About precharge resistor while using secondary PS for LB

General discussion of using Roboclaw motor controllers
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ugur1yildiz
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Joined: Fri Feb 08, 2019 7:56 am
About precharge resistor while using secondary PS for LB

Post by ugur1yildiz »

Hi,

Considering the below setup given in Roboclaw 2x15A datasheet, as SW1 and SW2 are off the driver LEDs are constantly flashing. Because of the leakage current through R1(1Kohm) the driver tries to start but it cannot do so. Due to this leakage current the battery depletes in the long term.

Does anybody have any suggestion?

Image

Thanks
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Basicmicro Support
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Joined: Thu Feb 26, 2015 9:45 pm
Re: About precharge resistor while using secondary PS for LB

Post by Basicmicro Support »

Yes. Add a secondary pre-charge switch on the resistor. The Resistor is just eh absolute simplest pre-charge option. Adding a manual switch is the second. Then it gets complicated(timing circuit and relay to drive a contactor for the main power connection for example).
ugur1yildiz
Posts: 5
Joined: Fri Feb 08, 2019 7:56 am
Re: About precharge resistor while using secondary PS for LB

Post by ugur1yildiz »

Then, it's LED blinking behavior is expected and normal as both switches off ?

Thanks,
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Basicmicro Support
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Re: About precharge resistor while using secondary PS for LB

Post by Basicmicro Support »

If all switches are off there is no power to the Roboclaw so there shouldnt be any blinking.

If you use the bare simplest circuit there is a small amount of power getting to the Roboclaw(1ma with a 1k resistor). This will not usually be enough power to run the Roboclaw but could cause the LEDs to glow a bit.

If something else is happending I'll need to see what you are describing. Please email a small video to support@basicmicro.com
Konkurs101
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Joined: Tue Oct 20, 2020 9:43 am
Re: About precharge resistor while using secondary PS for LB

Post by Konkurs101 »

Basicmicro Support wrote: Mon Sep 28, 2020 8:15 am If all switches are off there is no power to the Roboclaw so there shouldnt be any blinking.

If you use the bare simplest circuit there is a small amount of power getting to the Roboclaw(1ma with a 1k resistor). This will not usually be enough power to run the Roboclaw but could cause the LEDs to glow a bit.

If something else is happending I'll need to see what you are describing. Please email a small video to support@basicmicro.com
Okay, so that's what I was happening when I started using my Roboclaw and saw that the LEDs kept functioning although I had switched everything off. I've -somehow- managed to solve it thanks to beginner magic, but now I'll know what happened.

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