Can I power this with an inverter and a step-down transformer?

You shouldn't need to use a step-down transformer. The 300 W is the power the inverter can produce. This isn't a voltage rating. If the inverter is producing the correct voltage for the pitching machine you're good to go. 300 watts just means that the inverter can easily handle the 90 watts the pitching machine needs. The pitching machine will draw the current it needs as long as you provide the correct voltage. Watts (power) is simply voltage times current (amps). So, if the pitching machine needs 120 VAC and the inverter produces 120 VAC you don't need anything else. Plug the machine in and have fun.

Sounds complicated, but it should work. Inverters are very efficient, around 90% and 300W is enough to cover the rule of thumb that an inverter should be rated for twice the power a motor requires.

There's no telling how efficient the stepdown transformer will be. It would be better just to get the right inverter in the first place.

Should work.

The 300 watt inverter is a maximum rating, not what it always uses or puts out.

If a circuit only draws 90 watts, the transformer on needs to handle 90 watts.

That said, most motors use a lot more current/power when first started as they come up to running speed.

I'd look for a transformer rated at about 150 watts.

If used 2 5v AC components, one had a step up transformer and one a down could I ability my total homestead? The toaster in my homestead demands 1350 watts. ability = Volts * Amps The voltage on your place is a hundred and twenty volts. 1350 = a hundred and twenty * Amps Amps = 11.25 the ability going into the transformer = the ability popping out of the transformer enable’s say which you purchase 2 5v AC components and a step up transformer to strengthen the voltage from 10v to a hundred and twenty v. The step up ratio = a hundred and twenty / 10 = 12 / a million ability in = ability out Volts in * Amps in = Volts out * Amps out 10 * Amps in = a hundred and twenty * 11.25 Amps in = a hundred thirty five amps in accordance the equation, you may purchase 2 5v AC components and a step up transformer. That sound like a sure guess!!! This transformer demands a hundred thirty five amps of AC contemporary to offer the a hundred and twenty volts. this is a huge issue. So, your each and all the 5 v AC components would have sixty seven.5 amps flowing by it. this is an extremely, very, very, massive issue. sixty seven.5 amps of AC contemporary will soften the wires interior the 5 v AC furnish. Your 5 v AC furnish is designed to furnish 5 v to small toys that require under 15 amps. The circuit breakers on your place are designed to close off the electricity if the present flowing to a receptacle exceeds 15 amps. the electrical powered wires on your place are designed to hold no extra suitable than 15 – 20 amps. extra contemporary would soften the wires and could start up a hearth interior the partitions of your place.