Monthly Archives: April 2012 - Page 2

A little demo of the openASC -> amp control

I did some programming today when I got tired of working and “clocked out”. I managed to find a bug in the openASC bus protocol which hadn’t appeared until now, but after some thinking I found the problem and fixed it. Then I continued on implementing the openASC control for the amplifier which seem to work pretty fine now but there are some things still do be done. On the video I demo a bit jumping between segments on the current band and the idea is to implement this so it becomes fully automatic in the future but right now we need to chose the segment ourself, the band is however automatically selected. I also show that we can toggle on/off the amplifier and put it on operate/standby mode.

More to come…

Amplifier control demostration

I did a little video of the progress of the amplifier control unit. I managed to get some basic functions working and after the video was made I also managed to get the rack unit to send data to the openASC box, which through a menu you can see the state of the amplifier and control it with the external keypad.

The ringing sound is from the gears, hopefully it will go away after I put some grease on them. Everything isn’t perfectly centered so I don’t want to put much tension on them.

More control system progress

Today I spent another 6 hours in the lab at work. I am now almost finished with all the electronics for the amplifier control. What is left to do is to add the attenuation for the power meter, fix cables between the PTT input and the control board plus some mechanical job. I need to make the plates that holds the stepper motors and I might make them out of thicker aluminum so that I can make a hole for the variable resistors which makes it impossible for them to turn around if the nut happen to get loose (from vibration or something). That way the positioning can not be totally off or fail (except if the pot gets bad but that is detectable). I will also need to spend some time in the lathe making knobs for the back of the stepper motors for manual tuning.

It feels good, now I need to clean my desk at work so I have some room to put the stuff up so I can write the firmware for it. Later I will extend the system by measuring grid current, anode voltage, anode current etc. The amplifier has got built in grid protection so I don’t need to worry about that.