4 channel Blynk Board

Hello, Guys
This is my college project. In this project, we have made 4 channel Relay board with built-in wemos D1 Mini as controller.we have made this PCB layout in EDA online pcb design tool. It is really easy to use.We have made this PCB by the manual etching process.
Many thanks to @Costas for helping me.& as all always many thanks to Blynk team for making Amazing Platform.
You can access my project here & you can also make changes to it.


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Always good to see people etching their own pcbs :slight_smile:

Great project!

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some recommendations:

  • in next pcb design use cooper pour. it will reduce by ~80% the amount of cooper should be removed, thus prolong the etcher lifetime / save money / environment

  • for high current zones (relays for example) use wider traces and bigger pads. there are online trace width calculators for this. bigger pads are also welcomed on high heat parts or mechanical stress suspected zones, like buttons, connectors, fuse holders etc.

  • i do not know the transistor type used for the relays, (maybe it is already built in), but usually on inductive loads (coils, relays, motors) it is good practice to use diodes to neutralise the voltage coming from the coil kickback when turning off the transistor. without diode, it can kill the mosfet / transistor. (you can find lots of info online)


Thank you so much @wanek.I will consider all the parameters you mentioned.