linear slider limit switch circuit which diodes ?

[jerry creaney]

Hi Guys building a linear slider with limit switches 12 volt 20 rpm DC geared motor , so start up current is not great 2 amps give or take
I am unable to determin the requirements for the diods any advise would be greatly appreciated. Jerry.

 

[Reloadron]

Can you post a circuit?

Ron

 

[jerry creaney]

Hi Ron
Its just a linear slider belt driven 12 DC motor start up current around two amps with a limit switch at each end trying to determin the requirements of the diods my electronics is a bit rusty

 

[JimB]

There are several ways of implementing a circuit like this, some of those ways may use diodes.

A bit more information about what you are trying to do, and how you propose to do it would be useful and enable us to give good advice.

Our crystal ball is a bit rusty.

JimB

 

[Reloadron]

Hi Ron
Its just a linear slider belt driven 12 DC motor start up current around two amps with a limit switch at each end trying to determin the requirements of the diods my electronics is a bit rusty

OK, but as Jim mentions, several circuits like this use diodes in a few different ways. I can tell you this, if at anytime during operation the actual motor's current will be passed through a diode the diode needs to be able to handle the motor current. I had a few drawings of circuits like this. Here is an example of the limit switches in series with diodes across them. For a 2 Amp load I would likely use a 3 Amp diode like maybe a 1N5404.

The lower example in the drawing does not require diodes with the limit switches. Also keep in mind when using diodes as shown above the diodes will have a forward voltage drop of around 0.75 volts when conducting so in the above example with 12 volts for example applied the motor will see about 11.25 volts. Generally not a big deal and again this is just one example.

Ron

 

[dr pepper]

I'd go for bigger than 1n4001, a 1n5404 or 6a4 or something like that, a 2 amp motor will generate a fair bit of backflash.

 

[jerry creaney]

Thank you Guys really appreciate your time and expertese Thank you Jerry Creaney