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Electronics => Beginners => Topic started by: Mepakos on August 01, 2019, 08:22:48 am

Title: changing diode and capacitors
Post by: Mepakos on August 01, 2019, 08:22:48 am
I need help guys. If you reverse the two diodes and capacitors what would happen?
Title: Re: changing diode and capacitors
Post by: ogden on August 01, 2019, 08:28:06 am
Quote from: Mepakos on August 01, 2019, 08:22:48 am
I need help guys. If you reverse the two diodes and capacitors what would happen?

Draw schematic, compare to original. What you see?
Title: Re: changing diode and capacitors
Post by: Mepakos on August 01, 2019, 09:20:15 am
I think no current flows through D2?
Title: Re: changing diode and capacitors
Post by: ogden on August 01, 2019, 09:34:59 am
Quote from: Mepakos on August 01, 2019, 09:20:15 am
I think no current flows through D2?

Why you think so? Hint: Tr1 is transformer, it means AC voltage source. Look at both circuits assuming that all capacitors are non-polar, think again what happens. [edit] Do you really think that reversing diodes can introduce such a fundamental change as removing current from one of diodes? Why?
Title: Re: changing diode and capacitors
Post by: Mepakos on August 01, 2019, 09:58:08 am
Because of the direction. I read that current flows only from anode to kathode of a diode and cant flow from kathode to anode.  If thats not the case maybe nothing would change if i reverse them.
Title: Re: changing diode and capacitors
Post by: Zero999 on August 01, 2019, 10:14:49 am
Quote from: Mepakos on August 01, 2019, 09:58:08 am
Because of the direction. I read that current flows only from anode to kathode of a diode and cant flow from kathode to anode.  If thats not the case maybe nothing would change if i reverse them.
The transformer outputs AC.

In the original schematic, assuming node B is 0V, D1 conducts when the AC cycle is positive and D2 conducts when it's negative. If their polarities were reversed, then this would be the opposite.