Circuit Design
What you need to know about some of the components
Capacitor
The Capacitor and the Inductor in this circuit act to stabilize the voltages that are output by the transistor. We use values between 100pF-100 microF.
Power Supply
We chose a true 12 Volt power supply for our circuit. This means that the V+ is 12 V and the V- is 0V.
Transistor
The Transistor is acting as a switch in our circuit. We use the arduino to PWM this to deliver a higher voltage and current to our circuit. We chose an N-channel Mosfet because we had those parts on hand. Ideally we would have used a P-channel but with Covid-19 purchasing additional parts was unfeasible.
Diode
We chose high switching diodes for our circuit to better control where the current would flow.
Inductor
The Capacitor and the Inductor in this circuit act to stabilize the voltages that are output by the transistor. We use values between 100pH-100 microH.
Step 1
The user inputs their desired voltage on the keypad and presses enter.
Step 2
The Arduino then calculated the appropriate PWM value to output. The Arduino will then output the appropriate voltage to control the MOSFET
Step 3
At this point the MOSFET is regulated by the Capacitor and the Inductor. The Load (Electrochemical Cell) is in parallel with the Capacitor.
Step 4
In parallel with the Capacitor is a voltage divider to which an Analog pin is wired. This allows the Arduino to sense the voltages that are across the Load. If the voltages are higher than expected the Arduino will compensate for that by raising or lowering the PWM rate depending on if the voltage is higher or lower than the expected voltage.
Step 5
In series with the load is a measurement resistor that is used to measure the current through the Load.
How Does It Perform?
Analysis
This diagram shows exactly how the power circuit works. The PWM values of the Arduino are mapped to the maximum and minimum values of the user's powers supply. The diode, inductor, and capacitor stabilize the voltages by continuing to supply current and voltage even when the circuit is "off" or when the PWM is in the "low" state.
