1

This is my first question on Stack Exchange.

I am in the process of simulating a wireless charger coil setup on LTSpice. I have tried a Royer/Baxandall oscillator to provide the necessary sinusoidal waveform. I would like to try it with an H-Bridge inverter (learned from here: https://www.youtube.com/watch?v=Z1dYlZASnS0). I am providing the timing waveforms for the gate using pulses generated by the inbuilt pulse generator. However, since I have to realize this circuit on a breadboard, using signal generators and setting delays is not feasible.

I am looking to simulate a circuit in LTSpice (and can subsequently be created on a breadboard) that can generate a square wave of 50% duty cycle and vary between 10k-100k (as in, the circuit should be able to reliably generate waveforms of that frequency range). These are basically to replace the pule generators I am currently using. Also, along with this, I need to delay the pulses for C2 and C3.

enter image description here

My line of thinking - I create a schmitt trigger to generate the original waveform for C1. Then, I can use a digital logic inverter to provide the waveform for C4 (which is just C1'). But, this will introduce a delay in the C4 timing signal which might be problematic during runtime. However, I cannot think of any way to actually delay the waveforms as required for C2 and C3.

Any and all help is greatly appreciated. If you would like the .asc file for simulation, please let me know how I can attach them.

Karan Venaik
  • 11
  • 2
  • See if [this](https://electronics.stackexchange.com/q/372155/95619) doesn't help. It looks very similar to your problem. – a concerned citizen Oct 30 '20 at 07:52
  • S1 to S4 - where are these on your schematic? – Andy aka Oct 30 '20 at 09:39
  • My apologies @Andy. The S should be replaced by C i.e. C1, C2, C3, C4. – Karan Venaik Oct 30 '20 at 09:42
  • Then fix your question please and explain why you need to delay the pulses to C2 and C3. Are you trying to prevent shoot-through? – Andy aka Oct 30 '20 at 09:44
  • An explanation to the pulses and their delays was provided in the video linked in my initial question. Let us consider the BJTs as switches. At any given instance, Q1 and Q4 must be in opposite states (when one is closed switch, the other is open and vice versa). Thus, their pulses most be inverted. Similarly the switches Q2 and Q3 must also be in opposite states at any given time. However, the Q2 (and by extension, Q3) must be set-reset once during each high pulse provided to Q1. This is the reason for the delay on pulse for Q2. – Karan Venaik Oct 30 '20 at 09:52
  • @KaranVenaik You have the same problem as in the link I posted: the drivers are all referenced to ground, and your pulses can be driven from a proper PWM generator. The only things you need to change (or not) are the voltage and the load. In rest, there even is the code for an `.asc` file to test. It's practically a given. – a concerned citizen Oct 30 '20 at 13:24

0 Answers0