Crash course in unit conversions please!

Technician · Post by **Technician** » Sun Sep 09, 2018 4:41 pm

Thanks for the clarification Volrem. With regards the injector voltage you advise is negative, as that voltage is rising vertically, would that not be positive rather than negative?

If I'm misunderstanding that please advise how it is being read!

volrem · Post by **volrem** » Sun Sep 09, 2018 6:03 pm

If you prefer then we could call it:

Positive and negative side (just as battery positive and negative).
Positive and ground side
Power and ground
Power and control
and so on.

You see high voltage on negative side because high voltage is applied to positive side. When other side of injector is not grounded then there is no current flow and no voltage injector. Because of this you can see same voltage on both sides.

If you look carefully you can see that current starts to flow when you have positive voltage on one side and no voltage (ground) on the other side.

There is no point discussing why current flow stops and then goes negative while nothing changes in voltage. This is too complicated and don't think about it for now. There is different thread about it here in forum.

Technician · Post by **Technician** » Sun Sep 09, 2018 8:49 pm

Thanks Volrem I'll have another look at the scope trace and read through your post again and follow it through.

RYM6746 · Post by **RYM6746** » Mon Sep 10, 2018 6:53 pm

Every amps clamp I have ever used or seen has the conversion printed on the side. As every amps clamp I have used gives a voltage reading out of the amps clamp leads. So when you attach it to scope/multimeter you can work out what the amperage is you are measuring.

Technician · Post by **Technician** » Mon Sep 10, 2018 7:11 pm

Thanks RYM, this is all new area of understanding at the moment but I'm sure the penny will drop fairly quick with a bit more use and experience using the scope.

PicoScopes
& kits

For vehicle manufacturers

EV kits and
accessories

Noise, Vibration and Balancing

Milliohm tester

Pressure sensors

Current clamps

Breakout
leads/boxes

Accessories

Automotive Forum