Diodes and AC power dont play nice.
Posted: Wed Dec 09, 2015 10:37 amI've put this here hoping it may assist anyone else in a similar situation.
I built a controller with three individual components, 2 of which need a fan. As such and to save hours of unnecessary fan runtime I wanted the fan to run when either of the two units were plugged in but not power up the other unit (wired in parallel). This would leave live pins on the other unit exposed which is not safe to have in the house. Diodes were suggested, which are like a one way valve, and I purchased some but the fan refused to turn. It was trying but not getting anywhere. Diodes being a one way valve was only allowing half the power of the AC current through, in a nutshell just the forward movement of the electrons and stopping the rest. A little bit more complex than that but diodes are not good in ac circuits. They have their applications but keep their limitation in mind.
What you need, and I found works, is a TRIAC. Basically two diodes with a gate that allows current to flow through them in both directions when the gate is powered up but not when no juice through it. It allows the power to flow freely (almost) with less loss of power.
Not being an electronics whiz it took me a few days to figure out what was going on. Hate someone else to have the same issue.
I built a controller with three individual components, 2 of which need a fan. As such and to save hours of unnecessary fan runtime I wanted the fan to run when either of the two units were plugged in but not power up the other unit (wired in parallel). This would leave live pins on the other unit exposed which is not safe to have in the house. Diodes were suggested, which are like a one way valve, and I purchased some but the fan refused to turn. It was trying but not getting anywhere. Diodes being a one way valve was only allowing half the power of the AC current through, in a nutshell just the forward movement of the electrons and stopping the rest. A little bit more complex than that but diodes are not good in ac circuits. They have their applications but keep their limitation in mind.
What you need, and I found works, is a TRIAC. Basically two diodes with a gate that allows current to flow through them in both directions when the gate is powered up but not when no juice through it. It allows the power to flow freely (almost) with less loss of power.
Not being an electronics whiz it took me a few days to figure out what was going on. Hate someone else to have the same issue.