# Power pulse generate 30V 400A

1. ## Power pulse generate 30V 400A

Hello!

Please suggest how to generate pulse with 100-200us rise and fall time, 500-1500us duration. Voltage/current precision regulated 0-30V, 0-400A depending of load.

•

2. ## Re: Power pulse generate 30V 400A

If the duty cycle respectively average power is low, I would suggest an analog output stage, powered by a capacitor bank. Take care that the output transistors are specified for linear operation.

For higher average power, we would prefer switched mode design, but involves higher circuit effort and less clean output.

3. ## Re: Power pulse generate 30V 400A

Is this a spot welder?

•

4. ## Re: Power pulse generate 30V 400A

An LC ckt should do it, say we charge a cap to 60V and run it through an L to give a 400A peak, the Zo = 0.15 ohms

thus the L required = 0.0225 x C

larger components give a longer pulse, for 1 Hz say F = 1/ 2.pi SQRT(LC) and, 0.15 = SQRT ( L/C ) [Zo]

So 39.47 = 1 / LC and 0.0225 = L/C thus; 39.47 = 1 / ( 0.0225 C^2 ), thus C = 1.06F & L = 23.87 mH

[ check 1/(2.pi SQRT(L.C)) = 1Hz - tick ]

So a 100A SCR fired from a 1F cap, will give a pulse of 0.5 sec wide, 400A peak ( assuming no losses ) delivered via the 23.87mH coil ( 400A pk rated ) - at the end of which the current will be zero ( SCR will turn off ) and the cap volts will be zero - ready to re-charge to 60V - in this case ...

For your particular application a high power switch mode would work best with an SCR firing for the 100uS rise time,

pulse shaping LC circuits could also be employed

5. ## Re: Power pulse generate 30V 400A

Originally Posted by schmitt trigger
Is this a spot welder?
no, this is SMU for power device static characterization. Rdson measurement, etc

- - - Updated - - -

Originally Posted by Easy peasy
1 An LC ckt should do it...

2 For your particular application a high power switch mode would work best with an SCR firing for the 100uS rise time,

pulse shaping LC circuits could also be employed
and how to precisely regulate current/voltage in this cases?

now i making 100A, 20V pulses using power mosfet based (source follower) linar output stage with voltage and current feedback

•

6. ## Re: Power pulse generate 30V 400A

and how to precisely regulate current/voltage in this case?

now i making 100A, 20V pulses using power mosfet based (source follower) linar output stage with voltage and current feedback
30V/400A won't work differently. See post #2 about power supply options. Note that you can't have voltage and current control active at the same time. You'll either define a current pulse with optional voltage limiting or vice versa. For the the said purpose (Rdson measurement), I would expect underlying current control with voltage limiting.

7. ## Re: Power pulse generate 30V 400A

for 400A amp make everything 4 x bigger ...

8. ## Re: Power pulse generate 30V 400A

we have have made a range of electronic loads, you need large mosfet die in large packages on cooled heatsinks and very well designed gate drive, current sharing, layout, and Vmax / Imax control to take a 30V 400A source ( with large caps on it ) and have it available to go thru a switched device ...

--[[ ]]--