diff --git a/.claude/settings.local.json b/.claude/settings.local.json
index a0cfcd3..0830dee 100644
--- a/.claude/settings.local.json
+++ b/.claude/settings.local.json
@@ -4,7 +4,13 @@
       "Bash(if [ -d .cursor/rules ])",
       "Bash(then ls .cursor/rules)",
       "Bash(fi)",
-      "Bash(python:*)"
+      "Bash(python:*)",
+      "Bash(d:/tx/transformer/.venv/Scripts/python.exe:*)",
+      "Read(//d/**)",
+      "Bash(.venv/Scripts/python.exe draw_toroid.py:*)",
+      "Bash(.venv/Scripts/python.exe:*)",
+      "Bash(git add .gitignore test_optimizer.py .claude/settings.local.json presets/windings.json)",
+      "Bash(git commit -m \"$(cat <<''EOF''\nAdd .gitignore and commit pending changes\n\n- Add comprehensive .gitignore for Python, Flask, IDE, and project-specific files\n- Include test_optimizer.py\n- Update Claude settings and windings preset configuration\n\n🤖 Generated with [Claude Code](https://claude.com/claude-code)\n\nCo-Authored-By: Claude <noreply@anthropic.com>\nEOF\n)\")"
     ],
     "deny": [],
     "ask": []
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..b33773c
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,50 @@
+# Python
+__pycache__/
+*.py[cod]
+*$py.class
+*.so
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+
+# Virtual Environment
+.venv/
+venv/
+ENV/
+env/
+
+# Flask
+instance/
+.webassets-cache
+
+# IDE
+.vscode/
+.idea/
+*.swp
+*.swo
+*~
+
+# OS
+.DS_Store
+Thumbs.db
+
+# Project specific
+*.png
+sweep_results.csv
+old/
+
+# Local settings
+.claude/settings.local.json
diff --git a/presets/windings.json b/presets/windings.json
index 3d05668..a988a59 100644
--- a/presets/windings.json
+++ b/presets/windings.json
@@ -5,8 +5,8 @@
         "name": "primary",
         "taps": [
           0,
-          25,
-          50
+          50,
+          25
         ],
         "awg": [
           20,
@@ -23,10 +23,10 @@
           50
         ],
         "awg": [
-          20,
           22,
-          28,
-          28
+          22,
+          22,
+          22
         ]
       }
     ]
diff --git a/test_optimizer.py b/test_optimizer.py
new file mode 100644
index 0000000..6f76ded
--- /dev/null
+++ b/test_optimizer.py
@@ -0,0 +1,90 @@
+from model import TransformerModel
+from optimizer import TransformerOptimizer
+
+# Create the same transformer as in app.py
+primary_taps = [0, 75, 75]
+secondary_taps = [0, 100, 150, 150, 150]
+
+primary_Rp_per_turn = [0.01, 0.01]
+secondary_Rs_per_turn = [0.004, 0.024, 0.024, 0.024]
+
+tf = TransformerModel(
+    Ae_mm2=354.0,
+    Ve_mm3=43900.0,
+    use_core_loss_model=True,
+    Np_total=150,
+    Ns_total=250,
+    primary_taps=primary_taps,
+    secondary_taps=secondary_taps,
+    primary_Rp_per_turn=primary_Rp_per_turn,
+    secondary_Rs_per_turn=secondary_Rs_per_turn,
+)
+
+# Test case: 300Hz, 10ohm, 25W target
+print("Testing with B_max_T=0.3T:")
+opt = TransformerOptimizer(tf)
+result = opt.optimize(
+    load_ohms=10.0,
+    target_power_W=25.0,
+    freq_hz=300.0,
+    Vp_min=5.0,
+    Vp_max=50.0,
+    Vp_step=0.5,
+    B_max_T=0.3,
+    Vs_max=200.0,
+    core_loss_W=0.0,
+    power_tolerance_percent=2.0,
+)
+
+if result:
+    print(f"Optimizer result:")
+    print(f"  Primary tap: {result.primary_tap}, Secondary tap: {result.secondary_tap}")
+    print(f"  Vp_rms: {result.Vp_rms:.2f}V")
+    print(f"  Efficiency: {result.efficiency*100:.2f}%")
+    print(f"  Power out: {result.P_out_W:.2f}W")
+    print(f"  B_peak: {result.B_peak_T:.4f}T")
+    print()
+
+print("\nTesting with B_max_T=0.35T:")
+result2 = opt.optimize(
+    load_ohms=10.0,
+    target_power_W=25.0,
+    freq_hz=300.0,
+    Vp_min=5.0,
+    Vp_max=50.0,
+    Vp_step=0.5,
+    B_max_T=0.35,
+    Vs_max=200.0,
+    core_loss_W=0.0,
+    power_tolerance_percent=2.0,
+)
+
+if result2:
+    print(f"Optimizer result:")
+    print(f"  Primary tap: {result2.primary_tap}, Secondary tap: {result2.secondary_tap}")
+    print(f"  Vp_rms: {result2.Vp_rms:.2f}V")
+    print(f"  Efficiency: {result2.efficiency*100:.2f}%")
+    print(f"  Power out: {result2.P_out_W:.2f}W")
+    print(f"  B_peak: {result2.B_peak_T:.4f}T")
+    print()
+
+    # Now try manual settings to see what 85% efficiency looks like
+    print("Manual test - trying different tap combinations:")
+    for p_tap in [1, 2]:
+        for s_tap in [1, 2, 3, 4]:
+            for Vp in range(5, 51, 1):  # 5V to 50V in 1V steps
+                try:
+                    sim = tf.simulate(
+                        primary_tap=p_tap,
+                        secondary_tap=s_tap,
+                        Vp_rms=Vp,
+                        freq_hz=300.0,
+                        load_ohms=10.0,
+                    )
+                    eff_pct = sim['efficiency'] * 100
+                    if sim['P_out_W'] >= 20 and sim['P_out_W'] <= 30:  # Close to target
+                        print(f"  p={p_tap}, s={s_tap}, Vp={Vp}V: Pout={sim['P_out_W']:.1f}W, eff={eff_pct:.1f}%, B={sim['B_peak_T']:.4f}T, Pcore={sim['P_core_W']:.2f}W, Pcu={sim['P_cu_W']:.2f}W")
+                except Exception as e:
+                    pass
+else:
+    print("No solution found!")