# Simulation of a gas filled lamp as a load?

Discussion in 'CAD' started by John Strupat, Jan 12, 2004.

1. ### John StrupatGuest

Hi,

Anyone have any ideas on how to model a gas filled lamp as a load for an 500
KHz power source.

How about coupling to a ferrite core or a open wire coil to the lamp?

Any ideas would be appreciated.

Thanks,

John

2. ### Kevin AylwardGuest

Here is a CCFL model from my SuperSpice lib. There is an example in the
demo.

*************
..SUBCKT CCFL_XN _ssi_pin0_1 _ssi_pin1_10
*
V_ssi_pin1 _ssi_pin1_10 10 0
V_ssi_pin0 _ssi_pin0_1 1 0
www.anasoft.co.uk
*Generic Cold Cathode Floresent Lamp model
* This model may be freely copied and used, provided this copyright
notice is included
*The model is based on, where G is the instaneous conductance,
*I=G(V,I)*V and dG/dt = aI^2 +b(I/V)^2 + f(I/V)
* the most general model is dG/dt = aI^2 + kIV + cV^2 + d(I/V)^3
+b(I/V)^2 + f(I/V)
*Note: UIC "use initial conditions" in transient setup must be used
*The tanh, divide and multiple by 1000 is to from a convergence limIter
to 1000 amps
B2 1 3 i=1000*tanh(v(1,2)*v(4)/1000)
v1 3 2 dc 0
c1 4 0 1 ic=.001
*integrator time constant resistor, ideal is very large, however make it
as small as the specific circuit allows
r1 4 0 0.1
*change the numerical constants to change the on characteristics
*core ccfl equation
b1 4 0 i=-(2.5*I(v1)^2 - 5.0e4*(I(v1)/v(1,2))^2 + 275.0*I(v1)/v(1,2))
cstray 1 10 100p
rleak 1 10 10Meg
*
*strike control, r diode and c controls turn on time, rrect and c
controls turn off time
*full wave rectifier, will keep switch on unless frequency falls too low
b3 s_1 0 v=abs(v(1,10))
s1 10 2 s_2 0 ccfl_switch
Cconverge 10 2 10p
d1 s_1 s_2 diode
rrect s_2 0 500k
cton s_2 0 0.5e-6
..model diode d(rs=1k)
*
*sets the strike voltage and holding voltage. Vstrike=vt+vh Vhold=vt-vh
..model ccfl_switch sw(ron=1 roff=100e6 vh=100 vt=300)
*
*these clamps are not used in ordinary operation
d3 1 12 ccfc_clamp_diode
d4 1 12 ccfc_clamp_diode
*
..model ccfc_clamp_diode d(rs=1 bv=750)
..ends
****************

Kevin Aylward

http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.

"That which is mostly observed, is that which replicates the most"
http://www.anasoft.co.uk/replicators/index.html

"quotes with no meaning, are meaningless" - Kevin Aylward.  