The Control Panel

Propane lines | Control cabinet | Electrical
Future Work | Part Suppliers

Thermometers

For the basic electronics for the temperature monitors, I decided to use the LM35C circuit explained in detail in Ken Schwarz article. The basic circuit provides a voltage from 0-1V based on 10 mV per degree Celsius. Ken Circuit takes this voltage and conditions it to provide a low point and high point in case the probes are not accurate and sends it to a floating voltage DPM.

Once I built the circuit, I had lots of problems. The basic problem was that I couldn’t adjust the hot and cold pots in order to get it to read the right temperature. After discussing my problems with Ken, I changed the rate of the Resistors and Pots and even added Op amp buffering but still had the same kinds of problems.

What was my solution to these problems? I haven’t made any yet. My thought is to simplify the circuit to make the op amps a simple 1/10 gain amps and send the information to the control panel. I also had planned on using A/D control in my brewery so I can send the data directly to the A/D board and display it on the screen.

Pump Switches

For controlling the pumps, I used a couple of three way switches. Why Three-way you may ask? Three-way switched allow for three positions: Manual Override OFF, Manual Override ON, and Computer controlled. I originally attached the electrical to the pump directly to posts in the cabinet but this proved problematic when it came to moving the system or maintenance. Later revisions would see Connectors made of GFCI circuits mounted to the back of the control panel for easy disassembly and safety.

All electrical circuitry such as the meters, pumps and grainmill go through a 3 amp circuit breaker mounted on the front of the panel. Not fool proof but better than nothing.

The grain mill was connected to the panel via a key switch. No reason in particular other than it just looked cool. I thought it would be neat if the only way to start the process required a key.