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Basic Bridged-T Notch Filter

The program NOTCH calculates the required capacitor and resistor to null out an undesired frequency.

Inputs: inductance (H), frequency to nullified (Hz), resistance of the required coil (Ω)

Source: Rosenstein, Morton. Computing With the Scientific Calculator Casio: Tokyo, Japan. 1986. ISBN-10: 1124161430

Program NOTCH
244 Bytes, 12/22/2016

Code:
```10 DESTROY L,F,I,C,R 20 DISP “INDUCTANCE” @ WAIT 1 22 INPUT “in H: “; L 24 DISP “FREQUENCY” @ WAIT 1 26 INPUT “in Hz: “; F 28 DISP “COIL’S RESISTENCE” @ WAIT 1 30 INPUT “in Ω: “; I 40 C = 1/(2 * PI^2 * F^2 * L) 42 R = (PI * F * L)^2 / I 44 DISP “NOTCH CAPACITOR” @ WAIT 1 46 DISP C; “ F” @ PAUSE 48 DISP “NOTCH RESISTENCE” @ WAIT 1 50 DISP R; “ Ω”```

Notes:
Capital Omega Character (Ω): [ g ], [RUN] (CTRL), [ Q ]

Example: L = 0.12 H, F = 1170 Hz, Coil Resistance = 30 Ω
Output:
NOTCH CAPACITOR ≈ 3.08402 * 10^-7 F
NOTCH RESISTENCE ≈ 6485.04070 Ω
Reference URL's
• HP Forums: https://www.hpmuseum.org/forum/index.php
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