i want to check a series of diodes mounted on a pcb how can i do it
R Thread Starter raj90012000 Joined Mar 8, 2010 3 Mar 8, 2010 #1 i want to check a series of diodes mounted on a pcb how can i do it
beenthere Joined Apr 20, 2004 15,819 Mar 8, 2010 #2 Use a meter. If it has a PN junction check function, use that. Shorted and open diodes will be easy to spot. Forward conduction drops should be very similar for the same type of diode.
Use a meter. If it has a PN junction check function, use that. Shorted and open diodes will be easy to spot. Forward conduction drops should be very similar for the same type of diode.
S someonesdad Joined Jul 7, 2009 1,583 Mar 8, 2010 #3 See here for some basics. Note you can usually check the diodes in-circuit unless there are low impedance paths in parallel with them.
See here for some basics. Note you can usually check the diodes in-circuit unless there are low impedance paths in parallel with them.
R Thread Starter raj90012000 Joined Mar 8, 2010 3 Mar 19, 2010 #4 i m not asking abt to check a single diode i want to knw the technique for checking diodes connected in series
i m not asking abt to check a single diode i want to knw the technique for checking diodes connected in series
SgtWookie Joined Jul 17, 2007 22,230 Mar 19, 2010 #5 Pass a voltage-limited controlled current through the diodes wired in series, around 20mA. Each diode will drop a certain voltage across itself, depending upon the diodes used and the current. If the sum of the voltage drops is in the expected range, then it's likely that the diodes are all good. If the voltage is at the limit, one or more diodes are open. If the voltage is less than expected, one or more diodes are shorted.
Pass a voltage-limited controlled current through the diodes wired in series, around 20mA. Each diode will drop a certain voltage across itself, depending upon the diodes used and the current. If the sum of the voltage drops is in the expected range, then it's likely that the diodes are all good. If the voltage is at the limit, one or more diodes are open. If the voltage is less than expected, one or more diodes are shorted.