In this episode we are repairing a power output module (coil driver stage) for an eddy current dynamometer. If you not interested in electronic circuit talk, this video might be rather boring as there is no fire, bang or explosions, not even smoke ....
Now for the interested audience,... these module are essentially controlled rectifiers, directly powered by mains voltage, therefore lethal voltages inside.
A current demand is applied to the input and the output current is following pretty linear via a closed loop current regulator. The output is a DC current with 100Hz ripple. (on a 50Hz mains)
An eddy current dyno is essentially just a big inductor, obviously inheriting a time constant, back emf issues, etc, which the circuitry has to deal with as well,
The trigger circuit for the output bridge is a rather unusual design, so it's certainly worth a video.
And so was the fault, rather obvious what's wrong, but it took quite a while to get to the bottom of it.
The main purpose of the video is actually showing the customer what has been done, sorry for the shaky camera but the main focus has been on doing the job, the video is just a by product, as with most of my videos.
(c) 2020
www.dynoguy.co.uk
16 сен 2024
