The MOSFET and relay represent a SSR.
SSR driver, balanced h-bridge driver.
Used to drive a test load 50 watt lamp
At this design frequency the lamp strobe
And could cause severe seizures, don't try this if blinking light bother you, even normal people can get sick in the tummy and virtigo.
The pwm circuit can also be used to drive a opto-coupler and higher current transistors or MOSFETs.
I used this to charge large capacitor's 40k uf in a power supply for regulation of voltage at the output. A very large inductor is required to smooth the output for high current loads. Some may call the output of the large inductor a modified sine wave and it keeps the transformer from heating up and making lots of noise.
5uf = 20hz pwm use every third cycle to charge the caps
3uf = 30hz
2uf = 50hz
1.8uf = 60hz
1uf = 90hz
850nf = 100hz
800nf = 120hz
470nf = 200-240hz
