Jump to content
Electronics-Lab.com Community



Recommended Posts

I just have a quick diode question.
All I want to do is only let a 9VDC current flow in one direction!!  What kind of diode do I use??  I dont need to amplify or anything special.  Rectify? Zener? Switching? I really don't know the difference.
If you want to write a whole essay about diodes feel free but please post a short answer first.  I'm ordering stuff now.
Sorry for the dumb question

Link to comment
Share on other sites

Hi Um...Me123

Sorry for the dumb question

No question is too dumb, dumbness is to not ask! ;D

Now to your question!
You didn't supply us with enough information to properly answer your question!
How much current through the diode? That will determine the diode.

Up to 1 Amp a 1N400x diode will fit nicely, up to 3 Amp a 1N540x diode will fit,
for higher currents a diode at higer rating is needed. Look at datasheets, and
search the internet! The x in above diode names is a figure between 1 and 7.

Hey, the current from a battery can only flow in one direction, so maybee you
dont need a diode, the diode will waste about 0.5 to 1 volt of your battery
voltage! ;D

If you supply us with more information we can give you a more accurate

Link to comment
Share on other sites

Here's my project:
I have 2 circuit boards from an old remmote control car.  It was the type where you control both wheels individually.  Forward and backward for each.
So there are 4 wires going to 2 motors (which I cut off)  the voltage reverses for forward and backward.  What I'm going to do it conect it to 4 relays and use diodes to determin whch of the 4 it turns on.  (So basically the same wire may be positive or negative because it splits and has diodes.  Not sure of the amps but it runs on 9V.
I haven't decided on how to power the 9V be cause I'm using the relays to control 120VAC and other stuff (less than that)  I may use a small amp (so it's cheaper) transformer.

Link to comment
Share on other sites


Propotional means that you could move slowly with the car by just press the
controls a little bit. If its only zero or full speed backwards and forward it is
probably not propotional, and will work just fine here. Use some 1N4001,
they are cheap and redily available. And, yes, you should use a diode
backwards over the relays.

PIV means Peak Inverse Voltage and is the max voltage the diode can stand
in reverse.

BTW, how is it going with your PSU?


Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...