Reddit mentions of Ampeak 1000W Power Inverter Truck/RV Inverter 12V DC to 110V AC Converter with Dual AC Outlets 2.1A USB Modified Sine Wave Inverter

Dryers are 240. Many a/c systems are also 240. You may have other 240 outlets near your garage. Here is one for $220 or so: https://amzn.to/2IewHsz. With this one, you can change the plug and use the same one for 110 and 240 charging! Get one with multiple tips and you can keep it in the car for flexible charging everywhere. If you do this, sell the charger that came with your car on eBay. Don't need it.

Also, get at least a 1000 watt inverter like this one https://amzn.to/2rFVPNB. With this your car becomes your backup power. A fridge uses 75 watts or so an hour. Your car most likely stores 24,000 watt hours or running that fridge for 320 hours. Plus it makes for an awesome camping source of electricity.

I am amazed no one really mentions these two items as core to EV ownership that actually adds a ton of value.

I once sold an EVSE charger that came with my car for less than it cost for one that had dual charging and came with three different 240V AC plugs! Crazy to think people hire electricians to have a Level 2 charger installed for over a grand.

1. The output voltage depends on the transformer's primary:secondary ratio. They are unidirectional, so a transformer wound to supply 6V from a 120V source can be used to supply 120V from a 6V source.
   
   
2. The transformer design depends on your power requirements and voltages. The output has a centre tap to easily reverse the polarity through the windings (and thus create a basic AC input) without the use of an H-Bridge.
   
3. If you're looking to keep total costs down to under $15 per unit, something like this or this may be helpful.
   
   
   To answer your final question, it may prove safer, more efficient, and less expensive to use a commercially available inverter and inexpensive car battery to power all 20-30 bulbs from a common source.
   
   The linked inverter circuit is not terribly efficient, and the lower your input voltage, the more current drawn due to the conservation of energy. 3W at 6V means a 500mA draw from your cells, under ideal conditions. Increasing the input voltage decreases the current consumption, and extends the life of the batteries.
   
   If you like doing this kind of thing, making one to test would be fun! That being said, if you're planning to host an event, there may be plenty of other things on your mind that day, and taking 'home made high voltage supply' off that list might help.

[inverter](ampeak 1000w power inverter 12v dc to 110v ac dual ac outlets 2.1a usb car inverter https://www.amazon.com/dp/B071NZ8DSB/ref=cm_sw_r_cp_apa_i_NbC6Ab814KH3Z)
[solar controller](allpowers 20a solar charger controller solar panel battery intelligent regulator with usb port display 12v/24v https://www.amazon.com/dp/B01MU0WMGT/ref=cm_sw_r_cp_apa_i_adC6Ab4DAFH9X)
And ill add some sort of solar panel