Nigel Goodwin said:Because it would take 30A or so to blow it, the PCB track fused at a much lower current.
As this was an earth fault then surely the RCD would trip at the required 35mA?
Mike.
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Nigel Goodwin said:Because it would take 30A or so to blow it, the PCB track fused at a much lower current.
Pommie said:As this was an earth fault then surely the RCD would trip at the required 35mA?
Mike.
Pommie said:Chris,
Just rebuild the circuit, there is a good chance the transformer is not damaged as the PCB tracks acted as your fuse. However, you were lucky this time, had you handled the low voltage side of the board you could have been electrocuted. Hopefully, your first big bang scared the xxxx out of you as it did me and you will double check everything involving mains in the future. I had a very good friend who lost his life through a silly mistake like this.
Mike.
eblc1388 said:@HerbertMunch,
The scope lead clip is earthed, did you touch this earthed clip to any point on circuit which has LIVE potential?
HerbertMunch said:My house is only 2 years old; would this not have the new type of breaker?
Pommie said:Your house should have an RCD fitted. These trip when there is a difference of 35mA between live and neutral caused by current flowing to earth. In this case your scope earthed the supply and so it should have tripped. Check your consumer box, you should have a (maybe two) breaker(s) with the test button on them.
kchriste said:I think that your relay is wired wrong. It looks OK in the schematic, but on the PCB layout it appears that you've mixed up the coil connections with the NO and NC contacts!
3v0 said:A PCB layout program with schematic capture can prevent this type of error. It can save many hours of hand verifying the PCB with the schematic.
HerbertMunch said:You would think so wouldnt you! im using eagle, but i created the device footprint from scratch!
I totally agree with you though. It does save alot of time.