Wednesday 7th March 2001
Not much building has gone on over the last two weeks since I've
had the flu, but three acquisitions have taken place recently.
|Firstly, a very nice lady at RS components has made my life
substantially less frustration by kindly sending me a set of the new RS
catalogues. Their web site is all very well and good, but you do spend an awful
lot of time waiting for pictures and details to download. Flicking through the
paper catalogues is immeasurably faster and less frustrating. Thank you
Margaret for bending the rules a bit for me!
|Secondly, I have decided to buy a small arc welder so that I
can do some small welding jobs as well as my Dad. By pure chance I surfed the
Internet for welders and was pointed towards
This site was in fact part of a site under the heading
www.toolsonline.co.uk, and has a whole host of very
competitively priced tools including welders of various types and sizes, air
compressors, power tools, saws, tool boxes, garden tools, etc., etc.. What's
more the prices shown are inclusive of VAT and free delivery within the UK
mainland. The arc welder prices were considerably cheaper here than with those
nice people at RS.
|Thirdly, a friend of a friend had a spare oscilloscope that
they had hardly used over recent years, and were happy to sell me for a very
reasonable price. This will help my diagnostics no end, and reduce the number
of dead MOSFETs considerably (I hope). Thanks Alan for doing me such a good
|I had my first play with the oscilloscope to check whether my
assumptions about the radio receiver were correct. I wanted to reduce the
number of inputs my micro-controller needed to check in order to establish what
each of the receiver channels was doing. On the right is the display of the two
signals I will be monitoring. The top trace is the channel 1 signal. The bottom
trace is the combined pulse train for all the receiver channels. Each positive
transition on this bottom trace signals the end of the previous channel and the
beginning of the next one. By taking a note of the time of each transition, the
value for the channels can be measured. Synchronisation is achieved by checking
if the channel 1 signal (upper trace) is high just after a transition. If it
is, then we know where we are.
I really must get on with rebuilding the new motor controller
circuit and micro-controller interface circuit, now that I have confirmed my
assumptions about the receiver with the oscilloscope.