EEZ Bench Box 3

by Envox

Modular, open-source test & measurement chassis

View all updates Oct 21, 2020

Advice for assembling your BB3

by Denis Kotlar (a.k.a. prasimix)

The BB3 assembly season has begun! A good portion of backers have received their kits, assembled them, and have them up and running. However, in a small number of cases, some backers encountered issues with the supplied parts. The issues seen are:

  • The 16-pin IDC cable may be faulty (Item F, Fig. 3). The cable problem can be detected by visual inspection, and if it is connected between the AUX-PS and the MCU module, the MCU module will not work (nothing will appear on the display, no tone will be heard)
  • Missing M3 threads on two of the four holes on the Mean Well AC/DC converter mounting frame (Item 5, Fig. 1)
  • One Hexagonal M3×6 mm metal spacer (Item J, Fig. 3) may be missing
  • One or more M3×5 mm countersunk screws (Item M, Fig. 3) may be missing
  • You can find excess M3×4 mm screws (Item L, Fig. 3)
  • TFT display on enclosure front panel (Item 3, Fig. 1) came with broken glass

Feel free to contact us if you notice any such defect so that we can arrange a replacement.

One of our ardent supporters, GoJimmyPi, went a step further and addressed the issue of earthing (aka, grounding) the enclosure in a very creative way)! In fact, the enclosure is currently not completely unprotected because it has an earthed top cover when the Mean Well converters are connected. However, earthing for the front panel and bottom plate is missing.

In the assembly instructions, I added a link at the very beginning to Appendix A which describes what work is required if additional earthing is needed.

Thank you all for the helpful feedback, compliments, and comments. This feedback will help us push this project further. Feel free to join us on our Discord server and on the EEVblog forum where a lot of interesting discussions are taking place (a separate thread is available for BB3 Enclosure & Bare Boards backers).

About the Author

Denis Kotlar (a.k.a. prasimix)


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Support EEZ Studio Development

EEZ Studio is a cross-platform free and open source BB3 development environment but also attractive SCPI controller that is used to access many T&M devices using SCPI commands. Its development and support cost us money and your donation will help us to keep it alive and kicking.


BB3 - Starter (Without Peripheral Modules)

A BB3 enclosure kit without bare PCBs but with fully-assembled core modules (AUX-PS, MCU STM32F7, and BP3C DIB 3-slot backplane). The Starter provides an environment for experimenters who are willing to build their own modules or who want a specific BB3 configuration (such as a six-channel BB3).


BB3 - Two Channel (Full)

A BB3 starter kit and two full-featured DCP405 single-channel (40 V, 5 A) peripheral power modules, including an AC/DC power module for each. A two-channel programmable power source with advanced features: remote sensing, remote programming, a down-programmer, and additional OVP (with crowbar).


BB3 - Four Channel (Full)

A BB3 starter kit, two full-featured DCP405 single-channel (40 V, 5 A) peripheral power modules, and one dual-channel DCM220 peripheral power module. Includes all three necessary AC/DC modules. This is the two-channel full kit, expanded to include two additional programmable power sources.


DCP405 One Channel Module (Full)

A full-featured DCP405 single-channel (40 V, 5 A) peripheral power module with remote sensing, remote programming, a down-programmer and crowbar OVP. Includes an AC/DC module.


DCM220 Two Channel Module

A DCM220 dual-channel (2 x 20 V, 4 A) peripheral power module and its AC/DC module.


Cable Set

Two pairs of high quality, silicone, color marked (black-red), 1 m connecting cables; a pair of clip-on probes; and a pair of insulated crocodile clips.


BB3 Enclosure & Bare Boards

A BB3 enclosure kit with a wire harness, nuts and bolts for the three core modules, a 4.3" TFT touchscreen display, an encoder knob, and an 80 mm fan. Includes a set of bare PCBs for building the three core modules (AUX-PS, MCU STM32F7, and BP3C DIB 3-slot backplane) as well as PCBs for building one DCM220 two-channel peripheral power module and two single-channel peripheral power modules (either the DCP405 or the DCP405B, as they can be assembled using the same PCB). Suitable for builders with the necessary skill, time, and patience.



Envox d.o.o. is home of the Envox Experimental Zone (EEZ), an open source initiative to bridge the gap between DIY / hobbyist / educational / low-budget and professional / commercial test and measurement solutions.

Denis Kotlar (a.k.a. prasimix)

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