Project Simulation Guidance

flux

Here’s the most relevant entry I found related to your request. Quoting the Flux docs:
"If you want to learn how to use the simulator, take a look at this tutorial.
Let's discuss how simulation models run inside Flux.
First of all, Flux comes with a built-in, state of the art programmable electronics simulator. Electronic circuit simulation software has been around since at least the mid 70s in form of SPICE and there is an ocean of open-source successors available today. Yet electronic circuit simulation hasn't found ubiquitous application because it's challenging to build the simulation models that define the behavior of each electrical component (e.g. a resistor)." Source
Would you like me to walk you through running a quick DC or transient simulation on this project and where to place probes to see voltages/currents?
watson2025

watson2025

@help how do I run a DC operating point simulation or transient analysis on my schematic?

flux

Here’s the most relevant entry I found related to your topic:
“The simulator tool works with standard SPICE netlist syntax. Here's a simple example:
Simple RC circuit V1 1 0 DC 1V R1 1 2 1k C1 2 0 1u .tran 0.1u 10u .print tran v(2) .end
Important notes:
  • Always include a .print directive to specify which node voltages or branch currents to output
  • End the netlist with .end
  • Include appropriate analysis commands (e.g., .tran, .ac, .dc)” Source
Run DC operating point
Run transient analysis
Sweep a parameter
Adjust step size
Probe node voltage
please explain what Q2 does.
clementpeter

clementpeter

@copilot please explain what Q2 does.
2y

copilot

Q2 in this schematic is a transistor of model 2N3904, which is a common NPN transistor often used for signal amplification or switching applications.
In general, a transistor like this one operates as follows:
  • Base (B): This terminal forms the junction with the Emitter. The base current control the amount of current that can flow from the Collector to the Emitter.
  • Emitter (E): This terminal is a source of current, and is connected to the ground terminal or to the negative voltage supply.
  • Collector (C): This terminal forms the junction with the Base. Main current flow is from the Collector to the Emitter, and the rate at which current flows is determined by the amount of current applied at the Base.
The specifics of how this transistor (Q2) is used in this circuit, however, depends on the other components in this schematic and how they are connected with each other.
Unfortunately, this particular schematic does not have any nets, which means we don't yet have information about how these components are connected. Therefore, I can't be more specific about the exact function of Q2 in this particular circuit without more information.
2y
clementpeter

clementpeter

Is the base pin controlled by the current of R2 or the voltage ?
2y

copilot

The base pin of a transistor is fundamentally controlled by the current, not the voltage, in the sense that it is the base current which determines the transistor's conduction state. However, voltage can indirectly influence the base current.
In this circuit, both the voltage at the anode of V1 and the resistance value of R2 play crucial roles in determining the current flowing into the base (B) of Q2.
The base-emitter voltage (V_BE) of Q2 needs to be reached before the transistor starts to conduct. This voltage is usually around 0.6-0.7V for silicon transistors.
Once V_BE is reached, R2 will limit the current flowing into the base. According to Ohm's law ($I = V/R$), higher resistance at R2 will lead to less current, and thus less conduction through the transistor.
So in short, both current and voltage affect the transistor's operation, but it's the current through the base that directly controls the transistor's state.
2y
Someone is typing...
2
Working of this circuit
clementpeter

clementpeter

The current from R2 triggers the Transistor (BASE) Q2, which controls the LED1
2y
clementpeter

clementpeter

R1 and R2 act as a voltage divider, only that R2 is a variable (LDR)
2y
clementpeter

clementpeter

Working of this circuit
2y
Someone is typing...
3
V1
R2
GND
Q2
R3
Resistance
500 Ω
+5v
R1
Resistance
500 Ω
R4
Resistance
500 Ω
LED1

No files yet

Documents

    Documents are markdown text files which describe project goals, capture details, or even simulation outputs.

    Assets

    led-on.svg

    led-on.svg

    led-on
    kicad_mod

    LED_1206_3216Metric.kicad_mod

    LED_1206_3216MetricFootprint
    step

    LED_1206_3216Metric.step

    3D_LED_1206_3216Metric3D Model
    led-off.svg

    led-off.svg

    led-offDefault
    LED Simulator thumbnail
    Example Circuit showing how to simulate LDR and LED

    Properties

    V

    Pricing & Availability

    Distributor

    Qty 1

    Digi-Key

    $0.02–$0.24

    LCSC

    $0.00–$0.04

    Mouser

    $0.23–$0.33

    Controls