copilot

• Pin + is connected to R1:P1 and L1:1 via Net 3.
• Pin P3 is connected to U2:2 via Net 1.
• Pin P4 is connected to Net 2.
• Pin - doesn't have a specific net assignment in your project's description.

• The AC inputs are usually connected to pins P3 and P4.
• The DC output is typically across pins + (positive) and - (negative).

• Connect the AC power source to D1:P3 and D1:P4.
• Connect load/next circuit stage from D1:+ and D1:-.

copilot

• IC: BP2861CJ
• Bridge Rectifier: For converting AC to DC. e.g., ABS10
• Inductor: Needed for the buck converter. e.g., CD54NP-220MC or CD75T125NP-471KC
• Capacitors: For filtering. e.g., C1206X103K102T or 6.3TZV330M6.3X8
• Resistors: For current sensing and feedback.
• FET: Internal to the BP2861CJ
• LED String: Utilize existing LED components such as S2-2835WOA-1W
• Fuse: e.g., TB60

1. AC Input and Rectification:
   • Use the AC-LINE and AC-NEU as the AC input.
   • Connect AC-LINE and AC-NEU to the bridge rectifier BD1.
2. Rectifier Output Smoothing:
   • Connect the DC output of BD1 to a smoothing capacitor like C1.
3. Buck Converter Stage:
   • Connect BD1:+ to U1:HV.
   • Connect U1:DRAIN to L1:1.
   • Connect L1:2 to LED string's anodes.
   • Place a capacitor (e.g., C3) parallel to the output for smoothing.
   • Connect feedback and compensation resistors to U1:CS.
4. LED Output Stage:
   • Ensure the LED array supports the output voltage of $81 \, V$ and current of $105 \, mA$.
   • Connect LEDs in series to achieve the required voltage and current.
5. Feedback and Current Sensing:
   • Calculate and connect appropriate resistor values for feedback and current sensing, ensuring the output voltage and current are within required parameters.
   • Use resistors like R1, R2, and feedback connections to U1:CS.

• Ensure all components are rated for the voltages and currents involved, especially the input stage and smoothing capacitors.
• The power factor correction might require more components if required.
• Validate design calculations such as inductor and capacitor values using design formulas for buck converters.

copilot

• Input Voltage (V_in_rms): 220 V AC
• Input Power (P_in): 9 W
• Power Factor (PF): 0.5
• Output Current (I_out): 30 mA
• Frequency: 100 Hz

1. Calculate DC Input Voltage after Rectification (V_in_dc):
   The AC RMS voltage is converted to a DC peak voltage using the formula:
   $$V_{\text{in\_peak}} = V_{\text{in\_rms}} \times \sqrt{2}$$
   The average rectified voltage can be approximated as:
   $$V_{\text{in\_dc}} = \frac{2 \cdot V_{\text{in\_peak}}}{\pi}$$
2. Calculate the Load Resistance (R_load):
   Using the power factor and input power:
   $$R_{\text{load}} = \left(\frac{V_{\text{in\_rms}}^2}{P_{\text{in}} \times PF}\right)$$
3. Calculate Capacitance (C):
   The ripple voltage ($V_{\text{ripple}}$) is estimated using:
   $$V_{\text{ripple}} = I_{\text{out}} \times \frac{1}{f \times C}$$
   Solving for $C$, we have:
   $$C = \frac{I_{\text{out}}}{V_{\text{ripple}} \times f}$$

Python
import numpy as np

# Given values
V_in_rms = 220  # RMS input voltage in V
P_in = 9       # Input power in W
PF = 0.5       # Power factor
I_out = 30e-3  # Output current in A
f = 100        # Frequency in Hz

# Step 1: Calculate the DC input voltage after rectification
V_in_peak = V_in_rms * np.sqrt(2)
V_in_dc = (2 * V_in_peak) / np.pi

# Step 2: Calculate the load resistance
R_load = (V_in_rms**2) / (P_in * PF)

# Assume ripple voltage as 5% of V_in_dc for calculation
V_ripple = 0.05 * V_in_dc

# Step 3: Calculate the capacitance
C = I_out / (V_ripple * f)

V_in_dc, R_load, V_ripple, C

• DC Input Voltage (after rectification): ( 198.07 , \text{V} )
• Load Resistance (R_load): ( 10755.56 , \Omega )
• Assumed Ripple Voltage (5% of DC voltage): ( 9.90 , \text{V} )
• Capacitance (C1): ( 30.29 , \mu\text{F} )