S A M C H I N

how to make almost anything | fall 2017

Week 8: Output Devices


Week 8. Output Devices. This week I returned to the solenoids I made in Week 6. I began trying a new two-layer board. The top layer is ground and the bottom layer is vinyl. (I plan on substituting this vinyl for heat-resistant epoxy in newer revisons.)





When designing these two layer boards it is important to connect all of the copper tape directly to the pad with solder for a reliable connection.
This revision still didn't work and had issues with the power, so I re-designed the board again.

This board seemed more viable. I added some resistors to bias the board properly and a capacitor to the regulator for the feedback loop.

Note: for people using the RFD16N05LSM MOSFETs, the data sheet Vgs is incorrect 1-2V is not the correct range. Refer to the performance curve diagram for the correct details.
After (finally!) properly biasing the MOSFETs, it works: