diff options
Diffstat (limited to 'plugins/ZamTube/triode.cpp')
| -rw-r--r-- | plugins/ZamTube/triode.cpp | 33 |
1 files changed, 22 insertions, 11 deletions
diff --git a/plugins/ZamTube/triode.cpp b/plugins/ZamTube/triode.cpp index 35e0b35..dfa2505 100644 --- a/plugins/ZamTube/triode.cpp +++ b/plugins/ZamTube/triode.cpp @@ -24,6 +24,18 @@ T Triode::compute(T a, T R, T Vg, T Vk) { } T Triode::getIa(T Vgk, T Vpk) { + static bool prepared = false; + static double coeff[3]; + + if (!prepared) { + const double L2 = log(2.0); + const double scale = 2e+9*pow(L2, kx-2.0)/(8.0*pow(kp, kx)); + coeff[0] = 8.0*L2*L2*scale; + coeff[1] = kx*kp*L2*4.0*scale; + coeff[2] = (kp*kp*kx*kx + L2*kp*kp*kx - kp*kp*kx) * scale; + prepared = true; + } + if (Vpk < 0.0) { //printf("Less than zero!\n"); Vpk = 0.0; @@ -32,14 +44,16 @@ T Triode::getIa(T Vgk, T Vpk) { Vgk = 0.0; } - T e1 = Vpk*log1p(exp(kp*(1./mu+Vgk/pow(kvb+Vpk*Vpk, 0.5))))/kp; - if (e1 < 0) { - return 0.; - } - T test = 1e+6*pow(e1, kx) / kg1; - //printf("XXX Ip=%f lut=%f diff=%f vgk=%f vpk=%f\n", test, test2, test2-test, Vgk, Vpk); - return test; + double A = 1./mu + Vgk / sqrt(kvb + Vpk*Vpk); + return (coeff[0] + coeff[1]*A + coeff[2]*A*A) / kg1; + /* exact solution (takes > 300x longer) + e1 = Vpk*log1p(exp(kp*(1./mu+Vgk/sqrt(kvb+Vpk*Vpk))))/kp; + if (e1 < 0) { + return 0.; + } + return 1e+6*pow(e1, kx) / kg1; + */ } T Triode::evaluateImplicitEquation(T Vak, T Vgk, T a, T R){ @@ -55,13 +69,10 @@ T Triode::iterateNewtonRaphson(T x, T dx, T Vgk, T a, T R){ Triode::Triode() { - insane = true; - - //12AX7 EHX-1 + //12AX7 RSD-1 kvb = 300.; mu = 103.2; kx = 1.26; kg1 = 446.0; kp = 3.4; } - |