Re: [CAD_CAM_EDM_DRO] Re: Gecko E-Stop recommended configuration

mariss92705@... wrote:

> Tom,
>
> The cap can be 100V. Its purpose is to assist the main filter cap in
> the power supply because the switch contact resistance decouples the
> filter cap from the drive.
>
> An important modification should be made that I overlooked in the e-
> stop switch circuit. A power resistor of 0.1 ohm per volt of power
> supply voltage should be placed in the ground leg of the switch. For
> instance if your power supply voltage is 68VDC, use a 6.8 ohm
> resistor. This will limit the dynamic break current to 10A. Wattage
> depends on the mass being decelerated during an e-stop, 10W is a good
> starting point.
>
> Regards to the circuit you sent. I will contact you off list about
> it. It has some problems.

You can take a look at the 2nd circuit diagram at
http://pico-systems.com/EMC.html it uses a small relay and a
modest power resistor to gradually charge the capacitors in the
servo or stepper drives, then closes a high current contactor to
supply the motor currents to the drives. When powering down,
it uses the same resistor to drain the caps in the drives, and brake
the motors, if necessary. I have been using this circuit on my
servo drives for almost 3 years.

Jon