Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


transistor blown up

Views: 1965

#81657

transistor blown up | 29 December, 2018

We are using a smps for our comm pcb , a relay and a current sensor, which uses 4.2v, 12v and 5v respectively. We are controling one phase of a three phase 5hp water motor. Also smps circuit and relay output are in parallel so output load doesnt effecting our smps. Problem is when we tested our complete device in lab on a room heater of 2kw its working fine however when tested in field on dol starter type 5hp motor our device fuse(3A) and transistor s9014 and s8550 blown up.

reply »

#81662

transistor blown up | 2 January, 2019

Either the extra current draw to overcome inertia on the motor start up, or back EMF from the motor?

reply »

SMT Assembly machines

SMT Replacement Nozzles