Today, I completed the initial design of the enclosure for the 1×2 audio switcher. Although this “enclosure” isn’t yet a true casing in the strict sense, it currently consists of a frame structure built with four standoffs. Still, in my view, this form is already quite close to the final product.
The internal PCB circuit adopts a stacked structure, comprising two simple, clearly divided circuit boards: one dedicated to battery charging and discharging management, and the other focused on audio signal switching control.
Although the overall circuitry is not complicated, there are still a few details worth documenting and sharing:
First is the audio signal switching section. I deliberately avoided using common electronic switch ICs or simple mechanical toggle switches. The main reason is that electronic switch ICs tend to continuously consume power even in standby mode, while traditional mechanical switches, although reliable, simply don’t feel “cool” enough.
In the end, I opted for a magnetic latching relay as the core solution. While this is still fundamentally a mechanical structure, it requires short electrical pulses to drive, making it more energy-efficient. More importantly, it allowed me to learn and apply more electrical knowledge during the build — making the process both fun and technically enriching.
I also explored something new in the power management section. Given the constraints on size and capacity, I chose a small-capacity lithium battery this time, which differs from the large-capacity lithium battery solutions I’m more familiar with.
Whether for charging or protection, the parameters and implementation methods are slightly different. To adapt to this, I selected a new power management IC and successfully completed the design and debugging.
Though this was a new approach for me, the general principles of lithium battery management are quite consistent, so the process went smoothly.
The two design details that gave me the greatest sense of achievement are:
Audio Mute Button: I used a tactile switch to achieve a bi-stable toggle with each press. This makes the operation more intuitive and straightforward, while also keeping the front panel design clean and minimal — aligned with the concept of “foolproof operation.”
Charging Status Indicator: Next to the Type-C charging port, I added a dual-color LED that lights up red during charging and green when the battery is fully charged. Like the mute button, this approach aims to convey clear and concise information through a minimalist design language.
Next, I plan to spend some time creating a REAL enclosure to turn this prototype into a more polished, usable product.