Site under construction — check back daily for updates
Capacitor Visualizer
Electronics + Circuit Fabrication
A physical circuit designed to demonstrate the use of a capacitor as a timer through charging, discharging, and visible LED output.
Type
Analog Circuit
Timing
Capacitor
Interface
PBNO Push Buttons
Circuit
ACES PCB
Enclosure
3D Printed
Project Context
The Capacitor Visualizer was developed to demonstrate how a capacitor can be used as a timer. The project progressed through a breadboard prototype, a soldered ACES PCB, and a final 3D-printed enclosure.
Reference
01
Charging and discharging a capacitor is translated into a visible change through a yellow LED and a red/green bi-colour LED.
The main circuit components are three 470 Ω fixed resistors, one yellow LED, one bi-colour LED, a 1mF capacitor, and two PBNO push buttons.
The push buttons control the charging and discharging states of the capacitor, making its behaviour visible through the LED outputs.
02
The circuit visualizes the time required for a capacitor to accumulate and release charge.
Capacitance is measured in farads. The report also uses tau as a measurement of the charging time of a capacitor. One tau represents the time required for the capacitor to charge to 63% of the source voltage.
The next tau represents the time required to charge to 63% of the remaining source voltage. After five taus, the capacitor is considered charged.
03
Different resistance and capacitance combinations were compared using theoretical and observed charging times.
Resistance
Capacitance
Theoretical 5τ
Observed 5τ
1,000,000 Ω
10 µF
500 s
540 s (6V)
10,000 Ω
100 µF
50 s
120 s (7V)
470 Ω
1000 µF
2.35 s
12 s (7.65V)
04
The LED states provide a visual representation of current flow as the capacitor charges and discharges.
Charge
Button 1
Pressing the first PBNO button causes current to flow clockwise. The red LED turns on and slowly dims as the capacitor fills.
Discharge
Button Released
When button 1 is released, current flows counter-clockwise as the capacitor releases its stored charge.
Dual Input
Both Buttons
When both buttons receive input, current flows clockwise, the capacitor fills halfway, and the red and yellow LEDs remain on without dimming.
05
Development began by assembling and testing the circuit on a breadboard.
The breadboard prototype was the first of three stages in the project. The circuit was assembled using the required components and tested before progressing to the permanent PCB.
Breadboard Prototype
Initial capacitor visualizer circuit
06
Once the breadboard prototype was functional, the circuit was transferred to a permanent PCB.
An ACES PCB was provided for the second stage of the project. The circuit components were soldered to the board and the completed PCB was tested before moving into the enclosure.
07
The completed PCB was integrated into a 3D-printed ACES case to create the finished device.
The enclosure was the third stage of the project after breadboard testing and PCB assembly.
The final assembly uses four heat synced rivets, the ACES Capacitor Visualizer PCB, a female barrel jack, and the 3D-printed ACES case.
08
Parts Table
Qty.
9V DC Alkaline Battery
1
Female Barrel Jack
1
470 Ω Fixed Resistor
3
5mm Bicolor LED (R/G)
1
5mm Yellow LED
1
1mF Capacitor
1
PBNO Push Buttons
2
3D Printed ACES Case
1
Heat Synced Rivets
4
ACES Capacitor Visualizer PCB
1
Piece of Heat Shrink
1
Wires
Assorted
09
The final Capacitor Visualizer packages the charging and discharging circuit into a permanent PCB and 3D-printed enclosure.
Capacitor Visualizer
Completed device
PCB + Enclosure
Final circuit assembly