Light Box Project
Light Box Project
Embedded Files
A portable light with the ability to modulate brightness and switch between blinking and continuous modes, with a custom-made PCB and 3-D printed enclosure.
A portable light with the ability to modulate brightness and switch between blinking and continuous modes, with a custom-made PCB and 3-D printed enclosure.
User Needs
Switch operated
On/off switch
Toggle between continuous/blinking modes
Rotary knob to adjust brightness
Portable
Self-contained, single-sided printed PCB board
Under 3 inches in all dimensions
Under 0.5 lb
Safety
Powered with a voltage-regulated, 9v battery
Survives 3 foot drop
Enclosure is sealed and air gaps are minimized
Secure mounting of all internal components
Reduced protrusion of switches and knobs
Ease of Use
Battery replacement under 5 minutes
Replicable
CAD drawings and models
Costs ≤ $20 to duplicate
Design Specifications
Circuit Schematic
A circuit was modeled in KiCAD and printed onto a single-sided PCB board. This circuit used a 5V voltage regulator to provide power to 555 timers. The 555 timers were used to create PWM signals to alter brightness and a slower, 2 Hz signal for the blinking stage. BJTs were used alongside switches to combine the signal from the 555 timers with the original 9 V battery power.
A circuit was modeled in KiCAD and printed onto a single-sided PCB board. This circuit used a 5V voltage regulator to provide power to 555 timers. The 555 timers were used to create PWM signals to alter brightness and a slower, 2 Hz signal for the blinking stage. BJTs were used alongside switches to combine the signal from the 555 timers with the original 9 V battery power.
PCB
Enclosure CAD
Exploded View of Box
Exploded View of Box
PCB included
Upside-down Exploded View of Box
Upside-down Exploded View of Box
PCB included
The PCB is placed upside-down and attached to the middle section of the box via bolts and nuts. The upside-down configuration leaves more room for the battery and wires after soldering.
The PCB is placed upside-down and attached to the middle section of the box via bolts and nuts. The upside-down configuration leaves more room for the battery and wires after soldering.
Testing
Testing
Blinking Frequency
Blinking Frequency
To determine the blinking period, the amount of time on the oscilloscope screen was divided by the number of blinks that occurred during that time.
Duty Cycle
Duty Cycle
The duty cycle was calculated by dividing the time the LED was on by the amount of time between blinks.
Mode Brightness
Mode Brightness
The brightness was estimated using the max voltage across the LED during blinking mode.
The device met the ideal values for blinking, duty cycle, and consistent brightness.
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