Can we fix a dead nebula projecting spaceman?

Summary

The transcript describes troubleshooting an astronaut nebula laser projector that arrived dead on delivery. The user methodically tests each component, determining the power cable was faulty. Upon disassembly, the internal construction and circuits are compared to a previous model, revealing differences in the power supply, control boards, motors, and unusual optical assembly. Although fixed with a new cable, the performance seems inferior to the prior version, but still produces an intricate laser effect when directly illuminating the optical components.

Takeaways

• 😀 The video details repairing a broken astronaut nebula projector.
• 😞 The projector was dead on arrival but the seller refunded and didn't want it returned.
• 🔌 The projector cable was faulty, replacing it fixed the issue.
• 👀 The internal design was very different from a similar previously repaired projector.
• 🔋 It uses a buck regulator power supply circuit to provide efficient 3.6V.
• 👂 Infrared remote control signal is passed directly to the LED board.
• ⚙️ The LED board can drive 4 motors, a laser and RGB LEDs.
• 🔦 The optical assembly is less efficient than the previous projector.
• 🪟 A rotating rippled glass disc and mirror reflect the laser beam.
• 📐 Firing the raw laser through the optics creates a complex morphing effect.

Q & A

What was the issue with the astronaut nebula projector that arrived?

It was completely dead on arrival, even though nothing looked burnt or damaged. It simply would not power on.

What was determined to be the root cause of the issue?

The faulty cable - once it was swapped out with a cable from another unit, the projector began working.

How does the infrared receiver function if it's enclosed inside the backpack?

It's unclear how the infrared signals can reach the receiver inside the enclosure. This was noted as a questionable design choice.

How does the optical assembly in this unit differ from the previous one examined?

Instead of a spinning diffraction disc, there is a rotating mirrored rippled glass disc that the LED shines through. This provides a more complex rippling effect.

Why is the light output of this projector less than the previous one?

The light passes through the rippled disc twice, losing intensity. The previous design had simpler, more direct optics.

What regulated power supply circuitry was found in the lower section?

A buck regulator using an MT2492 chip, along with an inductor, filters the input down to a steady 3.6V supply for the circuits.

What functionality does the microcontroller section provide?

It controls the motor, laser and LEDs via transistors and MOSFETs. There are 4 motor channels and 3 LED channels for red, green and blue.

What simple hack provided an interesting alternate lighting effect?

Shining the laser directly into the optical assembly, rather than the LED. This created a complex rippling projection.

Why might there be 4 motor channels when only 1 motor is used?

It's unclear - perhaps for compatibility with other products or configurations that need more motors.

What are the overall conclusions about this astronaut projector?

While an easy cable fix, the optics don't perform as well as the previous unit. But the circuitry and mechanics are still quite interesting.