted R1 47R R2 is used by the piezo to improve audio response 1K typically The resistor fitted should ideally be selected to produced the greatest audio output R3 is used to limit cur...

Page 9: ...Christchurch NZ MReX PCB User Guide V1 02 WTE Limited 2021 Christchurch New Zealand Page 9 of 13...

Page 10: ...Christchurch NZ MReX PCB User Guide V1 02 Piezo connection The following images guide the connection of the piezo and required resistors WTE Limited 2021 Christchurch New Zealand Page 10 of 13...

Page 11: ...Christchurch NZ MReX PCB User Guide V1 02 WTE Limited 2021 Christchurch New Zealand Page 11 of 13...

Page 12: ...Christchurch NZ MReX PCB User Guide V1 02 Physical Dimensions Overall board dimensions WTE Limited 2021 Christchurch New Zealand Page 12 of 13...

Page 13: ...hat are imposed on importation No User Serviceable Components There are no user serviceable components within the product RoHS and WEEE Compliance MReX is fully compliant with the European Commission...

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