Hello, I try to simulate under Kicad V8.0.6 a Cockcroft-Walton Generator. To not start from scratch I try to use a circuit with CD40106 (already answered in this forum) and I get an error when interconnecting pins to this device for Spice simulation. Here spice result :
Ok thank @janharm I download the spice model from TI website, I use (or want to use) 40106 not 4049, not understand “gnd 0” ?!!? sorry.
Following your suggestion, I duplicate the first cell like this :
Nice the simulation works, I would expect that the generator should generate a high voltage. Note the inverters connect the output to 9V (when high) or 0V (when low) so the voltage vout will not rise above 9 Volts. In this sense the simulation is correct.
Thanks @RobK you’re right, in my mind it’s based on CW but it is close too a charge-pump, I don’t know how to name it?
The simulation fail probably due CD40106 simulation file not including good AC performance (which I don’t know how to add it). A classic CW uses an sinusoidal AC source, here the first door is used as an oscillator, others are used to “phase shift” the signal (Each cell invert previous) these out-of-phase signals are then used to control the different sections of diodes and capacitors. It is not the “classic” topology where only one AC signal fuels the entire waterfall. In other words, it is an implementation of load pump that uses serial inverters to provide clock signals (with phase alternation) to each “floor” of diodes/capacitors, rather than a single AC source as in the traditional CW. It is a clever method for generating load pump tensions without the need for multiple transformers or complex external clock sources. Probably we need to use a better diode model and Capacitor too? No idea …
Excellent! I discover this circuit thanks to you! I’ll try to simulate this on Kicad (that use ngpice) to observe the same signal reaching 50V at the end! thanks to you
Thank you @paulvdh for the link. It seems that Ngspice is more limited than LTspice at least for this type of representation. Even with simplified models of inverter and diodes it seems that the resolution with Ngspice confronts concerns of convergence and singular matrix. @RobK On your diagram I see a 10nS TD and a VHIGH = 9V Can you give the models you use for the inverter and the diodes? Perhaps they will work with Ngspice?
Here my new schematic :