Majorman controls

I don't know about others but would love to see a pic of the controls you build unless they are proprietary. I built a lot of controls myself in the pass. Very interesting work.

I'll second that.

When I worked at the cannery, I built and/or rebuilt a couple of control panels as well. Nothing nearly as complex, but did work with Programmable Controllers, electrical and pneumatics.

Nothing really complicated but one or two have chips. Most are straight forward analogue systems. Here are a couple but I will get some pictures of some of the others and post later.




This one is used on potato, onion and sugar beet harvesters to control the depth of the digger or the height of a topper.




This is the simple sensor that goes with it, we make around 100 of these a year. Originally I bought in a sensor, approved for military use thinking it would be indestructible. Our farmers destroyed it in a matter of hours and, at 300 English pounds each, they were totally uneconomic. This little sensor is filled with potting compound so it is totally water proof and you could drive a machine over it without harming it, when complete.



This is a simple applicator that is used for applying a powder dressing to seed potatoes as the are being planted. It controls an auger type applicator, running the electric motor with pulses.

Nothing wrong or old fashioned about robust analog controllers. They are reliable and with discrete components can be repaired. Well done and impressive. Jim

This is what started my career in electronics way back in the early 1970's, a combine harvester forward speed control that adjusted forward speed around a set point based on engine and machine loading and the grain loss at the straw walkers, wind blast and sieve pan. Took it to Claas and spent five years developing it on their machines. It worked well but, at that time, operators did not like their machine being controlled by a green box in the corner of the cab.



Then I got into designing and building controls for other agricultural machines. This control panel from 2000 was used on a potato harvester. First time a touch control system had been used but all the buttons are membrane switches and control a thyristor based system to latch circuits on and off. Joysticks were used to control elevator functions and potentiometers to control web speeds.




This is another design from the early 2000's for a crop sprayer. The sprayer used three separate spray booms in one so that if different rates were required for, say, liquid fertiliser, all three could be switched on to increase the application rate, or switched off as required. Then there were the individual boom section controls. This again, used thyristor for switching and holding on valves as required from a push button controller on the hydrostatic drive controller, within reach of the drivers thumb. All this now is done with a chip today, but this system is repairable by, say a local TV or radio repair man who does not need special tools or programs. I do not think we ever had a failure on this control so it was pretty robust and many were sold.

Other than radios and amplifiers, the biggest was a one off campus radio station. From the turn tables connections and tape players, to the VU meters and transmitter input, it was built. We even made the preamps and adjusted levels for broadcast. The transmitter (Low Power Broadcast brand) was purchased. The interesting but troublesome issue was it failed to work when turned on. The antenna was intended to be a capacitor coupling to the Buildings Wiring. After some substantial investigation, it turned out the master building input circuit breaker (Mains) were magnetic trip devices. They were wound with a thousand turns of fine wire and acrted as perfect chokes for the frequency of the station. Each was bridged with a capacitor and all was well. Jim

Great looking work, thank you for sharing.
Randy