Hi fellows,
some of you might already be familiar with www.falstad.com and the awesome work mr. Falstad has done. I happen to like particularly his analog circuit simulator (www.falstad.com/circuit) since I'm currently working with basic circuit analysis teaching at the university.
This circuit applet mentioned can be used to study the KA7500 (and like) smps controllers as well. I created a simplified applet to clarify the function of the dead time control, output control and feedback pins of the chip. My aim is to help anyone confused with the controller - although I'm studying it still myself.
To use my small code, open the original applet from the link above and select "blank circuit" from the "circuits". Make sure you spread the window as large as possible. Then click File -> Import and paste the following code on the blank space:
$ 3 5.0E-6 1.5 50 5.0 50
t 736 128 768 128 0 1 -12.0 -5.0E-13 100.0
t 736 240 768 240 0 1 -7.0 0.7270829465156723 100.0
150 680 128 736 128 1 2 0.0
150 680 240 736 240 1 2 5.0
I 680 168 680 136 0 0.5
I 680 280 680 248 0 0.5
150 584 120 624 120 1 2 0.0
150 584 232 624 232 1 2 5.0
w 624 232 680 232 0
w 624 120 680 120 0
155 424 128 504 128 0 0.0
w 520 192 536 192 0
w 536 192 536 96 0
w 536 96 424 96 0
w 424 96 424 128 0
w 520 128 584 128 0
w 536 192 536 240 0
w 536 240 584 240 0
w 584 224 560 224 0
w 560 224 560 112 0
w 560 112 584 112 0
w 560 112 560 56 0
152 360 296 408 296 1 2 0.0
w 680 296 680 280 0
w 408 296 640 296 0
w 640 296 680 296 0
w 640 296 640 184 0
w 640 184 680 184 0
w 680 184 680 168 0
a 280 200 328 200 2 5.0 0.0
a 280 256 328 256 2 5.0 0.0
v 240 208 280 208 0 0 40.0 0.5 0.0 0.0 0.5
w 328 256 328 304 0
w 328 304 360 304 0
w 360 288 344 288 0
w 344 288 344 208 0
w 344 208 344 200 0
w 344 200 328 200 0
I 408 248 408 208 0 0.5
w 408 248 408 296 0
w 408 208 408 160 0
w 408 160 424 160 0
w 280 248 216 248 0
w 216 248 216 192 0
w 216 192 280 192 0
R 216 192 216 112 0 4 1000.0 3.0 3.0 0.0 0.5
d 344 368 304 368 0
a 400 368 344 368 3 5.0 0.0
a 400 456 344 456 3 5.0 0.0
d 344 456 304 456 0
w 304 368 280 368 0
w 280 368 280 264 0
w 280 368 280 456 0
w 280 456 304 456 0
w 768 224 792 224 0
w 768 112 792 112 0
w 792 112 792 224 0
w 792 112 792 56 0
R 792 56 736 56 0 0 40.0 12.0 0.0 0.0 0.5
L 560 56 512 56 0 1 false 5.0 0.0
w 768 144 776 144 0
R 240 208 152 208 0 0 40.0 0.0 0.0 0.0 0.5
r 800 328 800 392 0 10.0
r 864 416 864 480 0 10.0
g 864 480 864 496 0
w 800 328 800 144 0
w 800 144 776 144 0
w 864 416 864 256 0
w 864 256 768 256 0
g 800 392 800 496 0
R 280 456 192 456 0 0 40.0 0.0 0.0 0.0 0.5
x 480 37 635 43 0 24 Output control
x 189 83 249 89 0 24 f(osc)
x 130 186 178 192 0 24 DTC
x 167 435 265 441 0 24 feedback
o 62 4 0 34 5.0 0.4 0 -1
o 63 4 0 34 5.0 0.4 0 -1
Finally click "Import" and you will see the circuit in front of you. To use it, I suggest setting the Simulation speed to minimum and then you may change the DTC and feedback voltages and analyse the effects on the 10 ohm load resistor voltages.
Have fun!
some of you might already be familiar with www.falstad.com and the awesome work mr. Falstad has done. I happen to like particularly his analog circuit simulator (www.falstad.com/circuit) since I'm currently working with basic circuit analysis teaching at the university.
This circuit applet mentioned can be used to study the KA7500 (and like) smps controllers as well. I created a simplified applet to clarify the function of the dead time control, output control and feedback pins of the chip. My aim is to help anyone confused with the controller - although I'm studying it still myself.
To use my small code, open the original applet from the link above and select "blank circuit" from the "circuits". Make sure you spread the window as large as possible. Then click File -> Import and paste the following code on the blank space:
$ 3 5.0E-6 1.5 50 5.0 50
t 736 128 768 128 0 1 -12.0 -5.0E-13 100.0
t 736 240 768 240 0 1 -7.0 0.7270829465156723 100.0
150 680 128 736 128 1 2 0.0
150 680 240 736 240 1 2 5.0
I 680 168 680 136 0 0.5
I 680 280 680 248 0 0.5
150 584 120 624 120 1 2 0.0
150 584 232 624 232 1 2 5.0
w 624 232 680 232 0
w 624 120 680 120 0
155 424 128 504 128 0 0.0
w 520 192 536 192 0
w 536 192 536 96 0
w 536 96 424 96 0
w 424 96 424 128 0
w 520 128 584 128 0
w 536 192 536 240 0
w 536 240 584 240 0
w 584 224 560 224 0
w 560 224 560 112 0
w 560 112 584 112 0
w 560 112 560 56 0
152 360 296 408 296 1 2 0.0
w 680 296 680 280 0
w 408 296 640 296 0
w 640 296 680 296 0
w 640 296 640 184 0
w 640 184 680 184 0
w 680 184 680 168 0
a 280 200 328 200 2 5.0 0.0
a 280 256 328 256 2 5.0 0.0
v 240 208 280 208 0 0 40.0 0.5 0.0 0.0 0.5
w 328 256 328 304 0
w 328 304 360 304 0
w 360 288 344 288 0
w 344 288 344 208 0
w 344 208 344 200 0
w 344 200 328 200 0
I 408 248 408 208 0 0.5
w 408 248 408 296 0
w 408 208 408 160 0
w 408 160 424 160 0
w 280 248 216 248 0
w 216 248 216 192 0
w 216 192 280 192 0
R 216 192 216 112 0 4 1000.0 3.0 3.0 0.0 0.5
d 344 368 304 368 0
a 400 368 344 368 3 5.0 0.0
a 400 456 344 456 3 5.0 0.0
d 344 456 304 456 0
w 304 368 280 368 0
w 280 368 280 264 0
w 280 368 280 456 0
w 280 456 304 456 0
w 768 224 792 224 0
w 768 112 792 112 0
w 792 112 792 224 0
w 792 112 792 56 0
R 792 56 736 56 0 0 40.0 12.0 0.0 0.0 0.5
L 560 56 512 56 0 1 false 5.0 0.0
w 768 144 776 144 0
R 240 208 152 208 0 0 40.0 0.0 0.0 0.0 0.5
r 800 328 800 392 0 10.0
r 864 416 864 480 0 10.0
g 864 480 864 496 0
w 800 328 800 144 0
w 800 144 776 144 0
w 864 416 864 256 0
w 864 256 768 256 0
g 800 392 800 496 0
R 280 456 192 456 0 0 40.0 0.0 0.0 0.0 0.5
x 480 37 635 43 0 24 Output control
x 189 83 249 89 0 24 f(osc)
x 130 186 178 192 0 24 DTC
x 167 435 265 441 0 24 feedback
o 62 4 0 34 5.0 0.4 0 -1
o 63 4 0 34 5.0 0.4 0 -1
Finally click "Import" and you will see the circuit in front of you. To use it, I suggest setting the Simulation speed to minimum and then you may change the DTC and feedback voltages and analyse the effects on the 10 ohm load resistor voltages.
Have fun!
Thats a neet little thing, few things though, how do you change the error amp input voltages? V+ V-? And the Output Control doesn't work, If you put it low it doesn't go to signle ended mode (parellelled outputs). this is just a few little things I notice.
BTW good job on making that, I couldn't do it.
BTW good job on making that, I couldn't do it.
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