Hi Robert,
I checked USPTO and found you hold 5 patents.

I like to listen to your advices, experiences and lessons all ears.

Several things for me to file patents are:
1. The circuits must be novel, and it will be applied in the industry
without doubt.

For example, they must be dramatic advantages over current ones in one
of following respects: speed, performance, saving power or saving
logic.

2. The 'novel' circuit must have potential buyers to make money.

3. History will keep your invention as a record and the circuit can go
into textbooks.

But basically, making money is the most important factor to file a
patent.

Weng