How to amplify trapezoidal current signal on an inductor

crutschow

Joined Mar 14, 2008
38,681
Below is the LTspice simulation of a conceptual design using the PWM scheme to maintain the constant current during the 400μs period.
The PWM (from V6 and V7) generates about 7.5% ripple for the duty-cycle and frequency shown.

You would likely need to monitor the inductor current and use feedback from that to adjust the pulse-widths and duty-cycle to maintain the desired currents.

1576395619816.png
 

Thread Starter

msamet

Joined Oct 20, 2017
12
Below is the LTspice simulation of a conceptual design using the PWM scheme to maintain the constant current during the 400μs period.
The PWM (from V6 and V7) generates about 7.5% ripple for the duty-cycle and frequency shown.

You would likely need to monitor the inductor current and use feedback from that to adjust the pulse-widths and duty-cycle to maintain the desired currents.

View attachment 194563
Thanks very much
Current feedback measurement is required to monitor the inductor current right? A current sense amplifier maybe ?
And MCU that controls the bridge in PWM mode at high switching chopper frequency ?
 
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Danko

Joined Nov 22, 2017
2,220
How did the bottom pulse effected like that? and did you set the timings by trial and error?
Current of V6 compensates losses in R3, R_M2_ON and R_M4_ON.
So V_V6 = I_L1_desired * (R3+ R_M2_ON + R_M4_ON).
V6 changes polarity in time, while HV pulse (7us) lasts.
 
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