When I first started designing my brewing system back in September 1994, there was one issue that I really struggled with and that was the issue of Proportional Control versus Binary Control of the electric heater elements. I was committed to using a PC to control the brewing system, but I was trying to decide if I should use an analog output of the ADIO board to control the power delivered to the electric heater elements (in the true spirit of RIMS) or if I should simply switch the electric heater elements on and off.
In September 1994, Mac had designed a RIMS controller board which was sold commercially (for a limited time). Mac also owned an IBM DACA.
"You probably don't need to go with analog output to control proportionally with all that I/O power (of the IBM DACA). You can easily use an I/O bit to control a zero-crossing solid (state) relay. By using a control pulse which is proportional to the difference between the set point and the actual you can do most of your work in software."
Mac also introduced me to the LM34. Mac had just completed,
" the first version of an 8 channel analog input module that plugs into the LPT port of an IBM PC."
Later, to be published in,
After reading Mac's column in,
I sent him E-mail in October 1995 asking him for advice on a wort level indicator. Mac introduced me to the MPX2100. In the "Further Reading" section of Mac's "Fundamentals" article, he referred to,
This book contained the schematic for the circuit which I used
as my wort level indicator.
Regardless of how you define RIMS, I need to recognize Rodney for his contribution. Rodney's two articles,
inspired me to pursue a computer-controlled brewing system.
Danny is a good friend and an ex-coworker (I worked with Danny
for almost four years at IBM). Danny helped me with the electrical
aspects of interfacing the ADIO board with the SSRs and with the
pressure transducer wort level indicator.
Willie is my brother-in-law, Speedy is my cousin and Nino and
Patsy are my inlaws. Willie welded the brewing system rack for
me and Speedy painted it. Nino and Patsy drove the rack in the
back of their small pickup truck from New Mexico to Northern California.
I am very fortunate to have inherited this very generous and caring
My cousin Tom took my 10 gallon Cornelius keg, called in a few
favors, and transformed it into an 12 gallon, electro-polished,
I've managed to save over $4,000 in receipts, but I couldn't begin to guess at how many hundreds of hours that I have invested in this brewing system. And only the most understanding wife in the world would put up, and at times even encourage, such a gross waste of time and money.