> For the complete documentation index, see [llms.txt](https://mujoseph.gitbook.io/mujoseph-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://mujoseph.gitbook.io/mujoseph-docs/emma-mk1-drsstc/hardware-overview/electrical-design/busbar-periscope.md).

# Busbar Periscope

Like the [primary coil](/mujoseph-docs/emma-mk1-drsstc/hardware-overview/electrical-design/primary-coil.md), the busbar periscope was fabricated by [SendCutSend](https://sendcutsend.com/) out of 63 mil (1.6 mm) thick copper sheet. Both ends have two holes for M5 screws (plus a flat washer, lock washer, and nut), which were used to fasten to the [MMC Bank PCB](/mujoseph-docs/emma-mk1-drsstc/hardware-overview/electrical-design/pcb-design/mmc-bank.md) and the primary coil.

The busbar periscope provides a low-resistance, low-inductance path for the primary current between the *MMC Bank PCB* and the primary coil.

<div data-with-frame="true"><figure><img src="https://2297250131-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FzNHSl7dsTOS0XjlMXnIe%2Fuploads%2Fnd4GRVtwbYT7eV76hLPq%2Fimage.png?alt=media&amp;token=7a6b5124-5501-4f9f-9644-c091f21f7d4b" alt=""><figcaption><p>Left: Bus Bar Periscope<br>Center: Bus Bar Periscope connecting the MMC Bank PCB to the Primary Coil<br>Right: The Bus Bar Periscope exits the Ebox assembly via a slot through polycarbonate top. The<br>slot is capped with a 3D printed PETG hatch cover (A)</p></figcaption></figure></div>