50/​60 Hz ripp­le when the tes­ter is con­nec­ted

The CAN-Bus Tes­ter 2 cau­ses a ripp­le fre­quen­cy on the bus at mains fre­quen­cy (50 or 60 Hz) when used with the inclu­ded power sup­ply.
The pro­blem is con­cept indu­ced, con­cerns all swit­ching power sup­plies and is defin­ded by the para­si­tic capa­ci­ty bet­ween mains- and secon­da­ry side of the cir­cuit. Thats the rea­son for a small ripp­le on the bus. Depen­ding on how many nodes are on the bus and how their inputs are wired, the phe­no­me­non is seen more or less.
Usual­ly this makes no trou­ble. Only on a bus with very few nodes and a high poten­ti­al dif­fe­rence (com­mon mode) an inter­fe­rence is theo­reti­cal­ly pos­si­ble.
Pos­si­bi­li­ties for cor­rec­tive actions :
  1. If your bus sup­plies vol­ta­ges, then try to run the tes­ter from the bus and remo­ve the tes­ters power sup­ply. The tes­ter works fine with bus vol­ta­ges from 9V.
  2. Sup­ply your tes­ter from a bat­te­ry, a rech­ar­ge­ab­le power bank or the like.
  3. Con­nect the ground of the power sup­ply to the ground-poten­ti­al of your bus. The­re­fo­re you would need an adap­ter or you open the dc-cable or dc-plug of the power sup­ply.

    50 Hz ripp­le over­lay­ed to CAN-messa­ges
    Ope­ra­ti­on with ground-con­nec­tion to bus-ground-poten­ti­al


    Ope­ra­ti­on with bat­te­ry-pack

CAN-Bus Tes­ter 2

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