Diode question for "electric" guy (custom light / bike / wire question)......

[~TABASCO~]

I think I need one of these for my new light set up.... So I can do a few functions. I have used them before..... What I dont know is how many wats might I need.... This is a very low powered 'trigger' wire for a relay...

Im looking at a 12V - 5W Diode.... Would this work as my "one way" Diode ?

I think my toggle I have used for years is a 12V - 2.5W toggle...... (so Im thinking this will work)

This photo is not a part number or any type of code, it's a generic photo of what the "look" was I used in the past........


Thank you -

 

[cyclemike4]

Hello Tabasco. I am unsure of what you are using the diodes for but in your statement you mentioned a one way diode. I suspect you are using it to prevent back feed from and LED circuit back into your electrical system. If you are using the diode in a reversed polarity or reversed bias and it is only blocking D.C. power a 5 watt capable diode is plenty big enough. you will have no trouble at all. It really is over kill but that is ok. If you are using the diode in a forward polarity or biased circuit then it will drop only .6 volts across it and the rest will be going to the load. At that time you will have to calculate the power of the load and size the diode accordingly. Forward biased is negative power is on the striped end and positive power is on the unmarked end. wired that way it will pass current, drop .6 of a volt across it and it will dissipate heat. Wattage matters then because the load determines the current through it. Reversed biased is negative power wired to the unmarked end and positive power to the striped end. that way it will block current and no current is passed. As long as you don't put more voltage in reversed biased than the component peak reverse voltage rating it will not pass current and will not produce heat. In a 12 volt system about any diode will be good for that. Not sure this helps or not hope it does. A little circuit diagram would help me so I could see why and how you are using the diode. Good luck I am sure you may already have this done and working!

 

[patrickg450]

Are you installing new lights? What are they rated at?

A Watt is the unit of electrical power equal to one ampere under the pressure of one volt.......

 

[~TABASCO~]

Are you installing new lights? What are they rated at?

A Watt is the unit of electrical power equal to one ampere under the pressure of one volt.......

Installing more lights... Needed for BDR....

 

[~TABASCO~]

Hello Tabasco. I am unsure of what you are using the diodes for but in your statement you mentioned a one way diode. I suspect you are using it to prevent back feed from and LED circuit back into your electrical system. If you are using the diode in a reversed polarity or reversed bias and it is only blocking D.C. power a 5 watt capable diode is plenty big enough. you will have no trouble at all. It really is over kill but that is ok. If you are using the diode in a forward polarity or biased circuit then it will drop only .6 volts across it and the rest will be going to the load. At that time you will have to calculate the power of the load and size the diode accordingly. Forward biased is negative power is on the striped end and positive power is on the unmarked end. wired that way it will pass current, drop .6 of a volt across it and it will dissipate heat. Wattage matters then because the load determines the current through it. Reversed biased is negative power wired to the unmarked end and positive power to the striped end. that way it will block current and no current is passed. As long as you don't put more voltage in reversed biased than the component peak reverse voltage rating it will not pass current and will not produce heat. In a 12 volt system about any diode will be good for that. Not sure this helps or not hope it does. A little circuit diagram would help me so I could see why and how you are using the diode. Good luck I am sure you may already have this done and working!

Thank you....... PM sent.

 

[nd4spdbh]

Sounds like you are wanting to trigger a relay from multiple sources (ie high beam switch and a separate anytime switch) and want to isolate those sources so back feed doesn't occur.

Just look up the draw of the triggering circuit via specs of the relay it will be listed. I'd imagine damn near negligible, a 2.5w diode will likely be more than sufficient.