IGBT simple series resonance modelling not working

[Simon Australia.]

Hi there

I have a problem. I am using Circuitmaker PRO (student version) and
specifically the simulation component SPICE in it to model simple
resonance and IGBT switching.

1. I initially constructed a circuit with a capacitor in series with
an inductor and used a signal generator model to feed the simple
circuit with a square wave at the resonant frequency. It worked. I
identified a siginficant gain across the coil due to voltage
magnification.

2. I then placed a DC source in series with the same capacitor/coil
combination but this time placed an IGBT (the switch) in series
sinking to ground. I sent a square wave into the gate of the IGBT. I
wanted to achieve the same result as in (1) above. IT DIDNT WORK. I
have tried having the IGBT above the cap/coil combination and below
it. I have tried reverse biasing part of the square wave and that
didnt work.

Do I need to change the modelling program... it still uses spice...

I would have thought that it was possible to use an IGBT as a switch
to create a square wave through the cap/coil combination. CAN SOME ONE
GUIDE ME RE THE STRUCTURE OF THIS SIMPLE SERIES RESONANT CIRCUIT WITH
A IGBT SWITCH?

I would really appreciate some ideas on this....

Kind Regards
Simon

 

[Terry Pinnell]

Hi there

I have a problem. I am using Circuitmaker PRO (student version) and
specifically the simulation component SPICE in it to model simple
resonance and IGBT switching.

1. I initially constructed a circuit with a capacitor in series with
an inductor and used a signal generator model to feed the simple
circuit with a square wave at the resonant frequency. It worked. I
identified a siginficant gain across the coil due to voltage
magnification.

2. I then placed a DC source in series with the same capacitor/coil
combination but this time placed an IGBT (the switch) in series
sinking to ground. I sent a square wave into the gate of the IGBT. I
wanted to achieve the same result as in (1) above. IT DIDNT WORK. I
have tried having the IGBT above the cap/coil combination and below
it. I have tried reverse biasing part of the square wave and that
didnt work.

Do I need to change the modelling program... it still uses spice...

I would have thought that it was possible to use an IGBT as a switch
to create a square wave through the cap/coil combination. CAN SOME ONE
GUIDE ME RE THE STRUCTURE OF THIS SIMPLE SERIES RESONANT CIRCUIT WITH
A IGBT SWITCH?

I would really appreciate some ideas on this....

Kind Regards
Simon

Can you show your schematic? Either in ASCII here, or (preferably) as
an image at a specified web page, or attached to a post in
alt.binaries.schematics.electronic.

 

[R.Legg]

Hi there

I have a problem. I am using Circuitmaker PRO (student version) and
specifically the simulation component SPICE in it to model simple
resonance and IGBT switching.

1. I initially constructed a circuit with a capacitor in series with
an inductor and used a signal generator model to feed the simple
circuit with a square wave at the resonant frequency. It worked. I
identified a siginficant gain across the coil due to voltage
magnification.

2. I then placed a DC source in series with the same capacitor/coil
combination but this time placed an IGBT (the switch) in series
sinking to ground. I sent a square wave into the gate of the IGBT. I
wanted to achieve the same result as in (1) above. IT DIDNT WORK. I
have tried having the IGBT above the cap/coil combination and below
it. I have tried reverse biasing part of the square wave and that
didnt work.

If all these are in series, there's no bias provided for the IGBT's
drain. Your simulated signal generator can source and sink current -
the IGBT can only sink current. The IGBT and it's biasing static DC
load must be placed in series with the DC source, forming a loop. The
series LC circuit is placed across the static load element or across
the IGBT DS terminals.

RL